lab-on-chip: pdms microdevice for mirna detection from ...in a cost-effective way a whole analytical...
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Lab-on-chip: PDMS microdevice for miRNAdetection from biological samples
Federica Barbaresco
Supervisors: Prof. Fabrizo Pirri and Prof. Matteo Cocuzza
Submitted and published works
• Canavese G., Ancona A., Racca L., Canta M., Dumontel B., Barbaresco F., Limongi T., Cauda
V., Nanoparticle-assisted ultrasound: a special focus on sonodynamic therapy against cancer,
Chemical Engineering Journal, 340, (2018) pp.155-172.
• Scordo G., Barbaresco F., Bertana V., Potrich C., Lunelli L., Cocuzza M., Marasso S. L.,
Pederzolli C., Pirri C. F., Lab-on-chip for precision medicine. In: 3th edition of the Nanoinnovation
Conference & Exhibition, Roma, 14-16th September, 2018., in press.
List of attended classes• 01REIRR - Terapie avanzate (nanomedicina, terapia genica e cellulare) in chirurgia
(29/06/2018,4 cfu)
• 01LXBRW - Life Cycle Assessment (LCA) (02/07/2018, 5 cfu)
• 01MQLKI - X-ray diffraction by material (exam planned, 5 cfu )
• 02LCRKG – Fisica di superfici ed interfacce (exam planned, 3 cfu)
• 01QORRV - Writing Scientific Papers in English (27/06/2018, 3 cfu)
• 01RISRV - Public Speaking (01/09/2018, 1 cfu)
• 02LWHRP - Communication (04/09/2018, 1 cfu)
Novel contributions
Addressed research questions/problems• Enhance the MiRNA purification and successive detection by increase the Surface-
to-Volume ratio in the reaction chamber.
• From ASYMMETRIC DROP to SPIRAL CHIP
• Increase of the
Surface/Volume Ratio:
ൗ𝑺𝑺𝒑𝒊𝒓𝒂𝒍
𝑺𝑫𝒓𝒐𝒑=9.6
• Lab-on-chip
Research context and motivation• Circulating microRNAs (miRNAs) are a class of endogenous small single-stranded
RNAs which emerged as key players in the post-transcriptional regulation of gene
expression. Synthesized in the cell nucleus, and active in the cytoplasm on
sequence-specific of target messenger RNAs, microRNAs can be secreted in
circulation as cell-free entities. In fact, circulating miRNAs have been detected in
every body fluid, including blood plasma, protected in the extracellular environment
by vescicles or in protein complexes.
• The regulation exerted by miRNAs affects a
variety of fundamental cellular processes
including cell development and proliferation and
cell death. Thus, MiRNAs have gained clinical
relevance as their aberrant expression has been
shown to correlate with the pathogenesis and
progession of several diseases, including cancer.
• Due to miRNAs relevance and easy accessibility, there is an increasing interest in
circulating microRNAs as potential minimally invasive biomarkers for the prognosis,
diagnosis and assessment of response to treatment in personalized medicine.
• Lab-on-chip (LOC) approach could offer several advantages to the introduction of
miRNAs analysis in the clinical practice. Microfluidic devices would allow to integrate
in a cost-effective way a whole analytical process reducing its complexity, time of
analysis, sample and reagents volumes.
Adopted methodologies• Microfluidic devices dimensions are characterized by optical and FESEM microscopy.
• Functionalization times are evaluated by observing the absorption of fluorescent synthetic MiRNA
by fluorescence microscopy.
Future work• Optimize the functionalization dynamic time on spiral device
• Measure the limit of MiRNA detection (LoD)
• Detect MiRNAs from different biological fluids (BSA, Plasma, Blood, Saliva, Urina)
• Automatize the whole process
PhD program in
Electrical, Electronics and
Communications Engineering
XXXIII Cycle
Spiral Fabrication Process
• The microdevice is formed by a polymeric reaction chamber made of PDMS sealed with a flat
silicon surface. The mold of the reaction chamber is made of SU-8 2150 deposited on a silicon
wafer by a photolitographic process and then silanizated by CH₃SiCl₃. PDMS (10:1 w/w) ispoured into the mold for casting on a hot plate at 120 °C for 15 minutes. The molded reaction
chamber is sealed with a silicon surface through a thin intermediate layer of PDMS (10:1 w/w)
spinned on silicon surface at 2000 rpm for 5s and at 4000 rpm for 60s and pre-reticulated on a
hot plate at 70°C for 6 minutes. Finally the top and the bottom parts of the device are bonded by
means of O2 plasma treatment (300W, O2 30%, 2 min) and located in oven at 90°C for 2 hours to
perform reticulation.
Functionalization Time
• Spiral device is functionalized with a silane mixtures containing APTMS (0.1% v/v) and PEG-s
silane (0.9% v/v) through a wet functionalization at 60 °C in dynamic regime (2 μL/min) at
different times to assess the best absorpion of MiRNA on microdevice.
APTMSPEG-s
PDMS PDMS