wound healing ppt
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“ God heals, and the doctor
takes the fees ”
Benjamin Franklin(American Statesman, scientist, Philosopher)
Phases of Healing Inflammatory (Reactive) Haemostasis Inflammation
Proliferative (Regenerative/Reparative) Epithelial migration proliferation Maturation
Maturational (Remodeling) Contraction scarring Remodeling
Cutaneous Wound Healing
1. By Primary Intention
2. By Secondary Intention
3. By Tertiary Intention
Secondary Union differs from
Primary Union by:
Larger clot or scab rich in fibrin or fibronectin
More intense inflammation
Much larger amounts of granulation tissue formed
Involves wound contraction
Factors affecting Wound Healing
Infection Nutrition ( proteins, vit.C, vit.A, Zn, Fe) Steroids / Adriamycin Mechanical factors (a) Increased pressure/torsion) (b) Ischemia Malnutrition Advanced age Ionising Radiation Diabetes Mellitus
Growth Factors affecting Wound
Healing at Different Stages
Epithelial Proliferation: EGF TGFa KGF HGFMonocyte chemotaxis: PDGF FGF TGFbFibroblast Migration: PDGF FGF TGFbFibroblast Proliferation: PDGF FGF EGF TNFAngiogenesis: VEGF Ang FGFCollagen Synthesis: TGFb PDGFCollagen secretion: PDGF FGF EGF TNF TGFb inhibits
Growth Factors in Wound Healing
Increase size of cells
Increase number of cells
Pleiotropic effects i.e initiate cell proliferation, migration, differentiation, contractility, enhance synthesis of specialized proteins eg. Collagen in fibroblasts
Act in autocrine, paracrine, or endocrine manner
STEM CELLSHomeostatic relation between replication and
differentiation of stem cellsCells differentiate progressively as they migrate
into the upper layers of the epitheliumIn the skin stem cell niches are in the basal layer
Characteristics of Stem cells 1. Self renewal capacity2. Asymmetric replication.
Regenerative MedicineRegenerative MedicineGoal: Goal: Regeneration and repopulation of damaged
organ using embryonic or adult stem cells.
Therapeutic CloningTherapeutic Cloning Patients cell Enucleated oocyte
Nuclear transfer embryo
Nuclear transfer blastocyst
Embryonic stem cells
Blood cells Neurons Muscle cells
Potential Therapeutic Strategies
1. Transplanting stem cells into area of injury
2. Use of stem cell systems to produce large amounts of differentiated cells for transplantation
Repair By Connective Tissue includes: Angiogenesis 1. Vasculogenesis 2. Angiogenesis)
Deposition of ECM
Migration and Proliferation of Fibroblasts
Maturation and Reorganisation of Fibrous Tissue.
Fetal Wound Healing
Younger the fetus less noticeable is the scar Fetal fibroblasts even in adult transplantation heals with
the absence of inflammation Theory: that wound fibroblasts do not become
myofibroblasts until late in gestation. IL6 is high in adult stimulated fibroblasts compared to
fetal stimulated ones with coincides with increased inflammation in adults
Thrombospondin 1 decreases with increase in gestation. It destabilizes matrix contracts in the EC space, facilitates mitogenesis and chemotaxis. Promotes cell associated protease and self supports matrix turnover. Thus inflammation would decrease and there would be less scarring
Aberrations of Aberrations of HealingHealing
Keloids: Females>Males Blacks>Whites/ Familial Outgrows the wound Rarely subsides leads to pathologic
scarring in other areas of
the body. In bones- Osteoarthritis
common on the face shoulders back and
Hypertrophic Scar Females=Males Not race related/ familial Remains within the
wound Subsides with time
Flexor surfaces affected
2. intralesional Triamcinolone
3. Excision and skin grafting
5. Surgery f/b post op interstitial
Excessive granulation tissue which protrudes above the level of the skin & hinders re epithelialisation is called “EXUBERANT GRANULATION or PROUD FLESH! Rx: Cautrise or surgically resect the tissue
Rx of Aberrations
Keloid Hypertrophic scar
Low level laser therapy.
Negative pressure wound therapy(NPWT).
Collagen & chondroitin sulphate : Integra
Apligraftrade: skin substitute containing collagen and seeded cells
Alloderm: immunologically inert, nonliving, allogenic, acellular dermal matrix with intact basement membrane prepares wound bed for grafting
Used for simple shallow wound dressing Protects from water loss mechanical injury and drying
TransCyte (ECM matrix generated by allogenic human dermal fibroblasts serves as a matrix for neodermis generation
ORCEL: Composite cultured skin. Fibroblasts, keratinocytes seeded on opposite sides of bilayered matrix of bovine collagen
Dermagraft living allogenic dermal fibroblasts grown on a degradable scaffold. Good resistance to tearing
Biosynthetic porcine derived xenograft
Collagen has been crosslinked with aldehyde
Can be conveniently stored at room temperature
long shelf life.
perforated or non-perforated
Partial thickness, donor sites, sandwich autografts, and to cover full thickness wounds prior to grafting.
comprised of small intestine submucosa acellular collagen matrix. Chance of rejection
beta-Glucan stimulates the macrophage activity and promotes rapid wound healing.
Beta-Glucan Collagen mesh or Glucan II (Beta-Glucan) mesh. . Rapid healing without dressing changes painless treatment.
Natural dressingHoney-impregnated dressing Chronic unhealing wounds. Impregnated into a compress of EVA (ethylenevinylacetate) mesh
Honey cleans the wound without disturbing it Removing the dressing causes no damage no known side effects
Systemic delivery of oxygen to the tissues unit which has been compressed to approximately 2-2.4 ATA.
Stimulates angiogenesis and fibroblast migration, enhances neutrophil and antibiotic killing action, and suppresses alpha toxin production in gas gangrene.
Total Contact Casting A treatment used for successful offweighting
of plantar foot ulcerations.
Provides decreased plantar surface pressures over wounded areas of the foot, by redistributing weight bearing over the entire lower leg.
a novel hydrogel, to seal wounds and at the same time deliver an
"They're like rebar when you're building
something with concrete,
They give the cement something
to hang onto."
encapsulate living cells in the
hydrogel and then inject the
gel into secondary sites without harming