大网膜联合组织工程心肌移植改善大鼠心肌梗死后移植细胞的存活

Omentum wrapped MSCs-PLGA engineer heart tissue improve transplanted cell survival in myocardial infarction rats

目的观察大网膜增加组织工程心肌（EHT）血供，改善微环境后对大鼠心肌梗死模型上移植细胞存活的影响。方法结扎雌性Sprague-Dawley（SD）大鼠左冠状动脉，制作心肌梗死模型。以雄性大鼠骨髓间充质干细胞（MsCs）为种子细胞，种植于共聚乙交酯-丙交酯（poly lactic acid-CO-glycolicacid,PLGA）补片上构建EHT。符合心肌梗死标准的动物随机分成网膜EHT组、单纯EHT组、心肌梗死组和假手术组，每组6只鼠。组织工程心肌植入后4周，用TUNEL法检测移植细胞凋亡，标本取材做病理学检查，免疫组化方法检测内皮细胞标志物vWF表达。结果TUNEL检测发现EHT植入后1周网膜EHT组移植细胞凋亡少于单纯EHT组（P〈0．05），2周、4周时两组间凋亡无明显差异（P〉0．05）。vWF染色发现EHT植入后1周、2周、4周网膜EHT组微血管密度均高于单纯EHT组（P〈0．05）。结论网膜包裹MSCs-PLGA构建的EHT覆盖于心肌梗死表面后能够通过增加微血管密度，改善局部微环境，减少移植细胞的早期凋亡，促进移植细胞的存活。

Objective We construct engineer heart tissue （EHT） with MSCs and PLGA. We grafted the EHT onto the surface of female myocardial infarction SD rats. We hypothesized that omentum wrapped MSCs-PLGA EHT would improve transplanted cell survival when the ischemie was attenuated. Methods MSCs were isolated fi＇om male SD rats and cultured on PLGA polymers in vitro. Eight weeks after female SD rats were subjected to left anterior descending ligation, two treatments were conducted： MSCs-PLGA EHT implantation （group E）, and omentum wrapped MSCs-PLGA EHT implantation （group O）. Control group underwent no treatment （group C）. The myocardial infarction group （group MI） underwent LAD ligation only. 4 weeks after EHT transplantation, the following variables were evaluated： cell apoptosis by TUNEL staining, microvascular density by immunochemistry staining of vWF, specimen staining by picrosirins red. Results Transplanted ceil apoptosis was significantly reduced in group 0 compared with group E one week after EHT implantation （ P 〈 0.05）. Farter W characterized microvascnlar density was higher in group 0 compared with group E （ P 〈 0.05）. Picmsirins red staining showed infarction ventricular wall thickness of group 0 was significantly increased compared with group MI and group C （ P 〈 0. 05）. Conclusion Transplantation of MSCs-PLGA EHT with great omentum wrapping resulted higher microvessel density. The ameliorate reduced ceil apoptosis