组织工程技术修复皮肤缺损的动物实验

目的　探索应用组织工程技术修复包括皮下组织的皮肤缺损的方法。方法　长枫杂交仔猪 2 0只 ,取腹部 2cm× 2cm全厚皮肤 ,酶消化法获取表皮细胞与成纤维细胞。经原代培养 ,将处于对数生长期的表皮细胞、成纤维细胞分别与 30 %氧化异丙烯F 1 2 7(pluronicF 1 2 7)混匀成细胞悬液后 ,种植于聚羟基乙酸 (polyglycolicacid ,PGA)形成细胞 生物材料复合物 ,用于修复自体背部直径 4cm皮肤缺损 ,以单纯生物材料 (PGA 30 %氧化异丙烯F 1 2 7)修复作为对照组。术后 1、2、4、8周取材 ,通过组织学方法评价新生组织。结果　实验组 :第 1周 ,形成含表皮与真皮两层结构的组织工程化皮肤 ;第 2周 ,表皮与真皮均较前增厚 ;第 8周 ,组织工程化皮肤的结构与正常皮肤相似 ,仅缺乏毛发、毛囊和汗腺等附属器。对照组 :则无皮肤形成 ,仅见大量肉芽组织。结论　以原代培养的表皮细胞与成纤维细胞作为种子细胞 ,PGA 30 %氧化异丙烯F 1 2 7为细胞载体的方法可修复皮肤缺损。

Repair of porcine full-thickness skin defects by tissue engineering technique

Purpose To explore a feasible method to repair full-thickness skin defects utilizing tissue engineering techniques. Methods The skin specimens were cut from abdomen of Changfeng swines, then keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA and type II collagenase. The cells were seeded in Petri dishes for primary culture. When they were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the dishes. A biodegradable material-Pluronic F-127 was prefabricated and mixed with these cells, and then the cells-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology was observed in 1, 2, 4 and 8 weeks postsurgery. Results The keratinocytes and fibroblasts survived and secreted matrix in the three-dimensional structure and continued reproducing. The cells-Pluronic-PGA compounds could repair autologous full-thickness skin defects. Histologically, the tissue engineered skin was similar to normal skin with stratified epidermis overlying a moderately thick dermis. Conclusion Tissue engineered skin can repair autologous full-thickness skin defects with primary-cultured keratinocytes and fibroblasts as seed cells and PGA-Pluronic as a cell carrier.