scar formation

• Scar formation


  1. Hemostatic plug formation

  2. Inflammation

  3. Cell proliferation

  4. Granulation tissue formation

  5. Connective tissue deposition

  6. Scar formation
• Macrophages


  M1 (classically activated) - inflammatory, microbicidal

  M2 (alternatively activated) - anti-inflammatory, promote repair
• Angiogenesis


  1. Vasodilation

  2. Pericyte separation

  3. VEGF release

  4. Tip cell formation

  5. Endothelial cell proliferation

  6. Capillary tube formation

  7. Basement membrane deposition

  8. Pericyte recruitment
• Transforming growth factor beta (TGF-β)

  Stimulates fibroblast migration and proliferation

  Increases collagen and fibronectin synthesis

  Inhibits metalloproteinases and extracellular matrix degradation

  Inhibits lymphocyte proliferation and leukocyte activity
• Granulation tissue


  • Newly formed blood vessels (capillaries)

  Fibroblasts

  Inflammatory cells (lymphocytes, macrophages)

  Edema
• Scar maturation


  Decrease in fibroblast proliferation

  Decrease in new blood vessel formation

  Increase in collagen synthesis
• Myofibroblasts


  Fibroblasts that acquire smooth muscle features and help in scar contraction
• Tissue remodeling


  Balance between extracellular matrix synthesis and degradation

  Matrix metalloproteinases (MMPs) degrade extracellular matrix

  Tissue inhibitors of metalloproteinases (TIMPs) inhibit MMPs