universitÀ degli studi di trieste - units.it
TRANSCRIPT
UNIVERSITÀ DEGLI STUDI DI TRIESTE
XXX CICLO DEL DOTTORATO DI RICERCA IN
NANOTECNOLOGIE
INNOVATIVE APPROACH FOR THE TREATMENT
AND THE DIAGNOSIS OF RHEUMATOID ARTHRITIS EXPLOITING POLYMERIC BIODEGRADABLE NANOPARTICLES
TARGETING SYNOVIAL ENDOTHELIUM
Settore scientifico-disciplinare: MED/04 DOTTORANDO Federico Colombo
COORDINATORE Prof.ssa Lucia Pasquato
SUPERVISORE DI TESI Paolo Macor, PhD
ANNO ACCADEMICO 2016/2017
Tomyfamily,
Iwillalwaysbegratefultoyou
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease affecting joints due to the persistent
inflammation of the synovial tissue. It affects 1% of the worldwide population with high
socioeconomiccosts.Patientsusuallyrequirelifetimetreatmentsinordertopreventlatestage
ofthedisease,whichleadstoaconditionofdisabilityandpain.Despitetheintroductionof
biological drugs, Methotrexate (MTX) is still the gold standard. However, it shows some
weaknesssuchasinefficacyoradverseeventsafterlongtermusage.Forthisreason,thereis
theneedtodevelopdrugswithan improvedsafetyprofileandhighertherapeuticefficacy.
Moreover, it isofprimary importancetodevelopdiagnosticswithenhancedsensitivityand
tissuespecificity.
Inordertomeettheseneeds,thepurposeofthisworkistodevelopananotechnologicalagent
capabletodeliveryitscontent,suchasdrugsordiagnostictracers,specificallyintopathological
joints,avoidinghealthytissues.
Theseaimshavebeenachievedexploitingpeculiar featuresofbiodegradablenanoparticles
(BNPs), such as improved pharmacokinetic and bioavailability, associated with a peptide
specificfortheinflamedsynovia.Recently,theheterogeneityofthemoleculespresentinthe
endotheliumhasallowedtodeveloppeptidescapabletotargetvesselsofspecifictissues.In
thisproject,acyclicpeptideabletotargetthemicrovasculatureoftheinflamedsynoviahas
beenexploitedtodriveBNPsonlyintoinflamedjoints.
BNPshavebeencharacterizedfortheirphysicochemicalfeatures,polymers’toxicityanddrug
release.Targetedpolymericnanoparticles(tBNPs)demonstrated,bothinvitroandinvivo,to
preferentiallybindinflamedsynovialtissue,andtheiraccumulationdependsonthedegreeof
inflammation.
TargetedBNPsloadedwithMTXshowedhigherefficacycomparedtofreeMTXintwodifferent
animalmodelsofRA.Inaddition,areduceddoseoftBNPs-MTXdemonstratedtomaintainits
efficacy,showingfewersideeffectscomparedwithsystemicadministrationoffreeMTX.This
newtherapeuticapproachprovidedanewmechanismofactionfromapprovedtherapyand
suggestpotentialapplicationinnon-respondingpatients.
AlltheseevidencehighlightthepotentialuseoftBNPsasabiocompatibleandadaptabletool
forthediagnosisandthetreatmentofRAshowingimportantefficacy,reducedsideeffectsand
withthepotentialtoenhancethesensitivityofseveralimagingtechnologies.
Tableofcontents
1. Introduction.................................................................................................................1
1.1. Rheumatoidarthritis........................................................................................................2
1.1.1. Aetiology........................................................................................................................3
1.1.2. Genetics..........................................................................................................................4
1.1.3. Environmentalfactors....................................................................................................5
1.1.4. Epigenetics.....................................................................................................................6
1.1.5. Pathophysiology.............................................................................................................6
1.1.6. Localinflammation.........................................................................................................9
1.1.7. Fromlocaltosystemicinflammation...........................................................................11
1.1.8. Adaptiveimmunity.......................................................................................................13
1.1.9. Innateimmunity...........................................................................................................13
1.2. Neoangiogenesis............................................................................................................14
1.3. Animalmodelsofrheumatoidarthritis..........................................................................16
1.3.1. Collageninducedarthritis(CIA)....................................................................................16
1.3.2. Antigen-inducedarthritis(AIA)....................................................................................17
1.3.3. OthermodelsofRA......................................................................................................17
1.4. Treatmentofrheumatoidarthritis.................................................................................18
1.4.1. SyntheticDMARDsandglucocorticoids.......................................................................19
1.4.2. Methotrexate...............................................................................................................19
1.4.3. BiologicalDMARDs.......................................................................................................20
1.4.4. TargetedsyntheticDMARDs........................................................................................21
1.4.5. SideeffectsofRAtherapies.........................................................................................21
1.5. NanotechnologyandNanomedicine..............................................................................22
1.5.1. Nanocarriers.................................................................................................................23
1.5.2. Biodegradablepolymers..............................................................................................26
1.5.3. Propertiesandrationaldesignofnanoparticles..........................................................27
1.6. Passiveandactivetargeting...........................................................................................30
1.6.1. Passivetargeting..........................................................................................................31
1.6.2. Activetargeting............................................................................................................31
1.7. Targetingagentsforrheumatoidarthritis......................................................................32
1.7.1. Recombinantantibodiesandtheirfragments.............................................................33
1.7.2. Peptides........................................................................................................................34
1.7.3. Targetingthevasculature.............................................................................................35
2. Aimandrationaleofthethesis..................................................................................36
3. Materialsandmethods..............................................................................................39
3.1. Productionofthetargetingmolecule.............................................................................40
3.2. Purificationofthetargetingmolecule............................................................................40
3.3. SDSpageandWesternblotofthetargetmolecule.........................................................41
3.4. Nanoparticlesproduction...............................................................................................41
3.5. CharacterizationofnanoparticlesbyDLS,Nanoparticlestracking,TEMandSTEM.........42
3.6. MTTviabilityassay.........................................................................................................42
3.7. ReleaseofMTXfromnanoparticles................................................................................43
3.8. Labellingofthetargetedmoleculeandnanoparticles....................................................43
3.9. Stainingoftissuesections..............................................................................................44
3.9.1. Preparationofparaffinembeddedsectionsofhumansynovialtissues......................44
3.9.2. PreparationoffrozensectionsofAIAandCIA.............................................................45
3.9.3. Stainingoffrozensectionswithantibodies.................................................................45
3.9.4. Stainingoffrozensectionswithnanoparticles............................................................46
3.9.5. StainingofviableEA.hy926cellswithnanoparticles...................................................47
3.9.6. Microscopesusedinthiswork.....................................................................................47
3.10. Imagingflowcytometer.................................................................................................47
3.11. ELISAonEA.hy926.........................................................................................................48
3.12. Antigeninducedarthritis(AIA).......................................................................................48
3.13. Collageninducedarthritis(CIA)......................................................................................50
3.14. HematoxylinEosinstaining............................................................................................51
3.15. Bloodanalysis................................................................................................................52
3.16. ELISAmouseanti-collagenantibodies............................................................................52
3.17. ELISAratanti-mBSAantibodies......................................................................................52
3.18. Numberofpolymorphonuclear(PMN)leukocytes.........................................................53
3.19. MultiplexELISA..............................................................................................................53
4. Resultsanddiscussion...............................................................................................54
4.1. Designandcharacterizationofbiodegradablenanoparticles..........................................55
4.1.1. Designandcharacterizationofthetargetingmolecule...............................................55
4.1.2. Designandcharacterizationoftargetednanoparticlesforrheumatoidarthritis........59
4.1.3. BiocompatibilityofnanoparticlesandMTXreleasekinetics........................................64
4.2. Targetingtheendothelialtissueoftheinflamedsynovia...............................................66
4.2.1. BindingandinternalizationofBNPsandtBNPswithEA.hy926cellline......................66
4.2.2. InvivobiodistributionofBNPsandtBNPsinaAIAratmodel......................................72
4.2.3. InvivobiodistributionofBNPsandtBNPsinCIAmousemodel...................................74
4.3. Preclinicalstudiesinamodelofpolyarthritis.................................................................77
4.3.1. EfficacyoftBNPs-MTXinCIAmousemodel.................................................................77
4.3.2. EvaluationoftoxiceffectsinCIAmicetreatedwithtBNPs-MTX.................................80
4.3.3. Cytokinesmultiplexanalysis........................................................................................81
4.4. MechanismofactionofMTXencapsulatedintotBNPs...................................................84
4.4.1. EfficacyandsideeffectsoftBNPs-MTXtherapyinAIAratmodel...............................84
4.4.2. tBNPs-MTXreduceneoangiogenesisoftheinflamedsynovia.....................................87
5. Conclusion.................................................................................................................90
6. References.................................................................................................................94
Acknowledgement..........................................................................................................111
Listoffigures
Table1:Classificationcriteriaforrheumatoidarthritis2010ACR/EULAR.................................3
Figure1:RoleoftheadaptiveimmunityinRA...........................................................................5
Figure2:PathogeneticmodelofRA...........................................................................................8
Figure3:Earlyimmuneresponse.............................................................................................10
Figure4:Jointandsynovialtissue............................................................................................11
Figure5:Basicstructureoforganicnanocarriers.....................................................................26
Figure6:Biodistributionofnanoparticles................................................................................29
Figure7:Passiveandactivetargeting......................................................................................32
Figure8:Antibodiesandtheirfragmentsusedastargetingmolecules...................................35
Figure9:Targetingmolecule....................................................................................................56
Figure10:Studyofcolocalization............................................................................................58
Figure11:Schematicrepresentationofpolymericnanoparticles...........................................60
Figure12:3Dmodelofthetargetingmolecule.......................................................................62
Figure13:Nanoparticlescharacterization...............................................................................64
Figure14:Evaluationofnanoparticles’toxicityinvitro...........................................................66
Figure15:Targettheinflamedsynovialtissue.........................................................................68
Figure16:BindingandinternalizationofBNPsandtBNPswithEA.hy926..............................71
Figure17:InvivobiodistributionoftBNPsandBNPsinamodelofratAIA.............................74
Figure18InvivobiodistributionoftBNPsandBNPsinamodelofmouseCIA........................76
Figure19.HaematoxylinEosinstaining...................................................................................77
Figure20:EfficacyoftBNPs-MTXinCIAmodel........................................................................79
Figure21:BloodanalysisandgaingrowthinCIAmouse.........................................................81
Figure22:MultiplexcytokineprofilesinCIAmice...................................................................83
Figure23:EfficacyandbloodanalysisinAIArattreatedwithtBNPs......................................86
Figure24:C3stainingofAIArats’synovialtissues...................................................................87
Figure25:vWFstaininginAIArats’synovialtissues................................................................89
Listofabbreviations
A2 Adenosinereceptor2
ACPAs Antibodiestocitrullinatedproteinantigens
AIA Antigeninducedarthritis
AICAR 5-aminoimidazole-4-carbox-amideribonucleotide
APCs Antigenpresentingcells
APRIL Aproliferationinducingligand
APS Ammoniumpersulfate
ARA AmericanRheumatismAssociation
BALT Bronchus-associatedlymphoidtissue
BCIP 5-Bromo-4-Chloro-3-Indolyl-phosphate
Bcl-2 B-celllymphoma2
bDMARDs Biologicaldisease-modifyingantirheumaticdrugs
bFGF Basicfibroblastgrowthfactor
BLyS B-lymphocytestimulator
BNPs Biodegradablenanoparticles
BRM Biologicalresponsemodifier
BSA Bovineserumalbumin
C Constantdomain
CAIA Collagenantibody-inducedarthritis
cAMP Cyclicadenosinemonophosphate
CD14 Clusterofdifferentiation14
CD20 Clusterofdifferentiation20
CD44 Clusterofdifferentiation44
CD68 Clusterofdifferentiation68
CD80 Clusterofdifferentiation80
CD86 Clusterofdifferentiation86
CDR Complementaritydeterminingregion
CFA CompleteFreudAdjuvant
CHO ChinesHamsterOvary
CIA Collageninducedarthritis
CME Clathrin-mediatedendocytosis
CRP C-reactiveprotein
CTRL Control
CXCL12 C-X-CMotifChemokineligand12
CXCL8 C-X-CMotifChemokineligand8
CXCR1 C-X-CMotifChemokinereceptor1
CXCR2 C-X-CMotifChemokinereceptor2
CXCR4 C-X-CMotifChemokinereceptor4
DAPI 4',6-diamidino-2-phenylindole
DAS Diseaseactivityscore
DHFR Dihydrofolatereductase
DLS Dynamiclightscattering
DMARDs Disease-modifyingantirheumaticdrugs
DMEM Dulbecco'sModifiedEagle'sMedium
DMSO DimethylSulfoxide
EDTA Ethylenediaminetetraaceticacid
EES Extravascularextracellularspace
ELISA Enzyme-linkedimmunosorbentassay
EMA EuropeanMedicinesAgency
EPR Enhancedpermeabilityretention
ESR Erythrocytesedimentationrate
EULAR EuropeanLeagueAgainstRheumatism
Fab Fragmentantigen-binding
FasL Fasligand
FBS Fetalbovineserum
Fc Fragmentcrystallisable
FDA FoodandDrugAdministration
FGF-2 Fibroblastgrowthfactor-2
FITC FluoresceinIsothiocyanate
FLS Fibroblast-likesynoviocytes
GRA Granulocytes
H Heavychain
HA Hyaluronicacid
HIF Hypoxiainduciblefactors
HLA Humanleucocyteantigen
HRP Horseradishperoxidase
i.p Intraperitoneal
i.v Intravenous
iBALT Inducedbronchus-associatedlymphoidtissue
ICAM-1 Intercellularadhesionmolecule-1
IFA IncompleteFreundAdjuvant
IL-1b/a Interleukin1b/a
IL1/2/6/…. Interleukin1/2/6/….
JAK Januskinase
KC Keratinocyte-derivedcytokine
L Lightchain
LYM Lymphocytes
M-CSF Macrophagescolony-stimulatingfactor
M-CSF Granulocytescolony-stimulatingfactor
MAP44 MBL-associatedproteinof44kDa
MBL Mannose-bindinglectin
mBSA Methylatedbovineserumalbumin
MCP-1 Monocytechemotacticprotein1
MG-CSF Granulocytes-macrophagescolony-stimulatingfactor
MHC Majorhistocompatibilitycomplex
MIP-1a MacrophageInflammatoryProteins1a
MIP-1b MacrophageInflammatoryProteins1b
MLS Macrophageslikesynoviocytes
MMP1 Matrixmetalloproteinases1
MMP10 Matrixmetalloproteinases10
MMP3 Matrixmetalloproteinases3
MMP8 Matrixmetalloproteinases8
MMP9 Matrixmetalloproteinases9
MMPs Matrixmetalloproteinases
MON Monocytes
MPS Mononuclearphagocytesystem
MRI MagneticResonanceImaging
MTT 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan
MTX Methotrexate
MWCO Molecularweightcut-off
MWNTs Multi-wallednanotubes
NBT NitroBlueTetrazolium
NC Normalizedcounts
NETs Neutrophilextracellulartraps
NHS N-Hydroxysuccinimide
NLRs Nucleotide-bindingoligomerizationdomain(NOD)likereceptors
NOD Nucleotide-bindingoligomerizationdomain
NPs Polymericnanoparticles
NSAIDs Non-steroidalanti-inflammatorydrugs
NTA Nanoparticletrackinganalysis
OD OpticalDensity
PAD Peptidylargininedeaminase
PBS Phosphatebufferedsaline
PCL Poly(e-caprolactone)
PDGF Platelet-derivedgrowthfactor
PDGF-b Platelet-derivedgrowthfactorb
PDI Polydispersityindex
PEG Polyethyleneglycol
PEG-b-PLA COOH-poly(ethyleneglycol)-b-polylactide
PET Positronemissiontomography
PFA Paraformaldehyde
PLA Poly(lactide)
PLGA Poly(lactide-co-glycolide)copolymers
PLT Platelets
PMMA Poly(methylmethcrylate)
PMN Polymorphonuclearcells
PTPN22 Proteintyrosinephosphatasenon-receptortype22
PTX Paclitaxel
RA Rheumatoidarthritis
RANKL ReceptoractivatorofNF-κBligand
RBC Redbloodcells
RF RheumatoidFactor
RT Roomtemperature
scFv Singlechainfragmentvariable
SDF-1 Stromal-derivedfactor1
SDS-PAGE SodiumDodecylSulphate-PolyAcrylamideGelElectrophoresis
STAT Signaltransducerandactivatoroftranscription
STEM Scanningtransmissionelectronmicroscopy
SWNTs Single-wallednanotubes
TB Tuberculosis
tBNPs Targetedbiodegradablenanoparticles
TBS Tris-bufferedsaline
TCRs T-cellreceptors
TEM Transmissionelectronmicroscopy
TEMED N,N,N’,N’tetrametiletilendiamina
TGF-beta Transforminggrowthfactor-beta
TGFb Transforminggrowthfactorb
Th T-helper
Th17 T-helper17
TMB 3,3ʹ,5,5ʹ-Tetramethylbenzidine
TNF-a Tumornecrosisfactora
Treg RegulatoryhelperT-cell
TRITC Tetramethylrhodamine
TRLs Toll-likereceptors
V Variabledomain
VCAM-1 Vascularcelladhesionmolecule-1
VEGF Vascularendothelialgrowthfactor
vWF VonWillebrandfactor
WBC Whitebloodcells
ζ Zetapotential
1
1. Introduction
Introduction
2
1.1. Rheumatoidarthritis
Rheumatoid arthritis (RA) is a systemic autoimmunedisease (Firestein 2003)(Smolen et al.
2007)characterizedbythechronicinflammationofjointandbonedestruction(Aletahaetal.
2010)(Smolen et al. 2016). Despite new therapies improve patients’ outcomes with RA,
complete remission is still a challenge and patients are treated throughout their life.
Historicallytheterm“Rheumatoidarthritis”wascoinedbyAlfredBeringGarrodin1859and
approvedbytheAmericanRheumatismAssociation(ARA)in1941(TodescoS2002).Casesof
osteoarthritisandankylosesspondylitis,butnotofRA,werereportedfromskeletalremainsin
EuropeandnorthAfrica(Aceves-Avilaetal.1998).Differently,characteristicRAlesionswere
found in palaeopathological specimens in Native American tribes in North America (19).
Interestingly, in these regions the incidence of RA remains really highwith 5% of disease
incidence. Instead, the worldwide incidence is 0.5-1%, becoming the most common
autoimmuneinflammatoryarthritisinadults(Helmicketal.2008).Comparedwiththegeneral
population,patientswithRAshowanincreasedriskofmortality,mainlyduetoanincreased
riskofcardiovasculardeath(Gabriel2008).Dependingonthestudiedpopulation,theaverage
age of the onset for rheumatoid arthritis ranges from early 40s to late 50s (Innala et al.
2014)(Symmonsetal.2002).Thediseaseismorefrequentinwomanthaninmenwitharatio
of3to1suggestingapathologicalroleofhormonalfactors(Scottetal.2010).TheRAburden
ischaracterizedbydirectandindirectcosts.Thedirectcostsassociatedwiththetreatments
haveincreasedinthelast20yearsduetotheintroductionofbiologicaldrugs.Despitethese
drugs improve patients’ quality of life, the indirect costs are still high due to the loss of
productivity(absencefromwork).InItaly,accordingtotherecentliterature,thetotalsocial
costassociatedwithRAis€3.5billionperyearwithameanof€13.595peradultpatient.In
particular,21%ofthetotalcostsaredirectcostswhile79%areindirectcosts.Thesecostsare
inlinewiththeotherEuropeancountriesandthetotalmeanannualcostisestimatedatabout
€25.1 billion (Benucci et al. 2016). RA is characterized by the chronic inflammation of the
synovialmembrane,whichleadstoitshyperplasia.Duringthedisease,thesmalldiarthrodial
jointsofhandsandfeetareaffectedfirstinasymmetricmanner(Firestein2003).Themain
clinicalsymptomsassociatedwithRAareswellingofjoints,morningstiffnessandpaindueto
the progressive cartilage degradation and bone erosion. These symptoms together with
radiologicaldataandtheserologicalpresence/absenceandtypeofautoantibodiesareneeded
Introduction
3
todiagnosethedisease,itsdegreeandtochoosetherighttreatmentstrategy.Tothisaim,the
American College of Rheumatology (ACR) and the European League Against Rheumatism
(EULAR)developedclassificationcriteriatodefinetheRAseverity(Table1).Accordingtothese
criteria,whichprovidesascorefrom0to10,thescoreof³6itsindicativeofthepresenceof
definiteRA(Aletahaetal.2010).
ACR/EULAR2010criteria SCORE
1.Jointinvolvement
• Onemediumtolargejoint 0
• Twototenmediumtolargejoints 1
• Onetothreesmalljoints(largejointsnotcounted) 2
• Fourtotensmalljoints(largejointsnotcounted) 3
• Morethantenjoints(atleastonesmalljoint) 5
2.Serology
• NegativeRFandnegativeACPA 0
• LowpositiveRForlowpositiveACPA 2
• HighpositiveRForhighpositiveACPA 3
3.Acutephasereactants
• NormalCRPandnormalESP 0
• AbnormalCRPorabnormalESP 1
4.Durationofsymptoms
• Lessthan6weeks 0
• 6weeksormore 1
Table1:Classificationcriteriaforrheumatoidarthritis2010ACR/EULAR.
1.1.1. Aetiology
Theleadingcauseofrheumatoidarthritisisstillunclear,howeverseveralstudiessuggestthat
environmental factors and genetic predisposition increase the probability to develop RA
(McInnes&Schett2011a).Usually,patientsaredivided into seropositiveand seronegative
regarding thepresenceorabsenceofautoantibodies specific for citrullinatedautoantigens
(antibodiestocitrullinatedproteinantigens(ACPAs))andautoantibodiesspecificforselfIgG-
Introduction
4
Fc(rheumatoidfactor(RF)).Two-thirdsofthepatientsareseropositiveandshowworstclinical
symptomscomparedtoseronegativepatients.Moreover,theaetiologyfortheseronegative
is less well understood compared to the seropositive, probably because of a lack of
homogeneous features (Malmströmetal.2016).Despite the fact thatboththeRFandthe
ACPAsarepresentinthebloodbeforethefirstsymptomsofthedisease,theRFislessspecific
(Aggarwaletal.2009).Indeed,itoccursinotherinflammatoryconditions,whiletheACPAsare
detectedinlessthan2%inhealthyindividuals(Malmströmetal.2016).
1.1.2. Genetics
Aspreviouslymentioned,geneticfactorshaveakeyroleinthepathogenesisofRA.Indeed,
very interesting epidemiological studies, linking the genetic features to the pathology,
demonstrated that native American-Indian populations have high occurrence of RA (5.3-
6.8%)(DelPuenteetal.1989)(Harveyetal.1981)whereasruralAfricanpopulations(Beighton
etal.1975)(A.J.Silmanetal.1993)andsomepopulationsfromsouth-eastAsia(Dansetal.
1997),China(Zengetal.1997)andJapan(Shichikawaetal.1999)showlowoccurrence(0.2-
0.3%). Other studies have proved a fourfold increased risk of RA in monozygotic twins
comparedtodizygotictwins(MacGregoretal.2000)(AJSilmanetal.1993).Moreover,itis
knownthatapositivefamilyhistoryincreasestheriskofRAfromthreetofivetimes(Smolen
etal.2016).Recently,genome-wideassociationstudieshaveidentifiedmorethanahundred
lociassociatedwithrheumatoidarthritis(Consortium2007)(Stahletal.2010).Amongthese
loci,themajorhistocompatibilitycomplex(MHC)classII,knowninhumanashumanleucocyte
antigen(HLA)classIIandresponsiblefortheantigenpresentationtoT-helper(Th)cells,was
extensivelystudied.ParticularHLAalleleslikeHLA-DR1andHLA-DR4wherefoundwithhigh
frequenciesintheseropositivepatientaffectedbyRAifcomparedwithhealthyindividuals.
Theseallelesshareacommonaminoacidsequence(knownasthesharedepitope)(Gregersen
etal.1987) inthethirdhypervariableregion(calledpocket4(P4))ofthebetachain inthe
peptidebindinggroove.Aminoacidsfoundinposition11,71and74(Raychaudhurietal.2012)
confer apositive charge to theP4,which isnot able to accommodatepeptides containing
arginineduetoitspositivecharge(Scallyetal.2013).However,whenanarginineisconverted
inaneutralcitrullinethepeptideisabletofitintheP4andsoitcanbepresentedtotheT-
helpercell(Figure1).Theconversionofargininetocitrullineisperformedbyanenzymecalled
peptidylargininedeaminase(PAD).Indeed,ithasbeendemonstratedthatPADisoverexpress
<3%&.0,(%/.3!
!
! ! U!
.&!-/$$O&+5,8'%+0!0,&/35!8,35!+E7.$,&+!%.!$-.I+!1@'09,I.:!+%!'8;!Q^^S2B!$/8/('!7'&%/(8+$!1]%.8%!
+%!'8;!Q^=^2!'30!%+E%/8+!0,$%!1F..!+%!'8;!Q^=V2;!a$,'889B!/3!7'%/+3%$!'44+(%+0!#9!)"B!%*+!(/%&,88/3+!
'#8+!%.!$7+(/4/('889!#/30!%*+!7.(I+%!@S!?'$!4.,30!/3!7+7%/0+$!4&.-!:/-+3%/3B!'55&+5'3!1]('889!
+%!'8;!Q^=P2B!4/#&/3.5+3!1b'-+$!+%!'8;!Q^=^2B!rO+3.8'$+!1R+&$%3+&!+%!'8;!Q^=V2!'30!%97+!<<!(.88'5+3!
1[*+-/3!+%!'8;!Q^=V2;!"3.%*+&!5+3+!'$$.(/'%+0!?/%*!%*+! /3(&+'$+0!&/$I! %.!0+:+8.7!)"! /$! %*+!
@F@LQQ!17&.%+/3!%9&.$/3+!7*.$7*'%'$+!3.3O&+(+7%.&!%97+!QQ2!5+3+;!"!-,%'%/.3!/3!%*/$!5+3+!
/3(&+'$+$!%*+!FO(+88!'(%/:'%/.3!%*&+$*.80!8+'0/35B!0,&/35!%*+!%*9-/(!$+8+(%/.3B!%.!'!%*9-.(9%+$!
4'/8,&+!%.!0+8+%+!',%.&+'(%/:+!FO(+88$!1)/+(I!+%!'8;!Q^^Y2;!!
!
^+5)&/,!_,-'9/,':,%./,1(1H%+A/,+00)$+%?,+$,-8;,,F*+!4/5,&+!$*.?$!%*+!'3%/5+3!7&+$+3%'%/.3!.4!(/%&,88/3'%+0!7+7%/0+$!/3!(.-78+E!?/%*!%*+!HW"OC)!-.8+(,8+$;!HW"OC)!'88+8+$!'&+!
'$$.(/'%+!?/%*!&*+,-'%./0!'&%*&/%/$!'30!'&+!I3.?3!'$!%*+!$*'&+0!+7/%.7+;!<3!7'&%/(,8'&B!%*+!7.(I+%!S!1@S2!/$!7.$/%/:+89!(*'&5+0!
'30B!,$,'889B!('33.%!#/30!7.$/%/:+89!(*'&5+0!'-/3.'(/0$!$,(*!'$!'&5/3/3+;!"8%*.,5*B!(/%&,88/3'%+0!'-/3.'(/0$!1&+0!&/35$2!*':+!
'!3+,%&'8!(*'&5+!%*,$!('3!#+!'((.--.0'%+0!/3%.!%*+!@SB!?/%*!%*+!(.3$+A,+3%!'3%/5+3!7&+$+3%'%/.3!%.!%*+!F[)!.3!'!FO(+88;!
D.&+.:+&B!F[)!('3!0/&+(%89!&+(.53/M+$!(/%&,88/3+!/3!7.$/%/.3!OQB!O=!'30!Q!.4!.%*+&!7+7%/0+$B!$,(*!'$!(.88'5+3!<<!'30!"O+3.8'$+;!J/5,&+!%'I+3!4&.-!D'8-$%&.-!j;!+%!'8;!L'%!)+:!<--,3.8B!Q^=V;!1D'8-$%&q-!+%!'8;!Q^=V2;,
!"!"9"! :$;+&'$0/$%14,<1*%'&2,
a7!%.!3.?!$+:+&'8!+3:/&.3-+3%'8!4'(%.&$!'$$.(/'%+0!?/%*!%*+!7'%*.5+3+$/$!.4!)"!*':+!#++3!
/0+3%/4/+0;!"-.35!%*+$+B!(/5'&+%%+!$-.I/35!/$!I3.?3!%.!#+!.3+!.4!%*+!-.$%!/-7.&%'3%!4'(%.&$
?*/(*!-'9!%&/55+&!%*+!.3$+%!.4!%*+!0/$+'$+!1]/8-'3!+%!'8;!=XXV2;!)+(+3%!-+%'O'3'89$/$!$%,09!*'$!
&+7.&%+0!'! %?.O4.80! /3(&+'$+0!&/$I!.4!0+:+8.7/35!)"! 4.&!-'8+!$-.I+&$!(.-7'&+0!?/%*!3.3O
$-.I+&$;!J.&!?.-+3B %*+!&/$I!4.&!$-.I+&$!/$!=;P!%/-+$!*/5*+&!%*'3!3.3O$-.I+&$ 1],5/9'-'!+%!
'8;!Q^=^2;!F*+&+!'&+!-'39!0/44+&+3%!*97.%*+$+$!%.!+E78'/3!%*+!-+(*'3/$-!#9!?*/(*!(/5'&+%%+!
$-.I+!+3*'3(+!%*+!&/$I!%.!0+:+8.7!%*+!0/$+'$+;!<3!Q^^Z!*':+!#++3!0+-.3$%&'%+0!%*'%!$-.I/35!
/3(&+'$+$!%*+!+E7&+$$/.3!.4!7+7%/098'&5/3/3+!0+/-/3'$+!Q!1@"CQ2!+3M9-+ /3!%*+!8,35!-,(.$'B
?*/(*!/3!%,&3!/3(&+'$+$!%*+!7&.(+$$!.4!(/%&,88/3'%/.3!1D'I&95/'33'I/$!+%!'8;!Q^^Z2;!L+:+&%*+8+$$B!
/3!'00/%/.3! %.!(/5'&+%%+!$-.I/35B!#'(%+&/'8! /34+(%/.3$!('3! /3(&+'$+! %*+!7&.%+/3!(/%&,88/3'%/.3;!
<30++0B!/%!/$!?+88!I3.?3!%*+!8/3I!#+%?++3!)"!'30!/34+(%/.3$!#9!6#178%1#$#4'-!9(40(5')(-;!"$!'!
Introduction
6
matteroffact,patientswithRAhavehigherantibodytitreforP.Gingivaliswhichcorrelates
withhigherconcentrationofC-reactiveproteinandRA-associatedautoantibodies(Mikulset
al. 2009). Moreover, this bacterium has its own PAD enzyme able to switch arginine in
citrulline.Forthisreason,amodelofmolecularmimicryhasbeenhypothesized.Accordingto
thismodel,whentheimmunesystemreactsagainstP.Gingivalisinfection,antibodiesagainst
its citrullinatedpeptides areproducedand,due to thehigh similarity, the immune system
toleranceiscompromisedinducingtheepitopespreadingtoselfcitrullinatedproteinsleading
toastrongautoimmuneresponse(Hajishengallis2014)(Wegneretal.2010).Otherinfectious
agentslikeEpstein-BarrvirusandEscherichiacoliareknowntotriggerRAbymolecularmimicry
and,recently,gutmicrobiomehasbeenstudiedforitsrolefortheprimingandprogressionof
thedisease.
1.1.4. Epigenetics
Epigeneticprocessesareheritablechangesinthegeneexpressionwithoutmodificationinthe
DNAsequence.ThisispossibleduetoDNAmethylationorhistonesandchromatinassociated
proteins post-translational modifications such as acetylation, methylation and
phosphorylation. These processes lead to a very complex networkwhere genes are finely
regulated throw their activation or silencing. Epigenetic contributions to the onset and
progressionofRAhavebeenrecentlyhighlighted.Indeed,tendifferentmethylatedpositions
wereidentifiedasresponsibletoincreasetherisktodevelopRA(Liuetal.2013).Moreover,it
wasdemonstratedthatkneeandhipRAfibroblast-likesynoviocytes(FLS)showdifferentDNA
methylation signature of genes encoding the JACK-STAT pathway, explaining, partly, the
different degree of inflammation between joints (Ai et al. 2016). Another mechanism of
epigeneticregulationisrepresentedbymanymicroRNAs.TheycantargetmRNAsleadingto
an additional regulation of different genes in different cells type such as lymphocytes,
macrophagesandFLS(Blümletal.2011).
1.1.5. Pathophysiology
Asalreadymentionedabove,thecauseofthediseaseisstillunclear.Whatweknowisthat
environmental factors, a characteristic genotype, post-translationalmodification andother
kindsofgeneexpressionregulationscontributetotheonsetofthedisease.Accordingtoone
of the latest review published on Nature Review Rheumatology by V. Malmstrom et al.
Introduction
7
(Malmström et al. 2016) during the development of the pathology, there are four phases
(Figure2).Thefirstphaseiscalled"triggering".Atthisstage,themucosalsurfaces,suchasthe
lining of the lungs, gums and intestinal mucosa, together with environmental stimuli and
geneticriskfactorstriggertheimmuneresponseagainstself-peptides.Inthesecondphase,
called “maturation”, the immune systemmatures and spreads its epitopes, enhancing the
antibodytitreofRFandACPA.This immuneresponsedoesnotoccur in the jointsbut into
lymph nodes and/or into other secondary lymphoid tissue where T-cells and B-cells are
activatedandproliferate.Thethirdphasecalled“targeting”ischaracterizedbythepresence
of the clinical signs, suchasbone lossand jointpain. Specifically,ACPAsmaydirectlybind
osteoclasts,which in responseproduceC-X-CMotifChemokineLigand8 (CXCL8)knownas
interleukin8(IL8).Itcanactsasgrowthfactorforosteoclastsoraspaininducerwhenitbinds
their receptors, C-X-C Motif Chemokine receptor 1 (CXCR1) and CXCR2, expressed on
nociceptivenerves.Thelastphase,called“fulminantdisease”,ischaracterizedbythesynovitis.
Indeed, ACPAs can bind citrullinated histones causing the neutrophil extracellular traps
(NETosis).Moreover,othercitrullinatedproteinscanbeboundbyToll-likereceptors (TRLs)
expressedonsynovialcellsandAPCs,whichinturnproducepro-inflammatorycytokineslike
tumor necrosis factor (TNF), interleukin-6 (IL-6) and matrix metalloproteinases (MMPs),
responsible for the cartilage and bone destruction. According to this model, the immune
system is firstactivated inadifferent tissuebya local inflammationandthenthis immune
responsetargetthejoints,developinganinflammationcascadeleadingtoanestablishedRA.
<3%&.0,(%/.3!
!
! ! Z!
!
^+5)&/,3_,@1%.'5/$/%+*,0'(/9,':,-8",,F*/$!4/5,&+!$*.?$!4.,&!7*'$+$!.4!%*+!0/$+'$+!0+:+8.7-+3%;!@*'$+!=!m%&/55+&/35n_!+3:/&.3-+3%'8!4'(%.&$!'30!5+3+%/(!4'(%.&$!
+3*'3(+! %*+! ',%./--,3+! &+$7.3$+! '%! %*+!-,(.$'8! $,&4'(+;! @*'$+! Q! m-'%,&'%/.3n_! /3! %*+! 89-7*./0! .&5'3$B! %*+! /--,3+!
&+$7.3$+! -'%,&+$! '30! /3(&+'$+$! %*+! (.3(+3%&'%/.3! .4! ',%.'3%/#.0/+$! $,(*! '$! "[@"! '30! )J;! @*'$+! P! m%'&5+%/35n_!
',%.'3%/#.0/+$! &+'(*! /3%.! %*+! $93.:/'8! %/$$,+!?*+&+! %*+9!'(%/:'%+!.$%+.(8'$%$!?*/(*! /3! %,&3!7&.0,(+
Introduction
9
1.1.6. Localinflammation
Followingthismodelofpathogenesis,thepossiblefirstlocalinflammationmayoccurinthe
lungmucosa.Severalfindingssupportthismodel.Amongthese,ithasbeenshownthatpatient
with early ACPA-positive RA presented macroscopic and microscopic changes, such as
inflammatory cells infiltration, of the lungmucosa, whereas seronegative RA patients and
healthy individuals do not show any changes (Reynisdottir et al. 2014). Anotherwork has
demonstrated that bronchus-associated lymphoid tissue (BALT), described as a mucosal
lymphoidorgan,weremainlyfoundinRApatientscomparedwithhealthy.Interestinglythey
correlatewithanincreasedtissuedamage,suggestinganimportantroleinthepathogenesis
duetotheoverexpressionofPAD2andtheproductionofchemokinesandcytokines(Rangel-
Morenoetal.2006).Moreover,itisknownthatsmokeandothernoxiousagentsincreasethe
expressionofPADs,whichcorrelatewithanincreasedamountofcitrullinatedproteins,inthe
bronchialtissueofpatientswithRA(Makrygiannakisetal.2008).Alltheseevidencesuggest
that antigen presenting cells (APCs), like dendritic cells, macrophages and B-cells, locally
activatedbyneo-citrullinatedantigensmaytriggerT-cellmediatedimmunity(Figure3).
However,sincenotallseropositivepatientswithRApresentinflammationorchangesinthe
lungmucosa, possibly other tissues are able to trigger the first immune response. Among
them, themost accredited are the gums, probably because of the peridontitis caused by
phorphiromonasgingivalis,andtheintestinaltractduetochangesinthegutmicrobiota.
ItisevidentthatRAisaclinicalconditioncharacterizedbyacomplexcrosstalkbetweenthe
adaptiveandtheinnatepartsoftheimmunesystem.Inparticular,thecomplementsystem
hasanimportantroleinthispathology(Trouwetal.2017).Indeed,complementproteinsC3
andC4havebeenshowntodecreaseinjointsofRApatientsbecauseofconsumption(Swaak
etal.1987),whilecomplementactivationfragments,suchasthemembraneattackcomplex
sC5b-9andthecleavage fragmentsBb,were increasedseveral times (Brodeuretal.1991).
