The effect of form of carboxymethyl-chitosan dressings on biological properties in wound healing

Chitosan and its derivative have been widely used for wound healing applications, but the effect of the chitosan form on wound healing related properties has been less exploited. To this aim, water-soluble carboxymethyl-chitosan (CMCS) crosslinked by 10 wt.% genipin was fabricated in three different forms of dressings, i.e. hydrogel, membrane and sponge. The properties of dressing were evaluated and compared in terms of surface morphology, mechanical properties, water absorption rate, gas permeability, coagulation performance and biological responses in vitro and in vivo. The results showed that the prepared CMCS sponge dressing with porous structure exhibited the best water absorption, gas permeability, hemostatic performance and promoting effect on human skin fibroblast proliferation. The sponge sample overall had the highest expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1), while the CMCS hydrogel was favorable for stimulating the expression of matrix metalloproteinase-1 (MMP-1). Furthermore, the CMCS sponge dressing demonstrated the best performance in wound closure and accelerating wound repair in-vivo, showing the fastest epithelization, and best healing performance with the well-structure of epidermis and well-arranged collagen in the dermis. On the other hand, the CMCS hydrogel and membrane also demonstrated good biocompatibility, hemostatic properties and the capability to promote wound healing. Overall, CMCS sponge dressing demonstrated the optimal biological performances and excellent potential for the clinical wound healing applications.