Preparation and performance of artificial dermis based on recombinant humanized type III collagen and carboxymethyl chitosan

Artificial dermis is a biological substitute material that mimics the structure and function of human skin, which can protect wounds, guide the reconstruction of the dermal layer, and promote wound healing. Currently, most artificial dermis products employ collagen extracted from animals, but this poses potential risks of rejection and infection during clinical applications. The development of novel artificial dermis formulations capable of mitigating these limitations holds significant clinical importance. In this study, a bilayer artificial dermis composed of a silicone membrane and a collagen sponge was designed. The collagen sponge was formed through genipin-mediated cross-linking of recombinant humanized type III collagen (rhCOL III) and carboxymethyl chitosan (CMCS). The artificial dermis exhibited a bilayer structure comprising a silicone membrane layer and a collagen sponge layer. All artificial dermis groups exhibited favorable porosity, mechanical properties, and hydrophilicity. With increasing CMCS concentration, the material's swelling properties, moisture retention, and resistance to degradation gradually improved. Among these concentrations, CMCS contents of 3%(w/v) and 4%(w/v) exhibited the best performance. The results of hemolysis testing and various cell experiments indicated that the material had great blood compatibility and cytocompatibility. Mouse dorsal whole cortical defect models further confirmed that all experimental groups had been able to promote wound healing, with the 4%(w/v) CMCS group showing the fastest wound recovery rate. Histopathological analysis via hematoxylin and eosin and Masson's trichrome staining revealed well-organized collagen alignment in high-concentration CMCS groups, particularly in the 4%(w/v) CMCS group, accompanied by complete epidermal restoration and nascent skin appendage formation. The epidermis layer was restored to a smooth state and skin appendages were regenerated.