ACPAandRFmayinteractwithantigenspresentinthejointsformingimmunecomplexesable
toactivatethelocalcomplement(Suwannalaietal.2014).Othermolecules,releasedfromthe
extracellularmatrix of cartilage ormaterials from dead cells, can trigger the complement
activationthussuggestingthatthecomplementsystemhasaroleinbothearlyphaseandlate
phase of the disease (Sjöberg et al. 2005). It was demonstrated that both classical and
alternativepathwaysareinvolvedinthecomplementactivation,butonlythealternativewas
<3%&.0,(%/.3!
!
! ! =^!
4.,30!%.!#+!+$$+3%/'8!'30!$,44/(/+3%!4.&!%*+!.3$+%!'30!7&.5&+$$/.3!.4!%*+!0/$+'$+!1K'30'!+%!'8;!
Q^^V2;!<3$%+'0B!/$!3.%!9+%!(8+'&!%*+!&.8+!.4!%*+!8+(%/3!7'%*?'9;!<30++0!/%!?'$!0+-.3$%&'%+0!/3!
'3/-'8! -.0+8$! %*'%! %*+! -'33.$+O#/30/35! 8+(%/3! 1DKW2! ?'$! 3.%! &+A,/&+0! 4.&! %*+! 0/$+'$+!
0+:+8.7-+3%! 1K'30'!+%! '8;! Q^^Y2!*.?+:+&! #97'$$/35! %*+!DKW! %*&.,5*! %*+!DKWO'$$.(/'%+0!
7&.%+/3!.4!SSIC'!1D"@SS2!'3!/-7&.:+-+3%!.4!%*+!0/$+'$+!?'$!.#$+&:+0!1K'30'!+%!'8;!Q^=S2;!
!
^+5)&/,7_,P1&9?,+00)$/,&/2H'$2/",,"((.&0/35!%.!%*+!8'$%!I3.?8+05+B!%*+!4/&$%!/--,3+!&+$7.3$+!.((,&$!/3!%*+!8,35B!5,-!.&!/3%+$%/3'8!-,(.$';!F*+!4/5,&+!&+7&+$+3%$!
%*+!/--,3+!'(%/:'%/.3!/3!%*+!8,35!-,(.$'B!?*+&+!+3:/&.3-+3%'8!4'(%.&$B!$,(*!'$!3.E/.,$!'5+3%$B!0,+!%.!$7+(/4/(!$,$(+7%/#/8/%9!
5+3+$! 1+;5;! HW"OC)2! ('3! '(%/:'%+! 0+30&/%/(! (+88$B! -'(&.7*'5+$! '30! KO(+88$! %*&.,5*! FW);! F*+$+! 7&.(+$$+$! ('3! %&/55+&! %*+!
'(%/:'%/.3! .4! @"C$B! ?/%*! (.3$+A,+3%! )"O'$$.(/'%+0! 3+.! '3%/5+3$;! W'%+&B! KO(+88$! 7&+$+3%! 7.$%O%&'3$8'%/.3'889! -.0/4/+0!
',%.'3%/5+3$!%.!FO(+88$!?/%*!'!8.('8!7&.0,(%/.3!.4!',%.'3%/#.0/+$!'5'/3$%!(/%&,88/3'%+0!7+7%/0+$;!F*+!FO(+88O0+7+30+3%!KO(+88!
'(%/:'%/.3!,$,'889!.((,&$!/3!%*+!/30,(+0!#&.3(*,$O'$$.(/'%+0!89-7*./0!%/$$,+!1/K"WF2;!F*+!4/5,&+!/$!%'I+3!4&.-!D'8-$%&.-!j;!
+%!'8;!L'%!)+:!<--,3.8B!Q^=V!1D'8-$%&q-!+%!'8;!Q^=V2;!!
<3%&.0,(%/.3!
!
! ! ==!
!"!"C"! D&'0,4'*14,%',262%/0+*,+$<41001%+'$,
"8%*.,5*!"[@"$!*':+!#++3!(.3$/0+&+0!7'%*.5+3/(! 1f,*3!+%!'8;! Q^^V2B! %*+$+!'&+!7&+$+3%! /3!
$+&,-!9+'&$!#+4.&+!%*+!.3$+%!.4!%*+!0/$+'$+;!J.&!%*/$!&+'$.3B!%*+!7&+$+3(+!.4!%*+!"[@"$!/$!3.%!
$,44/(/+3%!4.&!%*+!.3$+%!.4!%*+!0/$+'$+!'30!'3!'00/%/.3'8!m*/%n!/$!3++0+0;!<30++0B!/%!*'$!#++3!
0+-.3$%&'%+0! %*'%! J(! .4! "[@"! '3%/#.0/+$! 4&.-! )"! 7'%/+3%$! $*.?! 0/44+&+3%! 589(.$98'%/.3!
7'%%+&3B!?*/(*!-'9!/3(&+'$+!%*+!'44/3/%9!4.&!%*+/&!J[%)<!+3*'3(/35!%*+!/348'--'%/.3!1).-#.,%$!
+%! '8;! Q^=U2;! "$! 7&+:/.,$89! 0/$(,$$+0B! $+:+&'8! $%,0/+$! /30/('%+! %*'%! $7+(/4/(! F! (+88O-+0/'%+0!
/--,3+!&+$7.3$+!'5'/3$%!',%.'3%/5+3$!%'I+!78'(+!.,%$/0+!%*+!6./3%$;!"%!'!(+&%'/3!7./3%B!%*+!
8.('8!/348'--'%/.3B!?*/(*!7&.#'#89!$%'&%$!/3!%*+!8,35!-,(.$'!1$++!7'&'5&'7*!=;=;V2B!'(A,/&+$!'!
$9$%+-/(!4+'%,&+;!F*+&+4.&+B!KO(+88$!&+'(%!%.!7.$%O%&'3$8'%/.3'889!-.0/4/+0!',%.'3%/5+3$!'30B!
*+87+0!#9!'3!HW"!(8'$$! <<O0+7+30+3%!FO(+88! &+$7.3$+B!-/5&'%+!'30!7&.8/4+&'%+! /3%.! %*+! 6./3%!
(':/%9B!7&.-.%/35!%*+!/348'--'%/.3!.4!%*+!$93.:/,-;!<3!7*9$/.8.5/('8!(.30/%/.3$!1J/5,&+!S'2B!
%*+! $93.:/'8!-+-#&'3+! 7&.:/0+$! 3,%&/+3%$! %.! %*+!
('&%/8'5+$! '30! 8,#&/('%+$! %*+! 6./3%$! 7&+:+3%/35!
&,##/35;! "3'%.-/('889! /$! 0/:/0+0! /3%.! %?.!
(.-7'&%-+3%$_! %*+! /3%/-'8! 8/3/35! 8'9+&! '30! %*+!
$,#8/3/35!8'9+&;!F*+!!/3%/-'!8'9+&!/$!-'0+!.4!'!%*/3!
8'9+&! .4! (+88$B! -'/389! 4/#&.#8'$%! 8/I+! $93.:/.(9%+$!
1JW]2!'30!-'(&.7*'5+$!8/I+!$93.:/.(9%+$!1DW]2;!JW]!
+E7&+$$!(.88'5+3!<j!'30!jB!:/-+3%/3!'30!$+(&+%+!'!
7&.%+/3!&+$7.3$/#8+!4.&!%*+!6./3%$N!8,#&/('%/.3B!%*+!$.!
('88+0! 8,#&/(/3;! <3$%+'0B! DW]! +E7&+$$! -'(&.7*'5+!
$,&4'(+!-'&I+&$B!$,(*!'$![CVZB!J(!&+(+7%.&$B![C=SB!
'30! '#,30'3%! HW"OC)! 1K'&%.I! p! J/&+$%+/3!
Q^==21J/&+$%+/3! Q^=P2;! F*+! /348'-+0! $93.:/'8! -+-#&'3+! /$! (*'&'(%+&/M+0! #9! /33'%+! '30!
'0'7%/:+!/--,3+!(+88$!/34/8%&'%/.3!1J/5,&+!S#2;!F*/$!/$!7.$$/#8+!0,+!%.!%*+!/3(&+'$+0!(9%.I/3+$!
(.3(+3%&'%/.3! '30! #+(',$+! .4! '! *97.E/(! +3:/&.3-+3%! ?*/(*! %&/55+&$! %*+! +E7&+$$/.3! .4!
'0*+$/.3!-.8+(,8+$!.3!$93.:/'8!-/(&.:+$$+8$!1]M+I'3+(M!+%!'8;!Q^^X2;!F*+$+!-.8+(,8+$!'88.?!
8+,I.(9%+$! '0*+$/.3B! +E%&':'$'%/.3! '30! $93.:/'8! %/$$,+! /34/8%&'%/.3;! F*+! /348'-+0! $93.:/,-!
#+('-+! %*/(I+&! 0,+! %.! %*+! /3(&+'$+0! 3,-#+&! .4! JW]B! DW]! '30! #+(',$+! .4! %*+! 8+,I.(9%+$!
/34/8%&'%/.3;!DW]!0,&/35!%*+!/348'--'%/.3!7&.0,(+!*/5*!'-.,3%!.4!7&.O/348'--'%.&9!(9%.I/3+$B!
^+5)&/,6_,['+$%,1$(,2?$'A+19,%+22)/",
Introduction
12
chemokinesandgrowthfactors.AllthesefactorsareabletoactivateFLSandB-cell,whichin
turnproduceIL-6andmatrixmetalloproteinases(MMPs).Thus,thepositivefeedback loop,
generated by the paracrine/autocrine effects of these factors, leads to a perpetual
inflammation.Indeed,theinflamedhyperplasticsynovialtissueatthecartilage-boneinterface,
called pannus, behaves like a locally invasive tumor, where activated FLS, macrophages,
osteoclastsandlymphocytesareabletodestroyandinfiltratethelininglayerandthecartilage
(Bartok & Firestein 2011). The FLS proliferation is stimulated by growth factors like basic
fibroblastgrowth factor (bFGF) (Melnyketal.1990),platelet-derivedgrowth factor (PDGF)
(Moretal.2005)andtransforminggrowthfactor-beta(TGF-beta)(Allenetal.1990),released
by leukocytes. Moreover, the FLS apoptosis rate is decreased, probably because of p53
mutation(Firesteinetal.1997),B-celllymphoma2(Bcl-2)overexpression(Perlmanetal.2000)
orFasligand(FasL)dysregulation(Perlmanetal.2001).TheFLShaveaprimaryroleincartilage
invasion and degradation, indeed they secrete a broad set of MMPs responsible for this
process.Inparticular,duringthedisease,FLSstimulatedwithIL-1,TNF-betaandgrowthfactors
overexpress MMP1, MMP3, MMP10 (Tolboom et al. 2002), MMP8, MMP9, MMP11 and
MMP13(Moretal.2005).TheseenzymesareresponsibleforthecollagenIandIIdegradation,
leadingtothecartilagedestruction,increasingthespacebetweenjoints.Itwasdemonstrated
thatFLSproduceIL-6,promotingTh17differentiationandproliferation(Linetal.2012).FLS
feedtheinflammatoryprocesscontributingtotheformationofnewvessels,indeednumerous
pro-angiogenetic factors are produced. Among these, vascular endothelial growth factor
(VEGF) (Cho et al. 2002), fibroblast growth factor-2 (FGF-2) (Yamashita et al. 2002) and
interleukin-18(IL-18)(Moreletal.2002)contributetotheinflammatoryprocessandpannus
formationdue to thenewvesselsgrowth.However, the formationofnewvesselsand the
productionofMMParenotsolelyresponsiblefortheprogressionofcartilageinflammation
anddestruction,sincefibroblastscandirectlyinteractwithT-cells,B-cells,andosteoclasts.The
latteristheprimaryresponsibleforthedestructionanddeformationofthebonesduetotheir
acidenzymaticmachinery(abletodestroymineralizedcartilageandbones).Lesionsofbones
andcartilageareprogressivelyinvadedbyleukocytes,whichintheendreachthebonemarrow
increasingtheinflammatoryprocess(Jimenez-Bojetal.2005).Itisknownthatmacrophages
colony-stimulating factor (M-CSF) and the receptor activator of NF-κB ligand (RANKL) are
principallyresponsiblefortheosteoclastssurvival,activationanddifferentiation(Glantschnig
et al. 2003). However, TNF-a, IL-1, IL-6 and IL-17 play a central role in the activation and
Introduction
13
differentiationofosteoclasts(Schett&Teitelbaum2009).Indeed,treatmentsabletotarget
these cytokines were effective for the prevention of bone destruction (McInnes & Schett
2011).
1.1.8. Adaptiveimmunity
It is known that adaptive immunity has a pivotal role in the pathogenesis of rheumatoid
arthritis. In particular, T-cells (CD4+) are activated through the interaction with antigenic
peptide fragment presented by HLA class II expressed by professionals APC. Recently,
enormousattentionhasbeenfocusedontype17helperT-cell(Th17).Thisparticularsubsetof
Thelpercellshaspro-inflammatoryphenotypethatproducesTNF-aandinterleukin17A,17F,
IL-21andIL-22(Miossecetal.2009).ThesynovialfluidofRApatientscontainsmanycytokines
thatpromotethedifferentiationofTh17andsimultaneouslysuppressthedifferentiationof
regulatoryhelperT-cell(Treg).Thisprocessbreakshomeostasisinfavorofapro-inflammatory
processbycreatinganimbalancebetweenpro-inflammatorycytokines,chemokines,adhesion
proteinsandgrowthfactors.Indeed,itwasdemonstratedthatthisequilibriumcanberestored
byTNF-ainhibitorsprovingthekeyroleofTNF-aintheinflammatoryprocess(Nadkarnietal.
2007).Moreover,TNF-aandIL-17Aareabletoactivatefibroblastsandchondrocytes,fueling
theinflammatoryprocess(Zupanetal.2013)(Mundy2007).B-cells,togetherwithT-cells,have
acentralroleinthepathogenesis,mainlyproducingIgGACPA.Inthesynovialtissue,B-cells
areoftenaggregatedtoT-cells,formingthesocalledectopic(ortertiary) lymphoidfollicles
(Jing&Choi2016)(Timmeretal.2007).ThisstructurepromotesB-cellsurvivalandproliferation
through the expression of a proliferation-inducing ligand (APRIL), B-lymphocyte stimulator
(BLyS)andseveraldifferentchemokines(Seyleretal.2005).
1.1.9. Innateimmunity
Asalreadydescribedintheparagraph“localinflammation”,thecomplementsystem,whichis
partoftheinnateimmunesystem,hasanimportantroleinthedevelopmentofRA.Moreover,
cellsoftheinnateimmunesystemcontributetothesynovialmembraneinflammationbecause
ofthemastcells,macrophagesandnaturalkillercellsinfiltration.Neutrophilsalsoparticipate
inthesynovitisbutaremainlylocatedinthesynovialliquid.Amongthesecells,Macrophages
areconsideredthemainactorsbecauseoftheircytokinesproduction.Indeed,theysecretea
great cytokine portfolio such as TNF-alpha, IL-1, IL-6, IL-12. Moreover, they release
Introduction
14
chemokines,leukotrienes,prostaglandins,andcomplementproteins.Allthesemoleculeshave
thepossibilitytoincreasethevascularpermeability,whichinturnincreasecellextravasation
(Duque&Descoteaux2014).Usually,Macrophagesareactivatedbytolllikereceptors(TLR)
and nucleotide-binding oligomerization domain (NOD) like receptors (NLRs). In addition,
macrophagescanbeactivatedbycytokines,immunecomplexesandlipoproteins(McInnes&
Schett2011b).MacrophagesmaturationandsynovialinfiltrationarepromotedbyM-CSF,G-
CSFandgranulocytes-macrophagescolony-stimulatingfactor(MG-CSF)whichenhancetheir
migration from the bonemarrow to the inflamed tissue (Cornish et al. 2009).Mast cells,
activatedbyTLR,FcreceptorsgorFcreceptorseproducecytokines,chemokines,proteases
and vasoactive amines while Neutrophils produce prostaglandins, reactive oxygen
intermediatesandproteases(Cascãoetal.2010).
1.2. Neoangiogenesis
Theformationofnewcapillariesfrompre-existingvesselsisaprocesscalledneoangiogenesis.
Thisisacomplexandwell-orchestratedprocesswhichinvolvesmanycelltypesandmediators.
Itoccursinphysiologicalconditionsduringorgandevelopment,growthandtissueremodeling
duetothereorganizationofthebloodvessels(Konistietal.2013).Thevesselshaveaninner
layer formed by endothelial cells with a surrounding basal lamina, pericytes and smooth
musclescells(Bergers2005).Ithasbeendemonstratedthatprecursorsofendothelialcellsare
CD34+cells,whichexpressthevascularendotheliumgrowthfactor(VEGF)receptor2.These
cellsexpressalsotheCXCR4andmigrateinresponsetostromal-derivedfactor(SDF)-1orVEGF.
(Peichevetal.2000)(Asahara1997).Severalfactorssuchascytokines,chemokines,molecules
forcelladhesionandgrowthfactorsstimulatethemigrationandactivationofthesecells.Once
thesecellsareactivated,theystarttodisrupttheunderlyingbasalmembrane invadingthe
extracellularmatrix.TheseproliferatingcellsfollowtheVEGFgradienttoreachthetissueof
interestwheretheyorganizedthe lumenandthefinalshapeofthevesselwiththehelpof
pericytesattractedduetothesecretionoftheendothelialcellPDGFb(Bergers2005).
Neoangiogenesis, as already mentioned, is a physiological process, however it plays an
important role in several pathological processes. Usually, damaged tissues face hypoxic
conditions which, in turn, promotes the formation of new vessels in order to restore the
regular blood supply and therefore a suitable amount of oxygen. The hypoxia is a shared
conditionofmanydifferentpathologieslikeautoimmuneandcancerdiseases.InRA,during
Introduction
15
thechronicinflammationofthesynovialtissue,synovialfibroblastsacquireahighproliferative
phenotype,moreover,duetothehuge leukocytes infiltration,there isan increasedoxygen
consumption.DifferentstudieshavedemonstratedthatVEGF,pro-inflammatorycytokineslike
IL-6 and matrix metalloproteinases expression (MMP1 and MMP3) are associated to the
hypoxiainduciblefactors(HIF)activation(Lu&Kang2010)(Ahnetal.2008).Therefore,hypoxia
not only plays a fundamental role in the formation of new vessels but contributes to the
degradationofcartilagebytheexpressionofmetalloproteases.TheRAsynovialmembrane,
infiltratedbyleukocytes,expressespro-inflammatorycytokinessuchasIL-1,IL-6,TNF-alpha
andtransforminggrowthfactorbeta(TGFb)whichareabletoincreasetheexpressionofVEGF
(Marrellietal.2011).Chemokinesechemokinesreceptorscontributetotheformationofnew
vesselswhich promotes inflammation of the synovialmembrane. One of themost potent
chemokines is the CXCL12, also called stromal cell-derived, which is overexpressed in
inflammatorydisease.ItsreceptorCXCR4isexpressedbyhemopoieticstemcells,monocytes
andlymphocytesandexertsahomingfunction.CXCL12-CXCR4systemisstronglyimplicated
in the neoangiogenesis. Itwas demonstrated that CXCL12 induces autocrine expression of
VEGFpromotingtheneoangiogenesis;inaddition,CXCR4knockoutmiceexhibitadecreased
vascularization(Pablosetal.2003).Althoughchemokinesareresponsible forthe leukocyte
homingintheinflamedsynovialtissue,theexpressionofcellularadhesionmolecules(CAMs)
expressedbyendothelialcellsplayacrucialroleinleukocyteadhesionandtransendothelial
migration.Atthebeginning,leukocytetetheringandrollingaremediatedbyE-selectinsandP-
selectinswhilethefirmadhesionismediatedbyintercellularadhesionmolecule-1(ICAM-1)
and vascular cell adhesionmolecule-1 (VCAM-1) able to bindb2 integrin anda4b2 integrin
respectively(Szekanecz&Koch2008).Ofextremeinterestistheintegrinavb3whichisinvolved
inneoangiogenesisandhavebeenfoundtobeoverexpressedindamagedtissue(Szekanecz
etal.2009).ItsrelevancewasalsodemonstratedinanimalmodelsofRA,wheretheblocking
of the avb3 reduced neoangiogenesis, cell infiltration, pannus formation and cartilage
degradation (Storgardet al. 1999). For these reasons, inorder to reduceneoangiogenesis,
drugsabletoblockthisintegrinweredevelopedbuttheywereineffectiveinhumanclinical
trials(Lainer-Carr&Brahn2007).Although,duetoitsoverexpressioninbloodvesselsoftumor
endothelial cells or in inflamed kidney tissue, peptides containing aminoacids Arg-Gly-Asp
(RGD),abletobindtheavb3,havebeenusedtodeliveranticanceroranti-inflammatorydrugs
directlyinthetissueofinterest(Danhier,Breton,etal.2012)(Duriguttoetal.2017).
Introduction
16
1.3. Animalmodelsofrheumatoidarthritis
Severalexperimentalanimalmodelsofrheumatoidarthritishavebeendevelopedinorderto
understandetiologyandpathogenicmechanismsofthisautoimmunedisease.Today,these
modelsare importanttotestnewtherapeutics,studytheirpharmacokinetics,effectiveness
andsideeffects(Asquithetal.2009).Despitetheprogressmadetodevelopanimalmodelsof
arthritis, eachmodel showspeculiar features. Indeed, themodel to use should be chosen
according to theaimof the research taking intoaccount its pros and cons.Moreover, the
results obtainedwith animalmodels should be assessed carefully because of the intrinsic
differencesbetweenhumanandotheranimals(Huetal.2013).
1.3.1. Collageninducedarthritis(CIA)
The discovery of anti-collagen antibodies, that have been found in the serum of patients
affectedbyrheumatoidarthritis,wasthemotivationtodevelopanexperimentalmodelbased
on type II collagen. Itbecamethebestmodel to testnewtherapeutics, suchasbiologicals
DMARDs,andtounderstandpathogenicmechanismsofthedisease.Thereasonofthesuccess
liesinthefactthatitsharesseveralaspectsofthehumandisease.Indeed,theonsetofCIAis
mainlydependentonT-cellsandB-cellswithahugeimmuneresponseagainstcollagentypeII,
whichisoneofthemaincomponentsofthecartilage(Brandetal.2007).Thisexperimental
methodbasedontheintradermalinjectionoftypeIIcollagenwasdescribedforthefirsttime
in1977byTrenthametal.(Trenthametal.1977).Thankstothisanimalmodel,theroleofT
lymphocytes,inparticularhelperT-cells,hasbeenclarified,indeedhasbeenshownthatthey
areessentialfortheonsetandprogressionofRA(Klareskogetal.1983).Themodeldevelops
apolyarthritis,whereeachmousecanshowadifferentnumberofjointsinvolvedanddifferent
degreeofinflammationforeachjoint.Itischaracterizedbyasynovialhyperplasia,cartilage
andbonedegradationassociatedtoasynovialmembraneleukocyteinfiltration(Trenthamet
al.1977).DBA/1(H-2q)isthemousestrainassociatedwiththehighestpercentageofdisease
incidence(80-90%),althoughseveraltransgenicHLA-DRmousestrainhasbeengeneratedin
ordertostudyspecificHLAsusceptibilityandinvolvementinthepathogenesis.Forexample,
humanizedHLA-DR4-transgenicmiceweregeneratedtounderstandthehigherRAincidence
infemale(Tanejaetal.2007).Moreover,ithasbeendemonstratedthatarthriticsynoviumof
CIAmouse is characterized by an active angiogenesis suggesting that VEGF/VEGF receptor
Introduction
17
pathwaycouldbeapotentialtherapeutictarget(Raatzetal.2012).Furthermore,ithasbeen
foundthatcomplementsysteminhibitionplaysaroleinCIAmodel,reducingtheprogression
andtheonsetofthedisease(Linton&Morgan1999).
1.3.2. Antigen-inducedarthritis(AIA)
Theantigeninducedarthritismodelisanexperimentalproceduretodevelopmonoarthritis.
First, animalsare immunizedwith two intra-dermal injectionsofmethylatedbovine serum
albumin(mBSA)oranotherantigen,inducinganimmuneresponseagainsttheproteinwitha
productionof anti-antigen antibodies. Then, the sameantigen is injected into a knee joint
cavity inducing the formation of immune complexes and consequently the inflammation
(Griffiths1992).Threedaysafter,theinflammationisevidentduetotheswollenkneejoint.
The inflammatory process reaches the highest degree after one week, when synovial
hyperplasia, erosion of cartilage and bone are evident by histological analysis. The tissue
damageiscausedbybothinnateandadaptiveimmunity.Itwasdemonstratedthatpurified
helperTcells,previouslysensitizedformBSAandinjecteddirectlyintothejointtogetherwith
theantigenwereabletoinducetheinflammationintonotimmunizedanimals(Klasenetal.
1986).Inaddition,thecomplementsystemhasaleadingroleinthismodel,indeedhavebeen
studiedthatanimalwithAIA,iftreatedwithanti-C5antibodiesorC5aantagonistshoweda
decreasedjointswellingandalowerhistopathologicalscore(Woodruffetal.2002).Moreover,
inflamedsynovial tissuesof theanimalwithAIAhavebeenassociatedwithahighervessel
density proving the fundamental role of the neoangiogenesis in this model. Indeed, the
knockoutofthegeneVEGFB,agrowthfactorthatbelongstothevascularendothelialgrowth
factorfamily,reducedthesynovialinflammationandthevasculardensity(Mouldetal.2003).
Thismodelwasextensivelyusedtostudypathogenicmechanisms,butithasbeenovercome
bytheCIAmodelbecauseofthereasondescribedinthepreviousparagraph.AlthoughAIAis
consideredobsoletetoinvestigatepathogenicmechanism,thismodelisstillexcellent,atleast
in the first step, to study thebiodistributionof new classes of therapeuticswhich aims to
specificallytargettheinflamedsynovialtissue(Macoretal.2012)(Duriguttoetal.2017).
1.3.3. OthermodelsofRA
Otherrheumatoidarthritismodelshavebeendevelopedovertheyears.Amongthese,oneof
thefirstmodelsofrheumatoidarthritisisbasedonFreund’sadjuvantandforthisreasonitis
Introduction
18
called “adjuvant induced arthritis”. Freund’s adjuvant is amix ofmineral oil and antigens,
whichactsasaboosteroftheimmuneresponse.Thismodelhasbeenusedtoinvestigatethe
role of T-cells, which are stimulated by the adjuvant injection to start the inflammatory
process. The rat strain is important for thedevelopmentof inflammation, indeed Lewisor
Sprague-Dawleystrainsareconsideredsusceptible strains showing35%of incidence,while
Buffaloandotherstrainsareconsideredresistantstrainsshowing10%ofincidence.After10-
15days,theinducedarthritisbecomesstablefor2-3weeks.Afteramonththesymptomsare
reduced.Theadjuvant-inducedarthritisbyFreund’scompleteadjuvantischaracterizedbythe
ankyloses,whichcausesthepartialorcompletestiffnessofthejoint in50%oftheaffected
animals.Moreover,cartilageandboneerosionsareusuallyobserved inanimalsdeveloping
theinflammation(Pearson1956).Althoughthismodelissimpletodevelopanditrequiresa
shorttime,ontheothersideitisimportanttonotethatthismodeldoesnotfullyreflectthe
complexity of the disease and it is not suitable for long-term studies. Another model to
mentionisthecollagenantibody-inducedarthritis(CAIA).ThismodelissimilartoCIA,andis
often used to test new therapeutics. It is induced by the administration of a cocktail of
antibodiesagainstcollagen.Theadvantageofthismodelliesinitsspeedofactionanditcan
beusedforseveralstrainsofmice,eveningeneticallymodifiedmice.However,themodelis
expensiveandveryfastandaggressivecomparedtoCIA,thereforeitislesssuitabletostudy
chronicaspectofthedisease(Khachigian2006).
1.4. Treatmentofrheumatoidarthritis
The comprehension of new molecular mechanisms underlies rheumatoid arthritis has
improvedthediagnosisandtherapyofthedisease.Surely,anearlydiagnosisisessentialfora
successful therapy. Indeed, treat the disease as early as possible allows avoiding cartilage
degradation and bone remodelling which lead to a disability condition (Isaacs 2010). As
discussedinparagraph1.1,newclassificationcriteriaforrheumatoidarthritiswerepresented
in2010.Thesereducedtheshortcomingofthepreviouscriteriabyincreasingthesensitivityof
21%(Radneretal.2014).Then,inordertounderstandwhetherthetreatmentiseffectiveor
not,twodifferentsystemstoevaluatethedisease-activityhavebeendeveloped.TheAmerican
College of Rheumatology (ACR) improvement criteria assesses, in percentage, the relative
efficacyofthetreatmentcomparedtoanothertherapyorplacebo.TheACR20,whichreflect
the20%ofimprovement,comparedtothebaseline,isconsideredasminimalresponse,while
Introduction
19
theACR50(50%)isamoderateresponseandtheACR70(70%)isthemajorresponse.TheACR
criteriaarewidelyusedinclinicaltrials.Bycontrast,thediseaseactivityscore(DAS),using28
joints(DAS28),isusefulfordailypractice.Indeed,ittakesintoaccountdifferentparameters
liketenderand/orswollenjointcount,globalhealth,erythrocytesedimentationrateortheC-
reactiveproteinconcentration.Withaspecialequation,theDAS28iscalculatedasanumber
whichreflectstheactivitydisease:high,moderate, lowandremission(Smolenetal.2016).
However,thesesystems,abletoevaluatethediseaseactivity,areusefulforthefollow-upof
patientswithRA,butitisimportanttoevaluatethestructuraldamageofcartilageandbone.
Forthisreason,radiographicimages,MRIscansandultrasoundanalysisareoftenperformed
tohighlightjointnarrowingspace,cartilageandboneerosion(Bugattietal.2012).
ThetreatmentofRAhaschangedoverthelastthirtyyearsimprovingqualityoflifeofaffected
patients.Thiswaspossiblebecauseoftheintroductionofanewclassofdrugscalleddisease-
modifyingantirheumaticdrugs (DMARDs). Indeed,drugsbelonging to thisclassareable to
reduce structural damage while non-steroidal anti-inflammatory drugs (NSAIDs) do not
interferewiththejointdamage.However,theseareusedtoreducejointpainandstiffness.By
contrast,glucocorticoidsact likeDMARDs, reducingdiseaseprogression ina rapidmanner,
howeverseveralimportantsideeffectswereassociatedwiththeirlongtermuse.DMARDsare
dividedintotwocategories:syntheticDMARDsandbiologicalDMARDs(bDMARDs),alsocalled
biologicalresponsemodifier(BRM)(vanVollenhoven2009).
1.4.1. SyntheticDMARDsandglucocorticoids
AmongsyntheticDMARDs,leflunomide,sulfasalazine,hydroxychloroquineandmethotrexate
are extensively used to treat RA and according to EULAR recommendation the treatment
shouldstartwithoneofthesedrugsincombinationwithlowdoseofglucocorticoids.However,
methotrexateisconsideredtheanchordrugbecauseitshowsasuperioroutcomecompared
withotherDMARDsandbecause it hasbeendemonstrated thatmethotrexatehas a safer
profilethatothersyntheticDMARDs,probablybecauseofitslowdoseofadministration.
1.4.2. Methotrexate
Methotrexate (MTX) is a chemical compound analog to folic acid capable to inhibit the
dihydrofolate reductase (DHFR), an enzyme essential for the synthesis of tetrahydrofolate
(THF). THF is a cofactor involved in nucleic acids synthesis, highly required during cell
Introduction
20
proliferation.Ithasbeenwidelyusedasachemotherapeuticagenttotreatneoplasticdisease
andinthemid-1980sitwasintroducedatlowdosesforthetreatmentofrheumatoidarthritis.
Initially, the therapeutic effect ofMTX on rheumatoid arthritiswas attributed solely to its
ability to reduce the number of high proliferative cells, such as lymphocytes and other
inflammatorycellsresponsiblefortheinflammation.Othermechanismsofactionhavebeen
recently demonstrated. Among them, the most accredited is that MTX inhibits 5-
aminoimidazole-4-carbox-amideribonucleotide(AICAR)transformylaseincreasingtheAICAR
levels,thusleadingtothereleaseofintracellularadenineandadenosineintotheextracellular
space.Subsequently,extracellularadenosinethatbindsadenosinereceptor2(A2)increases
cyclic adenosinemonophosphate (cAMP)with consequent immunosuppression due to the
reducedproductionofpro-inflammatorycytokinessuchasTNF-aand IL-1b.Moreover, the
activationofA2 receptors induces theproductionofanti-inflammatory cytokines like IL-10
(Johnston-Cox et al. 2012). AlthoughMTX is themost effective drug comparedwith other
DMARDsandbDMARDs, somepatientsdonot respond,othersdevelop resistanceorhave
importantsideeffectsafterprolongeduse.Mostseveresideeffectsassociatedwitha long
termuseofMTXare:hepaticfibrosis,pulmonaryfibrosis,fatigueandrenalinsufficiency(Tian
&Cronstein2007).
1.4.3. BiologicalDMARDs
Inthemid1970’sanewtechnologyallowsproducingmonoclonalantibodies(Kohler&Milstein
1975).Thistechnologicalprogressopenstheroadtoanewtreatmentopportunitycalledthe
antibody therapy. The potential of this treatment was immediately obvious, indeed new
moleculescouldbedesignedandproducedforaspecific targetexpressedonspecificcells,
tissuesororgans.Thisopportunityallowedtoincreasedrugspecificitydecreasingtoxiceffects
relativetotraditionalchemicalcompounds,whichusuallyactwithunclearmechanisms.Atthe
moment, fourdifferent targetscanbestruckwithbDMARDs forRA treatment:TNF-a, IL-6
receptor,CD20andCD80/CD86(Smolenetal.2016).Inparticular,TNF-ainhibitorswerethe
firstbiologicalsdevelopedtotreatRA.ThefirstmonoclonalantibodyapprovedblockingTNF-
awasInfliximab(ReviewedinCampbelletal.2011),achimerichuman-mousemonoclonalIgG.
Whereas,AdalimumabwasthefirstfullhumanIgGapprovedtoneutralizeTFN-a(Rau2002).
Both became very popular because of the central role of TNF-a in the pathogenesis and
progressionofRA.TNF-aisproducedmainlybyT-cellsandmacrophagesinfiltratedintothe
Introduction
21
synovialmembraneanditsinhibitionwasassociatedtoadecreasedlevelofpro-inflammatory
cytokines such as IL-1, IL-6, IL-8 and the growth factor GM-CSF (Butler et al. 1995). The
effectivenesshasbeendemonstratedinanimalmodelsofRAwheretheanti-TNF-atreatment
reduces paw swelling and histological severity (Williams et al. 1992). These improvements
where than confirmed in humans by several studies showing that anti-TNF-a inhibition
prevents bone structural damage, improves physical function while slowing radiographic
changesinjoints(Ma&Xu2013)(Chenetal.2006).
1.4.4. TargetedsyntheticDMARDs
ThelatestdrugapprovedtotreatRAisTofacitinib,aJanuskinase(JAK)inhibitor.Drugsableto
targetonespecificmolecule, like JAK inhibitors,are included inanewclassofdrugscalled
“targeted” synthetic DMARDs. It interferes with the JAK-STAT signaling pathway, which is
activatedbyseveralpro-inflammatorycytokinesandgrowthfactorssuchasIL-6,interferon-g
andGM-CSF.Oncethispathwayisactive,itpromotestheexpressionofinflammatorygenes
orgenes involved incellsurvivalandproliferation(Ivashkiv&Hu2003).Overaperiodof2
years,TofacitinibwassuperiorifcomparedwithMethotrexate,bothasmonotherapy(Leeet
al.2014).
1.4.5. SideeffectsofRAtherapies
Aspreviouslymentioned,accordingtotheEULARrecommendationthefirstlinetreatmentis
basedonDMARDs.Inparticular,thegoldstandardtotreatRAisstillMTXduetoitsacceptable
safetyprofile,lowcostandgreatefficacytopreventcartilageandbonedestruction(Shindeet
al.2014).Indeed,biologicalsdrugsshowsimilarimprovementthanMTX(Favallietal.2012)
butareassociatedwithmoreseveresideeffects.Amongthese,raredemyelinatingsyndromes,
lupus-like reactions, bacterial infections and the reactivation of tuberculosis (TB) are
associatedwiththeinhibitionofanti-TNF-a(Botsios2005);commonbuttolerablesideeffects
likeinjection-sitereactionandinfusionarealsorelatedtotheTNF-ablocking(Scott&Kingsley
2006). Safety concernswere reportedabout Tofacitinib treatment,where respiratory tract
infection, headache, and diarrheawere themost common side effects (Fleischmann et al.
2012)(vanVollenhovenetal.2012).DespiteMTX is still theanchordrug to treatRA, some
issuesarereportedsuchasmouthulcers,gastrointestinalintolerance,bonemarrowandliver
toxicity.Someofthesesideeffectscouldbeovercomewithfolatesupplementation(Whittle
Introduction
22
&Hughes2004).However,onethirdofthepatientstreatedwithMTXhadtodiscontinuethe
treatmentafter2years,whilemorethan50%discontinuedthetreatmentafter5years(Leeet
al.2014).Somepatientsdiscontinuedthistherapybecauseof inefficacywhileotherdueto
sideeffects.Pharmacogenetics’studieshavebeenperformedinordertofindgeneswhichcan
helptopredictMTXtoxicitybutinconsistentdatahavebeenproduced(Romaoetal.2014).
1.5. NanotechnologyandNanomedicine
The termnanotechnology isdefined in literaturewithdifferentshades toexplain itsbroad
meaningandthewiderangeofmethods,toolsandpossibleapplication.Forthepurposeof
thisworkthesuitabledefinition isthatacceptedbytheEuropeanMedicinesAgency(EMA)
basedonthedefinitionsprovidedbytheUKRoyalSocietyandRoyalAcademyofEngineering
report (Dowling et al. 2004), the European Science Foundation foresight study on
nanotechnology(Moran2005)andtheVisionpaperandBasisforstrategicresearchagenda
forNanomedicineby theEuropeanTechnologyPlatformonNanomedicine (Boisseauet al.
