Tissue-engineered acellular dermis repairs a skin ulcer：its preparation and healing mechanism / 中国组织工程研究

ABSTRACT

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.