中文摘要：

目的探讨转染血管内皮细胞生长因子（VEGF）基因的大鼠骨髓间充质干细胞（MSCs）同种异体移植促进缺血皮瓣的血管新生，从而提高皮瓣存活率的可能性。方法体外分离、培养、鉴定SD大鼠MSCs，PcDNA3．1（-）／VEGF165质粒转染MSCs，免疫荧光方法检测MSCs体外表达VEGF的情况，CM-DiI标记MSCs。SD大鼠随机分3组：A组[PcDNA3．1（-）／VEGF165质粒转染的MSCs移植]、B组（单纯MSCs移植）、C组（DMEM-F12培养基）。每只大鼠背侧皮下按组分别注射细胞悬液和培养基，注射后ELISA法连续检测大鼠血浆VEGF浓度，注射后第4天掀起1个蒂在尾侧的9cm×2cm的随意皮瓣。在术后第14天分别观察皮瓣的存活率、激光多普勒血液监测仪监测血流灌注、CD34免疫组织化学检测皮瓣毛细血管密度、荧光显微镜检测MSCs在皮瓣内的分布和存活状况。结果转染VEGF165基因的MSCs体外和体内检测均高表达VEGF165蛋白。A、B、C三组的皮瓣存活率分别为（83．1±2．6）％、（66．4±6．1）％、（51．5±7．5）％（P〈0．05）；A、B、C三组的毛细血管密度（条／mm^2）分别为：89．2±6．1、57．1±4．7、28．7±2．8（P〈0．05）；血流灌注比值A组高于B、C两组，B组高于C组（P〈0．05）；转染VEGF165基因的MSCs移植SD大鼠皮瓣后，MSCs存活并参与血管新生。结论转染VEGF基因的大鼠MSCs体外培养后异体移植可促进缺血皮瓣的血管新生，提高存活率。

英文摘要：

Objective To investigate the feasibihty of transplantation of mesenchymal stem cells （MSCs） transduced by vascular endothelial growth factor （VEGF） gene into iscbemic random skin flap in the rats with increased neovascularization. Methods MSCs were isolated from SD rat bone marrow and cultured in vitro. Plasmid PcDNA3. 1 （ - ）/VEGF165 containing VEGF gene was transfected into the MSCs by Geneporter2. MSCs without transduction were used as controls. Immunofluorescence was used to detect the expression of VEGF protein in MSCs in vitro. The MSCs were stained with CM-DiI. Thirty rats were randomly divided into 3 groups equally. The rats in group A were injected with MSCs transducted with PcDNA3.1 （ - ）/VEGF165 plasmid, those in group B with MSCs, and those in group C with only medium. ELISA was used to quantify VEGF levels in plasma from animals after injection of VEGF-transduced MSCs. Four days after injection, random dorsal skin flaps measuring 9 cm × 2 cm were elevated and treated at the same time. The skin flap survival rates were measured on the day 14 after operation. The blood perfusion of flap was monitored by the laser Doppler flowmetry, and the capillary density of flap was detected by CD34 immunofluorescence. The labeled MSCs were searched by fluorescent microscope. Results Transplanted MSCs expressed VEGF highly in vitro and in vivo. Transplanted MSCs survived and were incorporated into the capillary networks in the ischemic flaps of SD rats. The flap survival rate, capillary density and the blood perfusion of the flaps in group A were significantly higher than those in the other two groups （P 〈 0.05 ）. Conclusion MSCs transducted with PcDNA3.1 （ - ）/VEGF165 plasmid can increase ischemic flaps neovascularization and augment the survival areas.