2005). Therefore, according to those documents, Nanotechnology is defined as “the
productionandapplicationofstructures,devicesandsystemsbycontrollingtheshapeandsize
ofmaterialsatnanometrescale.Thenanometrescalerangesfromtheatomiclevelataround
0.2nm (2Å)up toaround1000nm”whileNanomedicine isdefinedas “theapplicationof
nanotechnologyinviewofmakingamedicaldiagnosisortreatingorpreventingdiseases. It
exploitstheimprovedandoftennovelphysical,chemicalandbiologicalpropertiesofmaterials
atnanometrescale”.Despite the termnanotechnologybecamepopular in1986, thanks to
ProfessorKimErikDrexlerwhouseditinthetitleofhisbook“EnginesofCreation:TheComing
EraofNanotechnology”(Drexler1986),thetermwascoinedbyProfessorNorioTaniguchiin
1974todescribetheprecisionmanufactureofmaterialswithnanometretolerances(Taniguchi
&Others1974).However,itisimportanttomentionthegreatcontributiongivenbyRichard
Feynmanduringhisprovocativetalkunderthetitle“There’splentyofroomatthebottom”to
theCaliforniaInstituteofTechnology.Heforeseesthepotentialtocontrolsingleatomsand
molecules improving theperformanceof instruments suchas theelectronmicroscopes. In
conclusion,heforesees“Nanotechnology”.Thattalk influencedthescientificcommunityto
challenge this research field and leading to the development of the scanning tunnelling
microscope and the atomic force microscope (Toumey 2009), breakthroughs which were
predicted by Feynman’s talk years before. The potential offered by nanotechnology is still
Introduction
23
underestimated, but the field of medicine is going to be revolutionised. Indeed, the
opportunitytobuildstructuresinthesamescalesizeofthebiomoleculesenhanceabroadset
ofdrugsfeatures.
1.5.1. Nanocarriers
The success of nanotechnology is due to the excellent anduniqueproperties offered by a
material in its nanometre scale. Nanomaterials find application in many different fields:
electronics, green technology and alternative energy, coatings, industrial chemistry,
nanorobotics,cosmeticsandbiomedical.Forexamples,silvernanoparticlesarewidelyusedin
disinfectants (LeOuay& Stellacci 2015)while titanium dioxide and zinc oxide are used in
sunscreenandcosmetics(Smijs&Pavel2011).Thefieldofmedicineisgoingtochangefast
due to the influence of nanotechnology leading to the new field called nanomedicine. In
particular,nanoparticlesarethemainapplicationofnanotechnologyinthemedicalfield(Kim
etal.2010).Thesuccessofnanoparticlesliesintheadvantagesofferedincomparisonwiththe
free drugs. Indeed, drugs encapsulated in nanoparticles are protected from the biological
environment, where enzymes could degrade rapidly drugs. Nanocarriers improve the
concentrationofthedrugsintotheselectedtissueandchangethepharmacokineticsofadrug.
Moreover, nanocarriers increase the intracellular penetration allowing different entrance
mechanisms,differentfromthoseusedbythefreedrugs.Thesamenanoparticles’features
arenowexploitedtoimprovediagnosis,increasingthecontrastandthesensitivityofcurrently
useddiagnosticprobes(Peeretal.2007).Inaddition,nanoparticlesallowtocarryatthesame
time diagnostic tracers and therapeutic compounds opening the way to the so called
theranostics, or allow to deliver two drugs simultaneously, an option called combination
therapy (Farokhzad & Langer 2009). Several different kinds of nanocarriers have been
produced, characterized and finally used for many different purposes: polymer-drug
conjugates, lipid-based nanocarriers such as liposomes and micelles, carbon nanotubes,
dendrimers, gold nanoparticles, nanoshells and polymeric nanoparticles (Figure 5).
Nanoparticlescanbedividedintotwoclasses:organicandinorganicnanoparticles.Inorganics
nanoparticlesaremadeofmetalatoms(metallic),non-metalatoms(organic)oramixtureof
metalandnon-metal(semi-conducting).Eachofthesetypesofnanoparticlesshowspeculiar
features and are used for different application.Metallic nanoparticles usually findmedical
application as diagnostic probes formagnetic resonance imaging (MRI), positron emission
Introduction
24
tomography(PET),X-rayandopticalimaging.Organicnanoparticlescanbemadeofdifferent
polymersorlipidsandduetotheirbiodegradabilityarewidelyusedfordrugdelivery(Murthy
2007).
In1995thefirstformulationofliposomeshasbeenapprovedbyFoodandDrugAdministration
(FDA)underthetradenameDoxil(liposomesloadedwithdoxorubicin)forthetreatmentof
the Kaposi sarcoma. This formulation demonstrated an improved circulation half-life of
doxorubicinandanincreasedaccumulationinthetumourtissue(Barenholz2012)(Gabizonet
al. 2003). To this day, 11 different formulations of liposomes have been approved for the
treatmentofdifferentdiseases.Theyaresphericalvesiclesessentiallymadeofphospholipids,
which,duetotheiramphiphilicnature,areabletoself-assemblyinaqueoussolution.Thepolar
shell ismadeofa lipidbilayer,which isable tohold lipophilicmoleculesbetween the two
phospholipidsbilayer.Bycontrast,theaqueouscorecanbeloadedwithhydrophilicmolecules
(Pattni et al. 2015). The surface of these structures can be functionalized with different
moleculesinordertotargetspecifickindofcellsortissues.Despitethesuccessofliposomes
basednanocarriersasdrugdeliverysystems,theiruseisstilllimitedbysometechnicalreasons.
Indeed, liposomes are characterizedby low stability for long term storage and the limited
amountofdrugthatcanbeloaded(Sannaetal.2014).
Polymericmicellesareself-assembledcore-shellnanostructuresmadebyamphiphilicblock
copolymers.Inaqueoussolution,thehydrophobicregionsoftheblockcopolymersaggregate
in order to reduce contact with water molecules producing core-shell vesicles. These
structuresusuallyfoundapplicationinthedeliveryofhydrophobicdrugswhichcanbeloaded
intothecoreofthesestructures(Xuetal.2013).
Polymer drug conjugates were first described in 1977 when researchers reported no
immunogenicityofbovineserumalbumin(BSA)whenconjugatedtopolyethyleneglycol(PEG)
(Abuchowskietal.1977). Indeed,becauseof its lowimmunogenicity,PEGisthemostused
polymer tomakenanocarriers stealth to the immune system (Salmaso&Caliceti 2013). In
addition,PEGincreasesthesolubilityoftheattachedproteinsandincreasesproteins’half-life
inthebloodstreambecauseoftheirhighermolecularweight(Pasut&Veronese2012).The
prolongedhalf-lifeassociatetotheuseofPEG-conjugatedproteinwasdemonstratedwitha
commercialantibodycalledcertolizumabpegol,aFabfragment(describedintheparagraph
1.7.1)abletoblockTNF-aandconjugatedtoPEGof40kDa.Thisantibody,nowusedtotreat
RA,showshigher timeofcirculationanda lowerrateofkidneyelimination ifcompared to
Introduction
25
othercommerciallyavailableanti-TNF-a.Moreover,ahighertissuepenetrationwasreported
forPEGconjugatedantibodyfragment.Infact,PEGincreasesthemolecularweight,enhances
theretentiontimeintheinflamedtissue,wherethevesselsareusuallycharacterizedbytheir
highpermeability (Palframanet al. 2009).Another successfulpolymerusedasa conjugate
agentishyaluronicacid(HA).ThisisanaturalpolysaccharideabletobinditsreceptorCD44,
whichhasbeenfoundtobeoverexpressedininflamedsynovialtissue.Forthisreason,HAisa
moleculesuitable for targetdrugdelivery in inflamed jointsofRApatients. Indeed,HAhas
beenusedinconjugationwithMTXdemonstratingthatHA-MTXisabletoreachtheinflamed
jointinahigherconcentrationthusshowingasuperiortherapeuticefficacyifcomparedwith
thefreedrug(Shinetal.2014).Dendrimersaretree-likebranchedmacromoleculesmadeof
naturalorsyntheticelements.Theyhaveacentralinnercorewithradiallyattachedrepeated
units which possess several chemical functional groups nearby the surface (Pandita et al.
2014).Duetodifferentfunctionalendgroups,theyaremultivalentnanocarriersabletocarry
severalkindsofmolecules.Dendrimershavebeenusedtotreatanimalmodelofrheumatoid
arthritisshowinggreatabilitytoreduceosteoclastogenesisandtodecreasethesecretionof
pro-inflammatorycytokines(Bosch2011).
Carbon nanotubes are cylindrical nanostructure made of benzene rings. They can have
different structures such as single-walled nanotubes (SWNTs) andmulti-walled nanotubes
(MWNTs).Thelatterismadeofmultiplerolledlayersofgraphene(Eatemadietal.2014).These
nanostructureshavebeenexploitedmainlyfordiagnosticpurpose.Indeed, issuesregarding
their toxicity are still under debate and limit their prolonged therapeutic use. Although,
different approaches have been used to increase carbon nanotubes biocompatibility and
biodegradability. To this aim, chemically functionalised carbon nanotubes show reduced
toxicityandbetterdegradabilityduetotheoxidativeenzymes(Biancoetal.2011).
Polymericnanoparticles(NPs)representanotherclassofsuccessfulnanocarriers,whichhas
been used in medical application both for diagnostic and therapeutic purposes. They are
composed of block copolymerswith different hydrophilicity, length andmolecularweight,
whichspontaneouslyassemblesintoacore-shellstructureinanaqueousenvironment.High
amounts of therapeutics can be loaded into the core of these structures and, due to the
hydrophilic shell, encapsulated drugs are protected from the external environment (Hu &
Zhang2012). Initially,polymericnanoparticlesweremainlyproducedbynon-biodegradable
polymers, such as polystyrene, polyacrylates, poly (methyl methacrylate) (PMMA) or
<3%&.0,(%/.3!
!
! ! QV!
7.89'(&98'-/0+;! K+(',$+! .4! %*+/&! 3.3O#/.0+5&'0'#/8/%9B! %*+$+! 7'&%/(8+$! ,$,'889! *':+! #++3!
.7%/-/M+0!/3!.&0+&!%.!.#%'/3!'!4'$%!(8+'&'3(+!':./0/35!'((,-,8'%/.3!'%!'!%.E/(!8+:+8;!H.?+:+&B!
3.3O#/.0+5&'0'#8+!7.89-+&$!*':+!#++3!'$$.(/'%+0!?/%*!/348'--'%.&9!&+'(%/.3$!'30!(*&.3/(!
%.E/(/%9;!<30++0B!&+(+3%89!'3!/-7.&%'3%!?.&I!*'$!(.-7'&+0!%*+!(4!5(5#!+44+(%$!.4!#/.0+5&'0'#8+!
'30!3.3O#/.0+5&'0'#8+!7.89-+&/(!3'3.7'&%/(8+$!'0-/3/$%&'%+0!%*&.,5*!%*+!'/&?'9$! /3%.!%*+!
8,35$!$*.?/35!'3!/3(&+'$+0!+E7&+$$/.3!.4!7&.O/348'--'%.&9!(9%.I/3+$!$,(*!'$!<WOV!'30!FLJO"!
/3!-/(+! &+(+/:/35!7.89$%9&+3+!L@$! 1"&'5'.O]'3%/'5.!+%!'8;! Q^=V2;! F*,$B! /3! %*+! 8'$%! 9+'&$B! '3!
/3(&+'$+0!/3%+&+$%!*'$!#++3!4.(,$+0!.3!%*+!,$+!.4!#/.0+5&'0'#8+!7.89-+&$;!!
!
^+5)&/,>_,W12+*,2%&)*%)&/,':,'&51$+*,$1$'*1&&+/&2",,W/7.$.-+$!1=2!'&+!-'0+!.4!'!0.,#8+!8'9+&!.4!8/7/0$!?*/(*!('3!#+!8.'0+0!?/%*!0/44+&+3%!I/30$!.4!%*+&'7+,%/($!$,(*!'$!#/.8.5/('8$B!
$-'88!0&,5$B!3,(8+/(!'(/0$!1Q2;[email protected]+&/(!3'3.7'&%/(8+$!1S2!'&+!-'0+!.4!#/.0+5&'0'#8+!7.89-+&$!8/I+!7.89!18'(%/0+O(.O589(.8/0+2!
(.7.89-+&$!1@WR"2!'30!7.89!18'(%/0+2!1@W"2!'30!.%*+&!%97+$!.4!7.89-+&$!1V2;!K.%*!8/7.$.-+$!'30!7.89-+&/(!3'3.7'&%/(8+$!('3!
#+!4,3(%/.3'8/M+0!1P2!?/%*!'3%/#.0/+$B!%*+/&!4&'5-+3%$!.&!%'&5+%/35!7+7%/0+$;!@TR!/$!,$,'889!,$+0!%.!&+0,(+!%*+!/3%+&'(%/.3!?/%*!
%*+!-.3.3,(8+'&!7*'5.(9%+!$9$%+-!1D@]2;!F*+!4/5,&+!/$!'0'7%+0!4&.-!J+&&'&/!D!+%!'8;!L'%!)+:!)*+,-'%.8!Q^=U!1J+&&'&/!+%!'8;!
Q^=U2;!
!"?"7"! R+'(/5&1(1S4/,>'460/&2,
K/.0+5&'0'#8+! 7.89-+&/(! 3'3.7'&%/(8+$! '&+! %*+! -.$%! 7.7,8'&! '30! $,((+$$4,8! 3'3.('&&/+&$!
#+(',$+! %*+9! 7&.:/0+! '! (.3%&.88+0! &+8+'$+B! $,#(+88,8'&! $/M+! '30! #/.(.-7'%/#/8/%9;! KL@$N!
Introduction
27
polymerscanbesyntheticsuchaspoly(e-caprolactone)(PCL),poly(lactide)(PLA),poly(lactide-
co-glycolide)copolymers(PLGA)andpoly(aminoacids)orcanbenaturallikechitosan,alginate
and gelatine (Banik et al. 2016). PLGA is one of the most used polymer due to its
biodegradability.Itishydrolysedintwomonomers,oneoflacticacidandoneofglycolicacid
which are both non-toxic molecules for the human body. In the same way PLA is a
biocompatibleandabiodegradablepolymeranditismetabolizedinmonomericunitsoflactic
acid,whichisanaturalintermediateofanaerobicrespiration,showingverypoortoxicity.No
toxicity was reported also for PCL which is degraded by hydrolysis of its ester linkages
(Mahapatro & Singh 2011)(Kumari et al. 2010). PCL is characterized by very low in vivo
degradationtimeandhighdrugpermeabilityandforthesereasonsiswidelyusedfortissue
engineeringscaffolds(Uleryetal.2011).PLGA,PLAandPCLwereapprovedbyFDAforseveral
applicationsinhumanbody.
1.5.3. Propertiesandrationaldesignofnanoparticles
In order to design successful nanocarrierswith a higher therapeutic efficacy or diagnostic
sensitivenessitisfundamentaltorationallydesignnanocarrierswithtissuespecificityinorder
toavoidunspecificdistributionandlowaccumulationofthemoleculesinthetargetcell/tissue.
Toreachthisaim,arationaldesignshouldtakeintoaccountseveralphysicochemicalfeatures
ofthepolymersandthefinalstructure.Likewise,thedesignshouldconsidertheenvironment
inwhichnanocarrierswillbeinjectedandthebiologicalbarriertocrossandreachthefinal
target(Blancoetal.2015).Therouteofadministrationinfluencesthebiodistributionandthe
adsorption.Indeed,orallyadministratednanoparticleshavetocrossthegutmucosatoreach
the bloodstream. This route showed a slow rate of adsorption and only low amount of
nanoparticlesreachthetargettissue.Bycontrast,intravenouslyadministratednanoparticles
showed 100% of bioavailability and a fast biodistribution (Simon & Sabliov 2014).
Biodegradability and biocompatibility are indispensable traits to satisfy in order to design
nanocarriers,whichcanbeusedformedicalpurposes.Indeed,FDAbiodegradablepolymers
areusuallyusedtodevelopnewnanotechnologicaltherapeuticsanddiagnostics.Degradation
timeofbiodegradablepolymersdependonthelengthofthepolymerswhilethenanoparticles’
shapeismainlyaresultofthemolecularweightandthepolymerconcentrationaswellasthe
encapsulationefficiency(Danhier,Ansorena,etal.2012).Size,shapeandfeaturesoftheshell
surface,suchasthecharge,definetheirbiodistributionandstabilityinthebloodstream.Once
Introduction
28
inthecirculation,nanoparticlesmustavoidopsonisationandthencrossthebloodvesselsto
arrive in the target tissue. The process of opsonisation includes the adsorption of plasma
proteins, serum albumin, immunoglobulins and complement proteins on the surface of
nanoparticles.Theseproteinsformthesocalled“proteincorona”,whichisresponsibleofa
rapidclearance,hindranceoftargetingcapacity,andinductionoftoxicity(Nguyen&Lee2017).
Due to theseproteins adsorbedon the surface, nanoparticles are often recognizedby the
mononuclearphagocytesystem(MPS).TheMPSismainlycomposedbymacrophagesofthe
spleen, lymphnodesandliver,whichcontributetothephagocytosisandeliminationofthe
nanoparticles(Moghimi&Patel1998).Theformationoftheproteincoronaisinfluencedby
different factors such as surface charge, hydrophobicity, nanoparticles size and functional
groupsontheshell.Thebeststrategytodesign“stealth”nanoparticlesistocoverthesurface
with non-immunogenic and hydrophilicmolecules able tomask the hydrophobicity of the
nanoparticles. The most widely used molecule is PEG, already used in conjugation with
antibodiestoincreasetheirlifetime(seeparagraph1.5.1).Inthesameway,whenPEGisused
onthesurfaceofnanoparticles,itincreasesthecirculationtimeintheblood(Hamiltonetal.
2002).Moreover,itreducesnanoparticlesaggregationandproteincoronaformation(Fanget
al.2009).Theconformation, the lengthandthedensityofPEGarefeaturesthataffectthe
circulation time of nanoparticles. In general, long chain of PEG (20-50 kDa) are used in
conjugationwithsmallproteinthuspreventingrenalexcretion,whileshortPEGchains(3-10
kDa)areusuallyboundon largernanoparticles (50-100nm)becausean increaseddiameter
couldincreasetheinteractionwiththeMPS.Forwhatconcernsthedensity,itisknownthat
lowdensityofPEGonthesurfaceofnanoparticlesassumesa“mushroom”conformation,by
contrast,highdensityofPEGassumesa“brush”conformation.Thelatterincreasesthelifetime
duetothefactthathighdensityofPEGmasksthenanoparticlesfromtheMPS(Jokerstetal.
2011). Although, PEG is not the only stealthmaterial andother hydrophilic polymerswith
stealthpropertiescanbeusedsuchaspolaxamer,polyvinylalcohol,poly(aminoacids)and
polysaccharides(Huang&Guo2011).Advancedstrategiestoproducestealthnanoparticles
havebeendevelopedusingcellmembranesisolatedfromleukocytes(Parodietal.2012)or
red blood cells (Hu et al. 2011) showing an increased circulation time. Another important
characteristic is the dimension of the nanoparticles. Indeed, nanoparticles, in order to be
accumulated in the target tissue,must cross the blood vessel wall. Usually healthy blood
vesselshaveporesizeabout5nm.Thus,nanoparticleswithadiameterlessthan5nmquickly
<3%&.0,(%/.3!
!
! ! QX!
&+'(*! %*+! +E%&':'$(,8'&! +E%&'(+88,8'&! $7'(+! 1TT]2B!?*/8+! #/55+&! 3'3.7'&%/(8+$! &+-'/3! /3! %*+!
#8..0$%&+'-! 4.&! '! 8.35+&! %/-+;! ]/-/8'&89B! 3'3.7'&%/(8+$! $-'88+&! %*'3!V!3-!('3!+'$/89! &+'(*!
89-7*'%/(!:+$$+8!0,+!%.!%*+/&!7+&-+'#/8/%9;!]-'88!7'&%/(8+$!?/%*!'!*90&.093'-/(!0/'-+%+&!x!
U3-!'&+!,$,'889! 4/8%+&+0!#9!I/03+9!?*/8+!7'&%/(8+$!#/55+&! %*'3!Z!3-!'&+!3.%! 4/8%+&+0;! <3! %*/$!
7&.(+$$B! %*+! $,&4'(+! (*'&5+! +44+(%$! %*+! 48.?! .4! +8/-/3'%/.3B! /3! 4'(%! -.8+(,8+$! ?/%*! $/-/8'&!
0/'-+%+&!*':+!0/44+&+3%!4/8%&'%/.3!%/-+!0,+!%.!%*+!(*'&5+;!['%/.3/(!-.8+(,8+$!'&+!4/8%&'%+0!4/&$%B!
4.88.?+0!#9!3+,%&'8! '30!3+5'%/:+!-.8+(,8+$;!)+3'8! 4/8%&'%/.3! /$! %*+!-.$%! /-7.&%'3%!7&.(+$$!
'$$.(/'%+0!%.!%*+!(8+'&'3(+B!'8%*.,5*!$78++3!'30!8/:+&!'8$.!78'9!'!(+3%&'8!&.8+!/3!%*+!+8/-/3'%/.3!
.4!3'3.7'&%/(8+$;!L'3.7'&%/(8+$B!%..!#/5!%.!#+!+8/-/3'%+0!#9!%*+!I/03+9B!&+'(*!%*+!8/:+&!'30!%*+!
$78++3! ?*+&+! &+$/0+3%!-'(&.7*'5+$! /3%+&3'8/M+! 7'&%/(8+$! %*&.,5*! +30.(9%.$/$! '30! 0+$%&.9!
.7$.3/M+0!-'%+&/'8;!D.&+.:+&B!#.%*!8/:+&!'30!$78++3!+8/-/3'%+!7'&%/(8+$!?/%*!'!0/'-+%+&!.4!=^O
Q^!3-!#+(',$+!.4!%*+/&!7*9$/.8.5/('8!4,3(%/.3!1J/5,&+!V2!1W.35-/&+!+%!'8;!Q^^Z2;!!
!
^+5)&/,;_,W+'(+2%&+J)%+'$,':,$1$'H1&%+*9/2",,1'2!]/M+B!$*'7+!'30!$,&4'(+!(*'&5+!.4!%*+!3'3.7'&%/(8+$!(*'&'(%+&/M+!%*+/&!#/.O0/$%&/#,%/.3!'-.35!:'&/.,$!.&5'3$!$,(*!'$!8,35$B!
8/:+&B!$78++3!'30!I/03+9$;!D+0/,-!$/M+0!3'3.7'&%/(8+$!1Q^O=U^!3-2!-'/389!'((,-,8'%+!/3!%*+!8/:+&B!8+$$!/3!$78++3!'30!+$7+(/'889!
/3!8,35$;!F*+!$'-+!%&+30!*'$!#++3!&+7.&%+0!4.&!%*+!#/5!7'&%/(8+$!1y=U^!3-2!?/%*!'!*/5*+&!'((,-,8'%/.3!/3!%*+!8,35$;!<3$%+'0B!
$-'88!7'&%/(8+$!1xU!3-2!'((,-,8'%+!/3!%*+!I/03+9$;!1#2
Introduction
30
mechanism (Champion&Mitragotri 2006). Another endocytic pathway able to internalize
particleswithabigdiameteriscalledmacropinocytosis.Throughthispathway,itispossibleto
internalizedparticleswithadiameterbetween0.5and10µm.Instead,smallerparticleswith
a diameter of~120 nm are internalized through the clathrin-mediated endocytosis (CME).
ManyproteinsparticipateintheformationofCMEvesicles,inparticularclathrin,whichcoats
the vesicles inducing the curvature of the membrane. It has been proved that cationic
nanoparticlesmadeofPLA-PEGwithadiameterof~100nmareexclusively internalizedby
CMEendocytosis(Harush-Frenkeletal.2007).Thechargeeffectstheinternalization,indeed
positivelychargednanoparticlesareattractedbynegativelychargedcellsurfaceleadingtoan
enhanced internalization via CME (Yameen et al. 2014). Caveolae-mediated endocytosis is
anotherrouteofinternalizationwhichusesaspecificprotein(Caveolin)toformthevesicles
withaflask-shapedstructureof60-80nm(Doherty&McMahon2009).Thisisthepreferential
route used by viruses and other pathogens to enter into host cells because of bypass the
lysosomes(Carver&Schnitzer2003).Forthesamereason,thispathwayshouldbeconvenient
todeliveryDNAorproteins.Moreover, thispathway receivedgreatattentionbecause it is
involvedinthetrans-endothelialpathwaythuscouldbeexploitedtodesignparticlesableto
deliver its contentacross theendothelial tissue (Ohetal. 2007).However, areknown two
alternativemechanismsofinternalization,whichdonotrequirethepresenceofcoatproteins:
clathrin and caveolin-independent endocytosis. Usually, vesicles of these pathways can
internalizeparticleswithadiametersmallerthan90nm(Yameenetal.2014).
Takingintoaccountalltheseknowledge,itisreasonablethatnanoparticleswithadiameter
between100and200nmshouldbethebestchoicetoobtainalong-lastingcirculation.
1.6. Passiveandactivetargeting
Theprocessbywhichthenanoparticlesbindtheirtargettissuecanbepassiveoractive.The
passivetargetingdoesnotrequireaspecificsurfacefunctionalizationofthenanoparticlesand
the movement and interaction are based only on the morphology and chemicophysical
features. On the contrary, in the active targeting, particularmolecules conjugated on the
nanoparticles’surfaceareabletodrivethemintoaspecifictissue.
Introduction
31
1.6.1. Passivetargeting
ThepassivetargetingcoincideswiththeEnhancedPermeabilityRetention(EPR)effect.This
effect was discovered in 1986 by Matsumura Y. & Maeda H, who described the higher
accumulationofadrugpolymerconjugated, compared to the freedrug, into the tumorof
tumorbearingmice.Thiseffect is the resultof thepathophysiologic featuresof the tumor
hypervasculature coupled with poor lymphatic drainage (Figure 7) (Matsumura & Maeda
1986).Indeed,itisknownthattumorsites,aswellasinflamedtissue,arecharacterizedbya
prominentneoangiogeneticprocessinwhichbloodvesselshowedhighpressureandenhanced
permeabilityduetothefactthatfenestrationofbloodvesselinthispathologicaltissuescan
reach diameters of several µm (Hashizume et al. 2000). In the inflamed tissue, several
molecules such as histamine, bradykinin, leukotrienes, and serotonin contribute to the
increasedpermeability.Inaddition,lackoftightjunctionbetweenendothelialcellsandlackof
functionalsmoothmusclelayeraroundthebloodvesselsincreasetheprocessofextravasation
(Nehoffetal.2014).Instead,the“retention”istheresultofthelymphaticvesselsimpairment
reported in tumor mass and in the hyperplastic synovial tissue of RA patients and other
inflamedtissue.Indeed,thepoordrainageofthelymphaticvesselshasbeendemonstratedin
severalstudies,althoughitsmechanismisnotyetclear(Boutaetal.2015).Sincehealthytissue
doesnothavelargefenestrationinthebloodvesselsandshowsregularpressureandlymphatic
vesselsfunctions,nanocarrierspreferentiallyreachpathologicaltissueduetotheEPReffect.
Thismechanismofnanocarriers’distributionallows topassivelydeliverydrugswithhigher
concentration into theaffected tissue, increasing theeffectivenessandoftenavoiding side
effectsinhealthytissue(Maedaetal.2013).Itisknownthatsmallparticlesareabletoquickly
reachanddiffuseinthetargettissue,buttheirretentionwouldbelowandclearancewould
be fast. By contrast, particles with a bigger diameter reach their target slowly but their
retentionandclearancewouldbeenhanced.Thus,inordertoexploitthepotentialoftheEPR
effect,itisimportanttofindtherightcompromiseduringtheparticles’design(Blancoetal.
2015).
1.6.2. Activetargeting
Despiteadvantagesofthepassivetargeting,somelimitationsareknown.Indeed,duetothe
variabilitypresentamongtumorsorinflamedtissues,aninsufficientamountofnanocarriers
<3%&.0,(%/.3!
!
! ! PQ!
&+'(*! %*+! 0+$/&+0! %'&5+%;! D.&+.:+&B! %*+! 7'$$/:+! %'&5+%/35B! 0+$7/%+! %*+! T@)! +44+(%B! /$! 3.%!
$,44/(/+3%!%.!0/$%/35,/$*!*+'8%*9!%/$$,+!4&.-!7'%*.8.5/('8!%/$$,+!1]%+/(*+3!+%!'8;!Q^=P2;!J.&!%*/$!
&+'$.3B!%*+!&+$+'&(*!4.(,$+$!/%$!'%%+3%/.3!.3!%*+!'(%/:+!%'&5+%/35;!<3!'00/%/.3!%.!%*+!7'$$/:+!
T@)!+44+(%B! %*+!'(%/:+! %'&5+%/35!+E78./%$!-.8+(,8+$!'#8+! &+(.53/M+$!'! %/$$,+O$7+(/4/(!-'&I+&B!
?*/(*! /$! +E7&+$$+0! .&! .:+&+E7&+$$+0! #9! %*+! %'&5+%! %/$$,+! 1J/5,&+! Y2;! ]+:+&'8! $%,0/+$! *':+!
0+-.3$%&'%+0!%*'%!%'&5+%/35!3'3.('&&/+&$!*':+!'!$,7+&/.&!%*+&'7+,%/(!+44/('(9!'30!0/'53.$%/(!
$+3$/%/:/%9!(.-7'&+0!%.!,3%'&5+%+0!3'3.('&&/+&$!1@*/88/7$!+%!'8;!Q^=^2;!<3!'00/%/.3B!3'3.('&&/+&$!
?/%*! %/$$,+! $7+(/4/(/%9! ':./0! 0+8/:+&/35! 0&,5$! .&! 0/'53.$%/($! /3! *+'8%*9! %/$$,+! &+0,(/35! $/0+!
+44+(%$!1]%+/(*+3!+%!'8;!Q^=P2;!!
!
^+5)&/,C_,@122+A/,1$(,1*%+A/,%1&5/%+$5;!!F*+!4/5,&+!&+7&+$+3%$!3'3.7'&%/(8+$!%*'%!('3!0+8/:+&!%*+/&!7'98.'0!/3%.!%*+!/348'-+0!$93.:/'8!%/$$,+;!K+(',$+!.4!%*+!/3(&+'$+0!
7+&-+'#/8/%9! .4! %*+! #8..0! :+$$+8$B! 3'3.7'&%/(8+$! ('3! +'$/89! &+'(*! %*+! *97+&78'$%/(! $93.:/'8! %/$$,+! 1T@)! +44+(%2;! F*+! '(%/:+!
%'&5+%/35!('3!#+!'(*/+:+0!%*'3I$!%.!%'&5+%/35!-.8+(,8+$!(.36,5'%+0!.3!%*+!$,&4'(+!.4!%*+!3'3.7'&%/(8+$!'#8+!%.!#/30!$7+(/4/(!
8/5'30$!.3! %*+! %'&5+%!(+88$;!c/%*! %*/$! %'&5+%/35!$9$%+-$B!0&,5$!('3!#+! &+8+'$+0! /3!(8.$+!7&.E/-/%9!.4! %*+! %'&5+%!(+88$`%/$$,+!
'30`.&!/3$/0+!%*+$+!(+88$;!F*+!4/5,&+!/$!'0'7%+0!4&.-!@++&!C;!L'%!L'3.%+(*3.8B!Q^^Y!1@++&!+%!'8;!Q^^Y2;!
!"C"! M1&5/%+$5,15/$%2,<'&,&./)01%'+(,1&%.&+%+2,,
C/44+&+3%!(8'$$+$!.4!%'&5+%/35!'5+3%$!('3!#+!,$+0!0.!0+8/:+&9!3'3.('&&/+&$!/3!'!$7+(/4/(!%/$$,+_!
7&.%+/3$B!8/I+!'3%/#.0/+$!.&!%*+/&!4&'5-+3%$B!'7%'-+&$!13,(8+/(!'(/0$2!.&!.%*+&!$-'88!-.8+(,8+$!
Introduction
33
such as peptides, vitamins and carbohydrates (Peer et al. 2007). This approachpotentially
increasesthetherapeuticefficacy,avoidingoff-targetsideeffects.Moreover,areductionin
costsofdiseasemanagementisexpectedbecausethedosesrequiredtoachievesameefficacy
tountargeteddrugsmightbelower(Ferrarietal.2015).
1.7.1. Recombinantantibodiesandtheirfragments
Theantibodiesareheterodimericproteinscomposedoftwostructuralelementsdefinedas
Heavy(H)andLight(L)chainsbecauseoftheiraminoacidiccompositionandmolecularweight.
The heavy chain is made of 440aa with a molecular weight of 50kDa whereas the light
counterpartconsistsof220aawithamolecularweightof25kDa(Wangetal.2000).Eachchain
canbedividedintotwobasicbuildingblocks:thevariable(V)domain(NH2-terminal),ableto
interactwiththeantigen,andtheconstant(C)domain(COOH-terminal),responsibleforthe
effectorfunctionssuchasthemacrophagesbindingorthecomplementsystemactivation.The
heavychaindiffersfromthelightchainforthenumberandcompositionofthesefunctional
domains:thelightchaincontainsoneconstantdomain(CL)whereastheheavychaincouldbe
composedbyeitherthreeorfourconstantdomains(CH)(Figure8).Aspacerhingeregionis
located between CH1 and CH2 and confers particular flexibility to the final structure
(SchroederJr.&Cavacini2010).Dependingontheconstantcomposition,thehumanheavy
chainscouldbeclassifiedinto5isotypes:IgM,IgG,IgA,IgDandIgE.ThesubclassesIgMandIgE
havefourCHincontrasttotheothers,whichhaveonlythreeconstantdomainsandthehinge
region. In the variable domain three hypervariable loops are responsible for the antigen
identification, called complementarity determining region (CDR) (Kim et al. 2005). Three
functional domains can be identified by papain digestion: two identical Fab, “fragment
antigen-binding”,whichconsistofthewholeL-chainlinkedwiththeVHandtheCH1portion
oftheheavychain;oneFc,“fragmentcrystallisable”,madeoftwocovalentlylinkedCH2-CH3
(orCH2-CH3-CH4).Instead,theimmunoglobulincanbecleavedintwopartbypepsin:F(ab')2
fragmentandaFcfragment.TheFabcanbeseparatedintoavariablefragment(Fv),madeof
VHandVLresponsiblefortheantigenbindingandanotherfragmentcomposedoftheCLand
CH1.Takingadvantageofthisfunctionaldomains,differentfragmentshavebeendesignedand
producedbyrecombinant technology. Indeed, fundamentalwerethestudiesconductedby
KohlerandMilsteinin1975(Kohler&Milstein1975).TheyfindawaytoimmortalizeBcell
precursors through the fusion with mouse myeloma cells to generate stable monoclonal
Introduction
34
antibodyproduction.Althoughthistechniqueprovidesausefulmethodfortheproductionof
monoclonalantibodies,themurineoriginoftheantibodiescausesimmunogenicityinhumans
(Schroff et al. 1985)(LoBuglio et al. 1989). However, improvement of molecular biology
technique allows researchers to reduce the murine component in favor of the human
component, generating different kinds of antibodies such as chimeric, humanized or fully
human. Most successful engineered antibodies used are: the scFv (single chain fragment
variable) or Fab. However, some issues are associated with the small molecular size: fast
clearance,poorstabilityandmonovalentbindingtotheantigen.Although,inordertosolve
thisproblemtwodifferentengineeredantibodieshavebeendesigned:thescFv-Fcmadeof
thescFvfusedtotheCH3-CH2portion;thesocalled“minibody”madeofthescFvfusedtothe
CH3.Theseformatsshowedanimprovedpharmacokineticswithaprolongedcirculationtime,
increasedtissuepenetrationandenhancedepitopeselectivity(Olafsen&Wu2010).However,
manytypesoftheseantibodieshavebeenusedastherapeuticagents(immunotherapy)oras
targetingagentsfornanocarriers.
1.7.2. Peptides
Althoughtheantibodiesareusedastargetingagentsabletodeliverynanocarriersinaspecific
tissue, recently peptides have been usedwith great success. Due to their small size, high
stability,lowimmunogenicityandeasyproduction,peptideshavehugepotentialastargeting
agents(Sannaetal.2014)(Ferrarietal.2015).Peptidescontainingtheaminoacidicsequence
Arg-Gly-Asp(RGD)areabletobindintegrinsavb3,whichareexpressedonendothelialcellsof
the inflamed synovial tissue and tumours. Indeed, in a mice model of the syngeneic
transplantablelivertumor(TLT)havebeendemonstratedtheretardedtumorgrowthanda
prolongedsurvivaltimeofmicetreatedbypaclitaxel(PTX)-loadedRGD-nanoparticleswhen
comparedtonon-targetednanoparticles(Danhier,Pourcelle,etal.2012).Inthesameway,it
hasbeenprovedthatRGD-MTX-PLGA-Au(gold)nanoparticlesinjectedinamodelofcollagen-
inducedarthritishadasuperiortherapeuticefficacy,comparedwithuntargetednanoparticles,
withamuchsmallerdosageofMTXinthenanoparticles(Leeetal.2013).
<3%&.0,(%/.3!
!
! ! PU!
!
^+5)&/,=_,8$%+J'(+/2,1$(,%./+&,:&150/$%2,)2/(,12,%1&5/%+$5,0'9/*)9/2",,F*+! 4/5,&+! &+7&+$+3%$! %*+! $%&,(%,&+! .4! '! 4,88! /--,3.58.#,8/3! 1$%'&%/35! 4&.-! %*+! 8+4%2!?/%*! %*+! jWB! jHB! [W! '30! [H;! F*+3B!
4&'5-+3%$! $,(*! '$! J1'#2QB! J'#N! '30! '3.%*+&! 4.&-'%! 8/I+! %*+! ](J:! '30! ](J:OJ(! '&+! &+7.&%+0;! J/3'889B! '&+! &+7&+$+3%+0! $-'88!
%'&5+%/35!-.8+(,8+$!$,(*!'$!7+7%/0+$!'30!'7%'-+&$;!J/5,&+!'0'7%+0!4&.-!@++&!C;!L'%!L'3.%+(*3.8B!Q^^Y!1@++&!+%!'8;!Q^^Y2;!
!"C"9"! M1&5/%+$5,%./,;12*)41%)&/,
"$! '8&+'09! 0/$(,$$+0! /3! 7'&'5&'7*! =;QB! %*+! 3+.'35/.5+3+$/$! *'$! '3! /-7.&%'3%! &.8+! /3! %*+!
7'%*.5+3+$/$!.4! &*+,-'%./0! '&%*&/%/$;! J.&! %*/$! &+'$.3B! %*+!-/(&.:'$(,8'%,&+!.4! %*+! $93.:/'8!
%/$$,+!/$!#+(.-/35!'3!/3%+&+$%/35!%'&5+%!4.&!%*+!0/'53.$/$!'30!%&+'%-+3%!.4!%*/$!(*&.3/(!0/$+'$+;!
<30++0B!%*+!+30.%*+8/'8!%/$$,+!/$!%*+!4/&$%!#'&&/+&!%*'%!8+,I.(9%+$!*':+!%.!(&.$$!%.!/34/8%&'%+!%*+!
