Effects Of Carboxymethyl-chitosan On Wound Healing

Injury to the skin triggers a cascade of cellular and biochemical events including inflammation, new tissue formation and tissue remodeling, which finally lead to at least partial reconstruction of the wound area. Chitin is a poly-β(1→4)-N-acetyl-D-glucosamine found in the cell walls of fungi as well as in skeletal structures of numerous specimens of sponges, insects, crustaceans and other invertebrates. Chitosan is the alkaline deacetylated product of chitin. Both of chitin and chitosan do not dissolve in water due to their rigid crystalline structure formed by hydrogen bond through intra- and intermolecular. Carboxymethyl-chitosan (CMC) is a water-soluble chitin derivative and functional biomaterial which possesses many favorable biological properties such as biocompatibility, biodegradability and bioactivity. A myriad of studies have suggested that carboxymethyl-chitosan could effectively accelerate wound healing and reduce scar formation. However, the mechanisms underlying these effects have only been partially investigated.In this paper, effects of carboxymethyl-chitosan with different molecular weight on wound healing were investigated in vivo and in vitro. A second degree burn model was performed in rats and the accelerative effects of carboxymethyl-chitosan on wound repair were observed. Contents of transforming growth factor (TGF)-β1,interleukin(IL)-6 and matrix metalloproteinase (MMP)-1 in wounds were determined by enzyme-linked immunosorbent assay (ELISA). In vitro study evaluated the influence of carboxymethyl-chitosan on cytokines secretion of fibroblasts and macrophages.In vivo results showed that carboxymethyl-chitosan effectively accelerated the wound healing process in burned rats (P<0.05). Levels of TGF-β1, IL-6 and MMP-1 in carboxymethyl-chitosan groups were significantly elevated, compared with control group (P<0.05). In vitro results indicated that carboxymethyl-chitosan significantly promoted the proliferation of fibroblasts and stimulated its IL-8 and IL-10 secretion at different incubation time, but it did not affect collagen secretion of fibroblasts. Carboxymethyl-chitosan enhanced phagocytosis ability of macrophages, and increased its tumor necrosis factor (TNF)-αsecretion.In conclusion, carboxymethyl-chitosan promoted wound healing by activating macrophages, accelerating fibroblasts growth and exerting considerable effects on the secretion of a series of cytokines.