Wound healing involves three phases: inflammatory, proliferative, and maturational. Primary healing occurs when wound edges are in direct contact while secondary healing involves granulation tissue formation. Many factors can affect wound healing including infection, nutrition, steroids, ischemia, and diabetes. Growth factors are important for different stages of healing. Stem cells can help regenerate damaged tissue. Aberrations like keloids and hypertrophic scarring exist. New treatments include skin substitutes, dressings, growth factors, and therapies like hyperbaric oxygen and offloading casts.

1. WOUND HEALING

2. “ God heals, and the doctor
takes the fees ”
Benjamin Franklin(American Statesman, scientist, Philosopher)

3. Phases of Healing
 Inflammatory (Reactive)
Haemostasis Inflammation
 Proliferative (Regenerative/Reparative)
Epithelial migration proliferation Maturation
 Maturational (Remodeling)
Contraction scarring Remodeling

4. Cutaneous Wound Healing
1. By Primary Intention
2. By Secondary Intention
3. By Tertiary Intention

6. 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

8. 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

9. Growth Factors affecting Wound
Healing at Different Stages
Epithelial Proliferation: EGF TGFa KGF HGF
Monocyte chemotaxis: PDGF FGF TGFb
Fibroblast Migration: PDGF FGF TGFb
Fibroblast Proliferation: PDGF FGF EGF TNF
Angiogenesis: VEGF Ang FGF
Collagen Synthesis: TGFb PDGF
Collagen secretion: PDGF FGF EGF TNF
TGFb inhibits

10. Growth Factors in Wound Healing
 Increase size of cells
 Increase number of cells
 Inhibit apoptosis
 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

11. STEM CELLS
Homeostatic relation between replication and
differentiation of stem cells
Cells differentiate progressively as they migrate into the
upper layers of the epithelium
In the skin stem cell niches are in the basal layer
Characteristics of Stem cells
1. Self renewal capacity
2. Asymmetric replication.

12. Regenerative MedicineRegenerative Medicine
Goal: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

13. 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

14. Repair By Connective Tissue includes:
 Angiogenesis 1. Vasculogenesis
2. Angiogenesis)
 Deposition of ECM
 Migration and Proliferation of Fibroblasts
 Maturation and Reorganisation of Fibrous
Tissue.

15. 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

16. Aberrations of HealingAberrations of Healing
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
sternum
Hypertrophic Scar
 Females=Males
 Not race related/ familial
 Remains within the wound
 Subsides with time
 Flexor surfaces affected

17. 1.compression bandages
2. intralesional Triamcinolone
3. Excision and skin grafting
4. Laser
5. Surgery f/b post op interstitial
radiotherapy
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

18. Keloid Hypertrophic scar

19. Newer
Concepts
Low level laser therapy.
Negative pressure wound therapy(NPWT).

20. 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

21. Tegaderm
Used for simple shallow wound dressing
Protects from water loss mechanical injury and drying

22. 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

23. Dermagraft
living allogenic dermal fibroblasts grown on a degradable
scaffold. Good resistance to tearing

24. E-Z Derm
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.
OASIS
comprised of small intestine
submucosa acellular collagen
matrix. Chance of rejection

25. OPSITE

26. 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.

27. HONEYSOFT
Natural dressing
Honey-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

28. Hyperbaric Medicine
 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.

29. 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.

30. a novel hydrogel, to seal wounds and at
the same time deliver an antibacterial
punch
"They're like rebar
when you're building
something with
concrete,
They give the cement
something to hang
onto."
"MAX8,"
encapsulate living
cells in the
hydrogel and then
inject the gel into
secondary sites
without harming
the cells.