$93.:/,-!1J+&&'&/!+%!'8;!Q^=U2;!W++!+%!'8;!*':+!/$.8'%+0!'!7+7%/0+!?/%*!$7+(/4/(/%9!4.&!%*+!*,-'3!
'&%*&/%/(!$93.:/,-B!/3!7'&%/(,8'&!4.&!%*+!/348'-+0!-/(&.:'$(,8'%,&+B!#9!/36+(%/35!'!7*'5+!0/$78'9!
8/#&'&9!/3!'!*,-'3!$93.:/,-z][<C!-.,$+!%&'3$78'3%'%/.3!-.0+8;!F*+!/$.8'%+0!7+7%/0+!/$!-'0+!
.4!Y!'-/3.'(/0$!1[f]FHC)W[2!48'3I+0!#9!%?.!(9$%+/3+$B!?*/(*!(.3$%&'/3!%*+!(/&(,8'&/M'%/.3!.4!
%*+!7+7%/0+!1W++!+%!'8;!Q^^Q21\3,.*'!+%!'8;!Q^=U2;!F*/$!7+7%/0+!?'$!'8&+'09!,$+0!/3!4,$/.3!%.!
<WOS!/3!.&0+&!%.!0+8/:+&9!(9%.I/3+$!/3%.!%*+!*,-'3!)"!$93.:/,-!/3!%*+!][<C!-.,$+!E+3.5&'4%!
-.0+8B!7&.:/35!%*+!5&+'%!7.%+3%/'8!.4!%*+!7+7%/0+O%'&5+%/35!'77&.'(*;!a$/35!%*+!$'-+!$%&'%+59B!
%*/$!7+7%/0+!*'$!#++3!4,$+0!%.!%*+!J(!7.&%/.3!.4!%*+!'3%/O(.-78+-+3%
36
2. Aimandrationaleofthethesis
Aimandrationaleofthethesis
37
Theuseofimmunotherapyhasnowbecomepartofcommonclinicalpracticeforthetreatment
ofseveraldiseases.Indeed,immunotherapyiswidelyusedtotreatcancerandithasbeenused
to successful treat RA patients, improving their quality life. Although, their administration
recognizeandblockstheirtargetssystemicallyenhancingtheriskofdevelopingsideeffects,
suchasbacterialandviralinfections.Moreover,highcostsofbiologicaldrugsareholdingback
theirwidespreadusage.Forthesereasons,syntheticDMARDs,suchasMTX,arestilltheanchor
drugstotreatRA.Despitetheimprovements,patientsaretreatedlifetime,trueremissionis
achievedbyminorityandmostofthemhavetofacerelapses.
Inthisscenario,there istheneedtodevelopsmartdrugswithtissuespecificityabletoact
avoidingsystemiccomplications,increasingtheeffectivenessandreducingdosesandcosts.
Another importantaspect to improve is thediagnosisofRA.Accordingto theclassification
criteriaforrheumatoidarthritis2010ACR/EULAR,thediagnosisisbasedonclinicalobjective
evaluations,laboratorytestsandimaginganalysis.Today,radiographyisthemainstayforthe
diagnosisandfollow-upofRA,however,radiationslimititsusage.Moreover,thediagnosisof
thediseaseisstillchallengingduetothelackoftissuespecificcontrastagents.
For this reason, itwouldbeofgreat interest todevelopnewtherapeuticsable to increase
imagingsensitivityhighlightingsynovialinflammation,cartilageandboneerosionsmaintaining
lowtoxicityandinvasiveness,possiblydevelopinganapproachthatallowsthediagnosiswith
biocompatible materials, suitable for different imaging techniques such as radiography,
ultrasoundsandmagneticresonanceimaging.
Nanotechnologies, particularly nanoparticles, have peculiar characteristics able to satisfy
needs described above. In fact, nanoparticles can be functionalized with antibodies and
peptidesthatspecificallytargettissuesorcells,allowingthedeliveryofaconsiderableamount
oftheirpayloads(diagnostictracerordrugs).Thisstrategyshouldincreasetheconcentration
of drugs or diagnostics into the desired tissue, allowing the reduction of the dose with a
consequentreductionofcostsandsideeffects.
Ourgroupin2012developedananti-complementC5antibody(ScFv-Fc)abletospecifically
targetinflamedsynovialtissuesduetothesynovialhomingpeptidefusedwiththeFcportion
of thisantibody (Macoretal.2012).This strategydemonstrated that the targetedpeptide
increases the accumulation of therapeutic or diagnosticmolecules onto themicrovascular
endothelialtissueoftheinflamedRAtissue.
Aimandrationaleofthethesis
38
As amatter of fact, neoangiogenesis is a key process in the development of RAwith the
involvementofadhesionmolecules,cytokinesandchemokines,regulatingtheinflammatory
process and in particular allowing inflammatory cells infiltration in the synovial
microenvironment.
Theaimofthisworkistodesign,produceandcharacterizeadiagnosticordrugdeliverysystem
specificfortheinflamedsynovialtissuecombiningatargetingstrategybasedonthesynovial
peptidealreadyusedbyuswiththepotentialfeaturesofthebiodegradablenanoparticles.In
particular,thesynovialpeptide,specificfortheinflamedsynovia,hasbeenconjugatedonthe
surfaceofbiodegradablepolymericnanoparticles,whichinturncanbeloadedwithdrugs(in
thiscaseMTX)orconjugatedwithdiagnostictracers(Cy5.5,anearinfrareddye).Thisplanaims
to demonstrate in vivo, using animal models of rheumatoid arthritis, that targeted
nanoparticles(tBNPs),comparedtountargetednanoparticles(BNPs),areabletospecifically
targettheinflamedsynovialtissues.
Labelled tBNPs will have the possibility to concentrate into inflamed synovial
microenvironmentprovidinginformationaboutthestageofthepathology.
ThelocaldrugdeliverythroughtBNPs-MTXshouldprovidegreatertherapeuticefficacythan
freeMTX,usinglowerdosesofMTXencapsulatedintBNPs;thiswillretainitseffectiveness
reducingsideeffects.
39
3. Materialsandmethods
Materialsandmethods
40
3.1. Productionofthetargetingmolecule
Thesequenceofthesynovialpeptide,whichisapeptideof9aminoacids(CKSTHDRLC),used
todrivenanoparticlesintotheinflamedsynovialtissue,hasbeenpreviouslyclonedinfusion
withaScFv-Fcinordertogeneratethetargetingmolecule(Macoretal.2012).
ThemonoclonalcelllinetransfectedwiththevectorpcDNA3.1/Hygro+codingforthetargeting
molecule (ScFv-Fc-synovial peptide) has been cultured in the CELLineTM Device (BD
Biosciences).Thisdeviceisasmallbioreactor,whichallowsreachingahighamountofproteins
comparedwithtraditionalcultureflasks.First,thecellshavebeenexpandedinaT75tissue
cultureflaskinProCHO5(Lonza),penicillin10U/mL(Sigma),streptomycin1μg/mL(Sigma),L-
glutamine2mM(Sigma),FBS10%(fetalbovineserum)andHygromycinB200μg/mL(Sigma).
Oncetheconfluencehasbeenreached,thecellshavebeendetachedbyTrypsin0.25mM-EDTA
(Ethylenediamine tetraaceticacid) (Sigma)and resuspendedwith15mLProCHO5 (Lonza),
penicillin10U/mL(Sigma),streptomycin1μg/mL(Sigma),L-glutamine2mM(Sigma),FBS10%
(fetal bovine serum), Hygromycin B 200μg/mL (Sigma) to a final concentration of 1x106
cells/mL.Thus,cellshavebeenadded to thecultivationchamberwhile300mLofProCHO5
(Lonza)havebeenaddedtothenutrientsupplychamber.Thecellshavebeencultivatedat
37°Cwith5%ofCO2.Twiceaweekthesupernatantcontainingthetargetingmoleculehasbeen
collected from the cultivation chamberand replacedwith15x106 fresh cells. The collected
supernatanthasbeencentrifugedat1500gfor20minutestoremovedebridesandcells.
3.2. Purificationofthetargetingmolecule
ThetargetingmoleculehasbeenpurifiedbyaffinitychromatographyusingtheHiTraprProtein
AFF1mL (AmershamBiosciences). Thecolumnhasbeenequilibratedwith20mMsodium
phosphatebufferpH7(equilibratingbuffer)andthesupernatantpassedthroughthecolumn
withaflowof1mL/minutewiththehelpofaperistalticpump.Afterwards,thecolumnhas
beenwashedwith the sameequilibrating buffer and finally, the targetmolecule has been
elutedusing0.1MsodiumcitratebufferpH3.0(elutionbuffer).Fractionsof1.5mLhavebeen
collected and quickly equilibratedwith 300μL 1M Tris-HCl pH 9.0 (neutralizing buffer) to
restore the pH to a physiological value. Finally, these fractions containing the purified
antibodieshavebeendialyzedwithDPBSO/Nat4°quantifiedbyabsorbanceassayatA280nm
usingaspectrophotometer(EppendorfBioPhotometerPlus).
Materialsandmethods
41
3.3. SDSpageandWesternblotofthetargetmolecule
FractionscontainingthepurifiedtargetingmoleculeshavebeensubjectedtoanSDSpage.The
gels were characterized by stacking 4% and resolving 10% acrylamide concentration. In
particular,thestackingwasmadewithAcrylamide/Bis-acrylamide30%solution(Sigma),Tris-
HCl 130mM pH 6.8, SDS 0,1%, Ammonium persulfate 0,1% and TEMED
(N,N,N’,N’tetrametiletilendiamina) 0,01% (Sigma). The resolving was made with
Acrylamide/Bis-acrylamide30%solution(Acrylamide29.2g/Bis-acrylamide0.8gin100mLof
H2O)(Sigma),Tris-HCl400mMpH8.8,SDS0,1%,Ammoniumpersulfate(APS)0,1%,TEMED
0,01%(Sigma).ThegelshavebeenpreparedbyMini-PROTEAN,TetraVerticalElectrophoresis
Cell,Bioradwithathicknessof0.75mm.Forreducedconditions,sampleshavebeendilutedin
samplebuffer(Tris-HCl61.5mMpH6.8,SDS2.5%,Glycerol10%,bromophenolblue0,0025%,
β-mercaptoethanol)andthenboiledfor5’.Therunhasbeenperformedinrunningbuffer(Tris-
HCl50mM,Glycine384mM,SDS0,1%)at15mAuntilproteinsreachedtherunninggel,then
the current has been increased to 20mA. Proteins separated by SDS page have been
transferredtonitrocellulosemembrane(GEHealthcare,AmershamUK)byWesternblotusing
aMiniTrans-Blot®Module,Bio-rad.Thetransferhasbeenperformedat3.5mAcm2for45’in
transfer buffer (Tris-HCl 25mM, Glycine 192mM,Methanol 20%, pH 8.3). Afterwards, the
membranehasbeenblockedwith2%ofskimmilk(S.M.)inPBSat4°Covernight.Then,the
membranehasbeenwashedthreetimeswithwashbuffer(0,1%ofTween20(Polyoxyethylene
Sorbitanmonolaurate)(Sigma) inPBS)andincubated1hRT(roomtemperature)inagitation
withtheprimaryantibodymouseanti-SV5-biotinylated(homemadeproduced)diluted1:2000
inthediluentbuffer(0,1%S.M.and0,05%Tween20inPBS).Thenthemembranehasbeen
washed three timeswithwash buffer and incubated 30’ RT in agitationwith Streptavidin-
alkalinephosphatase(Sigma)diluted1:2000indiluentbuffer.Finally,themembranehasbeen
washed three times and developed with 0,3 mg/ml of BCIP (5-Bromo-4-Chloro-3-Indolyl-
phosphate, Sigma) and 0,6mg/ml of NBT (Nitro Blue Tetrazolium, Sigma) in alkaline
phosphatasebuffer(Tris-HCl100mM,NaCl0,1M,MgCl25mM,pH9.6).
3.4. Nanoparticlesproduction
In collaboration with Prof. Luis Nunez founder of BioTarget, company based in Chicago,
nanoparticleshavebeenproducedunder class 100 clean roomconditionusing apatented
Materialsandmethods
42
technologyandmethodologydescribedinthepatentnumberUS20080187487A1.Polymers
used are: COOH-poly(ethylene glycol)-b-polylactide (PEG-b-PLA) and Poly(caprolactone)-
COOH(PCL).MethotrexatehasbeenpurchasedfromTEVA.Thetargetingmolecule,provided
byus,havebeenconjugatedonthesurfaceofthenanoparticlesexploitingitsprimaryamines,
whichcanreactwithpolymersfunctionalizedwithNHSgroups.Nanoparticlesproducedhave
beenresuspendedinPBSpH7.4with10%ofbovineserumalbumin(BSA).
3.5. CharacterizationofnanoparticlesbyDLS,Nanoparticlestracking,
TEMandSTEM.
Nanoparticles produced have been characterized by Dynamic light scattering (DLS). The
hydrodynamicdiameterdistributionhasbeenmeasuredusingaMalvernNanoZSinstrument
(MalvernInstruments,Ltd,Malvern,UK).Then,nanoparticlesdiluted1:100inultrapureH2O
have been analyzed by Malvern NanoSight LM10. Through this technique diameter and
numberofnanoparticleshavebeendetermined.Fortransmissionelectronmicroscopy(TEM)
analysis, nanoparticles have been diluted 1:50 in ultrapure H2O and then a drop of
nanoparticles’solutionhavebeendepositedonacarbonfoilsupportedoncoppermicrogrids.
ImageshavebeenacquiredbyPhilipsCM100TEmicroscope(PhilipsResearch,Eindhoven,The
Netherlands) operating at 80kV. For scanning transmission electron microscopy (STEM)
analysis,nanoparticleshavebeendiluted1:50inultrapureH2Oandimagesacquiredwitha
GAIA3Tescanmicroscopy(Tescan,CzechRepublic)withaSTEMdetectoroperatingat30kV.
3.6. MTTviabilityassay
InordertotesttheabilityofBNPs-MTXtoaffectendothelialcellsandtodemonstratethat
emptyBNPsdonotshowtoxiceffects,5x103EA.hy926cellshavebeenseededinwellsofa96
wellcellcultureplate(Sarstedt).Cellshavebeenculturedat37°Cwith5%ofCO2inDulbecco's
Modified Eagle's Medium (DMEM) supplemented with penicillin 10U/mL (Sigma),
streptomycin1μg/mL(Sigma),L-glutamine2mM(Sigma)andFBS10%.Aftercellsadheredto
thewells, different amounts of nanoparticles have been incubated for 48h. Then, 20µL of
[5mg/mL] MTT formazan (1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan) have been
addedtoeachwellfor4h.Afterwards,theplatehasbeencentrifugedat2250ginorderto
precipitatealltheformazancrystalsandthesupernatanthavebeendiscarded.Finally,each
wellhasbeenresuspendedwith200µLofdimethylsulfoxide(DMSO)andtheabsorbancehave
Materialsandmethods
43
beenmeasuredat570nmbyInfiniteM200Proplatereader(Tecan).The%ofviablecellshave
beencalculatedusingnottreatedcellsasthereferenceof100%viable.
3.7. ReleaseofMTXfromnanoparticles
ThereleaseofMTXfromnanoparticleshasbeenquantifiedbydialysis. Inparticular,200µL
[2mg/mL] of nanoparticles have been placed in a dialysis device for small volumeswith a
dialysis membrane characterized by a molecular weight cut-off (MWCO) of 3,5 kDa and
immersedin10mLofPBSpH7.4at37°Cinslightagitationfor24h.Duringthefirsthour,200µL
ofPBSofthedialysishasbeencollectedevery15’,whileinthesecondhouronlytwosamples
havebeencollected(every30’).Then,onlyonesamplehasbeencollectedat3,4and5h.The
lastsampleshavebeencollectedat24h.Asacontrol,thesameprocedurehasbeenusedto
quantify the dialysis release of 200µL of non-encapsulatedMTX [2mg/mL]. 150µL of each
samplecollectedhasbeenplaced ina96wellplate (Corning96well flat clearpolystyrene
plate)andquantifiedbyspectrophotometric readingsat310nmby InfiniteM200Proplate
reader(Tecan).Theopticaldensityof150µLofMTX[2mg/mL]dilutedin10mLofPBShave
beenusedasthereferenceof100%ofMTXreleased.TheamountofreleasedMTXhavebeen
calculatedasfollow:(ODsamplesx100)/OD100%MTXinsolution.
3.8. Labellingofthetargetedmoleculeandnanoparticles
Thetargetingmoleculeandthenanoparticleshavebeenlabelledwithfluorescentprobesin
order to be detectable with several techniques. In particular, Fluorescein Isothiocyanate
Isomer I (FITC) (Sigma)havebeenused for green fluorescenceat 488nm,while FluoroLink
Cy5.5MonofunctionalDye(GEHealthcare)havebeenusedfornear-infraredfluorescenceat
695nm.ForFITClabeling,1mgofnanoparticleshavebeencentrifugedat5900gfor1’30”and
resuspendedin500µLofsodiumcarbonatebufferpH9.3(repeatthisstepthreetimes).Then,
50µLofFITC[1mg/mL]inDMSOhasbeenaddeddropbydropinslightagitationandfinally
placed in a rotating mixer overnight (O/N) at 4°C. Afterwards, add NH4Cl to a final
concentrationof50mMandincubate2hat4°C.Finally,nanoparticleshavebeencentrifuged
at5900gfor1’30”andresuspendedin500µLofPBS(repeatthisstepthreetimes).Thesame
procedurehasbeenusedtolabel1mgoftargetingmoleculebyreplacingthecentrifugation
stepwith a dialysis performedO/N at 4°C using dialysis tubeswith aMWCO of 12.4 kDa
(Spectra/Por). Instead, for theCy5.5 labelingacommercial kithasbeenused to labelboth
Materialsandmethods
44
nanoparticlesand the targetedmolecule.First, 1mgofnanoparticlesor targetingmolecule
have been resuspended in 1mL of sodium carbonate buffer pH 9.3, respectively by
centrifugation and by dialysis as described for FITC labeling. Then, the solutions with
nanoparticles or the targeting molecule have been incubated into the commercial vials
containingthepowderofCy5.5for30’RT.Toeliminatetheexcessofdye,nanoparticleshave
beencentrifugedat5900gfor1’30”andresuspendedinPBSpH7.4(repeatthisstepthree
times),whilethetargetingmoleculehasbeendialyzedusingdialysistubeswithaMWCOof
12.4 kDa. The amount of Cy5.5 associated with the nanoparticles or with the targeting
moleculehasbeenquantifiedbyspectrophotometricmethods.Amolarextinctioncoefficient
of250,000M-1cm
-1at678nmhasbeenusedforCy5.5,whileamolarextinctioncoefficientof
68,000M-1cm
-1at494nmhasbeenusedforFITC.
3.9. Stainingoftissuesections
3.9.1. Preparationofparaffinembeddedsectionsofhumansynovial
tissues
Paraffin embedded synovial tissues, obtained from patients with RA, have been kindly
providedbyProf.JessicaBertrand.First,sectionsof7µmthickhavebeencutbymicrotome
hyraxm55(CarlZeiss),driedfor2hatRTandbakedat55°Cfor2h.Sliceshavebeende-waxed
byimmersioninXylenetwicefor5’followedbyonewashin100%Ethanol(2’),onein96%
Ethanol (2’), one in 80% Ethanol (2’)and one in 70% Ethanol (2’). Then, slides have been
rehydrated indistilledH2Ofor2’andthensoaked inTBS for2’.Antigenretrievalhasbeen
performedenzymaticallywitha solutionof0.05%Trypsin,0.5%CaCl2 indistilledH2O.Few
dropsofthissolutionhavebeenplacedontheslicesandincubatedat37°Cfor20’.Afterward,
sliceshavebeenwashedwithdistilledH2Oandblockedfor30’atRTinahumidchamberwith
blockingbuffer(2%serumoftheanimalinwhichhasbeendevelopedthesecondaryantibody
inPBS)inordertopreventunspecificantibodybinding.Theexcessofblockingbufferhasbeen
removed and the primary antibody (concentration depends on the primary antibody, see
below)hasbeenincubatedat4°CO/Ninthediluentbuffer(0,2%BSAand0,05%Tween20in
PBS).Then,onewashof5’withgentlerockinghasbeenperformedinPBSandtwowashesof
5’havebeendonewith1‰ofTritonx100inPBS.Asecondaryantibodyconjugatedwitha
fluorescent probe and diluted (concentration depend on the secondary antibody) in the
Materialsandmethods
45
diluentbufferhasbeenincubatedatRTfor1h.Threewasheshavebeenperformedasbefore
andnucleihavebeenstainedwithDAPIdilutedinPBS1:1000incubatedfor5’atRT.Finally,
usualwasheshavebeendoneandsliceshavebeenmountedwithMowiolanti-fademedium
(Polysciences, Inc.). Sometimes, a secondary antibody conjugated to streptavidin has been
used,inthiscase,anadditionalstepofwashesandincubationwithbiotinconjugatedprobe
wasrequired.
StainingwithScFv-Fc-synovialpeptide(targetmolecule)
Thismoleculehasbeenusedwithafinalconcentrationof10µg/mLandincubatedat4°CO/N.
Co-staininghavebeenperformedwith the targetmolecule already conjugated toCy5.5or
FITC. Otherwise, in order to detect the target molecule, a mouse anti-SV5 (homemade
antibodyused1:200inthediluentbuffer)abletobindthetagsequenceSV5presentintothe
targetmoleculehavebeenused.Finally,agoatanti-mouseAlexaFluor488(ThermoFisher)or
agoatanti-mouseAlexaFluor594(ThermoFisher)havebeenused1:200indiluentsolution.
StainingofvWF.
Arabbitanti-vWF(Dako)hasbeenused1:400inthediluentbuffer,inturn,recognizedwith
goatanti-rabbit-Cy3(Jackson)1:200indiluentbuffer.
StainingofCD34+.
Arabbitanti-CD34(Bioss)hasbeenused1:200inthediluentbuffer,inturn,detectedwitha
goatanti-rabbit-Cy3(Jackson)1:200inthediluentbuffer
Stainingofnuclei
NucleihavebeenstainedwithDAPI(4',6-diamidin-2-phenylindole)(Sigma)diluted1:1000in
PBS.
3.9.2. PreparationoffrozensectionsofAIAandCIA
Tissuescollectedfromratsandmicehavebeenincludedinabiocompatiblegelatinousmatrix
withpolyvinylalcohol10%andpolyethyleneglycol4%(TissueTekOCT)andfinallyfrozenat-
80°C. Sections of 7µm thick have been cut by cryostat Leica CM3050 S equippedwith a
microtomeat-22°C.SectionsaredriedO/NatRTandthenstoredat-20°C.
3.9.3. Stainingoffrozensectionswithantibodies
Sectionsstoredat-20°Chavebeenthawedfor5minutesatRTandfixedwithcoldAcetone
(CarloErba)for15’at4°C.Then,sectionshavebeenrehydratedwith0.9%NaCl.Sampleshave
Materialsandmethods
46
beenblockedwithblockingbuffer(2%ofserumoftheanimalinwhichhasbeendeveloped
thesecondaryantibodyinPBS)for30’RTinahumidchamber.Sectionshavebeenincubated
with the primary antibody (concentrations depend on the antibody, see below) diluted in
diluent(0,2%BSAand0,05%Tween20inPBS)at4°CO/Nandthenonewashof5’withgentle
rockinghasbeenperformedinPBSandtwowashesof5’havebeendonewith1‰ofTriton
x100inPBS.Afterwards,thesecondaryantibody(concentrationsdependontheantibody,see
below)dilutedindiluenthasbeenincubatedfor1hRTandthenwashedasbefore.Nucleihave
beenstainedwithDAPIdilutedinPBS1:1000incubatedfor5’atRT.Afterusualwashes,slices
have been mounted with Mowiol anti-fade medium. Sometimes, a secondary antibody
conjugated to streptavidin has been used, in this case, an additional step of washes and
incubationwithbiotinconjugatedprobeswasrequired.
StainingwithScFv-Fc-synovialpeptide(targetmolecule)
Thismoleculehasbeenusedwithafinalconcentrationof10µg/mLandincubatedat4°CO/N.
Co-staininghavebeenperformedwiththetargetingmoleculealreadyconjugatedtoCy5.5or
FITC. Otherwise, in order to detect the targetingmolecule, amouse anti-SV5 (homemade
antibodyused1:200inthediluentbuffer)abletobindthetagsequenceSV5presentintothe
targetingmoleculehavebeenused.Finally,agoatanti-mouseAlexaFluor488(ThermoFisher)
oragoatanti-mouseAlexaFluor594 (ThermoFisher)havebeenused1:200 in thediluent
buffer.
StainingofvWF.
Arabbitanti-vWF(Dako)hasbeenused1:400inthediluentbuffer,inturnrecognizedwith
goatanti-rabbit-Cy3(Jackson)1:200inthediluentbuffer.
StainingofC3
Agoatanti-C3(Cappel)hasbeenused1:50inthediluentbuffer,inturnrecognizedwithrabbit
anti-goat-TRITC(Sigma)1:100inthediluentbuffer.
Stainingofnuclei
NucleihavebeenstainedwithDAPI(4',6-diamidin-2-phenylindole)(Sigma)diluted1:1000in
PBS.
3.9.4. Stainingoffrozensectionswithnanoparticles
InordertostudythebindingofBNPsandtBNPsonthesynovialtissueofrats,sectionsstored
at -20°Chavebeenthawedfor5minutesatRTandfixedwith4%paraformaldehyde(PFA)
Materialsandmethods
47
(Sigma) for 15’ RT. Then, sectionshavebeen rehydratedwith0.9%NaCl andblockedwith
universalblockingbuffer(2%ofBSA,0,25%ofcaseinand0,10%ofgelatininPBS)for30’atRT
inahumidchamber.Afterwards,10µgofBNPs-FITCandtBNPs-FITChavebeenincubated1h
at37°C.Finally,threewasheshavebeenperformedtoremoveunspecificboundnanoparticles
andsliceshavebeenmountedwithMowiolanti-fademedium.
3.9.5. StainingofviableEA.hy926cellswithnanoparticles
EA.hy926endothelialcellshavebeenusedtotestthebindingoftBNPstoendothelialcells.In
particular,3x104cellshavebeencultured ineachwellofanX-wellTissueCultureChamber
(Sarstedt)forhigh-resolutionmicroscopy.Cellshavebeenculturedat37°Cwith5%ofCO2in
DMEM supplemented with penicillin 10U/mL (Sigma), streptomycin 1μg/mL (Sigma), L-
glutamine2mM(Sigma)andFBS10%.20x107BNPs-Cy5.5andtBNPs,normalizedafterCy5.5
labelingfortheirnumberofnanoparticlesbyNanoTrackanalysis,havebeenincubatedfor1h
at37°C.Afterwards,threewasheshavebeenperformedwithPBSandthencellshavebeen
fixed15’with4%PFA.OtherthreewasheshavebeenperformedtoremoveexcessofPFAand
finally nuclei have been stained with DAPI (4',6-diamidin-2-phenylindole) (Sigma) diluted
1:1000inPBS.Twomorewasheshavebeendoneandthenglassmicroscopeslideshavebeen
detachedfromthechambervesselinordertomounttheslideswithMowiolanti-fademedium.
3.9.6. Microscopesusedinthiswork
• ZeissAxioPlan2MicroscopySystem(CarlZeiss)equippedwithaAxioCamHR3camera.
• Nikon Eclipse Ti-E Live Cell Imaging System (Nikon) equipped with a Nikon DS-Qi2
camera and stage incubation system able to control temperature, humidity and
percentageofC02.
PostprocessingoftheimageshasbeenconductedwithFIJI(ImageJ)software.
3.10. Imagingflowcytometer
5x105EA-hy926havebeenculturedina6-weelcellcultureplate(Sarstedt)at37°Cwith5%of
CO2inDMEMsupplementedwithpenicillin10U/mL(Sigma),streptomycin1μg/mL(Sigma),L-
glutamine2mM(Sigma)andFBS10%.Thedayafter,cellshavebeenwashedtwotimeswith
PBS and 10µL of BNPs-FITC and tBNPs-FITC, normalized by fluorescence intensity by
spectrophotometricmethod,havebeenincubatedwithcellsfor1hat37°Cwith30%ofFBSin
Materialsandmethods
48
PBS.Afterwards,cellshavebeenwashedtwotimeswithPBSanddetachedwithtrypsin-EDTA
solution(0.5g/Lporcinetrypsinand0.2g/LEDTA)(Sigma)for5’at37°C.Finally,cellshavebeen
centrifugedwithDMEMmediumat500gfor10’andresuspendedin50µLof2%ofFBSinPBS.
Data have been acquired with FlowSight (EMD Millipore, USA) with a 20x objective and
analyzedusingIDEASsoftwareversion6.0.Cellsofeachsamplehavebeengatedinorderto
selectimageswithsinglecellsinfocus.Anerodemaskhasbeenusedtodefinetheinnerpart
ofthecell.Thismaskremovestwopixelsfromtheedgesofthestartingmaskusingbrightfield
imagesofthecells.Theratiobecomingfromtheintensityfluorescencebetweentheinsideof
thecellandthefluorescenceintensityofthetotalcellhasbeendefinedhasinternalization.
Negativescoresrepresentnointernalization,whilecellswithhighinternalizationhavepositive
scores.Representativeimagesfromcellspopulationshavebeenchosen.
3.11. ELISAonEA.hy926
3x104Ea.hy926cells/wellhavebeenseededina96wellcellcultureplate(Sarstedt)in200µL
of DMEM medium supplemented with penicillin 10U/mL (Sigma), streptomycin 1μg/mL
(Sigma),L-glutamine2mM(Sigma)andFBS10%.After24h,wellshavebeenwashedtwicewith
300µLofPBSandthenfixedwith200µLof1%PFAfor30’atRT.Afterwards,wellshavebeen
washedtwotimeswithPBSandthenblockedwith200µLof1%BSAinPBS.2,4µLofBNPs-FITC
and tBNPs-FITC,normalizedby fluorescence intensitybyspectrophotometricmethod,have
been incubated with cells for 1h at 37°C with 30% of FBS in PBS. In order to remove
nanoparticleswhichdonotbindcells,wellshavebeenwashedthreetimeswithPBS.Finally,
the intensityof fluorescencehasbeendetectedwithaFLUOstarOmegamicroplate reader
(BMGLabtech)at520nm.
3.12. Antigeninducedarthritis(AIA)
AntigeninducedarthritishavebeeninducedinmaleratsWistarHannoverstrainwithaweight
of120-150g.AnimalshavebeenpurchasedfromHarlanLaboratories(SanPietroalNatisone,
Italy)andmaintainedinClusterinBioMedicine(CBM,Basovizza,Trieste)facilitiesduringthe
studyofbiodistribution,whileanimalshavebeenmaintainedintheanimalhouseofTrieste
(UniversityofTrieste)forthestudyoftherapeuticefficacy.Experimentshavebeenconducted
followingtheEuropean(86/609/EEC)andItalianguidelines(D.L116/92)fortheinvivoanimal
experimentationaftertheapprovalbytheMinistryofEducation,UniversitiesandResearch
Materialsandmethods
49
(approval n° 220/2013-B) andby theethics committeeof theUniversityof Trieste.All the
experimental procedures have been conducted under total anesthesia by intraperitoneal
injectionofZoletil(25mg/Kg)andXylazine(7.5mg/Kg).Theimmunizationhasbeenperformed
with two intradermic injections (the secondone after oneweek) of 150µgofmethylated
bovineserumalbumin(mBSA)in200µLofNaCl0.9%physiologicsolutionandemulsifiedwith
200µLofCompleteFreudadjuvant(CFA)(Sigma).After14daysfromthesecondimmunization,
theinflammationhasbeeninducedbyinjecting100µgofmBSA(dilutedin100µLofphysiologic
solution) in the intraarticular right knee of the rats. The contralateral knee joint has been
injectedwiththephysiologicsolutionasthecontrol.
Studyofbiodistribution
ExploreOptixMXpre-clinicalopticalimagingsystem(GEHealthcare),equippedwithapulsed
laser diode and a time-correlated single-photon detector, have been used to evaluate the
biodistributionof4.8nmolofBNPs-Cy5.5andtBNPs-Cy5.5dilutedinphysiologicsolution(final
volume100µL)injectedintravenously(tailvein)2haftertheintraarticularinjectionofmBSA.
Theanatomicalregiontoscanhasbeenpreviouslyshavedtoavoidlaserscatteringcausedby
hair.Ablankimagehasbeenperformedbeforeintravenousinjectionoflabellednanoparticles.
Theanimalshavebeenmonitoredatmultipletimepointsusinga670nmpulsedlaserdiode
witharepetitionfrequencyof80MHzandatimeresolutionof12lightpulses.Fluorescence
emissionhasbeencollectedat700nmanddetectedthroughafastphotomultipliertubeand
ahighlysensitivetime-correlatedsingle-photoncountingsystem.Two-dimensionalscanning
regionsofinteresthavebeenselectedthroughspecificsoftwareandlaserpower,integration
timeandscanstep,whichhavebeenoptimizedaccordingtothesignalemitted.Thedatahave
beenrecordedastemporalpoint-spreadfunctions,andtheimageshavebeenreconstructed
as fluorescence intensity and fluorescence lifetime. After 23 days the animals have been
euthanizedundertotalanesthesia.Organshavebeenanalyzedexvivofortheirfluorescence
andthenembeddedinbiocompatiblegelatinousmatrixOCT(TissueTEK)andstoredat-80°C.
Bloodsampleshavebeencollectedforsubsequentanalysis.
Therapeuticefficacy
1mg/Kg/dayofMTXandtBNPs-MTXdilutedinphysiologicsolution(finalvolumeof500µL)
havebeenadministratedintra-peritoneumforthreedaysinratsdevelopingAIA.Theswelling
ofthekneeshasbeenmeasuredwithacaliper.Attheendofthestudy,animalshavebeen
euthanizedundertotalanesthesiaandthearticularcavitiesoftherightandleftkneeshave
Materialsandmethods
50
beenwashedseveraltimeswith2mLofPBSinordertocollectsynovialfluids.Moreover,part
ofthesynovialmembraneshavebeencollectedandembeddedinbiocompatiblegelatinous
matrixOCT(TissueTEK)andstoredat-80°C,whilethewholearticulationhasbeenembedded
inparaffinforhistologicalanalysisbyhematoxylineosinstaining.Bloodsampleshavebeen
collectedforsubsequentanalysis.
3.13. Collageninducedarthritis(CIA)
InordertodevelopCIAmodel,susceptiblemalemiceDBA/1Jstrainwithaweightof13-16g
havebeenused.MicehavebeenpurchasedfromHarlanLaboratories(SanPietroalNatisone,
Italy)andmaintainedintheMolecular&PreclinicalImagingCenters(UniversityofTurin,Italy)
duringthestudyofbiodistribution,whileanimalshavebeenmaintainedintheanimalhouse
ofTrieste(UniversityofTrieste)forthestudyoftherapeuticefficacy.Experimentshavebeen
conductedfollowingtheEuropean(86/609/EEC)andItalianguidelines(D.L116/92)forthein
vivoanimalexperimentationaftertheapprovalbytheMinistryofEducation,Universitiesand
Research(approvaln°220/2013-B)andbytheethicscommitteeoftheUniversityofTrieste.
Thefirstimmunizationhavebeenconductedwith50µLofasolutionmadeof25µL(4mg/mL)
ofbovinecollagentypeII(Chondrex)dilutedinaceticacid10mMand25µLofCFA(4mg/mL
ofM.Tuberculosis in 15% Arlacel A (Sigma) and 85% heavymineral oil (Sigma)). A second
immunizationhasbeenperformedtwoweekslaterwiththesameconcentrationofcollagen
typeIIusingIncompleteFreundAdjuvant(IFA)(withoutM.Tuberculosis).After20daysmice
showfirstsignsofRA.Erythemaandswellingcharacterizedtheearlystageofthediseasein
this model affecting randomly different paws with different degree of inflammation
(polyarthritis).Objectiveevaluationshavebeenperformedthreedaysperweekestablishinga
scorefrom0(noarthritis)to4(severeswellingandankyloses)foreachpaw.Theweightof
eachanimalhasbeenrecordedthreetimesperweekinordertocontrolsideeffects.
Studyofbiodistribution
Miceshowingsignsofarthritishavebeenenrolledintwodifferentgroups;onegrouphasbeen
injectedi.v.with0.5nmolofBNPs-Cy5.5andtheotheronehasbeentreatedwith0.5nmolof
tBNPs-Cy5.5. Animals previously anesthetized with Isoflurane have been scanned by IVIS
Spectrum2000invivoimagingsystem(PerkinElmer)attime0,1,6,24,72,96,168h.Atthe
endofthestudy,micehavebeeneuthanizedundertotalanesthesiainordertocollectorgans
suchaspaws,brain,liver,kidneys,spleen,lungsandheart.Theseorganshavebeenembedded
Materialsandmethods
51
inbiocompatiblegelatinousmatrixOCT(TissueTEK)andstoredat-80°C,exceptpawswhich
have been previously fixed in 10%neutral buffered formalin (BioOptica) for 24h and then
decalcifyingfor24hwithDecalcifyingSolution-Lite(Sigma).
Therapeuticefficacy
Five different groups of mice have been used to assess the therapeutic efficacy of MTX
encapsulated into tBNPs. Inparticular,onegrouphavebeentreated i.p.with200µLof the
sterilesalinesolution,onegroupwith1mg/Kgthreetimesperweek,onegroupwithMTX
3mg/Kgperweek,onegroupwithtBNPs-MTX3mg/Kgperweekandonegroupwith1mg/Kg
perweek.Allthetreatmentshavebeenadministratedi.p.inatotalvolumeof200µLofsterile
saline solution. Animals have been treated for 25 days and then euthanized under total
anesthesiawithZoletil(25mg/Kg)andXylazine(7.5mg/Kg).Organssuchaspaws,brain,liver,
kidneys,spleen,lungsandhearthavebeenembeddedinbiocompatiblegelatinousmatrixOCT
(TissueTEK)andstoredat-80°C,exceptpawswhichhavebeenpreviouslyfixedin10%neutral
bufferedformalin(BioOptica)for24handthendecalcifyingfor24hwithDecalcifyingSolution-
Lite(Sigma).Bloodsampleshavebeencollectedforsubsequentanalysis.
