制备组织工程脱细胞真皮修复皮肤溃疡创面的愈合机制

Tissue-engineered acellular dermis repairs a skin ulcer: its preparation and healing mechanism

背景:近年来,人尸体脱细胞真皮在真皮缺损、软组织充填中得到应用,但是该修复材料价格昂贵,来源相对有限。目的:分析组织工程脱细胞真皮修复皮肤溃疡创面的效果。方法:随机对照方法将S D大鼠分为自体未脱细胞网状层真皮组和脱细胞真皮组。采用低渗溶液、2.5 g/L胰蛋白酶、体积分数0.5%Triton X-100和PBS方法制备组织工程脱细胞真皮,建立大鼠皮肤溃疡创面模型,自体未脱细胞网状层真皮组移植自体断层皮片进行覆盖,脱细胞真皮组采用新型颗粒状组织工程脱细胞真皮进行修复,比较两组修复效果及对皮肤溃疡创面愈合的机制。结果和结论:(1)获得的组织工程脱细胞真皮为白色状,常温下大体观察呈颗粒状;(2)苏木精-伊红染色显示组织工程脱细胞真皮内部呈现出"树枝状"分布,并且胶原纤维束的间隙相对较大;(3)脱细胞真皮组植皮后2,3,4,8周创面移植皮肤成活率,显著高于自体未脱细胞网状层真皮组(P<0.05);(4)脱细胞真皮组大鼠植皮后3,4,8周创面收缩率显著高于自体未脱细胞网状层真皮组(P<0.05);(5)脱细胞真皮组创周正常皮肤胶原纤维束平均直径及间隙率显著高于自体未脱细胞网状层真皮组(P<0.05)。(6)结果提示:组织工程脱细胞真皮制备方法相对简单,制备条件温和,且制备的组织工程脱细胞真皮形态规则,修复皮肤溃疡创面效果理想,能降低真皮内D NA残留量,能显著改善体内某些生物力学特性,促进创面愈合。

BACKGROUND： In recent years, acel ular human cadaveric dermis has been applied for repairing dermal defects and fil ing soft tissues, but this repair material is expensive and difficult to obtain. OBJECTIVE： To explore the repair effect of tissue-engineered acel ular dermis on wound healing of skin ulcer. METHODS： Sprague-Dawley rats were randomly divided into autologous reticular dermis and acel ular dermis groups. The tissue-engineered acel ular dermis was prepared by hypotonic solution, 2.5 g/L trypsin, 0.5% Triton X-100 and PBS solution, and in the meanwhile, a rat model of skin ulcer was established. Then, autologous skin graft and tissue-engineered acel ular dermis were transplanted into the autologous reticular dermis group and acel ular dermal group, respectively. Subsequently, comparative study about the repair effect and relative mechanism between two groups was performed. RESULTS AND CONCLUSION： The tissue-engineered acel ular dermis showed a white and grainy shape at room temperature. And hematoxylin-eosin staining showed that： the internal structure of tissue-engineered acel ular dermis exhibited a dendritic distribution, and the gap between col agen fiber bundles was relatively large. At 2, 3, 4 and 8 weeks after dermal transplantation, the survival rate of skin graft in the acel ular dermis group was significantly higher than that in the autologous reticular dermis group （P 〈 0.05）. And the wound contraction rate in the acel ular dermis group was significantly higher than that of the autologous reticular dermis group at 3, 4 and 8 weeks after dermal transplantation （P 〈 0.05）. In addition, the average diameter and clearance rate of col agen fibers in the normal skin around wound in the acel ular dermis group were significantly higher than those of autologous reticular dermis group （P 〈 0.05）. To conclude, it is relatively simple to prepare tissue-engineered acel ular dermis under mild conditions, and the prepared tissue-engineered acel ular dermis presents a regular shape. Moreover, this acel ular dermis achieves desired outcomes in repairing dermal defects, which can promote wound healing by reducing the intradermal DNA residual and significantly improving some biomechanical properties in vivo.