Which type of collagen is most important is most important in wound healing.
a. Type I collagen is the major component of extracellular matrix in skin.
b. Type III, which is also normally present in skin, becomes more prominent and important during the repair process.
c. Process of healing involves : inflammation ; angiogenesis ; migration and proliferation of the fibroblasts; scar formation ; connective tissue remodeling.
d. In the process of migration and proliferation of the fibroblasts and collagen deposition; concurrently with epithelization, collagen fibrils become more abundant and bridge the gap.
e. At first a provisional matrix containing fibrin, plasma fibronectin,and typeIII collagen is formed.
f. This is replaced by the type I collagen.
g. TGF-B is the most important fibrogenic agent.
h. There are 27 different types of collagen in body, encoded by 41genes.
i. These are distributed in mainly three groups.
j. The first one: Fibrillar collagen- type I,II,III,V,XI
k. The second group: basement membrane collagen – TypeIV
l. Group three: Other collagens- type VI,VII,IX,XVII,XV, XVIII
m. Deficiency of each collagen is associated with the particular disease.
n. Fibrillart group is mainly involved in the process of wound healing.
o. Vitamin C is required for the hydroxylation of the procollagen of fibril group, so the Vit.C deficiency is associated with the delayed wound healing.