3.14. HematoxylinEosinstaining
Inorder toevaluate thehistological scoresof thepawscollected inCIAmice,Hematoxylin
Eosinstaininghavebeenperformedinthesesamples.Thespecimenshavebeenfixedin10%
buffered formalin solutionandembedded inparaffin. Fourmicrometer-thick sectionshave
beendewaxedbyimmersioninxylenetwicefor5’followedbyonewashin100%ethanol(2’),
onein96%ethanol(2’),onein80%ethanol(2’)andonein70%ethanol(2’).Afterward,slides
have been rehydrated in distilled H2O for 2’ and then stained with Hematoxylin for 40’’.
Sectionshavebeenwashedwithrunningtapwaterfor1’andthenstainedwithEosinfor20’’.
Thus,sectionshavebeenwashedwithrunningtapwaterfor1’thentheyhavebeensoakedin
95%ethanolfor30’’andtwicein100%ofethanolfor1’.Finally,sectionshavebeenwashed
twice in xylene for 1’ and mounted with Eukitt mounting medium (BioOptica). The
histopathologicalanalysishasbeenmadeincollaborationwithProf.ClaudioTripodoandDr.
BeatriceBelmonteatUniversityofPalermo(Palermo,Italy).
Materialsandmethods
52
3.15. Bloodanalysis
Bloodsamplescollectedfromratsandmicehavebeenanalyzedinordertoassessthenumber
of redblood cells,white blood cells andplatelets. 10µL of eachblood samples havebeen
analyzedbyABXMicrosES60(HoribaABXDiagnostics,France).Analysishasbeenconducted
incollaborationwithProf.GabrielePozzatoatOspedaleMaggiore(Trieste,Italy).
3.16. ELISAmouseanti-collagenantibodies
AnELISAtesthasbeenperformedinordertoverifythatallmiceenrolledinthestudydevelop
animmuneresponseagainstbovinecollagentypeII.Asolutionof5µg/mL(100µL/well)of
bovinecollagentypeII(Chondrex)incarbonatebuffer0,1MpH9havebeenusedO/Nat4°C
asthecoating.Thedayafter,wellshavebeenwashedthreetimeswithwashingbuffer(0,1%
Tween20inPBS)andblocked1hatRTwith200µLof2%skimmilkinPBS.Then,wellshave
beenwashedthreetimeswithwashingbufferandserumsamples,previouslydiluted1:2000
indiluentbuffer(0,05%Tween20and0,1%skimmilkinPBS),havebeenplacedineachwell
inafinalvolumeof100µL.Otherthreewasheshavebeendonewithwashingbufferandthen
thesecondaryantibodygoatanti-mouseAP(Sigma)hasbeendiluted1:2000 in thediluent
bufferandincubatedfor1hatRT.Finally,threewasheshavebeendonewithwashingbuffer
andthealkalinephosphatasesubstratep-nitrophenylphosphate(pNPP)(Sigma)hasbeenused
1mg/mLinglycinebuffer(0,1MGlycine,0,1mMMgCl2and0,1mMZnCl2,pH9.6)inorderto
develop the reaction. Theplate has beenmeasured at 405nmby InfiniteM200Proplate
reader(Tecan).
3.17. ELISAratanti-mBSAantibodies
In order to verify that rats enrolled in the study developed an immune response against
methylatedbovineserumalbumin(mBSA)anELISAtesthasbeenused.Asolutionof5µg/mL
(100µL/well)ofmBSA(Sigma)incarbonatebuffer0,1MpH9havebeenusedO/Nat4°Cas
thecoating.Thedayafter,wellshavebeenwashed three timeswithwashingbuffer (0,1%
Tween20inPBS)andblocked1hatRTwith200µLof2%skimmilkinPBS.Then,wellshave
beenwashedthreetimeswithwashingbufferandserumsamples,previouslydiluted1:2000
inthediluentbuffer(0,05%Tween20and0,1%skimmilkinPBS),havebeenplacedineach
wellinafinalvolumeof100µL.Threewasheshavebeendonewithwashingbufferandthen
Materialsandmethods
53
thesecondaryantibodyrabbitanti-ratbiotin(Sigma)hasbeendiluted1:4000inthediluent
bufferand incubated for1hatRT.After threemorewasheswithwashbuffer, streptavidin
conjugated to horseradish peroxidase (HRP)(Sigma) diluted 1:2000 in the diluent has been
incubatedfor30’atRT.Finally,threewasheshavebeendonewithwashingbufferandthe
peroxidasesubstrate3,3ʹ,5,5ʹ-Tetramethylbenzidine(TMB)(Sigma)hasbeenused(100µL)to
developthereaction,whichhasstoppedwith100µLofH2SO41M(Sigma).Theplatehasbeen
measuredat450nmbyInfiniteM200Proplatereader(Tecan).
3.18. Numberofpolymorphonuclear(PMN)leukocytes.
In order to measure the number of PMN leukocytes in synovial fluids of AIA rats, the
myeloperoxidaseactivityhasbeenmeasured.For thispurpose,a standardcurvewith rat’s
PMNwith known concentration (500000cells/mL) has been prepared.HundredμL of each
samplehasbeenloadedinwellofa96wellplatepolystyreneflatbottom(Costar)andthen,
100μLofperoxidasesubstrateTMB(Sigma)hasbeenaddedtoeachwell.Thecolorimetric
reaction has been stopped with 100μL of H2SO4 1M (Sigma). Finally, the plate has been
measuredbythespectrophotometricreader(ELISAreader,Anthos2020)at450nm.
3.19. MultiplexELISA
CytokinesandchemokineshavebeenquantifiedusingtheBio-PlexProMouseCytokines23-
plexAssay(BioRad),accordingtothemanufacturer’sinstructions.Serumsamplesofeachmice
grouphavebeenpooledandthen12,5µLhasbeenanalysedintriplicate.Inparticular,IL-1a,
IL-1b,IL-2,IL-3,IL-4,IL-5,IL-6,IL-9,IL-10,IL-12(p40),IL-13,IL-17A,KC,MCP-1,MIP-1a,MIP-
1b,Eotaxin,G-CSF,GM-CSF, INF-g,RANTESandTNF-ahavebeenanalysedbythismethod.
DatahavebeenacquiredwithBio-Plex200reader(BioRad)andanalysedwiththesoftware
Bio-PlexManagertocalculateresultsasconcentrationinpg/mL.
54
4. Resultsanddiscussion
Resultsanddiscussion
55
4.1. Designandcharacterizationofbiodegradablenanoparticles
4.1.1. Designandcharacterizationofthetargetingmolecule
The targeting synovial peptide, used in this study, is made of 9 aminoacids (CKSTHDRLC)
containingtwoflankingcysteines(Figure9b),whichconstrainthepeptideinacircularshape
improvingthebindingoftheconsensusmotif(aminoacidsDRL)toitscounterpart(Leeetal.
2002).Duetothesmallsizeofthesynovialpeptide,weavoidedtodirectlylinkthepeptideon
thenanoparticlesbecausepolymers, inparticular,PEGexposedonparticles’ surface,could
masktheexposureofthepeptide.Forthisreason,thesynovialpeptidehasbeenfusedtothe
FcofaScFv-Fc(Figure9A),whichactsasaspacerabletodisplaythepeptidefarfromthe
nanoparticles’surface.Thesequencecodingforthetargetingmoleculehasbeenclonedinthe
vectorpcDNA3.1/Hygro+; it contains the sequenceof a non-correlated ScFv, the sequence
coding for the hinge-CH2-CH3 of the rat IgG2b, the sequence for the SV5 tag (used for
detection)andthesequenceforthesynovialpeptide.Inordertoobtainastablecloneableto
producehighamountofthetargetingmolecule,thevectorcodingforitssequence,previously
checked by DNA sequencing, has been transfected inmammalian cells of Chines Hamster
Ovary(CHO).The3Dstructureofthetargetingmoleculehasbeenpredictedthroughtheweb
serverPhyre2(Kelleyetal.2015),aimingtounderstandthepeptide’sorientationinthe3D
space andwhether the peptide could bemasked during the folding of the final structure
(Figure 9 C). The prediction is performed through a combination of multiple template
modelling and ab-initio folding simulation. The 94% of residues of the final 3D structure
reported in the figure9Chavebeenmodelledwithaconfidencehigher than90%andthe
peptide(Figure9Credbox)appearsavailabletointeractwithitscounterpart.
The targeting molecules have been produced and purified by affinity chromatography
exploitingthebindingbetweentheFcandtheproteinA.Themolecularweightandthequality
of the protein produced and purified have been assessed bywestern blot; as expected in
reducingconditions,themolecularweightofthemonomershavebeendeterminedas62kDa
andlowamountofaggregatedordegradedproteinshavebeendetected(Figure9D).
)+$,8%$!'30!0/$(,$$/.3!
!
! ! UV!
!
^+5)&/,E_,<1&5/%+$5,0'9/*)9/",,1"2!](*+-'%/(!&+7&+$+3%'%/.3!.4!%*+!%'&5+%/35!-.8+(,8+!-'0+!.4!'!3.3O(.&&+8'%+0!](J:!15&+9!jWOjH2!8/3I+0!%*&.,5*!'!*/35+!%.!
%*+!&'%!J(! 1#8,+![HQO[HP2;! <3! %,&3B! %*+!J(! /$! 4,$+0!?/%*!'3!]jU!%'5! 1(9'32B!?*/(*!+30$!?/%*! %*+!$93.:/'8!7+7%/0+! 1&+02;! 1K2!
](*+-'%/(! &+7&+$+3%'%/.3! .4! %*+! $93.:/'8! 7+7%/0+B!?*/(*! '$$,-+$! %*+! (/&(,8'&! $*'7+! 0,+! %.! %*+! 7&+$+3(+! .4! %*+! 48'3I/35!
(9$%+/3+$;!1[2!PC!$%&,(%,&+!.4!.3+!-.3.-+&!.4!%*+!%'&5+%/35!-.8+(,8+!7&+0/(%+0!?/%*!@*9&+Q!7&+0/(%/.3!%..8;!<3!%*+!&+0!#.E+$!
%*+!$93.:/'8!7+7%/0+;!1C2!c+$%+&3!#8.%!(.30,(%+0!/3!&+0,(/35!(.30/%/.3!.4!=^^35!.4!%*+!%'&5+%/35!-.8+(,8+!18'3+!=2B!?*/(*!
$*.?$!%*+!(.&&+(%!-.8+(,8'&!?+/5*%!.4!VQ!IC';!
"$!7&+:/.,$89!0/$(,$$+0B!%*+!$93.:/'8!7+7%/0+!/$!$7+(/4/(!4.&!%*+!-/(&.:'$(,8'&!+30.%*+8/'8!%/$$,+!
.4! %*+! /348'-+0! $93.:/'B! #,%! /%! /$! 3.%! 9+%! I3.?3! ?*/(*! /$! %*+! 7&.%+/3! +E7&+$$+0! .&!
.:+&+E7&+$$+0! &+$7.3$/#8+! 4.&! %*+! $+8+(%/:+! %'&5+%/35;! f3.?/35! %*+! /0+3%/%9! .4! %*/$! 7&.%+/3!
?.,80! #+! .4! 5&+'%! /-7.&%'3(+B! /30++0! %*/$! (.,80! #+! /3:.8:+0! /3! 7'%*.5+3+$/$;! <3! .&0+&! %.!
/0+3%/49!%*+!(.,3%+&7'&%!.4!%*+!$93.:/'8!7+7%/0+B!$93.:/'8!%/$$,+!4&.-!)"!7'%/+3%$!*':+!#++3!
0.,#8+!$%'/3+0!?/%*!%*+!%'&5+%/35!-.8+(,8+!'30!?/%*!-'&I+&$!+E7&+$$+0!.3!+30.%*+8/'8!(+88$;!
"!5+3+&/(!+30.%*+8/'8!-'&I+&!+E7&+$$+0!#9!'88!+30.%*+8/'8!(+88$B!$,(*!'$!%*+!:.3!c/88+#&'30!
J'(%.&! 1:cJ2B! *':+! #++3! ,$+0! 4/&$%! 1R&'53'3.! +%! '8;! Q^=Y2;! H.?+:+&B! %*+&+! ?'$! 3.! (.O
8.('8/M'%/.3!#+%?++3!%*+!%'&5+%/35!-.8+(,8+!'30!%*+!:cJ!1J/5,&+!=^!"2;!J.&!%*/$!&+'$.3B!)"!
$93.:/'8!%/$$,+$!*':+!#++3!$%'/3+0!4.&!%*+![CPS;!F*/$!/$!'!-'&I+&!4.&!*+-'%.7./+%/(!$%+-!(+88$!
'30!/$!*/5*89!+E7&+$$+0!.3!:'$(,8'&!+30.%*+8/'8!7&.5+3/%.&$!1f&',$+!+%!'8;!=XXV21]/03+9!+%!'8;!
Q^=S2;!<3!%*/$!('$+B!?+!4.,30!'!(.O8.('8/M'%/.3!#+%?++3!%*+
Resultsanddiscussion
57
theinflamedsynovia.OurfindingisalsosupportedbyLeeetal.whohaveisolatedthepeptide
provingitsabilitytobindthemicrovasculatureoftheRAsynovialtissue(Leeetal.2002).For
thesereasons,subsequentinvitroteststostudyandcharacterizetargeted-nanoparticleswill
beconductedonaendothelialcelllineEA.hy926.
In order to better identify the protein bound by the targeting molecule, an immuno-
precipitationfollowedbymassspectrometryanalysishasbeenconducted;inparticular,the
targeting molecules have been coupled to Sepharose beads and a lysate of EA.hy 926
endothelialcell linehasbeenusedas loadingmaterial.AScFv-FcfusedwithaRGDpeptide
coupledtoSepharosehasbeenusedasthecontrol.Severalproteinsdifferentiallyboundby
the synovial peptide have been identified, however, any of them could be reasonably
associatedwithasurfaceproteinofendothelialcells.Indeed,mostoftheproteinsidentified
comesfromtheinnerpartofthecells,soareincontrastwithourimmunofluorescencefindings
and literature. Probably, the method should be improved for the enrichment of surface
proteins.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! UZ!
!!
^+5)&/,!B_,F%)(?,':,*'9'*19+L1%+'$",,1"2!F*+!7/(%,&+!.3!%*+!8+4%!/$!'!)"!*,-'3!$93.:/'8!%/$$,+!(.O/3(,#'%+0!?/%*!%*+!%'&5+%/35!-.8+(,8+!15&++3!48,.&+$(+3(+2!'30!
'3%/O:cJ!1&+0!48,.&+$(+3(+2;!F*+!'&&.?$!*/5*8/5*%!%*+!(+88$!$%'/3+0!#9!%*+!%'&5+%/35!7+7%/0+B!?*/(*!0.!3.%!(.8.('8/M+!?/%*!%*+!
#8..0!:+$$+8$! $%'/3+0!0,+! %.! %*+! :cJ;! F*+!7/(%,&+!.3! %*+! &/5*%! /$! %*+! (.3%&.8B! %*,$!.389! %*+! $+(.30'&9!'3%/#.09!'3%/O&'%O
"8+E'SZZ!*'$!#++3!/3(,#'%+0;!L,(8+/!*':+!#++3!$%'/3+0!?/%*!C'7/!/3!#.%*!7/(%,&+$;!]('8+!#'&!S^!É-;!1K2!)"!*,-'3!$93.:/'8!
%/$$,+$! /3(,#'%+0! ?/%*! #.%*! %'&5+%/35!-.8+(,8+! '30! /%$! (.3%&.8! 1,3%'&5+%/35!-.8+(,8+2! /3! (.O$%'/3/35! 4.&! %*+! [CPS;! K.%*!
%'&5+%/35!'30!,3%'&5+%/35!-.8+(,8+$!'&+!'$$.(/'%+0!?/%*!5&++3!48,.&+$(+3(+B!%*+"! $93.:/'8! %/$$,+B! ?*+&+! /%! /$! (8+'&! %*+! #/30/35! .4! %*+! %'&5+%/35! -.8+(,8+! 15&++3!
Resultsanddiscussion
59
fluorescence)incolocalizationwiththeCD34(redfluorescence).NucleiarestainedwithDapi.Scalebar20µm.
4.1.2. Designandcharacterizationoftargetednanoparticlesfor
rheumatoidarthritis
According to the recent literature, already discussed in the introduction of this work,
nanoparticlescanbedesignedinordertoincreasespecificityforatargettissuereducingdoses
of drugs and their consequent toxicity. Following the rationale of the project, core-shell
biodegradable polymeric nanoparticles made of COOH-poly(ethylene glycol)-b-polylactide
(PEG-b-PLA) andPoly(caprolactone)-COOH (PCL)were produced in collaborationwith Prof.
Luis Núñez founder of BioTarget, a company based in Chicago. Due to their patented
technologyandmethodology(numberUS20080187487A1)basedonaelectrohydrodynamic
coaxial two-capillary system, polymeric nanoparticles can be customized; the shell can be
producedwithdifferentpolymersandlaterfunctionalizedwithtargetingmoleculesusingN-
Hydroxysuccinimide(NHS)ascouplingagent;thecorecanbeloadedwithdifferentdrugsand
diagnostictracers.Moreover,thedimensionofthenanoparticlescanbecontrolledbyvarying
the flow speed inside the capillaries. Four different kinds of biodegradable nanoparticles
(BNPs)wereproducedtodevelopthisproject(Figure11).Inparticular:BNPswithemptycore
andtheshellmadeofPEG-b-PLAandPCL,targetedBNPs(tBNPs)whichareBNPsconjugated
withthetargetingmolecule,BNPsloadedwithMTX(BNPs-MTX)andtBNPsloadedwithMTX
(tBNPs-MTX).
)+$,8%$!'30!0/$(,$$/.3!
!
! ! V^!
!
^+5)&/,!!_,F*./01%+*,&/H&/2/$%1%+'$,':,H'9?0/&+*,$1$'H1&%+*9/2",,]%'&%/35!4&.-!%*+!&/5*%_!KL@$!?/%*!7.89-+&/(!$*+88!1#8,+2!-'0+!.4!@TRO#O@W"B!@[W!'30!+-7%9!(.&+!1?*/%+2w!%KL@$!'&+!/0+3%/('8!
%.!%*+!KL@$!+E(+7%!4.&!%*+!%'&5+%!-.8+(,8+!8/3I+0!.3!%*+!$,&4'(+w!KL@$ODFG!'&+!/0+3%/('8!%.!%*+!KL@$!?/%*!DFG!8.'0+0!/3%.!
%*+!(.&+w!%KL@$ODFG!&+7&+$+3%!%*+!(.-78+%+!4.&-'%!.4!%*+!3'3.7'&%/(8+$B! 8.'0+0!?/%*!DFG!'30!7&.:/0+0!.4!%*+!%'&5+%/35!
-.8+(,8+!.3!%*+!$,&4'(+;!K+8.?B!%*+!$(*+-'%/(!&+7&+$+3%'%/.3!.4!3'3.7'&%/(8+$N!$,&4'(+!?/%*!%*&++!7.$$/#8+!.&/+3%'%/.3$!.4!
%*+!%'&5+%/35!-.8+(,8+;!F*+!'&&.?$!*/5*8/5*%!%*+!48+E/#/8/%9!.4!%*+!%'&5+%/35!-.8+(,8+;!!
)+(+3%89B! $+:+&'8! ?.&I$! *':+! #++3! 7,#8/$*+0! .3! %*+! ,$+! .4! %'&5+%+0! 3'3.7'&%/(8+$! /3!
#/.-+0/(/3+! 1]'33'! +%! '8;! Q^=S21J+&&'&/! +%! '8;! Q^=U2;! D.$%! .4! %*+$+! ?.&I$! 4.(,$! .3! %*+!
7*9$/(.(*+-/('8!7&.7+&%/+$!.4! %*+!3'3.7'&%/(8+$N! $%&,(%,&+!'30!.3! %*+! %'&5+%/35!-.8+(,8+$;!
D'39! 0/44+&+3%! -.8+(,8+$! *':+! #++3! ,$+0! 4.&! '! %/$$,+! $7+(/4/(! %'&5+%/35;! "-.35! %*+$+B!
'7%'-+&$B! 7&.%+/3$B! 4'%%9! '(/0$B! $,5'&$B! 7+7%/0+$B! '3%/#.0/+$! '30! %*+/&! 4&'5-+3%! *':+! #++3!
?/0+89!+-78.9+0!1)/(*'&0$!+%!'8;!Q^=Y2;!H.?+:+&B!'3%/#.0/+$B!0,+!%.!%*+/&!+E(+88+3%!4+'%,&+$B!
'&+! #+(.-/35! :+&9! 7.7,8'&;!C+$7/%+! %*+! 8'&5+! 3,-#+&! .4! 7,#8/('%/.3$! 4.(,$+0!.3! %'&5+%+0!
3'3.7'&%/(8+$B! :+&9! 4+?!?.&I$! '&+! 4.(,$+0!.3! %*+! (.36,5'%/.3!.4! %*+$+!-.8+(,8+$! .3! %*+/&!
$,&4'(+;!<30++0B!%*+&+!/$!%*+!3++0!%.!/-7&.:+!-+%*.0$!#9!?*/(*!%'&5+%/35!-.8+(,8+$!'&+!8/3I+0!
.3!%*+!$,&4'(+!.4!%*+!3'3.7'&%/(8+$;!<3!.,&!$%,09B!%*+!%'&5+%/35!-.8+(,8+$!*':+!#++3!(.,78+0!
%.! %*+! $,&4'(+! $,#$+A,+3%89! %*+! 3'3.7'&%/(8+$N! 7&.0,(%/.3! +E78./%/35! /%$! ':'/8'#8+! '-/3.!
5&.,7$;! K+(',$+! %*/$! I/30! .4! 4,3(%/.3'8/M'%/.3! /$! 3.%! .&/+3%+0! #,%! &'30.-B! /3! .&0+&! %.!
,30+&$%'30! 7.$$/#8+! (.,78/35! .&/+3%'%/.3B! '3! (4G-()(<#! $%,09! *':+! #++3! 7+&4.&-+0! /3!
(.88'#.&'%/.3!?/%*!).-/3'!\8/:'!1@'&%*+3.7+!a3/:+&$/%9!.4!L'78+$2!%.!7&+0/(%!%*+!3,-#+&!'30!
!"#$ %!"#$ %!"#$&'()*!"#$&'()*
+,-.*$/.00
(1-2.%342 5,0.+60.'.%/,%-.71%.
%!"#$
#89&:&#;<
#=;&">?*
#=;*
#89&:&#;<
#=;*
Resultsanddiscussion
61
positionoffreeaminogroupsavailablefortheconjugation.Tothisaimadetailed3Dstructure
have been performed showing the ScFv-Fc-targeting molecule folding in its dimeric form
(Figure12A).TheScFvfragmentandtheFchavebeenmodelledwithhighreliability,whilethe
linkerbetweentheVLandVHhasnotbeenmodelledbecausenosimilarcrystalstructures
werepresentinliterature.Thehingeregionhasbeenmodelledwithmediumreliabilityand
duetothepresenceoffourcysteines,samedisulphidebridgesmaybeformed.Moreover,by
definition,thehingeregion isextremelyflexibleandtheorientationoftheFcandtheScFv
couldbedifferentfromthisprediction.However,thetagSV5hasbeenmodelledwithmedium
reliabilityduetothepresenceofasimilarcrystalstructure.Thisinformationgivesconfidence
regardingtheorientationoftargetingpeptide,whichisfusedtothetag.Indeed,itispossible
tospeculatethatthetargetingpeptideprotrudesinthespaceavoidingunwantedinteraction
withpartsoftheownmolecule.However,thesynovialpeptidehasbeenmodelledwithlow
reliabilitybasedonacrystalstructurefragmentoftheE3ubiquitin-proteinligase.Despitethe
low reliability, 5 residues out of 9 are identical to those of E3 ubiquitin-protein ligase, in
particular the identical residues are located in both extremities of the sequence, which
containsthetwoflankingcysteinesresponsibleforthecircularizationofthepeptide.Thus,it
ishighlytruthfulthatthetargetingpeptideassumesacircularshapeexcludingotherpossible
folds.Toconclude, freeaminogroupsavailableonthesurfaceof thetargetmoleculehave
beenhighlighted(Figure12C). Inparticular,aminegroupsofLysresiduesarepresented in
purple,while theguanidiniumgroupofArg residues are shown inpink. In the3Dmodels,
reportedfromdifferentviewpoints,ispossibletoappreciatemanyfreeaminogroupsspreads
all over the surface of the targetingmolecule. Thus, is not possible to predict the correct
orientation,butthehighernumberoffreeaminogroupsarelocatedintheFcofthemolecule
withahigheravailabilityforthebinding.Consideringthisassumptioncorrect,itisreasonable
thatonlyonemonomerofthemoleculeisinvolvedinthebindingwiththepolymersofthe
nanoparticles, therefore the other monomer is available to display the targeting peptide
(Figure11).
)+$,8%$!'30!0/$(,$$/.3!
!
! ! VQ!
!
^+5)&/,!3_,7G,0'(/9,':,%./,%1&5/%+$5,0'9/*)9/",,1"2! PC! $%&,(%,&+! .4! %*+! ](J:OJ(! 4,$+0! %.! %*+! $93.:/'8! %'&5+%! 7+7%/0+! 7&+0/(%+0! /3O$/8/(.;! <3! 5&++3! &+5/.3$! .4! %*+!-.8+(,8+!
7&+0/(%+0!?/%*!*/5*!&+8/'#/8/%9w!/3!.&'35+!'&+!&+7.&%+0!&+5/.3$!7&+0/(%+0!?/%*!-+0/,-!&+8/'#/8/%9w!&+5/.3$!-.0+88+0!?/%*!8.?`3.!
&+8/'#/8/%9!'&+!$*.?3!/3!&+0;!1K2!F*+!%'#8+!&+7.&%$!-'/3!4+'%,&+$!.4!%*+!-.0+88/35!7&.(+$$!$,(*!'$!%*+!&+8/'#/8/%9B!%*+!%+(*3/A,+!
,$+0!4.&!%*+!-.0+88/35!'30!%*+!%+-78'%+!,$+0!4.&!+'(*!&+5/.3;!1[2!]%+&/(!*/30&'3(+!.4!%*+!%'&5+%!-.8+(,8+;!F*+!%?.!-.3.-+&$!
'&+!(.8.&+0!/3!?*/%+!'30!5.80!&+$7+(%/:+89;!@,&78+!$7.%$!&+7&+$+3%!W9$!&+$/0,+$B!?*/8+!7/3I!0.%$!&+7&+$+3%!"&5!&+$/0,+$;!K.%*!
W9$!'30!"&5!'-/3.!5&.,7$!('3!#+!':'/8'#8+!%.!#/30!%*+!7.89-+&$!.4!%*+!3'3.7'&%/(8+$N!$*+88;!\3!%*+!%.7!.4!%*+!4/5,&+!'&+!$*.?3!
%*+!$/0+!:/+?$!&.%'%+0!#9!X^|!'&.,30!%*+!g!'E/$B!/3!%*+!-/008+!%*+!%.7!:/+?!'30!4/3'889!%*+!#.%%.-!:/+?!?/%*`.,%!%*+!%'&5+%/35!
7+7%/0+;!
<3!5+3+&'8B!%*+$+!3'3.7'&%/(8+$!*':+!#++3!0+$/53+0!/3!.&0+&!%.!0+:+8.7!3'3.('&&/+&$!4.&!0&,5!
0+8/:+&9!.&!0/'53.$%/(!7,&7.$+B!?*/(*!-'9!4/30!'778/('%/.3!/3!%*+!-'3'5+-+3%!.4!)";!J.&!%*/$!
&+'$.3B! %*+$+! 3'3.$%&,(%,&+$! $*.,80! *':+! %*+! 4.88.?/35! 4+'%,&+$_! '! #/.(.-7'%/#8+! '30!
#/.0+5&'0'#8+!$%&,(%,&+B!'!3+5'%/:+!(*'&5+B!'!*90&.093'-/(!0/'-+%+&!x!Q^^3-!'30!'!5..0!
7.890/$7+&$/%9! /30+E! 1@C<2;! "$! 0/$(,$$+0B! %*+! #/.(.-7'%/#8+! '30! #/.0+5&'0'#8+! $%&,(%,&+! /$!
Domain/Fragment Residues Template Technique Reliability
scFv-heavy chain 1-121 4nyl(A) Transfer of coordinates high
linker 122-137 - Not modeled -
scFv-light chain 138-244 4nyl(B) Transfer of coordinates high
hinge 245-261 1IGT Comparative & ab initio modeling (Modeller) medium/low
Fc-CH2 262-370 1IGT Comparative modeling (Modeller) high
Fc-CH3 371-472 1IGT Comparative modeling (Modeller) high
Fc-tail 473-478 - Ab initio modeling (Modeller) low/no
SV5 479-492 2B5L(C) Transfer of coordinates medium
Targeting peptide 492-501 4GY5 Transfer of coordinate & mutagenesis with
PyMol low/no
!
"
#$
Resultsanddiscussion
63
fundamental to transfer this technology ina clinical context.Thenegativechargeprevents
undesired interaction with the MPS and shows low toxicity than positively charged
nanoparticles.Usually,thechargeisexpressedasZetapotential(ζ),whichreflexthechargeon
thenanoparticles’surface.Thediameterplaysanimportantroleintheclearance,circulation
time and internalizationmechanisms. To this aim, nanoparticleswith a diameter < 200nm
shouldguaranteeagoodcirculationtime.Finally,thePDIisanimportantparameter,which
describestheheterogeneityofthesizedistributionofmoleculesorparticlesinasolution.The
dispersityindexvaluerangesfrom0to1,wherevaluescloseto0areconsideredmonodisperse
whilevaluescloseto1areconsideredpolydisperse.Aftertheproduction,thenanoparticles
havebeencharacterizedbydynamiclightscattering(DLS),whichmeasuresthePDI,theZeta
potential,andthehydrodynamicdiameter.TheDLSdataconfirmanaveragehydrodynamic
diameterof150nm,anaveragePDIof0.3andaslightnegativechargebetween-6mVand-
9.6mV (Figure 13 A). Data obtained by DLS have been confirmed by nanoparticle tracking
analysis(NTA),atechniquesimilartotheDLS,whichgiveusadditionalinformationregarding
thenumberof nanoparticles in solution (Figure 13B). Indeed, through this technique, the
average diameter has been 170nm while the PDI about 0.2. Concerning the number of
nanoparticlesinsolution,theaverageconcentrationhasbeen3x1010particles/mL.Moreover,
information regarding themorphology and the state of aggregation has been collected by
transmission electron microscopy (TEM) (Figure 13, C and D) and scanning transmission
electronmicroscopy(STEM)(Figure13,EandF).
)+$,8%$!'30!0/$(,$$/.3!
!
! ! VS!
!
^+5)&/,!7_,41$'H1&%+*9/2,*.1&1*%/&+L1%+'$",,1"2! F*+! %'#8+! $,--'&/M+$!-'/3! 4+'%,&+$!.4! %*+!3'3.7'&%/(8+$;!"88! I/30$!.4!3'3.7'&%/(8+$!*':+!'!7.89-+&! (.3(+3%&'%/.3!.4!
=BVV-5`! -WB! ?*/8+! KL@$ODFG! '30! %KL@$ODFG! '&+! 8.'0+0! ?/%*! Q-5! `-W! .4! DFG;! <3$%+'0B! %*+! %'&5+%/35! -.8+(,8+! /$!
(.3(+3%&'%+0!=QÉ5!`-W!/3!%*+!%KL@$!'30!%KL@$ODFG;!F*+!8'$%!%*&++!(.8,-3$!$*.?!&+$,8%$!.#%'/3+0!#9!CW]_!*90&.093'-/(!
0/'-+%+&B!@C<!'30!l+%'!7.%+3%/'8;!1K2!F*+!%'#8+!$,--'&/M+$!0'%'!.#%'/3+0!#9!LF"!$,(*!'$!%*+!-+'3!0/'-+%+&B!%*+!3,-#+&!.4!
7'&%/(8+$!7+&!-W!'30!%*+!@C<;!1[2!FTD!/-'5+!.4!KL@$B!$('8+!#'&!=^^3-;!1C2!FTD!/-'5+!.4!%KL@$B!$('8+!#'&!=^^3-;!1T2!]FTD!
/-'5+!.4!%KL@$!/3!0'&I!4/+80!18+4%2!'30!#&/5*%!4/+80!1&/5*%2B!$('8+!#'&!U^^3-;!1J2!T38'&5+-+3%!.4!%*+!#&/5*%!4/+80!]FTD!/-'5+!.4!
%*+!%KL@$B!$('8+!#'&!=^^3-;!!
="!"9" R+'*'0>1%+S+4+%6,'<,$1$'>1&%+*4/2,1$(,PMX,&/4/12/,W+$/%+*2",,
<3!8/%+&'%,&+B!%*+!#/.(.-7'%/#/8/%9!.4!%*+!7.89-+&$!,$+0!4.&!%*+!7&.0,(%/.3!.4!%*+!3'3.7'&%/(8+$!
,$+0! /3! %*/$!?.&I!*'$!#++3!+E%+3$/:+89!0+-.3$%&'%+0;!H.?+:+&B! /%! /$!+$$+3%/'8! %.! %+$%! %*+/&!
#/.(.-7'%/#/8/%9!.3(+!%*+!3'3.7'&%/(8+$!'&+!4.&-+0;!<30++0B!%*+!$*'7+!'30!%*+!(*'&5+!(.,80!
/30,(+!%.E/(/%9!%.!%*+!(+88$B!$.!/%!/$!.4!7&/-'&9!/-7.&%'3(+!%.!'$$+$$!%*+/&!$'4+!7&.4/8+;!J.&!%*/$!
&+'$.3B!%?.!0/44+&+3%!(.3(+3%&'%/.3$!.4!3'3.7'&%/(8+$B! %'&5+%+0!'30!3.3O%'&5+%+0B!?/%*!'30!
?/%*.,%!DFG!*':+!#++3!/3(,#'%+0!?/%*!+30.%*+8/'8!(+88$!T";*9!XQV!'30!(.-7'&+0!?/%*!%*+!
$'-+!(.3(+3%&'%/.3!.4!4&++!DFG;!T30.%*+8/'8!(+88$!*':+!#++3!(*.$+3!'$!%*+!4/&$%!(+88$!%*'%!(.,80!
+3%+&!/3!(.3%'(%!?/%*!%*+!7'&%/(8+$!'4%+&!%*+/&!/3!:/:.!/36+(%/.3;!J&.-!%*+!5&'7*!/3!%*+!4/5,&+!=S!
"B!.#%'/3+0!4&.-!0'%'!(.88+(%+0!'%!SZ*B!/%!/$!7.$$/#8+!%.!3.%/(+!%*'%!+-7%9!3'3.7'&%/(8+$B!#.%*!
Resultsanddiscussion
65
BNPsandtBNPs,minimallyinfluencetheviabilityofthecells,showinganaverageviabilityof
78%comparedtonottreatedcells.Despitethestatisticaldifferencereportedbetweennot
treatedcellsandcellstreatedwithemptyBNPsandtBNPs,aviabilityof80%shouldnotbe
consideredanindexoftoxicity,sincethisresultdependsonthecell lineandtheconditions
usedforinvitrotests.Indeed,a98%oflivingcellshavebeenreportedusingsameemptyBNPs
andtBNPsandsameexperimentalcondition,butusingadifferentcelllinesuchasMDA231or
othercelllines(datanotshown).Instead,samevolumesofBNPs-MTXandtBNPs-MTXshowed
adecreasedpercentageoflivingcellscomparedtocellstreatedwithfreeMTX(yellowbars).
As expected, MTX encapsulated into nanoparticles had a superior cytotoxicity against
endothelial cells, proving thatnanoparticles are able toenter into cells delivering ahigher
amountofMTX.
Oncenanoparticleshavebeencharacterizedbytheirphysicochemicalpropertiesandfortheir
biocompatibilityitisimportanttostudythepharmacokineticreleaseoftheencapsulateddrug.
To this aim,BNPs-MTXhavebeendialyzed inPBSpH7.4at37° in slight agitationand the
releasedMTXhavebeenmeasuredbyUV-Visspectrophotometerat310nm.Thedrughasbeen
measuredfor24hoursandcomparedwiththereleaseofMTXnon-encapsulated(Figure14B).
Asshowninthegraph,morethan60%ofnon-encapsulatedMTXcomesoutfromthedialysis
tubeinfivehours,while40%ofMTXhavebeenreleasedfromtBNPs.However,aftertheinitial
release, a plateau is reached after 5 hours demonstrating that 50% ofMTX is still stable
encapsulated in the core of the nanoparticles for at least 24h. This result suggests that
nanoparticles,onceinjectedandreachedthetarget,mayrelease50%ofthedrugoveraperiod
longer than 24h. The initial fast release is known as “burst release”, a phenomenon
characterizing drug delivery systems. Indeed, numbers of papers have been published to
explain and overcome negative effects of this initial release (Huang & Brazel 2001).Main
reasonsconcerningthebursthavebeenassociatedwiththeshapeandporesizesofpolymeric
nanoparticlesaswellastothedruglowmolecularweight.Moreover,duringtheprocessofthe
drugencapsulation,partofthedrugentrappedintheshellcouldbequicklyreleasedcausing
thebursteffect.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! VV!
!
^+5)&/,!6_,PA19)1%+'$,':,$1$'H1&%+*9/2a,%'V+*+%?,+$,A+%&'",,1"2!DFF!:/'#/8/%9!'$$'9!,$/35!T";*9!XQV!(+88!8/3+;!F?.!0/44+&+3%!(.3(+3%&'%/.3$!.4!DFGB!KL@$ODFG!'30!%KL@$ODFG!*':+!#++3!
,$+0_!X3DB!=Z3D;!)+$7+(%/:+89!'&+!&+7&+$+3%+0!#9!9+88.?B!.&'35+!'30!0'&I!#8,+!#'&$;!DFG!+3('7$,8'%+0!/3%.!3'3.7'&%/(8+$!
$*.?+0!'!$,7+&/.&!(9%.%.E/(/%9!(.-7'&+0!%.!%*+!4&++!0&,5;!<3!.&0+&!%.!/3:+$%/5'%+!%.E/(!+44+(%$!.4!+-7%9!3'3.7'&%/(8+$B!#.%*!
KL@$!1&+0!#'&$2!'30!%KL@$!18/5*%!#8,+!#'&$2!*':+!#++3!%+$%+0!,$/35!$'-+!:.8,-+$!.4!3'3.7'&%/(8+$!,$+0!4.&!(+88$!%&+'%+0!?/%*!
DFG!8.'0+0!3'3.7'&%/(8+$;!J8,0'&'#/3+!1#8'(I!#'&2!*':+!#++3!,$+0!?/%*!'!(.3(+3%&'%/.3!.4!QZ3D!'$!'!7.$/%/:+!(.3%&.8!.4!I/88/35;!
