Asymmetric chitosan membrane containing collagen I nanospheres for skin tissue engineering.

A biodegradable chitosan membrane with an asymmetric structure, seeded with fibroblasts, was prepared as a novel skin substitute. Chitosan was cross-linked with genipin and then frozen and lyophilized to yield a porous asymmetric membrane (CG membrane). Nanoscale collagen I particles were injected into the CG membrane to form an asymmetric CGC membrane. The results reveal that the CG membrane treated with 0.125 wt % of genipin had a higher swelling ratio, porosity, and pore size. After 7 d of dynamic culture, many of the adhered cells exhibited a flat morphology and well spread on the surface of CGC membrane treated with 0.125 wt % of genipin. In animal studies, the CGC membrane seeded with fibroblasts and grown in vitro for 7 d was more effective than both gauze and commercial wound dressing, Suile, in healing wounds. An in vivo histological assessment indicated that covering the wound with the asymmetric CGC membrane resulted in its epithelialization and reconstruction. CGC membrane, thus, has great potential in skin tissue engineering.