一种新型的无细胞真皮替代物的研制及移植试验

Preparation and implantation of a new substitute of acellular dermal matrix

目的 研制带密集微孔的异种无细胞真皮替代物 ,提高真皮替代物与自体皮片复合移植的存活率。方法 采用机械的方法在异种无细胞真皮替代物上行密集的贯穿性打孔 ,孔径为 5 0 0～ 80 0 μm ,孔间距为3～ 5mm。将微孔无细胞真皮替代物埋入SD大鼠皮下 ,观察孔径大小的变化和新生血管的形成 ;同时将微孔无细胞真皮替代物与SD大鼠大张刃厚皮片复合移植 ,观察移植存活率及创面愈合情况。结果 在无细胞真皮替代物上打孔后可明显增强对创面基底血浆等渗液的渗透性 ,植入全层皮肤切除创面 ,基底血浆等渗液可通过孔隙渗透到无细胞真皮表皮面。埋入皮下 1周 ,孔隙仍较明显 ,部分孔隙可见有红细胞通过 ;2～ 3周时 ,新合成的胶原逐渐填充孔隙 ,孔腔变小。微孔无细胞真皮替代物与SD大鼠刃厚皮片复合移植的成活率为 89.5 % ,明显高于无孔的无细胞真皮替代物 (6 3.2 % ) ,创面愈合后外观光滑平整 ,具有良好的弹性及柔韧性。结论 带有密集微孔的无细胞真皮替代物可明显提高移植成活率 ,且不影响创面愈合后外观 。

Objective To prepare acellular xeno dermal substitute with micropores in order to promote engraftment rate of autologous skin combined with dermal substitute. Methods Acellular dermal substitute was punched mechanically to produce pores from 500～800 μm in diameter with partition width of 3～5 mm and then the microporous dermal substitute was implanation hypodermically in SD rats. The change of diameter of the pores and formation of new blood vessels in the dermal matrix were observed and then, the acellular dermal substitute was transplanted in one step to the full thickness defect wound combined with overlying sheet ultrathin skin in SD rats. The survival rate and quality of wound healing were assessed. Results Micropores punched on dermal substitute were responsible for the penetration of isotonic plasma. After the dermal substitute was grafted to the full thickness of skin excision wound, plasma could extravasate to the surface from the wound bed. Subdermal implantation of dermal matrix showed that 1 week postgrafting the pores were still obvious, and some of them filled with red blood cells, after 2 to 3 weeks, the diameter of the pores became smaller due to collagen deposition. The survival rate of autologous skin placed over porous dermal matrix was 89.5%, being significantly higher than the non porous dermal substitute(63.2%). Conclusion Microporous dermal matrix has higher take up rate than non porous one and good external appearance after wound healing, which would be an ideal dermal substitute.