\3!%*+!g!'E/$!%*+!>!.4!8/:/35!(+88$!*'$!#++3!('8(,8'%+0!(.-7'&+0!%.!3.%!%&+'%+0!(+88$!1=^^>!.4!8/:/35!(+88$2;!)+$,8%$!'&+!&+7.&%+0!
'$!%*+!-+'3!.4!#/.8.5/('8!%&/78/('%+!u`O!]C;!]%'%/$%/('8!$/53/4/('3(+!?'$!('8(,8'%+0!?/%*!\3+O?'9!"L\j"!-,8%/78+!(.-7'&/$.3!
%+$%;!T'(*!5&.,7!?'$!'3'89$+0!(.-7'&+0!%.!3.%!%&+'%+0!(+88$!5&.,7;!"88!%*+!5&.,7$!$*.?+0!'!$/53/4/('3%!0/44+&+3(+!(.-7'&+0!
%.!3.%!%&+'%+0!(+88$!?/%*!'!@!Ü!^;^^^=!á!àààà;!1K2!F*+!5&'7*!$*.?$!%*+!&+8+'$+!.4!DFG!/3!0/'89$/$!?/%*!@K]!7H!Y;S!'%!PY|[!/3!
$8/5*%!'5/%'%/.3!.:+&!'!7+&/.0!.4!QS*;!Q^^µW!.4!Q-5`-W!.4!4&++!DFG!1#8'(I!8/3+2!'30!KL@$ODFG!1#8,+!8/3+2!*':+!#++3!'3'89$+0!
/3!%&/78/('%+;!C,&/35!%*+!4/&$%!*.,&!$'-78+$!*':+!#++3!(.88+(%+0!+:+&9!=U!-/3,%+$!4&.-!%*+!0/'89$/$!'30!&+78'(+0!?/%*!4&+$*!@K]B!
%*+3!$'-78+$!*':+!#++3!(.88+(%+0!+:+&9!P^!-/3,%+$!0,&/35!%*+!$+(.30!*.,&!'30!4/3'889!.3+!$'-78+!7+&!*.,&!,3%/8!4/:+!*.,&$;!
F*+!8'$%!$'-78+$!*':+!#++3!(.88+(%+0!'4%+&!QS*;!]'-78+$B!/3!%&/78/('%+B!*':+!#++3!'3'89$+0!#9!$7+(%&.7*.%.-+%+&!'%!P=^3-!
'30!0'%'!*':+!#++3!&+7.&%+0!'$!%*+!-+'3!â!]C;!F?.O?'9!"L\j"!*'$!#++3!,$+0!%.!'$$+$$!$%'%/$%/('8!$/53/4/('3(+;!@!Ü!^;^^^=!á!
àààà;!
="7"! M1&5/%+$5,%./,/$('%./4+14,%+22)/,'<,%./,+$<410/(,26$';+1,
="7"!"! R+$(+$5,1$(,+$%/&$14+U1%+'$,'<,RG@2,1$(,%RG@2,Y+%.,:3".6F7A,
*/44,4+$/,
F*+!('7'(/%9!.4! %*+!$93.:/'8!7+7%/0+!%.!#/30!%*+! /348'-+0!$93.:/,-!*'$!#++3!%+$%+0! /3! %*+!
7'&'5&'7*!S;=;=!J/5,&+!=^B!?*+&+!)"!*,-'3!$93.:/'8!%/$$,+$!*':+!#++3!$%'/3+0!?/%*!%*+!%'&5+%!
-.8+(,8+;!D'(.&!+%!'8;!/3!Q^=Q!*':+!$*.?3!%*+!(&.$$O&+'(%/:+!.4!%*+!7+7%/0+!?/%*!.%*+&!$7+(/+$B!
7'&%/(,8'&89!&'%!'30!-.,$+;!H.?+:+&B!0,+!%.!%*+!4'(%!%*'%!%*+!$93.:/'8!7+7%/0+!/$!4,$+0!%.!'!
0/44+&+3%!](J:OJ(B!/3!.&0+&!%.!0+-.3$%&'%+!/%$!,3(*'35+0!4,3(%/.3'8/%9B!/--,3.48,.&+$(+3(+!
$%'/3/35!*'$!#++3!7+&4.&-+0!,$/35!/348'-+0!$93.:/'8!%/$$,+!.4!"<"!&'%$;!F*+!*+'8%*9!$93.:/'8!
%/$$,+! *'$! #++3! ,$+0! '$! '! (.3%&.8;! "$! $*.?3! /3! %*+! 4/5,&+! =U! "B! %*+! %'&5+%/35! -.8+(,8+B!
7&+:/.,$89! 8'#+88+0! ?/%*! [9U;UB! 7&+4+&+3%/'889! #.,30! %*+! /348'-+0! $93.:/'8! %/$$,+! 1&+0!
MTX 2uL [9
nM]
MTX 4uL [1
8nM]
BNPs-MTX 2u
L [9nM]
BNPs-MTX 4u
L [18n
M]
tBNPs-M
TX 2uL [9
nM]
tBNPs-M
TX 4uL [1
8nM]
BNPs 2ul
BNPs 4uL
tBNPs 2
uL
tBNPs 4
uL
Fludarabine 4
uL [28n
M]0
20
40
60
80
100%
livi
ng c
ells
MTT viability assay!
0 2 4 6 8 10 12 14 16 18 20 22 240
20
40
60
80
100
Time (hours)
% M
TX r
elea
se
Release of MTX from BNPs
MTX 2mg/mL
BNPs-MTX 2mg/mL****
"
Resultsanddiscussion
67
fluorescence) if compared with the healthy synovial tissue. Later, nanoparticles coupled
with/outthetargetmoleculesandlabelledwithFITChavebeenincubatedwithinflamedand
healthy synovial tissue (Figure 15 B). A higher number of green spots, in other words
nanoparticles, have been detected on the inflamed synovial tissue incubated with tBNPs
comparedwiththecontroltissue.Inaddition,veryfewspotshavebeenfoundonthestaining
performedwithuntargetedBNPsinbothinflamedandhealthysynovialtissues.Mostofthese
spotshavebeenlocalizedoutsidethetissues,probablybecauseofanonspecificbindingofthe
BNPs. As predicted from the 3Dmolecularmodels, performed during the design of target
moleculeandthetBNPs,theseexperimentsprovedthefunctionalityofthetargetingpeptide
oncefusedtotheScFv-Fcandalsowhenthetargetingmoleculeiscoupledwithnanoparticles.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! VZ!
!
^+5)&/,!>_,<1&5/%,%./,+$:910/(,2?$'A+19,%+22)/",1"2! <348'-+0! '30! *+'8%*9! $93.:/'! 4&.-! "<"! &'%$! 15&++3! ',%.48,.&+$(+3(+2! /3(,#'%+0!?/%*! %*+! %'&5+%!-.8+(,8+O[9U;U! 1&+0!
$%'/3/352;! L,(8+/! ?+&+! $%'/3+0! ?/%*! C"@<;! ]('8+! #'&! U^! É-;! 1K2! <348'-+0! '30! *+'8%*9! $93.:/'! 4&.-! "<"! &'%$! 1&+0!
',%.48,.&+$(+3(+2!/3(,#'%+0!?/%*!%KL@OJ<F[!'30!KL@$OJ<F[!#.%*!0+%+(%+0!'$!5&++3!$7.%$;!]('8+!#'&!U^!É-;!
Resultsanddiscussion
69
Asalreadyshown,thetargetingmoleculeisabletopreferentiallybindcellsoftheinflamed
synovialtissue.Moreover,oncethetargetmoleculeiscoupledwiththenanoparticles,these,
inturn,areabletotargettheinflamedsynovia.However,immunofluorescencestainingwith
nanoparticlesistroublesomeandresultsareusuallyqualitative.Indeed,thismethodrequires
theuseof fixativesolutionand theuseofdetergents,whichcanbe incompatiblewith the
stabilityofthenanoparticles.Thus,inordertoimproveourknowledgeaboutthetargetingand
the internalization into endothelial cells, in vitro experiments have been conducted with
EA.hy926 trying to overcome methodological problems. First, in order to investigate the
bindingandinternalization,livingEA.hy926cellshavebeenincubatefor1hwithbothBNPs-
Cy5.5andtBNPs-Cy5.5.Thefigure16Aclearlyshowsthebindingofbothkindsofnanoparticles
toEA.hy926,neverthelessitisnotpossibletounderstandwhetherthenanoparticlesareinside
thecellsoriftheyareonlyincontactwiththecellularmembrane.Forthisreason,inorderto
have quantitative data, an ELISA test has been performed on living EA.hy926. Results are
showninthefigure16B.ItisevidentthattBNPs-FITCareabletobindendothelialcellsmore
thanBNPsbecauseofthetargetingmolecule,whichiscapableofastablebinding. Instead,
BNPsbindcellsbychanceusingtheirchargeorpossiblehydrophobicinteraction.However,by
ELISAtestitisnotpossibletodiscriminatebetweenthosenanoparticlesthataresimplybound
tothecellsurfaceandthosethatareinternalized.Thus,apowerfulinstrumentcalledAMNIS,
combiningspeedandsamplesizeofflowcytometryandwiththeresolutionandsensitivityof
microscopyhasbeenusedtoquantifythenumberofcellsboundbytBNPs-FITCandBNPs-FITC.
Moreover, this method allows to quantify the percentage of internalised nanoparticles.
EA.hy926 cells have been incubated for 2hwith both BNPs-FITC and tBNPs-FITC and then
analysedbyAMNIS(Figure16C).ThegatehasbeenappliedforcellspositiveforFITCinorder
toquantifycellsboundbynanoparticles.About2.7%ofcellsincubatewithtBNPs-FITChave
beendetectedpositiveforFITCcomparewith0,7%ofcellsincubatedwithBNPs-FITC.Thisdata
confirms that tBNPs, due to the targetmechanism, are able to improve the binding with
endothelialcells.Duringtheanalysis,cellspositiveforFITC,soboundbynanoparticles,have
beenindividuallyphotographedwithamicroscopebothinbrightfieldandfluorescence.Then,
theimageshavebeenprocessedtodiscriminateifthenanoparticlesareinsideoroutsidethe
cells;adedicatedsoftwarecreatesamaskofthecellshapeusingthebrightfieldandthen,
mergingthefluorescenceimage,itdefinesthelocalizationofthenanoparticles.Thefigure16
DshowsrepresentativeimagesoftBNPs-FITCinsideacellandBNPs-FITCincontactwiththe
Resultsanddiscussion
70
cell membrane. Graphs reported in the figure 16 E, F and G summarize respectively data
regardingthepercentageofcellspositiveforFITC,thepercentageofinternalization,whichis
thesameforbothtBNPsandBNPs,andthefinalpercentageofcellsinternalizingparticles.It
ispossibletoconcludethatthepercentageofinternalizationdoesnotchangebetweenthe
BNPs and the tBNPs, however because the targetingmolecule increases tBNPs binding, as
consequence,percentageoftBNPsinternalisedishigher.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! Y=!
!
^+5)&/,!;_,W+$(+$5,1$(,+$%/&$19+L1%+'$,':,W4@2,1$(,%W4@2,R+%.,P8".?E3;",,1"2!T";*9XQV!(+88$!/3(,#'%+0!?/%*!%KL@$O[9U;U!'30!KL@$O[9U;U!4.&!=*!'%!PY|[!?/%*!U>!.4![\Q;!L,(8+/!.4!(+88$!*':+!#++3!$%'/3+0!
?/%*! C"@<!?*/8+! 3'3.7'&%/(8+$! 8'#+88+0!?/%*! [9U;U! *':+! #++3! 0+%+(%+0! '%! VXY3-! 13+'&! /34&'&+02;!c*.8+! (+88$! *':+! #++3!
0+%+(%+0!#9!0/44+&+3%/'8!/3%+&4+&+3(+!(.3%&'$%!1C<[2!#&/5*%!4/+80!'30!4/3'889!-+&5+0!?/%*!C"@<!'30!3+'&!/34&'&+0!(*'33+8$;!c*/%+!
'&&.?$!*/5*8/5*%!3'3.7'&%/(8+$;!]('8+!#'&!Q^µ-;!1K2!TW<]"!%+$%!7+&4.&-+0!.3!8/:/35!T";*9XQV!(+88$;!QBSµW!.4!%KL@$OJ<F[!'30!KL@$OJ<F[!*':+!#++3!/3(,#'%+0!?/%*!T";*9XQV!4.&!=*!'%!PY|[!?/%*!U>!.4
Resultsanddiscussion
72
at 525nm by ELISA plate reader. (C) EA.hy926 cells incubatedwith BNPs-FITC and tBNPs-FITC have been gated for their
fluorescenceusingascontrolnot-treatedcells.Thefirstplotshowsinfocusobjectsdescribedwiththe“aspectratio”(Yaxis)
definedastheminoraxisdividedbythemajoraxisanddescribeshowroundanobjectis,whiletheXaxisdefinesthe“Area”
inµm2.Inthesecondplot,theYaxisshowsthe“maxpixel”,whichmeasurethelargestvalueofthebackground-subtracted
pixelscontainedinintheinputmask,whiletheXaxisshowstheintensityoffluorescence.Thethirdplotshowsthe“frequency”
ofparticlesinternalizedontheYaxiswhileontheXaxisthe“internalization”isdefinedastheratiooftheintensityinsidethe
celltotheintensityoftheentirecellusingspecificmaskstodefinetheinnerpart.Finally,pixelsontheedgeofthemainmask
havebeenremovedbythe“erodemask”.Thehigherscorerepresentsagreaterconcentrationofintensityinsidethecell.Cells
with internalizednanoparticles typically havepositive scoreswhile cellswith no internalizationhavenegative scores. (D)
RepresentativeimagesacquiredduringtheanalysisoftwocellspositiveforFITC,onewithtBNPs-FITCandonewithBNPs-
FITC.Scalebar20µm.(E)ThegraphsummarisespercentageofcellspositiveforFITCwhenincubatedwithBNPs-FITCortBNPs-
FITCwhile (F) reports the percentage of internalization. (G) The percentage of cells with internalized particles has been
obtainedapplyingthe%ofinternalizationonthe%ofboundcells.
4.2.2. InvivobiodistributionofBNPsandtBNPsinaAIAratmodel
Intheparagraph4.2.1ithasbeendemonstratedthatthetargetingmoleculeandthetBNPs
wereabletopreferentiallybindinflamedsynovialtissueinvitro.Inordertoconfirmthisresult
invivo,4.8nMofCy5.5labelledontBNPsandBNPswereinjected,throughthetailvein,inrats
developinginflammationintherightknees.Thismodelofmonoarthritis,calledAIA,isauseful,
easyandquickmodeltostudybiodistributionofnewtherapeuticanddiagnosticcompounds
forthemanagementofRA.Afterthreedaysfromtheinductionoftheinflammationintheright
knee, nanoparticles have been injected and then followed for 23 days (Figure 17 A). The
animals, analysed following Cy5.5 by near infrared optical imaging, clearly show a higher
accumulationoffluorescenceintherightkneeoftheanimalsreceivingtBNPs-Cy5.5compared
to the contralateral knee (not inflamed) or animals treated with BNPs-Cy5.5. Plotting the
fluorescencedatafromfigureA,itispossibletoobtainthegraphofthefigure17B.Thegraph
highlightsanimprovedaccumulationoftBNPs-Cy5.5intherightinflamedknees,reachingthe
maximumafter7/8days.Inordertoassesstheaccumulationinothertissues,attheendof
thestudy,thefluorescencehasbeenmeasuredexvivointhemainorganssuchasliver,spleen,
lungs,kidneys,brain,heartandpaws.Indeed,fromthepicture17C,itispossibletoappreciate
thehigheraccumulationofnanoparticlesintotheliver,followedbykidneys.Itisinterestingto
noticethatthetargetmechanismscoupledontBNPsdidnot influencetheaccumulation in
theseorgans.Moreover,thehigherfluorescenceintensitydetectedintheliversuggeststhat
thesenanoparticles,asalreadystudiedbyourgroup,duetotheirphysicochemicalfeatures
are mainly eliminated through the bile in the gut and finally removed with the faeces.
Fluorescencedatadetectedonthekneeshavebeencorrelatedwiththeirswelling(Figure17
E),whichisthemaininflammatoryparametertoevaluateAIA.Itisimportanttonoticethat
bothtBNP-Cy5.5andBNPs-Cy5.5groupsofanimalshadthesameswellingforthe inflamed
)+$,8%$!'30!0/$(,$$/.3!
!
! ! YP!
I3++$!1&/5*%2!'30!*+'8%*9!I3++$!18+4%2B!*.?+:+&!%*+!48,.&+$(+3(+!/3%+3$/%9!.4!%KL@$O[9U;U!?'$!
*/5*+&!%*'3!%*+!(.3%&'8'%+&'8!I3++$!'30!I3++$!.4!'3/-'8$!&+(+/:/35!KL@$O[9U;U;!<3!'00/%/.3B!%*+!
4/5,&+!=Y!J!$*.?$!%*+!/--,3+!&+$7.3$+!'5'/3$%!-K]"B!%*+!'3%/5+3!,$+0!%.!/--,3/M+!%*+$+!
'3/-'8$! '30! %.! /30,(+! %*+! /348'--'%/.3;! F*+! 5&'7*! $*.?$! %*+! $'-+! A,'3%/%9! .4!
/--,3.58.#,8/3$!'3%/O-K]"B!(.34/&-/35!%*'%!%*+!*/5*+&!'((,-,8'%/.3!.4!%*+!%KL@$!/3%.!%*+!
/348'-+0! I3++! /$! 3.%! '! &+$,8%! .4! '! 0/44+&+3%! 0+5&++! .4! /348'--'%/.3! #,%! /%! /$! %*+! .,%(.-+!
.#%'/3+0!,$/35!'3!'(%/:+!%'&5+%/35;!F*+$+!&+$,8%$!.#%'/3+0!(4!5(5#!'&+!.4!5&+'%!/3%+&+$%!#+(',$+!
/%!7&.:+$!%*+!$,7+&/.&!'((,-,8'%/.3!.4!%'&5+%+0!3'3.7'&%/(8+$!(.-7'&+0!?/%*!%*+!,3%'&5+%+0!
3'3.7'&%/(8+$B!0+-.3$%&'%/35!%*'%!%*+!%'&5+%/35!-.8+(,8+!'(%/:+89!5,/0+$!3'3.7'&%/(8+$!/3!%*+!
/348'-+0!I3++$;!D.&+.:+&B!%*/$!/$!'3.%*+&!7&..4!%*'%!%'&5+%+0!3'3.7'&%/(8+$!(.,80!#+!%*+!I+9!
%.!.:+&(.-+!%*+!8'(I!.4!+44/('(9!.4!3'3.('&&/+&$!#'$+0!.3!'!7'$$/:+!0+8/:+&9;!<%!/$!&+'$.3'#8+!%.!
(.3(8,0+!%*'%!%KL@$!(.,80!#+!$%,0/+0!#.%*!'$!%*+&'7+,%/(!'30!0/'53.$%/(!'5+3%$!4.&!%*+!)"!
-'3'5+-+3%B!/-7&.:/35!%*+!+44/('(9!'30!%*+!$+3$/%/:/%9!&+$7+(%/:+89;!!
!
!"!!#$%%&
'"((#$%%&
&"&&#$%%&
)"!*#$%%&
+"'
,-.#-/0.1 2345
!"#$%&'()*)
"#$%&'()*)
24 48 72 96 192
264
336
576
0
1000
2000
3000
4000
5000 tBNPs InflamedBNPs InflamedBNPs HealthytBNPs Healthy
Two-way ANOVA***P< 0.001 **P< 0.01
*****
Time (h)
Inte
nsity
of f
luor
esce
nce
(IF)
*
+
"
)+$,8%$!'30!0/$(,$$/.3!
!
! ! YS!
!
^+5)&/,!C_,#$,A+A',J+'(+2%&+J)%+'$,':,%W4@2,1$(,W4@2,+$,1,0'(/9,':,&1%,8#8",,1"2!<-'5+$!'(A,/&+0!#9!%/-+!0.-'/3!.7%/('8!/-'5/35!.4!%?.!&+7&+$+3%'%/:+!"<"!&'%$!%&+'%+0!/3%&':+3.,$89!&+$7+(%/:+89!?/%*!S;Z!
3D!.4!%KL@$O[9U;U!14/&$%!&.?2!'30!KL@$O[9U;U!1$+(.30!&.?2;!F*+!48,.&+$(+3(+!*'$!#++3!4.88.?+0!4.&!'!%.%'8!.4!QP!0'9$;!F*+!
*/5*+$%!/3%+3$/%9!.4!48,.&+$(+3(+!?'$!0+%+(%+0!'%!0'9!Y!/3!%*+!&/5*%!I3++$!.4!%KL@$O[9U;U!%&+'%+0!&'%$;!J8,.&+$(+3(+!/3%+3$/%9!
*'$!#++3!&+7.&%+0!'$!3.&-'8/M+0!(.,3%$!1L[2;!1K2!F*+!5&'7*!$*.?$!48,.&+$(+3(+!/3%+3$/%9!'$!L[!.4!%*+!/-'5+$!'(A,/&+0!#9!
%/-+!0.-'/3!.7%/('8!/-'5/35;!J8,.&+$(+3(+!/3%+3$/%9!.4!%*+!&/5*%!'30!8+4%!7'?$!.4!%*+!'3/-'8!%&+'%+0!?/%*!%KL@$O[9U;U!*':+!
#++3!&+7.&%+0!&+$7+(%/:+89!'$!(.3%/3,.,$!#8,+!8/3+!'30!0.%%+0!#8,+!8/3+;!<3$%+'0B!%*+!48,.&+$(+3(+!/3%+3$/%9!.4!%*+!&/5*%!'30!
8+4%!7'?$!.4!%*+!'3/-'8$!%&+'%+0!?/%*!KL@$!*':+!#++3!&+7.&%+0!&+$7+(%/:+89!'$!(.3%/3,.,$!&+0!8/3+!'30!0.%%+0!&+0!8/3+;!1[2!TEO
:/:.!/-'5+$B!'(A,/&+0!#9!%/-+!0.-'/3!.7%/('8!/-'5/35B!.4!%*+!-'/3!.&5'3$!.4!%?.!&+7&+$+3%'%/:+!"<"!&'%$!%&+'%+0!&+$7+(%/:+89!
?/%*!%KL@$O[9U;U!'30!KL@$O[9U;U;!1C2!F*+!48,.&+$(+3(+!/3%+3$/%9!1+E7&+$$!'$!L[2!-+'3!â!]TD!.4!'88!&'%$!1%*&++!7+&!5&.,72!*'$!
#++3!&+7.&%+0;!1T2!F*/$!/-'5+!$*.?$!%*+!$?+88/35!/3!&+8'%/.3!?/%*!%*+!/3%+3$/%9!.4!48,.&+$(+3(+!&+(.&0+0!4.&!+'(*!7'?!'%!0'9!
Y;!K8,+!#'&$!&+7&+$+3%!0'%'!.4!&'%$!%&+'%+0!?/%*!%KL@$O[9UB!?*/8+!&+0!#'&$!'&+!0'%'!#+8.35/35!%.!KL@$O[9U;U!%&+'%+0!&'%$;!1J2!
TW<]"!%+$%!4.&!%*+!+:'8,'%/.3!.4!%*+!&'%!<5R!'3%/O-K]"!/3!#8..0!$'-78+$!.4!%*+!&'%$!%&+'%+0!?/%*!%KL@$O[9U;U!'30!KL@$O[9U;U;!
C'%'!'&+!&+7.&%+0!'$!%*+!-+'3!â!]TD!.4!%*&++!&'%$!7+&!5&.,7;!F?.O?'9!"L\j"!*'$!#++3!,$+0!%.!'$$+$$!$%'%/$%/('8!$/53/4/('3(+!
#+%?++3!5&.,7$!0,&/35!%*+!%/-+!/3!%*+!5&'7*!KB!?*/8+!,37'/&+0!7'&'-+%&/(!%O%+$%!*'$!#++3!,$+0!%.!'$$+$$!$%'%/$%/('8!$/53/4/('3(+!
/3!%*+!5&'7*!T;!@!Ü!^;^U!á!àw!@!Ü!^;^=!á!ààw!@!Ü!^;^^=!á!àààw!@!Ü!^;^^^=!á!àààà;!
="7"9"! !"#$%$&,S+'(+2%&+S)%+'$,'<,RG@2,1$(,%RG@2,+$,H#3,0')2/,0'(/4,
"4%+&!%+$%/35!%*+!'#/8/%9!.4!%KL@$!%.!$7+(/4/('889!#/30!%*+!/348'-+0!6./3%$!.4!'3!"<"!-.3.'&%*&/%/$B!
%*+!3+E%!$%+7!?'$!%.!$%,09!#/.0/$%&/#,%/.3!/3!'
Resultsanddiscussion
75
inthejoints.Onceanimals,inthiscasemice,developedthedisease,theywereenrolledintwo
groups,receivingtBNPsorBNPs.Micehavebeenscannedfor7daysandimagesofthelimbs
oftworepresentativemiceareshowninthefigure18A.Moreover,thearthritisscore,ranging
from0(noarthritis)to4(worstarthritis)andreflectingtheseverityofthedisease,havebeen
assessed inorder toassociate the fluorescencewithdiseaseprogression. It is important to
notice from figure 18 B that paws with the same score show a different intensity of
fluorescenceandthehighesthavebeendetectedinthepawofamousetreatedwithtBNPs-
Cy5.5.Infact,graphsofthefigure18Cshowahigherfluorescenceintensityatbothscore0
and3.Importantly,thestatisticalsignificancehasbeenreachedinthefirst24h.Thisresult,
however,divergesfromthebiodistributionobtainedinAIA,wherethehighestfluorescence
differencehasbeenreachedafter1week.Nevertheless,thesetwoRAmodelsarebasedon
twodifferentpathogenesisprocesses.Indeed,theAIAisanacutemodelandtheinflammation
increase together with the formation of new vessels, supporting the data showing a
progressiveaccumulationduringthefirstweek.Instead,theCIAisachronicmodelofRAwhere
the inflammationandthenewbloodvesselsarealreadyestablishedbeforethestudy,thus
tBNPsareabletoaccumulateimmediatelyaftertheirinjection.Ofinterestisthetrendshowed
bythetBNPs-Cy5.5fluorescence(figure18C),indeedtheinitialfluorescencepeak,duetothe
nanoparticles injectedinthetailvein, isfollowedbyadecreasefluorescenceintensity(6h),
probably due to the clearance of the excess of nanoparticles. Finally, the fluorescence
increased again after 24h in mice receiving tBNPs-Cy5.5 only, proving their accumulation
comparedwithBNPs.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! YV!
!
^+5)&/,!=,#$,A+A',J+'(+2%&+J)%+'$,':,%W4@2,1$(,W4@2,+$,1,0'(/9,':,0')2/,K#8",,1"2!<-'5+$!'(A,/&+0!#9!%/-+!0.-'/3!.7%/('8!/-'5/35!.4!%?.!&+7&+$+3%'%/:+![<"!-/(+!%&+'%+0!/3%&':+3.,$89!&+$7+(%/:+89!?/%*!
^;U!3D!.4![9U;U!#.,30!%.!%KL@$!14/&$%!7'3+82!.&!KL@$!1$+(.30!7'3+82;!F*+!48,.&+$(+3(+!*'$!#++3!4.88.?+0!4.&!'!%.%'8!.4!Y!0'9$;!
]%'&%/35!4&.-!%*+!4/&$%!&.?_!?&/$%!$EB!?&/$%!0EB!'3I8+!0E!'30!'3I8+!$E;!F*+!$(.&+!.4!+'(*!7'?!*'$!#++3!&+7.&%+0!.3!%*+!&/5*%!.4!
+'(*!&.?;!1K2!<-'5+$!.4!%?.!-/(+!'3I8+$B!%&+'%+0!&+$7+(%/:+89!?/%*!%KL@$O[9U;U!'30!KL@$O[9U;UB!$*.?!$'-+!'&%*&/%/(!$(.&+!
#,%!0/44+&+3%!48,.&+$(+3(+!/3%+3$/%9;!<30++0B!%*+!*/5*+$%!*'$!#++3!0+%+(%+0!/3!%*+!7'?!.4!%*+!%KL@$O[9U;U!%&+'%+0!-.,$+;!1[2!
F*+!5&'7*$!$*.?!%*+!/3%+3$/%9!.4!48,.&+$(+3(+!0+%+(%+0!4.&!'!%.%'8!.4!Y!0'9$!/3!7'?$!?/%*!$(.&+!^!15&'7*!'#.:+2!'30!7'?$!?/%*!
$(.&+!P!15&'7*!#+8.?2;!F*+!$%'%/$%/('8!$/53/4/('3(+!*'$!#++3!&+'(*+0!/3!%*+!4/&$%!QS!*!/3!%*+!7'?!.4!-/(+!%&+'%+0!?/%*!%KL@$O
[9U;U! 1#8,+! 8/3+2!(.-7'&+!?/%*!-/(+!&+(+/:/35!KL@$O[9U;U! 1&+0! 8/3+2;!J8,.&+$(+3(+! /3%+3$/%9!*'$!#++3!&+7.&%+0!'$!':+&'5+!
&'0/'3%!+44/(/+3(9!â!]C;!<3!%*/$!$%,09!*':+!#++3!+3&.88+0!Y!-/(+;!J.,&!.4!%*+-!%&+'%+0!?/%*!%KL@$O[9U;U!'30!%*&++!?/%*!KL@$O
[9U;U;!F*+!5&'7*!&+5'&0/35!%*+!$(.&+!^!%'I+$!/3%.!'((.,3%!U!7'?$!.4!%KL@$O[9U;U!%&+'%+0!-/(+!'30!Y!.4!KL@$O[9U;U;!<3$%+'0B!
%*+!5&'7*!.4!%*+!$(.&+!P!%'I+$!/3%.!'((.,3%!S!7'?!.4!%KL@$O[9U;U!%&+'%+0!-/(+!'30!S!.4!KL@$O[9U;U;!F?.O?'9!"L\j"!-,8%/78+!
(.-7'&/$.3$!%+$%!*'$!#++3!,$+0!%.!'$$+$$!$%'%/$%/('8!$/53/4/('3(+;!@!Ü!^;^U!á!àw!@!Ü!^;^=!á!ààw!@!Ü!^;^^=!á!àààw!@!Ü!^;^^^=!á!àààà;!
!"# $ # %&"# '%"# ($"# !$)"#
!"# $ # %&"# '%"# ($"# !$)"#
*+,-./01232
+,-./01232
456.* .7
456.* 87
9:;<= 87
9:;<= .7
456.* .7
456.* 87
9:;<= 87
9:;<= .7
+,-./01232
*+,-./01232
%&"#
1 6 24 72 96 1680
2!107
4!107
6!107
8!107
Time (h)
Avg
Rad
iant
Eff
icie
ncy
[p/s
/cm
2 /sr
] / [u
W/c
m2]
Score 0
BNPs-Cy5.5tBNPs-Cy5.5
****
** **
1 6 24 72 96 1680
2!107
4!107
6!107
8!107
Time (h)
Avg
Rad
iant
Eff
icie
ncy
[p/s
/cm
2 /sr
] / [u
W/c
m2]
Score 3
BNPs-Cy5.5tBNPs-Cy5.5*
*
***
>?@5=
!
!
A
B
A
A
B
B
>?@5="B
9
+
0
)+$,8%$!'30!0/$(,$$/.3!
!
! ! YY!
J,&%*+&B!?+!/3:+$%/5'%+!%*+!*/5*+&!/3%+3$/%9!.4!48,.&+$(+3(+!0+%+(%+0!'4%+&!=*!/3!6./3%$!.4!-/(+!
&+(+/:/35!%KL@$O[9U;U!'30!$(.&+0!'$!^!#9!+E%+&3'8!.#6+(%/:+!+:'8,'%/.3;!c+!?.30+&+0!/4!%*/$!
0/44+&+3(+!?'$!%*+!&+$,8%!.4!'3! /3/%/'8! /348'--'%.&9!$%'%+B!?*/(*! /$!3.%!7+&(+7%/#8+!?/%*! %*+!
.#6+(%/:+!+E'-/3'%/.3;!F.!%*/$!'/-B!?+!7+&4.&-+0!*'+-'%.E98/3!+.$/3!$%'/3/35!.4!6./3%$!$(.&+0!
'$!^B!4.,30/35!%*+!/3/%/'8!/34/8%&'%/.3!.4!%*+!$,#(*.30&'8!#.3+!#9!-.3.(9%+$!'30!3+,%&.7*/8$!
1J/5,&+!=X2;!F*/$!+:/0+3(+!*/5*8/5*%$!%*+!7.%+3%/'8!.4!,$/35!%KL@$!'$!'!0/'53.$%/(!%..8B!/30++0!
%*+9!$*.?!+'&89!/348'--'%/.3B!?*/(*!?'$!3.%!0+%+(%'#8+!#9!.#6+(%/:+!+E'-/3'%/.3!1$?+88/35B!
+&9%*+-'B!'3I98.$+2;!D.&+.:+&B!%*/$!$%,09!.4!#/.0/$%&/#,%/.3!7&.:+$!'!(.&&+8'%/.3!#+%?++3!%*+!
/3%+3$/%9! .4! 48,.&+$(+3(+! '30! %*+! 0+5&++! .4! /348'--'%/.3B!?*/(*! /$! '3! +$$+3%/'8! 4+'%,&+! %.!
0+%+(%!0/$+'$+!7&.5&+$$/.3!0,&/35!%*+!4.88.?O,7;!
! !
^+5)&/,!E",U1/01%'V?9+$,P'2+$,2%1+$+$5")+7&+$+3%'%/:+! /-'5+! .4! '! 6./3%! .4! [<"! CK"`=!-.,$+!?/%*! $(.&+! ^;! "&&.?$! */5*8/5*%! #.3+! /34/8%&'%/.3! #9!-.3.(9%+$! '30!
3+,%&.7*/8$;!F*/$!(.30/%/.3!0+-.3$%&'%+$!%*'%!6./3%$!,$,'889!$(.&+0!#9!^B!-+'3/35!3.!'&%*&/%/$B!/4!'3'89$+0!#9!*/$%.8.59!&+:+'8$!
%*+!/3/%/'8!/348'--'%.&9!$%'%+!0,+!%.!8+,I.(9%+$!#.3+!/34/8%&'%/.3!1#8'(I!'&&.?$2;!]('8+!#'&!Q^É-;!
="9"! @&/*4+$+*14,2%)(+/2,+$,1,0'(/4,'<,>'461&%.&+%+2,
="9"!"! :<<+*1*6,'<,%RG@2KPMX,+$,H#3,0')2/,0'(/4,
F*+!$%,0/+$!.4!#/.0/$%&/#,%/.3!7&.:+!%*+!$,7+&/.&!'((,-,8'%/.3!.4!%*+!%KL@$!(.-7'&+0!?/%*!
%*+!,3%'&5+%+0!KL@$!/3%.!%*+!/348'-+0!I3++$!.4!#.%*!'&%*&/%/(!-.0+8$;!H.?+:+&B!/3!.&0+&!%.!
0+-.3$%&'%+!%*'%!'!*/5*+&!'((,-,8'%/.3!-+'3$!*/5*+&!+44/('(9B!%*+!%*+&'7+,%/(!+44+(%!.4!%KL@$!
8.'0+0!?/%*!DFG!*'$!#++3! /3:+$%/5'%+0! /3
Resultsanddiscussion
78
Balthasar2003).Consideringthisinformation,onegroupofarthriticmicehasbeentreatedi.p.
withsalinesolution(asnegativecontrol);anothergrouphasbeentreatedwith1mg/Kgoffree
MTX three times per week and represents the positive control, adapting data present in
literature (Lange 2005)(Jung et al. 2015). Because nanoparticles persist in the inflamed
synoviumforaboutaweek,agroupofmicehasbeentreatedwithanequivalentdoseoftBNPs-
MTX,inparticularnot1mg/Kgthreetimesperweekbutasingledoseof3mg/Kgperweek.As
showninthegraph20A,thisdoseoftBNPs-MTX(continuousblueline)showedadecreased
arthriticscore,comparedtocontrolanimals(redline),provingitsefficacy.Thisresultisinline
withthetherapeuticeffectprovidedbythetreatmentwiththefreedrug.
Oneof theprimaryobjectivesof theproject is to demonstrate that the selectivedelivery,
whichincreasestheconcentrationofnanoparticlesandMTXintheinflamedjoints,mayallow
adosereductioncomparedtoastandardtreatment.Tothisaim,anothergroupofmicehas
beentreatedwithalowerdoseoftBNPs-MTXequivalentto1mg/Kgperweek(dottedblue
line).Evenwithalowerdose,thetargetingmechanismguaranteestherapeuticefficacyover
thefreedrug.
Asexpected,thegroupofmicetreatedwithasingleinjectionof3mg/KgoffreeMTX(dotted
blackline)didnotshowanyefficacycomparedtocontrolgroup,confirmingthatMTX,dueto
itsfastclearance,cannotbeadministratedonceperweek.
At the end of the study, mice have been euthanized and paws have been collected for
subsequentanalysis.Indeed,thetherapeuticefficacyofthetBNPs-MTXcomparedtocontrol
andfreeMTXhavebeenvalidatedbyhistologicalanalyses(Figure20B).Theseimageswere
then analysed and histological scores (Figure 20 C) show reduction of the cartilage and
subchondralboneinfiltration(Figure20E,D),aswellasareductioninthestromalproliferation
(Figure20G)inmicetreatedwiththeeffectivedosesoftBNPs-MTXandfreeMTX.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! YX!
!
