Evaluation of human skin substitute for burn wound coverage based on cultured epidermal autograft.

摘要

Four different human skin substitutes based on cultured keratinocytes were tested.;(I). The combination of cultured epidermal graft with collagen dermis membrane and fibrin. A human skin substitute consisting of human cultured keratinocytes, collagen dermis and fibrin was evaluated in 80 athymic mice divided randomly into four groups. The take rates of cultured graft with greater than 50% of wound area covered were 15--65%. The occurrence of purulent discharge on wound bed were 0--15%. Our results suggested that cultured cells are best grafted directly onto the wound bed or in combination with a thin layer of collagen or fibrin but not both.;(II). Evaluation of bilayer artificial skin Integral in a rodent model. The artificial skin (Integra) has been investigated in 3 x 3 cm fiffl-thickness skin defect 20 guinea-pigs. Good take rate of the artificial skin was observed in 18 of 20 animals. Two of the 20 wounds showed purulent discharge. In this animal model, clinical 'take' of the neodermis was achieved in 18/20 animals (90 per cent), while vascular ingrowth was observed in 14/20 animals (70 per cent). The results suggested that artificial skin in clean surgical wound is ready to incorporate into surrounding viable tissue.;(III). In vitro reconstitution of skin with cultured keratinocytes on acellular dermis. The growth of human keratinocytes on human acellular dermis was evaluated in a new culture system. Human keratinocytes were best seeded onto the dermis freshly sprayed with a thin layer of fibrin glue, and proliferative 3T3 feeder cells growing separately on the culture dish. However, there was no successful engraftment of the reconstructed skin because of severe inflammation leading to complete necrosis of grafted epithelium in animal experiment. Therefore cultivation of keratinocytes on acellular allogenic dermis is not recommended because of severe in vivo inflammation of the grafted dermis tissue.;(IV). The use of hyaluronic acid derivative membrane (Laser Skin as template for cultured keratinocytes . Composite Laserskin Graft consisting of autologous of keratinocytes and allogenic fibroblasts had 80% graft take rate in animal experiment. The 'take' rates on these two patients were 60% and 100%. The animal experiment and the preliminary clinical data showed that the Composite LaserSkin Graft is a good human skin substitute in terms of its durability, biocompatibility, high seeding efficacy for keratinocytes and high graft take rate and low infection rate.