Lando（R）双层人工皮对猪皮肤全层缺损创面血管化的影响

Effects of Lando（R） bilayer artificial skin on vascularization of wounds in pigs with full-thickness loss

目的 动态观察Lando^（R）双层人工皮（以下简称双层人工皮）应用于猪皮肤全层缺损创面血管化.方法 实验以8头一级藏猪为动物模型,体质量为30 ～ 35 kg,雌雄不限,在每头猪背部正中线两侧分别切取3个边长5 cm深达肌肉筋膜的正方形全层皮肤缺损创面,采用同体自身对照,右侧创面行双层人工皮移植术（实验组）,左侧创面以凡士林油纱覆盖（对照组）.分别于术后第3、7、14、21天按随机数字表随机处死猪,行创面大体观察,同时取材行苏木素-伊红（HE）染色、Masson三色染色后光镜下观察创面修复细胞、炎性反应、胶原纤维排列及支架降解情况,免疫组织化学法检测标本中CD31的表达并计数新生血管数目.结果 实验组创面较对照组干燥,感染发生率较低,肉芽组织生长较平整.光镜下见实验组较对照组组织充血水肿和炎性反应轻微,肉芽组织化速度快,于14d左右支架血管化已基本完成.随时间的延长,修复细胞逐渐减少,胶原纤维排列更为规整且粗大,支架有降解趋势.免疫组织化学结果显示,CD31表达阳性的新生血管数目两组于术后第3天无明显表达,于第7天开始升高,实验组于术后第14天达到高峰,对照组于第21天达到最高.实验组于术后第7、14天高于对照组,于21 d低于对照组,组间差异有统计学意义（P＜0.05）.结论 双层人工皮在创面愈合过程中可快速诱导血管生成,有利于新生真皮组织的重塑,从而改善创面愈合条件,为后续联合移植自体超薄皮片奠定基础.

Objective To investigate the effects of Lando^（R） bilayer artificial skin on vascularization of wounds in pigs with full-thickness loss.Methods There were eight pigs,every pig was inflicted with 6 full-thickness loss wounds on the back,which were divided into two groups for the study.The study group was covered by bilayer artificial skin,while the other received Vaseline gauze as control.For each group,at the 3,7,14 and 21 d,General situation of wounds were observed and wound specimens were obtained for hematoxylin and eosin （HE） staining,Masson staining and CD31 expression which was examined by means of immunohistochemistry method.Results Compared with the control group,wounds in study group were more dryer with lower incidence of infection.Granulation tissues in study group was relatively flat.HE staining demonstrated that granulation tissue in the study group increased faster than in control group,and less inflammation and tissue congestion and edema in the study group than in control.Collagen fibers in the study group were of more coarse and regular arrangement than in control.Dermal regeneration scaffolds were gradually of degradation with time.There was not significant expression of the CD31 at 3 d.The expression of the CD31 had an increasing tendency at 7 d in each group.The CD31 expression,in study group,reached a peak at the 14 d,while control group at the 21 d.The CD31 expression was higher in study group at the 7 d and 14 d than in control group.However,it was lower in study group at the 21 d when compared with control group.Conclusion Bilayer artificial skin can promote microvessel formation and provide favorable conditions for autologous split-thickness skin graft.