^+5)&/,3B_,P::+*1*?,':,%W4@2XD<Q,+$,K#8,0'(/9",,1"2!F*+!5&'7*!$*.?$!'&%*&/%/(!$(.&+$!.4
Resultsanddiscussion
80
(continuousblueline);tBNPs-MTX1mg/Kgonetimeperweek(dottedblueline).Thescoreshavebeenreportedasthemean
ofthesumofthescores±SEMassessedforeachpawofthemouse.Thescorevaluesrangefrom0(noarthritis)to4(highly
inflamed,swollenorankylosedpaw).StatisticalsignificancehasbeenassessedbyTwo-wayANOVAtest.P≤0.05=*;P≤0.01
=**;P≤0.001=***;P≤0.0001=****.(B)Histologicalimagesrepresentativeofeachgroupofmicetreatedinthisstudy.An
additional imageofahealthypawwasaddedtothepanelasthenegativecontrol.Thegrouptreatedwithsalinesolution
showstheworstprofilecharacterizedbyahyperplasticsynovialtissue,hugeinfiltrationofleukocytesandlossofcartilageand
bonestructure.(C)Histologicaltotalscorereportedasthemean±SDofthescoresassignedforeachmouseofthestudy.The
scoreistheresultofscoresassignedfor7differentparameterssuchassubchondralboneinfiltration(D),cartilageinfiltration
(E),fibrinoidnecrosis(F),stromalproliferation(G),lymphoidinfiltration(H),granulocyticinfiltration(I)andsynovialepithelial
proliferation(J).Statisticalsignificancehasbeenassessedbyunpairedparametrict-test.P≤0.05=*
4.3.2. EvaluationoftoxiceffectsinCIAmicetreatedwithtBNPs-MTX
One of the goals of this project is to demonstrate that same therapeutic effects can be
obtainedusingalowerdoseofdrugbytargetedapproaches.Asaresult,alowerdoseofthe
encapsulateddrugandadifferent routeofelimination (liver-bile-intestine) shouldcoincide
withlowersideeffects.Oneoftheparametersconsideredtoassesstoxicityisthereductionof
the bodyweight (Figure 21A). The histogram shows the reduction of gainweight inmice
treatedwithMTX3mg/Kgonceperweekcomparedtocontrolmiceandmicetreatedwith
both doses of tBNPs-MTX. Moreover, another parameter used to demonstrate less toxic
effects isbasedonbloodanalysis (Figure21B-G).ReductionofWBC,RBCandPLTusually
reflecttoxiceffectsofthetreatment.RegardingWBC,micetreatedwith1mg/KgofMTXthree
times per week showed a reduction compared with control mice, although no statistical
significancehasbeenreached.Onthecontrary,thestatisticalreductionhasbeenassessedfor
RBCandPLTinmicereceivingthistreatment.Despitethetherapeuticeffectsofthisdoseof
MTXsometoxiceffectswereevidentcomparedtocontrolanimals,whilemicetreatedwith
bothdosesoftBNPs-MTXdidnotshowanytoxiceffects.Asafetoxicologicalprofilehasbeen
alsodemonstratedinmicetreatedwithadoseof3mg/KgofMTX.Thiscouldbeagainjustified
bythefasteliminationofthesingledose.
BothgainweightandbloodanalysishighlighttoxiceffectsduetothetreatmentwithfreeMTX.
Bycontrast,MTXencapsulatedintBNPsshowedareallysafeprofileinCIAmice.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! Z=!
!
^+5)&/,3!_,W9''(,1$19?2+2,1$(,51+$,5&'R%.,+$,K#8,0')2/",,F*+!*/$%.5&'-$!&+7&+$+3%!0'%'!&+5'&0/35!-/(+!5&.?%*!1"2!'30!#8..0!'3'89$/$!$,(*!'$!cK[!1K2B!)K[!1[2B!@WF!1C2B!WgD!1T2B!D\L!
1J2B!R)"!1R2;!"88!*/$%.5&'-$!&+7.&%!0'%'!'$!%*+!-+'3!â!]C;!T'(*!(.8.,&+0!#'&!&+7&+$+3%$!'!0/44+&+3%!5&.,7!.4!-/(+_!&+0!#'&$!
$%'30!4.&!-/(+!&+(+/:/35!$'8/3+!13áU2w!#'&$!.4!-/(+!%&+'%+0!?/%*!DFG!=-5`!f5!PG!?++I!*':+!#++3!(.8.,&+0!?/%*!8/5*%!5&+9!
13áV2w!#'&$!.4!-/(+!%&+'%+0!?/%*!DFG!P-5`!f5!=G!?++I!*':+!#++3!(.8.,&+0!?/%*!0'&I!5&+9!13áS2w!8/5*%!#8,+!#'&$!$%'30!4.&!-/(+!
%&+'%+0!?/%*!%KL@$ODFG!P-5`!f5!=G!?++I!13áS2w!0'&I!#8,+!#'&$!$%'30!4.&!-/(+!%&+'%+0!?/%*!%KL@$ODFG!=-5`!f5!PG!?++I!
13áU2;!]%'%/$%/('8!$/53/4/('3(+!*'$!#++3!'$$+$$+0!#9!,37'/&+0!7'&'-+%&/(!%O%+$%;!@!Ü!^;^U!á!àw!@!Ü!^;^=!á!àà;!
="9"9"! H6%'W+$/2,0)4%+>4/Q,1$1462+2",
<3!.&0+&!%.!*':+!'!(.-78+%+!7/(%,&+!.4!%*+!/348'--'%.&9!7&.(+$$!%*'%!.((,&&+0!/3!-/(+!%&+'%+0!
?/%*!%KL@$ODFGB!$+&,-!$'-78+$!*':+!#++3!'3'89$+0!%.!A,'3%/49!(9%.I/3+!8+:+8$!#9!-,8%/78+E!
TW<]";!<3!%*/$!('$+B!%*+!/3%+&+$%!?'$!%.!,30+&$%'30!(9%.I/3+$!7&.4/8+$!/3!-/(+!%&+'%+0!?/%*!8.?+&!
0.$+$!.4!%KL@$ODFG!'30!DFG!(.-7'&+0!%.!%*+!(.3%&.8!5&.,7;!C+$7/%+!%*+!5&+'%!'-.,3%!.4!
Resultsanddiscussion
82
information that can be obtained, it is difficult to fully understand and contextualize their
variationintheinflammatorycellsnetworkhappenedinthischronicmodelofRA.Moreover,
theseprofilesconcernthesystemiccytokinesanddonotperfectlyreflectcytokineslevelsin
the inflamed synovia,where the local profiles could be different.Moreover, cytokines act
throughtheirreceptors,whichinturncanbeupregulatedordownregulatedtocompensate
cytokines low expression or overexpression. However, cytokines quantification gives a
reasonableideaoftheinflammatorylandscapeandshouldbeusedasadditionalinformation
to support or explain other data. Overall, from the results summarized in figure 22,mice
treatedwithtBNPs-MTXshowedanincreasedamountofIL-1ß,IL-2,IL-12p70,IL-17andMIP-
1a(Figure22B,C,I,K,X).Despitetheincreasedlevelsofthesecytokines,thelevelsofTNF-α,
which is thepivotalpro-inflammatorycytokine,havebeenunchangedcomparedtocontrol
mice. In addition, IL-6, also known for its central role in rheumatoid arthritis, have been
decreasedaswellasRANTES(regulatedonactivation,normalTcellexpressedandsecreted).
Thelatterisachemokinewithachemotacticroleprincipallyforleukocytes.KC(keratinocyte-
derivedcytokine)isanotherchemokinethathasbeenfounddecreasedcomparedtocontrol
groupofmice.Thischemokinehasneutrophilchemoattractantactivityandhasbeenproved
tobeinvolvedinneoangiogenesis(Vriesetal.2015).
Due to the therapeutic effects reached in the groupofmice treatedwith tBNPs-MTX, it is
possibletoconcludethat,probably,thedecreaselevelsofIL-6,RANTESandKCcouldbalance
theincreasedlevelsofpro-inflammatorycytokinessuchasIL-1b,IL-2,IL-12p70,IL-17andMIP-
1a.
Concerningcytokines levelsof themice treatedwithMTX,cytokinesprofile is substantially
differentthantBNPs-MTX,infactfollowingcytokineshavebeenincreased:IL-3,IL-10,IL-13,
Eotaxin,GM-CST,INF- g,MCP-1,MIP-1bandmostimportantlyTNF-a.Theincreasedlevelsof
thesecytokinesdemonstrateonceagaintheineffectivenessofthetreatmentwiththisdoseof
MTX.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! ZP!
! !
^+5)&/,33_,D)9%+H9/V,*?%'O+$/,H&':+9/2,+$,K#8,0+*/",,F*+!*/$%.5&'-$!&+7&+$+3%!0'%'!&+5'&0/35!%*+!'3'89$/$!.4!Q=!-.,$+!(9%.I/3+$;!"88!*/$%.5&'-$!&+7.&%!0'%'!'$!%*+!-+'3!â!]C!.4!
A,'0&,78/('%+!7..8+0!$+&,-!$'-78+$;!)+$,8%$!*':+!#++3!3.&-'8/M+0!4.&!%*+!%.%'8!7&.%+/3!(.3(+3%&'%/.3!/3!µ5;!T'(*!(.8.&+0!#'&!&+7&+$+3%$!'!0/44+&+3%!5&.,7!.4!-/(+_!&+0!#'&$!$%'30!4.&!-/(+!&+(+/:/35!$'8/3+!13áU2w!#'&$!.4!-/(+!%&+'%+0!?/%*!DFG!P-5`!
f5!=G!?++I!*':+!#++3!(.8.&+0!?/%*!0'&I!5&+9!13áS2w!0'&I!#8,+!#'&$!$%'30!4.&!-/(+!%&+'%+0!?/%*!%KL@$ODFG!=-5`!f5!PG!?++I!
IL-1a
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.2
0.4
0.6
0.8pg/mL/µg
IL-1b
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
5
10
15
20
25
pg/mL/µg
*** **
IL-2
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
5
10
15
20
pg/mL/µg
****
IL-3
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.2
0.4
0.6
0.8
pg/mL/µg
**
IL-5
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.5
1.0
1.5
pg/mL/µg
IL-6
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.5
1.0
1.5
pg/mL/µg
******
IL-10
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
2
4
6
8
pg/mL/µg
**
IL-12p40
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
2
4
6
8
pg/mL/µg
IL-12p70
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
2
4
6
8
10
pg/mL/µg
****
IL-13
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
5
10
15
pg/mL/µg
**
IL-17
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
1
2
3
4
pg/mL/µg
*****
Eotaxin
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
200
400
600
pg/mL/µg
**
G-CSF
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
2
4
6
8
10
pg/mL/µg
******
GM-CSF
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
1
2
3
4
pg/mL/µg
***
INF-g
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.5
1.0
1.5
2.0
2.5
pg/mL/µg
***
KC
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
1
2
3
4
pg/mL/µg ****
***
MCP-1
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
5
10
15
20
pg/mL/µg
**
MIP-1a
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0.0
0.2
0.4
0.6
0.8
1.0
pg/mL/µg
*******
MIP-1b
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
100
200
300
pg/mL/µg
***
RANTES
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
2
4
6
8
pg/mL/µg
*******
TNF-a
CTRL
MTX 3mg/K
g 1Xwee
k
tBNPs M
TX 1mg/ K
g0
20
40
60
80
100
pg/mL/µg
**
! " # $
% & ' (
) * + ,
- . / 0
1 2 3 4
5
Resultsanddiscussion
84
(n=5).Statisticalsignificancehasbeenassessedbyunpairedparametrict-test.P≤0.05=*;P≤0.01=**;P≤0.001=***;P≤
0.0001=****.
4.4. MechanismofactionofMTXencapsulatedintotBNPs.
4.4.1. EfficacyandsideeffectsoftBNPs-MTXtherapyinAIArat
model.
ThestudiesofbiodistributionprovethesuperioraccumulationofthetBNPsintotheinflamed
kneesofbothmodelsofAIAandCIAcomparedwiththeBNPs.Moreover,thesuperiorefficacy
oftBNPs-MTXhasbeenprovedinCIAmodel,withasaferprofileofthistreatmentcompared
withthefreedrug.However,wewonderedifthesepromisingresultsweredueonlytothe
targetingstrategy, thusahigherconcentrationofMTX into thesynovial tissue,orwhether
there was a contribution of a different mechanism of action of the drug encapsulated in
targetednanoparticles.
InordertodissectthemechanismofactionoftBNPsloadedwithMTX,thetreatmentofthe
AIAmodelhasbeen taken in considerationbecause it is known in the literature tobenot
treatablewithfreeMTX(Williamsetal.1996)(Williams2001).Infact,inthisacutemodel,the
inflammatorydamageismainlycausedbytheproductionofimmunecomplexesinthejoint
microenvironment, by the activation of the complement system and the subsequent
recruitmentofimmunecells.Inthisacutesituation(3-4days),MTXhasnotthetimetoreduce
theproductionofantibodiesanditsadministrationbecomeobviousineffective.
Threegroupsofratshavebeenenrolled:5ratsreceivedsalinesolutionascontrol,4ratswere
treated with MTX 1 mg/ Kg/ day and 5 rats were treated with tBNPs-MTX 1mg/Kg. The
treatments started simultaneouslywith the inductionof the inflammation.The fourthday,
animals have been euthanized and synovial liquids, blood and synovial tissue have been
collected.Asthemaininflammatoryindex,theswellinghasbeenmeasuredthefirstandthe
lastdayinordertocalculatethe∆reportedinthegraphofthefigure23A.Fromthisgraph,it
isevidentthattBNPs-MTXpreventstheinflammationcomparedwithbothratstreatedwith
salinesolutionandMTX.Moreover,toconfirmswellingdata,numberofPMNsinthesynovial
liquidhasbeenevaluated.Thus,inthefigure23B,ratstreatedwithtBNP-MTXpresentastrong
decreasednumberofPMNcellscomparedwithcontrolorMTXtreatedanimals.
Resultsanddiscussion
85
Inordertodemonstratethattheeffectsaredependingonthetreatmentandnottoareduced
immunizationoftheanimals,anti-mBSAIgGlevelshavebeenquantifiedintheserumofthese
animals(Figure23C).Fromthisgraph,itisevidentthatallanimalsdevelopedacomparable
immuneresponse.
Fromthedataobtainedsofar,itisclearthattBNPs-MTXwereabletopreventinflammation
inratAIAwherethesamedoseoffreeMTXwasineffective,providingtheindicationthatthe
mechanismsofactionofthetwotherapeuticapproachesaredifferent.
SideeffectsofthesetreatmentsshouldbecomparedwithdataobtainedinCIAmodel.Forthis
purpose,bloodsamplesoftheAIAratshavebeencollectedattheendofthetreatments(3
daystreatment)andanalysed.RBC,WBCandPLThavebeenquantified(Figure23D,EandF).
Inaddition,duetothefactthatMTXisassociatedtothebonemarrowsuppression(Limetal.
2005),withconsequentreductionofWBC,subpopulationsoflymphocytes,granulocytesand
monocyteshavebeenquantified(Figure23G,HandI).Asexpected,asignificantreductionof
whitebloodcellshasbeen reported in thegroupof rats treatedwith freeMTX,while rats
treatedwiththesamedoseoftBNPs-MTXshowedsimilarWBCthancontrolrats.Thisresult
highlights the fact that in our approach,MTX remainsmainly encapsulated into tBNPs, it
performsitsactivitydirectlyintheinflamedsynovia,decreasingsideeffectsassociatedwitha
non-specificdelivery.AlthoughthetotalnumberofWBCsremainedunchangedinratstreated
with tBNPs-MTX, a slightly reduced number of granulocytes have been found. Instead, a
reductionofmonocyteshasbeenobservedinbothMTXandtBNPs-MTXtreatedgroups,even
thoughnostatisticalsignificancehasbeenfound.
)+$,8%$!'30!0/$(,$$/.3!
!
! ! ZV!
!
^+5)&/,37_,P::+*1*?,1$(,J9''(,1$19?2+2,+$,8#8,&1%,%&/1%/(,R+%.,%W4@2",,1"2!)+$,8%$!.4!%*+!ã!$?+88/35!/3!--!.4!%*+!&/5*%!I3++$!.#%'/3+0!'4%+&!%*&++!0'9$!.4!%&+'%-+3%;!]?+88/35!.4!&'%$!%&+'%+0!?/%*!
$'8/3+!$.8,%/.3!/$!&+7.&%+0!/3!&+0B!/3!5&+9!$?+88/35!.4!&'%$!&+(+/:/35!=-5!`f5!`!0'9!.4!4&++!DFG!'30!/3!#8,+!%*+!$?+88/35!.4!&'%$!
%&+'%+0!?/%*!=-5!`f5!`!0'9!.4!%KL@ODFG;!1K2!F*+!5&'7*!$*.?$!%*+!3,-#+&!.4!@DL!`-W!/3!%*+!$93.:/'8!8/A,/0!.4!&'%$!%&+'%+0!
?/%*!$'8/3+!$.8,%/.3!1&+02B!&'%$!&+(+/:/35!=-5!`f5!`!0'9!.4!4&++!DFG!15&+92!'30!%&+'%+0!?/%*!=-5!`f5!`!0'9!%KL@ODFG!1#8,+2;!<3!
#.%*!5&'7*B!"!'30!K!0'%'!'&+!&+7.&%+0!'$!%*+!-+'3!â!]C;!U!&'%$!*':+!#++3!+3&.88+0!4.&!%*+!5&.,7$!%&+'%+0!&+$7+(%/:+89!?/%*!
$'8/3+!$.8,%/.3!'30!%KL@$ODFGB!?*/8+!S!&'%$!*':+!#++3!+3&.88+0!4.&!%*+!5&.,7!%&+'%+0!?/%*!4&++!DFG;!"!7'&'-+%&/(!,37'/&+0!
%O%+$%!*'$!#++3!,$+0!%.!'$$+$$!'!$%'%/$%/('8!$/53/4/('3(+;!1[2!C'%'!.#%'/3+0!#9!TW<]"!%+$%!4.&!%*+!+:'8,'%/.3!.4!<5R!'3%/O-K]"!/3!
&'%$N!$+&,-!.4!%*+!5&.,7$!'8&+'09!'3'89$+0!4.&!$?+88/35!'30!@DL;!F*+!#'&$!(.8.,&!4.88.?$!%*+!(.8.,&$!.4!7&+:/.,$!5&'7*$;!C'%'!
'&+!$*.?3!'$!%*+!-+'3!â!]C!.4!'!%+(*3/('8!%&/78/('%+!.4!7..8+0!$+&,-!4.&!+'(*!5&.,7!.4!&'%$;!F*+!5&'7*$!$,--'&/$+!&+$,8%$!.4!
%*+!#8..0!'3'89$/$!/3!&'%$!%&+'%+0!?/%*_!$'8/3+!$.8,%/.3!1&+0!#'&$2B!DFG!=-5`!f5`!0'9!15&+9!#'&$2!'30!%KL@$ODFG!=-5`!f5`!0'9!
1#8,+!#'&$2;!C'%'!*':+!#++3!&+7.&%+0!'$!%*+!-+'3!â!]C;!F*+!3,-#+&!.4!$'-78+$!4.&!+'(*!5&.,7!/$!'$!4.88.?_!$'8/3+!$.8,%/.3!
13áU2B!DFG!=-5`!f5`!0'9!13áS2w!%KL@$ODFG!=-5`!f5`!0'9!13áU2;!]%'%/$%/('8!$/53/4/('3(+!*'$!#++3!('8(,8'%+0!?/%*!'!7'&'-+%&/(!
,37'/&+0!%O%+$%;!@!Ü!^;^U!á!àw!@!Ü!^;^=!á!àà;!
)+$,8%$!'30!0/$(,$$/.3!
!
! ! ZY!
="="7"! %RG@2KPMX,&/()*/,$/'1$5+'5/$/2+2,'<,%./,+$<410/(,26$';+1,
C+$7/%+! %*+$+! 7.$/%/:+! &+$,8%$B! ?+! ?.30+&+0! '#.,%! %*+! -+(*'3/$-! .4! '(%/.3! .4! DFG!
+3('7$,8'%+0!/3!%KL@$;!C,+!%.!%*+!4'(%!%*'%!"<"!-.0+8!/$!7&/-'&/89!#'$+0!.3!%*+!4.&-'%/.3!.4!
/--,3+!(.-78+E+$! /3! %*+!'&%/(,8'&!(':/%9!?/%*!'!(.3$+A,+3%!'(%/:'%/.3!.4! %*+!(.-78+-+3%!
$9$%+-B!?+!'3'89$+0!?*+%*+&!%*+!'3%/O/348'--'%.&9!+44+(%!(.,80!&+0,(+!%*+!'(%/:'%/.3!.4!%*+!
(.-78+-+3%!$9$%+-;!F.!%*/$!'/-B! /348'-+0!$93.:/'8!%/$$,+$!.4!%*+!&'%$!+3&.88+0! /3!%*+!$%,09!
*':+!#++3!$%'/3+0!4.&!0+7.$/%$!.4
Resultsanddiscussion
88
SynovialtissueshavebeenstainedforthevWFinordertoverifythishypothesis,analysingthe
numberoftheformedvessel(Figure25A).Inthisfigure,fourrepresentativesynovialtissues
havebeenanalysed:ratstreatedwithsalinesolution,thesynovialtissueofahealthysynovia
(as a negative control), rats treatedwithboth tBNPs-MTXand freeMTX. It is evident that
synovialtissueoftBNPs-MTXtreatedratsshowsareducedvWFstaining,soareducednumber
ofbloodvessels,comparedwithsynovialtissuesofcontrolratsorratstreatedwithfreeMTX.
Fluorescence intensity of vWF of the rats enrolled in the study have been quantified and
summarized in the graph of the figure 25 B. The graph confirms a reduced vWF staining
compared with control rats and rats treated with free MTX. This result strengthens our
hypothesisbywhichMTXencapsulatedintotBNPsinterfereswiththeformationofnewvessels
ininflamedsynovium.ItispossibletospeculatethattheselectivedeliveryofMTXtoCD34+
cellsinsynovialtissue,whichisexpressedonprecursorsofendothelialcells,causesthedeath
ofthesecells,reducingthepossibilitytodevelopnewvesselsintheinflamedsynovialtissue.
Thisprocess ismandatoryfortheleukocytesrecruitment insynovialtissueandconsequent
progressionofinflammation.Thereducednumberofvesselsobservedintheinflamedsynovial
tissuesofratstreatedwithtBNPsmayjustifythedecreasednumberofinflammatorycellssuch
asPMNand,attheend,thereductionofthekneeswellingobservedintheseanimals(Figure
23BandA).
)+$,8%$!'30!0/$(,$$/.3!
!
! ! ZX!
!
^+5)&/,3>_,AI^,2%1+$+$5,+$,8#8,&1%2a,2?$'A+19,%+22)/2",,1"2!J.,&!&+7&+$+3%'%/:+!/-'5+$!.#%'/3+0!%*&.,5*!%*+!.:+&8'9!.4!%*+!?cJ!$%'/3/35!1&+02B!%/$$,+!',%.48,.&+$(+3(+!15&++32!'30!
3,(8+/!$%'/3/35!1C"@<2;!T'(*!/-'5+!/$!'!8'&5+!4/+80!.#%'/3+0!%*&.,5*!%*+!$%/%(*/35!.4!X!/-'5+$;!<3!'00/%/.3!%.!%*+!,$,'8!%*&++!
5&.,7$!.4!&'%$B!'$!'!3+5'%/:+!(.3%&.8B!'!*+'8%*9!$93.:/'8!%/$$,+!*'$!#++3!,$+0;!]('8+!#'&!Q^^É-;!1K2!D+'3!48,.&+$(+3(+!/3%+3$/%9!
.4!%*+!:cJ!3.&-'8/M+0!4.&!%*+!%/$$,+!'&+'!*'$!#++3!0+%+&-/3+0!#9!<-'5+b!$.4%?'&+!4.&!+'(*!+E7+&/-+3%'8!5&.,7;!J.&!+'(*!
$93.:/'8!%/$$,+!Q`P!&+5/.3$!.4!/3%+&+$%!1)\<$2!.4!%*+!8'&5+!4/+80!/-'5+$!*':+!#++3!'3'89$+0;!L,-#+&!.4!)\<$!'3'89$+0!4.&!+'(*!
5&.,7_! /348'-+0á=Zw!=-5`!f5`!0'9!.4!%KL@$ODFGá=Vw!=-5`!f5`!0'9!DFGá!=Sw!3+5'%/:+![F)WáZ;!]%'%/$%/('8!$/53/4/('3(+!*'$!
#++3!'$$+$$+0!%*&.,5*!'!7'&'-+%&/(!%O%+$%;!@!Ü!^;^U!á!àw!@!Ü!^;^=!á!àà;!
90
5. Conclusion
Conclusion
91
Rheumatoidarthritis isachronicautoimmunediseaseaffecting jointsduetothepersistent
inflammationof the synovialmembrane,which leads to a condition of disability andpain.
Despite the introduction of biological drugs,which improve patients’ quality life, they are
usuallytreatedlifelongandtrueremissionisrare.Moreover,biologicaldrugsshowseveralside
effectsforlongtermtreatmentsandsomepatientsdonotrespondtothiskindoftreatments.
ForthesereasonsMTX,belongingtothesyntheticDMARDsclass,isstillthecornerstoneofRA
treatmentbecauseofitssafeprofile,effectivenessandlowcost.However,someissuesarise
withMTXtreatmentduetothefactthat50%ofpatients,after5yearshavetodiscontinuethe
treatment because of inefficacy or side effects such as liver toxicity and bone marrow
suppression. According to the ACR criteria, early diagnosis is essential for a successful
managementinordertotreatpatientsassoonaspossibleavoidinglatephase(disability)of
thedisease.
Theattentionofourgroupwasrecentlyfocusedonthedevelopmentofananotechnological
approachtotreatanddiagnoseRAwithahigherefficacyandspecificity.Thisstrategyisbased
ontheuseofpolymericbiodegradablenanoparticlesabletotargetinaspecificmannerthe
inflamed synovial tissue due to targeting molecules conjugated on the surface of these
nanoparticles.Exploitingthisstrategy,theirpayloadcanbeaccumulatedintothedesiredplace
avoidingtoxiceffectsrelatedtosystemicadministration.
Inthisresearchproject,twodifferentcouplesofnanoparticleshavebeenproduced:acouple
ofemptynanoparticles,with(tBNPs)andwithout(BNPs)thetargetingmolecule,andacouple
of MTX loaded nanoparticles, with (tBNPs-MTX) and without (BNPs-MTX) the targeting
molecule.
AlldifferentnanoparticleshavebeencharacterizedbyDLS,TEM,STEMandNanoTrackinorder
toassesstheirsizedistribution,diameter,PDI,chargeandnanoparticlesconcentration.They
showedanaveragediameterofabout150nmwithaPDIof0.3andaslightnegativechargeof
-6mV.Thesecharacteristicsweredesignedforanidealdistributioninvivo, inparticularthe
sizeislargeenoughtoensurehighdosesoftheloadedcompoundand,atthesametime,allow
agooddistributionwithinthebody.Moreover,thelownegativechargeavoidstheinteraction
withseveralpositivebasalmembranes(likeinkidneysandlungs)andingeneralwithcells.
The biocompatibility of the shell’s nanoparticles has been tested showing that empty
nanoparticles,withandwithoutthetargetingmolecule,didnotshowtoxicityforcells.MTX
Conclusion
92
releasehasbeenmeasureddemonstratingthat50%ofthedrugwasstillencapsulatedinto
nanoparticlesafter24h.
The importance of a targeting agent on nanoparticles’ surface is still debated. Our data,
obtainedbothinvitroandinvivoclearlyevidencedtheincreasedabilityoftBNPstoselectively
accumulateintoinflamedsynovialtissue.Inparticular,tBNPsshowedahigheraccumulation
intheinflamedjointscomparedtoBNPsintwodifferentanimalmodels.
Despitethedifferencesseenintheanimalmodels,itisevidentthattBNPsarepromisingasa
diagnosticdeliverysystemabletopotentiallyincreasetheaccumulationofadiagnosticprobe
and,asaconsequence,thesensitivityofseveralimagingtechniques.Targetednanobubbles
through the synovial peptidewill represent a potential probe for functional imaging using
ultrasound,aswellas targetednanoparticles loadedwithcontrastagentsmaybeuseful in
NMRox-ray-basedapproaches.
The capacity of tBNP to accumulate in joints during the early phase of the inflammatory
process,whennophenotypicevidenceofthepathologyisdetectable,encourageourstudyto
developadiagnosticprobeforearlydiagnosis.Moreover,thecapacitytodiscriminatedifferent
degreeofinflammationwillprovidethebasistousethesameprobetofollowtheeffectiveness
ofthetherapyinuse.
ThecoreoftheprojectwastodemonstratethattBNPs,whichcombinetheactivetargeting
with the nanoparticles features, could provide a new therapeutic approach through the
selectiveaccumulationofMTXintheinflamedsynovialmicroenvironment.Toreachthisaim,
tBNP-MTXefficacyhasbeenfirststudiedinCIAmousemodelandtheninandAIAratmodel.
ResultsdemonstratedthattBNPs-MTXshowedsimilaroutcomethanfreeMTX,usingthesame
totalweeklydosebutalsoreducingthedoseofencapsulatedMTXto1/3,administeringitonce
perweek.Moreover, the therapeuticeffectswerealsoassociatedwitha safe toxicological
profile.
Partofthisworkhasbeendedicatedtoidentifyingthecounterpartofthetargetingmolecule.
Indeed, from the literature, it is known that the synovial homing peptide binds the
microvasculature of the inflamed synovial tissue, although the boundmolecule is not yet
recognized.Co-stainingimmunofluorescenceperformedwiththetargetmoleculeandmarkers
of endothelial tissues evidenced that the targetmolecule localizes onto CD34+ cells. Cells
expressingCD34insynovialtissuearemainlyprogenitorsofendothelialcellsandthisevidence
wasfundamentaltofirsthypothesizeandthendemonstrateadifferentmechanismofaction
Conclusion
93
of MTX once encapsulated into tBNPs. Due to the fact that nanoparticles impacted on
endothelialcells,wespeculatethatMTX(initially isolatedasacytotoxicdrug)could induce
CD34+celldeathand,asaconsequence,hasananti-neoagiogeneticeffect.Onthecontrary,
freeMTXusuallyplaysitsanti-inflammatoryeffectreducingthenumberofBandTcellsand
increasingadenineandadenosineintotheextracellularspace.Theformationofnewvesselsis
essentialforleukocytesmigrationandsynovialtissueinfiltration;thereductionofleukocytes
in synovialmicroenvironment brings to a reduction of the inflammatory process. Thiswas
particularly evident in an AIA rat model, where free MTX was ineffective. However, the
formationofnewvesselsinsynovialtissuewasreducedusingtBNP-MTX,preventingtheonset
ofthepathology.
Thiswork introduces an innovative approach todiagnoseand treatRA, basedon targeted
polymericnanoparticlesabletodelivertheirpayloadstothemicrovasculatureoftheinflamed
synovial tissue.Thisnanotechnologicalsystemduetotheactivetargetingshowsenormous
potentialincreasingsensitivityasadiagnostictoolandsimultaneouslyenhancingtherapeutic
effectsandreducingdosesandrelatedsideeffects.Thefocusofthisstudywastoimprovethe
managementofpatientsaffectedbyRA.However,severalotherarticularpathologies,where
neo-angiogenesisplaysapivotalroleintheinflammatoryprocess,canexploitthepotentialof
tBNPs.OsteoarthritisisprobablythefirstpathologywheretBNPscanfindapplication,indeed
itstreatmentremainsanunmetclinicalneed.Moreover,theabilityofthetargetingpeptideto
cross-react withmouse, rat and human inflamed synovial tissue suggest the possibility to
extendtheuseoftBNPstodogsandhorses,inwhicharticulardisordersarecommon,inorder
toprovideanewtherapeuticapproachandtocollectseveralpreclinicaldatabeforethefirst
useinhuman.
94
6. References
References
95
Abuchowski,aetal.,1977.Alterationofimmunologicalpropertiesofbovineserumalbumin
by covalent attachment of polyethylene glycol. The Journal of biological chemistry,
252(11),pp.3578–3581.
Aceves-Avila,F.J.etal.,1998.Paleopathology inOsseousremainsfromthe16thcentury.A
surveyofrheumaticdiseases.JournalofRheumatology,25(4),pp.776–782.
Aggarwal, R. et al., 2009. Anti-citrullinated peptide antibody assays and their role in the
diagnosisofrheumatoidarthritis.ArthritisCareandResearch,61(11),pp.1472–1483.
Ahn,J.K.etal.,2008.Roleofhypoxia-induciblefactor-1αinhypoxia-inducedexpressionsofIL-
8,MMP-1andMMP-3inrheumatoidfibroblast-likesynoviocytes.Rheumatology,47(6),
pp.834–839.
Ai,R.etal.,2016.Joint-specificDNAmethylationandtranscriptomesignaturesinrheumatoid
arthritisidentifydistinctpathogenicprocesses.Naturecommunications,7,p.11849.
Aletaha,D.etal.,2010.2010Rheumatoidarthritisclassificationcriteria:anAmericanCollege
ofRheumatology/EuropeanLeagueAgainstRheumatismcollaborativeinitiative.Arthritis
Rheum,62(9),pp.2569–2581..
Allen, J.B. et al., 1990. Rapid onset synovial inflammation and hyperplasia induced by
transforminggrowthfactorbeta.TheJournalofexperimentalmedicine,171(1),pp.231–
47.
Aragao-Santiago, L. et al., 2016. Compared in vivo toxicity in mice of lung delivered
biodegradableandnon-biodegradablenanoparticles.Nanotoxicology,10(3),pp.292–302.
Asahara,T.,1997.IsolationofPutativeProgenitorEndothelialCellsforAngiogenesis.Science,
275(5302),pp.964–966.
Asquith, D.L. et al., 2009. Animal models of rheumatoid arthritis. European Journal of
Immunology,39(8),pp.2040–2044.
Banda, N.K. et al., 2006. Alternative complement pathway activation is essential for
inflammation and joint destruction in the passive transfermodel of collagen-induced
arthritis.Journalofimmunology(Baltimore,Md. :1950),177(3),pp.1904–1912.
Banda,N.K.et al., 2014.Essential role for the lectinpathway in collagenantibody-induced
arthritisrevealedthroughuseofadenovirusprogrammingcomplementinhibitorMAp44
expression.Journalofimmunology(Baltimore,Md. :1950),193(5),pp.2455–68.
Banda,N.K.et al., 2007.PathogenicComplementActivation inCollagenAntibody- Induced
Arthritis in Mice Requires Amplification by the Alternative Pathway. The Journal of
References
96
Immunology,179(6),pp.4101–4109.
Banik, B.L., Fattahi, P. & Brown, J.L., 2016. Polymeric nanoparticles: The future of
nanomedicine.Wiley InterdisciplinaryReviews:NanomedicineandNanobiotechnology,
8(2),pp.271–299.
Barenholz,Y.,2012.Doxil® -ThefirstFDA-approvednano-drug:Lessons learned. Journalof
ControlledRelease,160(2),pp.117–134.
Bartok,B.&Firestein,G.S.,2011.Fibroblast-likesynovioctyes:keyeffectorcellsinrheumatoid
arthritis.ImmunolRev.,233(1),pp.233–255.
Beighton, P., Solomon, L. & Valkenburg, H. a, 1975. Rheumatoid arthritis in a rural South
AfricanNegropopulation.Annalsoftherheumaticdiseases,34(2),pp.136–41.
Benucci,M.etal.,2016.CostsassociatedwithrheumatoidarthritisinItaly:past,present,and
future.ClinicoEconomicsandoutcomesresearch :CEOR,8,pp.33–41.
Bergers,G.,2005.Theroleofpericytes inblood-vessel formationandmaintenance.Neuro-
Oncology,7(4),pp.452–464.
Bianco, A., Kostarelos, K.& Prato,M., 2011.Making carbon nanotubes biocompatible and
biodegradable.ChemicalCommunications,47(37),p.10182.
Blanco, E., Shen, H. & Ferrari, M., 2015. Principles of nanoparticle design for overcoming
biologicalbarrierstodrugdelivery.NatureBiotechnology,33(9),pp.941–951.
Blüml, S. et al., 2011. Essential role ofmicroRNA-155 in the pathogenesis of autoimmune
arthritisinmice.ArthritisandRheumatism,63(5),pp.1281–1288.
Boisseau, P. et al., 2005. Vision Paper and a Basis for a Strategic Research Agenda for
NanoMedicine.
Bosch,X.,2011.Dendrimerstotreatrheumatoidarthritis.ACSNano,5(9),pp.6779–6785.
Botsios, C., 2005. Safety of tumour necrosis factor and interleukin-1 blocking agents in
rheumaticdiseases.AutoimmunRev,4(3),pp.162–170.
Bouta,E.M.etal.,2015.Theroleofthelymphaticsystemininflammatory-erosivearthritis.
SeminarsinCellandDevelopmentalBiology,38,pp.90–97.
Brand,D.D.,Latham,K.A.&Rosloniec,E.F.,2007.Collagen-inducedarthritis.NatureProtocols,
2(5),pp.1269–1275.
Brodeur, J.P. et al., 1991. Synovial fluid levelsof complementSC5b-9and fragmentBbare
elevatedinpatientswithrheumatoidarthritis.Arthritis&Rheumatism,34(12),pp.1531–
1537.
References
97
Bugatti, S. et al., 2012. Assessment of synovitis to predict bone erosions in rheumatoid
arthritis.TherapeuticAdvancesinMusculoskeletalDisease,4(4),pp.235–244.
Butler, D.M. et al., 1995. Modulation of proinflammatory cytokine release in rheumatoid
synovialmembranecellcultures.ComparisonofmonoclonalantiTNF-alphaantibodywith
theinterleukin-1receptorantagonist.EurCytokineNetw,6(4),pp.225–230.
Campbell,J.,Lowe,D.&Sleeman,M.A.,2011.Developingthenextgenerationofmonoclonal
antibodies for the treatmentof rheumatoid arthritis.British Journal of Pharmacology,
162(7),pp.1470–1484.
Carver,L.A.&Schnitzer,J.E.,2003.Caveolae:mininglittlecavesfornewcancertargets.Nature
ReviewsCancer,3(8),pp.571–581.
Cascão,R.etal.,2010.Neutrophilsinrheumatoidarthritis:Morethansimplefinaleffectors.
AutoimmunityReviews,9(8),pp.531–535.
Champion,J.A.&Mitragotri,S.,2006.Roleoftargetgeometryinphagocytosis.Proceedingsof
theNationalAcademyofSciencesoftheUnitedStatesofAmerica,103(13),pp.4930–4.
Chemin,K.etal.,2016.ANovelHLA-DRB1�10:01-RestrictedTCellEpitopefromCitrullinated
Type II Collagen Relevant to Rheumatoid Arthritis.Arthritis and Rheumatology, 68(5),
pp.1124–1135.
Chen,Y.F.etal.,2006.Asystematicreviewoftheeffectivenessofadalimumab,etanerceptand
infliximabforthetreatmentofrheumatoidarthritisinadultsandaneconomicevaluation
oftheircost-effectiveness.HealthTechnolAssess,10(42),p.iii–iv,xi–xiii,1-229.
Cho,M.-L.etal.,2002.Cyclosporineinhibitionofvascularendothelialgrowthfactorproduction
inrheumatoidsynovialfibroblasts.Arthritisandrheumatism,46(5),pp.1202–9.
Consortium, T.W.T.C.C., 2007. Genome-wide association study of 14 000 cases of seven
commondiseasesand3000sharedcontrols.Nature,447(7145),pp.661–678.
Cornish,A.L.etal.,2009.G-CSFandGM-CSFas therapeutic targets inrheumatoidarthritis.
NatureReviewsRheumatology,5(10),pp.554–559.
Danhier,F.,Ansorena,E.,etal.,2012.PLGA-basednanoparticles:Anoverviewofbiomedical
applications.JournalofControlledRelease,161(2),pp.505–522.
Danhier,F.,Pourcelle,V.,etal.,2012.TargetingoftumorendotheliumbyRGD-graftedPLGA-
nanoparticles.MethodsinEnzymology,508,pp.157–175.
Danhier,F.,Breton,A.Le&Préat,V.,2012.RGD-basedstrategiestotargetalpha(v)beta(3)
integrinincancertherapyanddiagnosis.MolecularPharmaceutics,9(11),pp.2961–2973.
References
98
Dans,L.F.etal.,1997.TheprevalenceofrheumaticdiseasesinaFilipinourbanpopulation:A
WHO-ILARCOPCORDstudy.JournalofRheumatology,24(9),pp.1814–1819.
Doherty, G.J. & McMahon, H.T., 2009. Mechanisms of Endocytosis. Annual Review of
Biochemistry,78(1),pp.857–902.
Dowling,aetal.,2004.Nanoscienceandnanotechnologies :opportunitiesanduncertainties.
LondonTheRoyalSocietyTheRoyalAcademyofEngineeringReport,46(July),pp.618–
618.
Drexler, K.E., 1986. Engines of Creation, The Coming Era of Nanotechnology.Garden City,
2017(1965),p.91109.
Duque,G.A.&Descoteaux,A., 2014.Macrophage cytokines: Involvement in immunity and
infectiousdiseases.FrontiersinImmunology,5(OCT).
Durigutto, P. et al., 2017. Targeted delivery of neutralizing anti-C5 antibody to renal
endotheliumpreventscomplement-dependenttissuedamage.Front.Immunol,8.
Eatemadi,A.etal.,2014.Carbonnanotubes:properties,synthesis,purification,andmedical
applications.NanoscaleResearchLetters,9(1),p.393.
Fang,C.etal.,2009.Functionalizednanoparticleswithlong-termstabilityinbiologicalmedia.
Small,5(14),pp.1637–1641.
Farokhzad,O.C.&Langer,R.,2009. Impactofnanotechnologyondrugdelivery.ACSNano,
3(1),pp.16–20.
Favalli, E.G. et al., 2012. The role of biologic agents in damage progression in rheumatoid
arthritis:indirectcomparisonofdatacomingfromrandomizedclinicaltrials.Therapeutic
AdvancesinMusculoskeletalDisease,4(4),pp.213–223.
Ferrari, M., Onuoha, S.C. & Pitzalis, C., 2015. Trojan horses and guidedmissiles: targeted
therapiesinthewaronarthritis.NatureReviewsRheumatology,11(6),pp.328–337.
Firestein,G.S.,2013.EtiologyandPathogenesisofRheumatoidArthritis.Kelley’sTextbookof
Rheumatology,NinthEdition,p.1059–1108.e5.
Firestein,G.S.,2003.Evolvingconceptsofrheumatoidarthritis.Nature,423(6937),pp.356–
361.
Firestein,G.S.etal.,1997.Somaticmutationsinthep53tumorsuppressorgeneinrheumatoid
arthritissynovium.ProceedingsoftheNationalAcademyofSciencesoftheUnitedStates
ofAmerica,94(20),pp.10895–900.
Fleischmann, R. et al., 2012. Placebo-Controlled Trial of Tofacitinib Monotherapy in
References
99
RheumatoidArthritis.NewEnglandJournalofMedicine,367(6),pp.495–507.
Gabizon, a, Shmeeda, H. & Barenholz, Y., 2003. Pharmacokinetics of pegylated liposomal
Doxorubicin: reviewofanimalandhumanstudies.Clin.Pharmacokinet.,42(5),pp.419–
436.
Gabriel, S.E., 2008. Cardiovascular morbidity and mortality in rheumatoid arthritis. The
Americanjournalofmedicine,121(10Suppl1),pp.S9-14.
Gerstner, C. et al., 2016. Functional and Structural Characterization of a Novel HLA-
DRB1*04:01-Restricted α-Enolase T Cell Epitope in Rheumatoid Arthritis. Frontiers in
Immunology,7,p.494.
Glantschnig,H.etal.,2003.M-CSF,TNFalphaandRANKligandpromoteosteoclastsurvivalby
signalingthroughmTOR/S6kinase.Celldeathanddifferentiation,10(10),pp.1165–1177.
Gragnano,F.etal.,2017.TheRoleofvonWillebrandFactorinVascularInflammation:From
PathogenesistoTargetedTherapy.MediatorsofInflammation,2017.
Gregersen,P.K.,Silver,J.&Winchester,R.J.,1987.Thesharedepitopehypothesis.Anapproach
tounderstandingthemoleculargeneticsofsusceptibilitytorheumatoidarthritis.Arthritis
Rheum,30(11),pp.1205–1213.
Griffiths, R.J., 1992. Characterisation and pharmacological sensitivity of antigen arthritis
inducedbymethylatedbovineserumalbuminintherat.AgentsActions,35(1–2),pp.88–
95.
Hajishengallis, G., 2014. Periodontitis: from microbial immune subversion to systemic
inflammation.NatureReviewsImmunology,15(1),pp.30–44.
Hamilton, A. et al., 2002. EORTC 10968: A phase I clinical and pharamacokinetic study of
polyethylene glycol liposomal doxorubicin (Caelyx®, Doxil®) at a 6-week interval in
patientswithmetastaticbreastcancer.AnnalsofOncology,13(6),pp.910–918.
Harush-Frenkel,O.etal.,2007.Targetingofnanoparticlestotheclathrin-mediatedendocytic
pathway.BiochemicalandBiophysicalResearchCommunications,353(1),pp.26–32.
Harvey, J.etal.,1981.Rheumatoidarthritis inaChippewaBand. I.Pilotscreeningstudyof
diseaseprevalence.Arthritisandrheumatism,24(5),pp.717–721.
Hashizume,H.etal.,2000.Openingsbetweendefectiveendothelialcellsexplaintumorvessel
leakiness.AmericanJournalofPathology,156(4),pp.1363–1380.
Helmick, C.G. et al., 2008. Estimates of the prevalence of arthritis and other rheumatic
conditionsintheUnitedStates.PartI.ArthritisandRheumatism,58(1),pp.15–25.
References
100
Hu, C.-M.J. et al., 2011. Erythrocytemembrane-camouflaged polymeric nanoparticles as a
biomimeticdeliveryplatform.ProceedingsoftheNationalAcademyofSciences,108(27),
pp.10980–10985.
Hu, C.M.J.& Zhang, L., 2012.Nanoparticle-based combination therapy towardovercoming
drugresistanceincancer.BiochemicalPharmacology,83(8),pp.1104–1111.
Hu, Y. et al., 2013. Advances in research on animal models of rheumatoid arthritis. Clin
Rheumatol,32(2),pp.161–165.
Huang,L.&Guo,S.,2011.NanoparticlesescapingRESandendosome:ChallengesforsiRNA
deliveryforcancertherapy.JournalofNanomaterials,2011.
Huang,X.&Brazel,C.S.,2001.Ontheimportanceandmechanismsofburstreleaseinmatrix-
controlleddrugdeliverysystems.JournalofControlledRelease,73(2–3),pp.121–136.
Innala, L. et al., 2014. Age at onset determines severity and choice of treatment in early
rheumatoidarthritis:aprospectivestudy.Arthritisresearch&therapy,16(2),p.R94.
Isaacs,J.D.,2010.Thechangingfaceofrheumatoidarthritis:sustainedremissionforall?Nat
RevImmunol,10(8),pp.605–611.
Ivashkiv, L.B.&Hu,X.,2003.The JAK/STATpathway in rheumatoidarthritis:Pathogenicor
protective?ArthritisandRheumatism,48(8),pp.2092–2096.
James, E.A. et al., 2010. HLA-DR1001 presents “altered-self” peptides derived from joint-
associatedproteinsbyacceptingcitrulline inthreeof itsbindingpockets.Arthritisand
Rheumatism,62(10),pp.2909–2918.
Jimenez-Boj, E. et al., 2005. Interaction between Synovial Inflammatory Tissue and Bone
MarrowinRheumatoidArthritis.TheJournalofImmunology,175(4),pp.2579–2588.
Jing,F.&Choi,E.Y.,2016.PotentialofCellsandCytokines/ChemokinestoRegulateTertiary
LymphoidStructuresinHumanDiseases.ImmuneNetwork,16(5),p.271.
Johnston-Cox,H.A.,Koupenova,M.&Ravid,K.,2012.A2adenosinereceptorsandvascular
pathologies.Arteriosclerosis,Thrombosis,andVascularBiology,32(4),pp.870–878.
Jokerst,J.Vetal.,2011.NanoparticlePEGylationforimagingandtherapy.Nanomedicine,6(4),
pp.715–728.
Jung,E.-G.etal.,2015.BrazilinisolatedfromCaesalpiniasappanL.inhibitsrheumatoidarthritis
activity in a type-II collagen inducedarthritismousemodel.BMCComplementaryand
AlternativeMedicine,15(1),p.124.
Kelley,L.A.etal.,2015.ThePhyre2webportalforproteinmodeling,predictionandanalysis.
References
101
NatureProtocols,10(6),pp.845–858.
Khachigian,L.M.,2006.Collagenantibody-inducedarthritis.NatureProtocols,1(5),pp.2512–
2516.
Kim,B.Y.S.,Rutka,J.T.&Chan,W.C.W.,2010.Nanomedicine.NewEnglandJournalofMedicine,
363(25),pp.2434–2443.
Kim,S.J.,Park,Y.&Hong,H.J.,2005.Antibodyengineeringforthedevelopmentoftherapeutic
antibodies.MolCells,20(1),pp.17–29.
Klareskog,L.etal.,1983.RoleofTlymphocytesincollagenIIinducedarthritisinrats.ClinExp
Immunol,51(1),pp.117–125.
Klasen,I.S.etal.,1986.Jointinflammationsandflare-upreactionsinmiceinducedbyahelper
Tcellclone.AgentsActions,19(5–6),pp.331–334.
Kohler, G. & Milstein, C., 1975. Continuous cultures of fused cells secreting antibody of
predefinedspecificity.Nature,256(5517),pp.495–497.
Konisti, S., Kiriakidis, S. & Paleolog, E.M., 2013. Angiogenesis in rheumatoid arthritis. In
Angiogenesis and Vascularisation: Cellular and Molecular Mechanisms in Health and
Diseases.pp.339–365.
Krause,D.S.etal.,1996.CD34:structure,biology,andclinicalutility.Blood,87(1),pp.1–13.
Kuhn, K.A. et al., 2006. Antibodies against citrullinated proteins enhance tissue injury in
experimentalautoimmunearthritis.JournalofClinicalInvestigation,116(4),pp.961–973.
Kumari,A.,Yadav,S.K.&Yadav,S.C.,2010.Biodegradablepolymericnanoparticlesbaseddrug
deliverysystems.ColloidsandSurfacesB:Biointerfaces,75(1),pp.1–18.
Lainer-Carr, D. & Brahn, E., 2007. Angiogenesis inhibition as a therapeutic approach for
inflammatorysynovitis.Natureclinicalpractice.Rheumatology,3(8),pp.434–42.
Lange, F., 2005. Methotrexate ameliorates T cell dependent autoimmune arthritis and
encephalomyelitisbutnotantibodyinducedorfibroblastinducedarthritis.Annalsofthe
RheumaticDiseases,64(4),pp.599–605.
Lee,E.B.etal.,2014.TofacitinibversusMethotrexateinRheumatoidArthritis.NewEngland
JournalofMedicine,370(25),pp.2377–2386.
Lee,L.etal.,2002.Identificationofsynovium-specifichomingpeptidesbyinvivophagedisplay
selection.ArthritisRheum,46(8),pp.2109–2120.
Lee,S.M.etal.,2013.Targetedchemo-photothermaltreatmentsofrheumatoidarthritisusing
goldhalf-shellmultifunctionalnanoparticles.ACSNano,7(1),pp.50–57.
References
102
Lim,A.Y.N.,Gaffney,K.&Scott,D.G.I.,2005.Methotrexate-inducedpancytopenia:Seriousand
under-reported?Ourexperienceof25casesin5years.Rheumatology,44(8),pp.1051–
1055.
Lin, J.etal.,2012.Cyr61 Induces IL-6ProductionbyFibroblast-likeSynoviocytesPromoting
Th17 Differentiation in Rheumatoid Arthritis. The Journal of Immunology, 188(11),
pp.5776–5784.
Linton, S.M. &Morgan, B.P., 1999. Complement activation and inhibition in experimental
modelsofarthritis.MolImmunol,36(13–14),pp.905–914.
Liu, Y. et al., 2013. Epigenome-wide association data implicate DNA methylation as an
intermediaryofgeneticriskinrheumatoidarthritis.Naturebiotechnology,31(2),pp.142–
7.
Lobo, E.D. & Balthasar, J.P., 2003. Pharmacokinetic-pharmacodynamic modeling of
methotrexate-induced toxicity in mice. Journal of Pharmaceutical Sciences, 92(8),
pp.1654–1664.
LoBuglio,A.F.etal.,1989.Mouse/humanchimericmonoclonalantibodyinman:kineticsand
immuneresponse.ProcNatlAcadSciUSA,86(11),pp.4220–4224.
Longmire,M.,Choyke,P.L.&Kobayashi,H.,2008.Clearancepropertiesofnano-sizedparticles
andmolecules as imaging agents: considerations and caveats.Nanomedicine (London,
England),3(5),pp.703–17.
Lu, X.&Kang, Y., 2010.Hypoxia andhypoxia-inducible factors (HIFs):master regulators of
metastasis.Clinicalcancerresearch :anofficial journaloftheAmericanAssociationfor
CancerResearch,16(2),pp.5928–5935.
Ma,X.&Xu,S.,2013.TNFinhibitortherapyforrheumatoidarthritis.Biomedicalreports,1(2),
pp.177–184.
MacGregor, A.J. et al., 2000. Characterizing the quantitative genetic contribution to
rheumatoidarthritisusingdatafromtwins.Arthritis&Rheumatism,43(1),pp.30–37.
Macor,P.etal.,2012.Treatmentofexperimentalarthritisbytargetingsynovialendothelium
withaneutralizingrecombinantantibodytoC5.ArthritisRheum,64(8),pp.2559–2567.
Maeda,H.,Nakamura,H.&Fang,J.,2013.TheEPReffectformacromoleculardrugdeliveryto
solidtumors:Improvementoftumoruptake,loweringofsystemictoxicity,anddistinct
tumorimaginginvivo.AdvancedDrugDeliveryReviews,65(1),pp.71–79.
Mahapatro,A.&Singh,D.K.,2011.Biodegradablenanoparticlesareexcellentvehicleforsite
References
103
directedin-vivodeliveryofdrugsandvaccines.JournalofNanobiotechnology,9(1),p.55.
Makrygiannakis, D. et al., 2008. Smoking increases peptidylarginine deiminase 2 enzyme
expression in human lungs and increases citrullination in BAL cells. Annals of the
rheumaticdiseases,67(10),pp.1488–92.
Malmström,V.,Catrina,A.I.&Klareskog,L.,2016.Theimmunopathogenesisofseropositive
rheumatoid arthritis: from triggering to targeting.NatureReviews Immunology, 17(1),
pp.60–75.
Marrelli,A.etal.,2011.Angiogenesisinrheumatoidarthritis:Adiseasespecificprocessora
commonresponsetochronicinflammation?AutoimmunityReviews,10(10),pp.595–598.
Matsumura,Y.&Maeda,H.,1986.ANewConceptforMacromolecularTherapeuticsinCancer
Chemotherapy:MechanismofTumoritropicAccumulationofProteinsandtheAntitumor
AgentSmancs.CancerResearch,46(8),pp.6387–6392.
McInnes, I.B.&Schett,G.,2011a.Thepathogenesisof rheumatoidarthritis.NEngl JMed,
365(23),pp.2205–2219.
McInnes, I.B.&Schett,G.,2011b.Thepathogenesisof rheumatoidarthritis.NEngl JMed,
365(23),pp.2205–2219.
Melnyk,V.O.etal.,1990.Synoviocytessynthesize,bind,andrespondtobasicfibroblastgrowth
factor.Arthritis&Rheumatism,33(4),pp.493–500.
Mikuls, T.R. et al., 2009. Antibody responses to Porphyromonas gingivalis (P. gingivalis) in
subjects with rheumatoid arthritis and periodontitis. International
Immunopharmacology,9(1),pp.38–42.
Miossec,P.,Korn,T.&Kuchroo,V.K.,2009. Interleukin-17andType17HelperTCells.New
EnglandJournalofMedicine,361(9),pp.888–898.
Moghimi,S.M.&Patel,H.M.,1998.Serum-mediatedrecognitionofliposomesbyphagocytic
cellsofthereticuloendothelialsystem-Theconceptoftissuespecificity.AdvancedDrug
DeliveryReviews,32(1–2),pp.45–60.
Mor,A.,Abramson,S.B.&Pillinger,M.H.,2005.Thefibroblast-likesynovialcellinrheumatoid
arthritis:Akeyplayerininflammationandjointdestruction.ClinicalImmunology,115(2),
pp.118–128.
Moran,N.,2005.AnESF–EuropeanMedicalResearchCouncils(EMRC)ForwardLookreport,
Morel, J.C.M. et al., 2002. Signal transduction pathways involved in rheumatoid arthritis
synovialfibroblastinterleukin-18-inducedvascularcelladhesionmolecule-1expression.
References
104
TheJournalofbiologicalchemistry,277(38),pp.34679–34691.
Mould,A.W.etal.,2003.Vegfbgeneknockoutmicedisplayreducedpathologyandsynovial
angiogenesisinbothantigen-inducedandcollagen-inducedmodelsofarthritis.Arthritis
andRheumatism,48(9),pp.2660–2669.
Mundy,G.R.,2007.OsteoporosisandInflammation.NutritionReviews,65(SUPPL.3).
Murthy,S.K.,2007.Nanoparticlesinmodernmedicine:stateoftheartandfuturechallenges.
Internationaljournalofnanomedicine,2(2),pp.129–41.
Nadkarni, S.,Mauri,C.&Ehrenstein,M.R.,2007.Anti-TNF-alpha therapy inducesadistinct
regulatoryTcellpopulationinpatientswithrheumatoidarthritisviaTGF-beta.JExpMed,
204(1),pp.33–39.
Nehoff, H. et al., 2014.Nanomedicine for drug targeting: Strategies beyond the enhanced
permeabilityandretentioneffect.InternationalJournalofNanomedicine,9(1),pp.2539–
2555.
Nguyen,V.H.& Lee, B.J., 2017. Protein corona:A newapproach for nanomedicinedesign.
InternationalJournalofNanomedicine,12,pp.3137–3151.
Oh,P.etal.,2007.Livedynamicimagingofcaveolaepumpingtargetedantibodyrapidlyand
specificallyacrossendotheliuminthelung.Naturebiotechnology,25(3),pp.327–337.
Olafsen,T.&Wu,A.M.,2010.Antibodyvectorsforimaging.SeminNuclMed,40(3),pp.167–
181.
Onuoha, S.C. et al., 2015. Rational Design of Antirheumatic Prodrugs Specific for Sites of
Inflammation.Arthritis&Rheumatology,67(10),pp.2661–2672.
LeOuay,B.&Stellacci,F.,2015.Antibacterialactivityofsilvernanoparticles:Asurfacescience
insight.NanoToday,10(3),pp.339–354.
Pablos,J.L.etal.,2003.Synoviocyte-DerivedCXCL12IsDisplayedonEndotheliumandInduces
AngiogenesisinRheumatoidArthritis.TheJournalofImmunology,170(4),pp.2147–2152.
Padyukov, L. et al., 2004. A gene-environment interaction between smoking and shared
epitopegenesinHLA-DRprovidesahighriskofseropositiverheumatoidarthritis.Arthritis
andRheumatism,50(10),pp.3085–3092.
Palframan, R. et al., 2009. Use of biofluorescence imaging to compare the distribution of
certolizumab pegol, adalimumab, and infliximab in the inflamed paws of mice with
collagen-inducedarthritis.JournalofImmunologicalMethods,348(1–2),pp.36–41.
Pandita, D. et al., 2014. Dendrimers in drug delivery and targeting: Drug-dendrimer
References
105
interactionsandtoxicityissues.JournalofPharmacyandBioalliedSciences,6(3),p.139.
Parodi, A. et al., 2012. Synthetic nanoparticles functionalized with biomimetic leukocyte
membranespossesscell-likefunctions.NatureNanotechnology,8(1),pp.61–68.
Pasut,G.&Veronese,F.M.,2012.StateoftheartinPEGylation:Thegreatversatilityachieved
afterfortyyearsofresearch.JournalofControlledRelease,161(2),pp.461–472.
Pattni, B.S., Chupin, V. V. & Torchilin, V.P., 2015. New Developments in Liposomal Drug
Delivery.ChemicalReviews,115(19),pp.10938–10966.
Pearson,C.M..,1956.Studiesofpolyarthritisandotherlesionsinducedinratsbyinjectionof
mycobacterial adjuvant. I. General clinical and pathologic characteristics and some
modifyingfactors.Arthritis&Rheumatism,2(5).
Peer, D. et al., 2007. Nanocarriers as an emerging platform for cancer therapy. Nature
Nanotechnology,2(12),pp.751–760.
Peichev,M.etal.,2000.ExpressionofVEGFR-2andAC133bycirculatinghumanCD34(+)cells
identifiesapopulationoffunctionalendothelialprecursors.Blood,95(3),pp.952–958.
Perlman,H.etal.,2000.Bcl-2ExpressioninSynovialFibroblastsIsEssentialforMaintaining
MitochondrialHomeostasisandCellViability.J.Immunol.,164(10),pp.5227–5235.
Perlman,H.,Pagliari,L.J.&Volin,M.V,2001.Regulationofapoptosisandcellcycleactivityin
rheumatoidarthritis.Currentmolecularmedicine,1(5),pp.597–608.
Phillips,M.A.,Gran,M.L.&Peppas,N.A.,2010.Targetednanodeliveryofdrugsanddiagnostics.
NanoToday,5(2),pp.143–159.
Del Puente, a et al., 1989.High incidence andprevalenceof rheumatoid arthritis in Pima
Indians.Americanjournalofepidemiology,129(6),pp.1170–1178.
Pusztaszeri,M.P.,Seelentag,W.&Bosman,F.T.,2006. Immunohistochemicalexpressionof
endothelial markers CD31, CD34, von Willebrand factor, and Fli-1 in normal human
tissues. Immunohistochemical expression of endothelial markers CD31, CD34, von
Willebrandfactor,andFli-1innormalhumantissues,54(4),pp.385–95.
Raatz,Y.etal.,2012.Geneexpressionprofilingandfunctionalanalysisofangiogenicmarkers
inmurinecollagen-inducedarthritis.ArthritisResearch&Therapy,14(4),p.R169.
Radner, H. et al., 2014. Performance of the 2010 ACR/EULAR classification criteria for
rheumatoidarthritis:asystematic literaturereview.AnnalsoftheRheumaticDiseases,
73(1),pp.114–123.
Rangel-Moreno, J. et al., 2006. Inducible bronchus-associated lymphoid tissue (iBALT) in
References
106
patients with pulmonary complications of rheumatoid arthritis. Journal of Clinical
Investigation,116(12),pp.3183–3194.
Rau, R., 2002. Adalimumab (a fully human anti-tumour necrosis factor alpha monoclonal
antibody)inthetreatmentofactiverheumatoidarthritis:theinitialresultsoffivetrials.
Annalsoftherheumaticdiseases,61Suppl2,p.ii70-3.
Raychaudhuri, S. et al., 2012. Five amino acids in three HLA proteins explainmost of the
associationbetweenMHCandseropositiverheumatoidarthritis.Naturegenetics,44(3),
pp.291–6.
Reynisdottir,G.etal.,2014.Structuralchangesandantibodyenrichmentinthelungsareearly
featuresofanti-citrullinatedproteinantibody-positiverheumatoidarthritis.Arthritisand
Rheumatology,66(1),pp.31–39.
Richards, D.A., Maruani, A. & Chudasama, V., 2017. Antibody fragments as nanoparticle
targetingligands:astepintherightdirection.Chem.Sci.,8(1),pp.63–77.
Rieck,M.etal.,2007.GeneticvariationinPTPN22correspondstoalteredfunctionofTandB
lymphocytes.Journalofimmunology(Baltimore,Md :1950),179(7),pp.4704–4710.
Romao,V.C.etal.,2014.Threedecadesoflow-dosemethotrexateinrheumatoidarthritis:Can
wepredicttoxicity?ImmunologicResearch,60(2–3),pp.289–310.
Rombouts,Y.etal.,2015.Anti-citrullinatedproteinantibodiesacquireapro-inflammatoryFc
glycosylation phenotype prior to the onset of rheumatoid arthritis. Annals of the
rheumaticdiseases,74(1),pp.234–41.
Rothschild, B.M., Turner, K.R. & DeLuca, M.A., 1988. Symmetrical erosive peripheral
polyarthritisintheLateArchaicPeriodofAlabama.Science(NewYork,N.Y.),241(4872),
pp.1498–1501.
Salmaso, S.&Caliceti, P., 2013. Stealth properties to improve therapeutic efficacy of drug
nanocarriers.Journalofdrugdelivery,2013,p.374252.
Sanna,V.,Pala,N.&Sechi,M.,2014.Targetedtherapyusingnanotechnology:Focusoncancer.
InternationalJournalofNanomedicine,9(1),pp.467–483.
Scally, S.W. et al., 2013. A molecular basis for the association of the HLA-DRB1 locus,
citrullination,andrheumatoidarthritis.TheJournalofexperimentalmedicine,210(12),
pp.2569–82.
Schett,G.&Teitelbaum,S.L.,2009.OsteoclastsandArthritis.JBoneMinerRes,24(7),pp.1142–
1146.
References
107
SchroederJr.,H.W.&Cavacini,L.,2010.Structureandfunctionofimmunoglobulins.JAllergy
ClinImmunol,125(2Suppl2),pp.S41-52.
Schroff,R.W.etal.,1985.Humananti-murineimmunoglobulinresponsesinpatientsreceiving
monoclonalantibodytherapy.CancerRes,45(2),pp.879–885.
Scott,D.L.&Kingsley,G.H.,2006.Tumornecrosisfactorinhibitorsforrheumatoidarthritis.N
EnglJMed,355(7),pp.704–712.
Scott, D.L., Wolfe, F. & Huizinga, T.W., 2010. Rheumatoid arthritis. [Review]. Lancet,
376(England PT-Journal Article PT-Research Support, Non-U.S. Gov’t PT-Review NO-
(UnitedKingdomArthritisResearchUK)LG-EnglishDC-20100927),pp.1094–1108.
Seyler, T.M. et al., 2005. BLyS and APRIL in rheumatoid arthritis. Journal of Clinical
Investigation,115(11),pp.3083–3092.
Shichikawa,K.etal.,1999.Changesintheincidenceandprevalenceofrheumatoidarthritisin
Kamitonda, Wakayama, Japan, 1965-1996. Annals of the rheumatic diseases, 58(12),
pp.751–6.
Shin, J.M. et al., 2014. A hyaluronic acid–methotrexate conjugate for targeted therapy of
rheumatoidarthritis.ChemicalCommunications,50(57),p.7632.
Shinde, C.G. et al., 2014. Methotrexate: A Gold Standard for Treatment of Rheumatoid
Arthritis.JournalofPain&PalliativeCarePharmacotherapy,28(4),pp.351–358.
Sidney,L.E.etal.,2014.Concisereview:EvidenceforCD34asacommonmarkerfordiverse
progenitors.StemCells,32(6),pp.1380–1389.
Silman,A.J.etal.,1993.AbsenceofrheumatoidarthritisinaruralNigerianpopulation.Journal
ofRheumatology,20(4),pp.618–622.
Silman, A.J. et al., 1993. Twin concordance rates for rheumatoid arthritis: results from a
nationwidestudy.BrJRheumatol,32(10),pp.903–907.
Silman, A.J., Newman, J. &MacGregor, A.J., 1996. Cigarette smoking increases the risk of
rheumatoid arthritis. Results from a nationwide study of disease-discordant twins.
ArthritisRheum.,39(5),pp.732–5.
Simon,L.C.&Sabliov,C.M.,2014.Theeffectofnanoparticleproperties,detectionmethod,
delivery route and animal model on poly(lactic-co-glycolic) acid nanoparticles
biodistributioninmiceandrats.DrugMetabolismReviews,46(2),pp.128–141.
Sjöberg,A.etal.,2005.Theextracellularmatrixandinflammation:Fibromodulinactivatesthe
classicalpathwayofcomplementbydirectlybindingC1q.JournalofBiologicalChemistry,
References
108
280(37),pp.32301–32308.
Smijs,T.G.&Pavel,S.,2011.Titaniumdioxideandzincoxidenanoparticlesinsunscreens:Focus
ontheirsafetyandeffectiveness.Nanotechnology,ScienceandApplications,4(1),pp.95–
112.
Smolen, J.S. et al., 2007. New therapies for treatment of rheumatoid arthritis. Lancet,
370(9602),pp.1861–1874.
Smolen,J.S.,Aletaha,D.&McInnes,I.B.,2016.Rheumatoidarthritis.TheLancet,388(10055),
pp.2023–2038.
Stahl, E.A. et al., 2010.Genome-wide association studymeta-analysis identifies sevennew
rheumatoidarthritisriskloci.Naturegenetics,42(6),pp.508–14.
Steichen,S.D.,Caldorera-Moore,M.&Peppas,N.A.,2013.Areviewofcurrentnanoparticle
and targeting moieties for the delivery of cancer therapeutics. European Journal of
PharmaceuticalSciences,48(3),pp.416–427.
Stolt,P.etal.,2010.Silicaexposureamongmalecurrentsmokersisassociatedwithahighrisk
ofdevelopingACPA-positiverheumatoidarthritis.Annalsoftherheumaticdiseases,69(6),
pp.1072–6.
Storgard,C.M.etal.,1999.Decreasedangiogenesisandarthriticdiseaseinrabbitstreatedwith
an alphavbeta3antagonist.JournalofClinicalInvestigation,103(1),pp.47–54.
Sugiyama, D. et al., 2010. Impact of smoking as a risk factor for developing rheumatoid
arthritis: a meta-analysis of observational studies. Annals of the Rheumatic Diseases,
69(1),pp.70–81.
Suwannalai, P. et al., 2014. Low-avidity anticitrullinated protein antibodies (ACPA) are
associatedwithahigherrateofjointdestructioninrheumatoidarthritis.Annalsofthe
RheumaticDiseases,73(1),pp.270–276.
Swaak,A.J.G.etal.,1987.Ananalysisofthelevelsofcomplementcomponentsinthesynovial
fluidinrheumaticdiseases.ClinicalRheumatology,6(3),pp.350–357.
Symmons,D.etal.,2002.TheprevalenceofrheumatoidarthritisintheUnitedKingdom:new
estimatesforanewcentury.Rheumatology(Oxford,England),41(7),pp.793–800.
Szekanecz,Z.etal.,2009.Chemokinesandangiogenesisinrheumatoidarthritis.Frontiersin
bioscience(Eliteedition),1,pp.44–51.
Szekanecz, Z. & Koch, A.E., 2008. Vascular involvement in rheumatic diseases: “vascular
rheumatology.”ArthritisResearch&Therapy,10(5),p.224.
References
109
Taneja,V.etal.,2007.NewhumanizedHLA-DR4-transgenicmicethatmimicthesexbiasof
rheumatoidarthritis.ArthritisandRheumatism,56(1),pp.69–78.
Taniguchi,N.&Others,1974.Onthebasicconceptofnanotechnology.Proc.Intl.Conf.Prod.
Eng.Tokyo,PartII,JapanSocietyofPrecisionEngineering,pp.18–23.
Tian,H.&Cronstein,B.N.,2007.Understandingthemechanismsofactionofmethotrexate:
Implicationsforthetreatmentofrheumatoidarthritis.BulletinoftheNYUHospital for
JointDiseases,65(3),pp.168–173.
Timmer, T.C.G. et al., 2007. Inflammation and ectopic lymphoid structures in rheumatoid
arthritis synovial tissues dissected by genomics technology: Identification of the
interleukin-7 signaling pathway in tissues with lymphoid neogenesis. Arthritis and
Rheumatism,56(8),pp.2492–2502.
TodescoS,G.P.F.,2002.MalattieReumatiche,
Tolboom, T.C.A. et al., 2002. Invasive properties of fibroblast-like synoviocytes: correlation
withgrowthcharacteristicsandexpressionofMMP-1,MMP-3,andMMP-10.Annalsof
therheumaticdiseases,61(11),pp.975–80.
Too,C.L.etal.,2016.Occupationalexposuretotextiledustincreasestheriskofrheumatoid
arthritis: results from aMalaysian population-based case-control study.Annals of the
rheumaticdiseases,75(6),pp.997–1002.
Toumey,C.,2009.Plentyofroom,plentyofhistory.Naturenanotechnology,4(12),pp.783–
784.
Trentham, D.E., Townes, A.S. & Kang, A.H., 1977. Autoimmunity to type II collagen an
experimentalmodelofarthritis.JExpMed,146(3),pp.857–868.
Trouw, L.A., Pickering, M.C. & Blom, A.M., 2017. The complement system as a potential
therapeutictargetinrheumaticdisease.Naturereviews.Rheumatology.
Ulery, B.D., Nair, L.S. & Laurencin, C.T., 2011. Biomedical applications of biodegradable
polymers.JournalofPolymerScience,PartB:PolymerPhysics,49(12),pp.832–864.
vanVollenhoven,R.F.etal.,2012.TofacitiniborAdalimumabversusPlaceboinRheumatoid
Arthritis.NewEnglandJournalofMedicine,367(6),pp.508–519.
vanVollenhoven,R.F.,2009.Treatmentofrheumatoidarthritis:stateoftheart2009.Nature
ReviewsRheumatology,5(10),pp.531–541.
Vries, M.H.M. et al., 2015. CXCL1 promotes arteriogenesis through enhanced monocyte
recruitmentintotheperi-collateralspace.Angiogenesis,18(2),pp.163–171.
References
110
Wang, Z. et al., 2000.Universal PCRamplificationofmouse immunoglobulin gene variable
regions: the design of degenerate primers and an assessment of the effect of DNA
polymerase3’to5’exonucleaseactivity.JImmunolMethods,233(1–2),pp.167–177.
Wegner, N. et al., 2010. Peptidylarginine deiminase from Porphyromonas gingivalis
citrullinates human fibrinogen and α-enolase: Implications for autoimmunity in
rheumatoidArthritis.ArthritisandRheumatism,62(9),pp.2662–2672.
Whittle,S.L.&Hughes,R.A.,2004.Folate supplementationandmethotrexate treatment in
rheumatoidarthritis:areview.Rheumatology(Oxford,England),43(3),pp.267–71.
Williams, A.S. et al., 1996. A single intra-articular injection of liposomally conjugated
methotrexate suppresses joint inflammation in rat antigen-induced arthritis. British
journalofrheumatology,35(8),pp.719–24.
Williams,A.S.,2001.Ameliorationofratantigen-inducedarthritisbyliposomallyconjugated
methotrexate is accompanied by down-regulation of cytokine mRNA expression.
Rheumatology,40(4),pp.375–383.
Williams,R.O.,Feldmann,M.&Maini,R.N.,1992.Anti-tumornecrosisfactoramelioratesjoint
disease inmurine collagen-induced arthritis. Proceedings of the National Academy of
Sciences,89(20),pp.9784–9788.
Woodruff,T.M.etal.,2002.AntiarthriticactivityofanorallyactiveC5areceptorantagonist
againstantigen-inducedmonarticulararthritisintherat.ArthritisandRheumatism,46(9),
pp.2476–2485.
Xu,W., Ling,P.&Zhang,T.,2013.Polymericmicelles,apromisingdrugdelivery systemto
enhancebioavailabilityofpoorlywater-solubledrugs.JournalofDrugDelivery,2013.
Yamashita,A.etal.,2002.Fibroblastgrowthfactor-2determinesseverityofjointdiseasein
adjuvant-inducedarthritisinrats.JImmunol,168(1),pp.450–457.
Yameen,B.etal.,2014. Insight intonanoparticlecellularuptakeandintracellulartargeting.
JournalofControlledRelease,190,pp.485–499.
Zeng,Q.,Huang,S.&Chen,R.,1997.[10-yearepidemiologicalstudyonrheumaticdiseasesin
Shantouarea].ZhonghuaNeiKeZaZhi,36(3),pp.193–197.
ZOLTÁNSZEKANECZ,TIMEABESENYEI,GYÖRGYPARAGH, andA.E.K.,2009.Angiogenesis in
rheumatoidarthritis.Autoimmunity,42(7),pp.563–573.
Zupan,J.,Jeras,M.&Marc,J.,2013.Osteoimmunologyandtheinfluenceofpro-inflammatory
cytokinesonosteoclasts.BiochemiaMedica,23(1),pp.43–63.
111
AcknowledgementsIwouldliketothankmymentorPaoloMacorPh.D.,whogavemethepossibilitytoworkinhis
laboratoryallowingmetoworkasbestIcould.IthankalsoProfessorDanieleSblatteroforhis
helpandsupport.
Surely,Ihavetothankallthepeopleworkinginthislab,ithasbeenapleasuretosharethis
timewithyou.
IwouldliketothankProfessorJessicaBertrandforgivingmetheopportunitytospendpartof
this work in her laboratory at the University Hospital of Magdeburg, Experimental
OrthopaedicsLaboratory.Manythanksalsotoallthepeopleinherlaboratory.
Onceagain,Iwouldliketothank:
Professor Claudio Tripodo and Beatrice Belmonte, who collaborated for the histological
analyses;StefaniaBiffi,whohelpeduswiththestudyofbiodistributioninrats;ProfessorEnzo
Terreno,PaolaBardiniandGiadaMarini,whocollaboratedforthestudyofbiodistributionin
mice;SabinePietkiewiczforherkindhelpwiththeImagingFlowCytometeranalysis;Professor
GabrielePozzato,whocollaborated for thebloodanalysis;RominaOliva,whocollaborated
withthestudyof3Dmodelling;EnricoRampazzoforhishelpwithTEMimagesandAnnalisa
Marcuzzi,whocollaboratedforthemultiplexcytokineanalysis.
