脂质体介导血管内皮生长因子对不同时间断蒂大鼠随意型皮瓣的影响

目的 通过血管内皮生长因子基因对大鼠随意型皮瓣的转染,探讨基因治疗对不同时间断蒂的大鼠随意型皮瓣成活的影响.方法 以SD大鼠为实验模型制作背部随意型皮瓣,实验组注入脂质体包裹的PcDNAVEGF165(目的 基因组),对照组分别注入PcDNA(空白质粒组)和生理盐水(生理盐水组),于用药后1、3、5、7 d,每组每时相点分别随机选取10只断蒂,断蒂后7 d处死大鼠,观察下述指标:①皮瓣成活率.②皮瓣组织标本行常规HE染色检测平均微血管数目及内径.③行VEGF免疫组织化学染色检测VEGF表达情况.④取皮瓣组织标本在电镜下观察超微结构.结果 ①皮瓣成活率:1、3、5、7 d断蒂实验组皮瓣成活率分别为(45.45±12.24)%、(82.95±3.81)%、(85.00±3.38)%、(85.96±3.25)%.1 d断蒂实验组与对照组比较差异无统计学意义(P>0.05),3、5、7 d断蒂各实验组明显高于相应对照组(P<0.05),3、5、7 d断蒂各实验组则随着断蒂时间的延迟差异无统计学意义(P>0.05).②平均微血管数目及内径:各实验组与相应对照组比较差异有统计学意义(P<0.05).③各实验组VEGF染色深度明显高于对照组(P<0.05).④超微结构:实验组内有新生血管形成,内皮细胞内可见较多粗面内质网,线粒体等结构,组织内成纤维细胞增多,细胞合成代谢旺盛.结论 皮下注射脂质体介导VEGF基因可提高皮瓣成活率,促进早期断蒂,是一种简单,高效,经济,相对安全的基因治疗方法.

Experimental study of the effect of liposome-mediated vascular endothelial growth factor gene on the flap survival in rats

Objective To investigate the effect of VEGF gene on the random flap survival after pedicle division at different time in rats. Methods The random-pattern flaps were formed on the back of the 120 SD rats. PcDNAVEGF165(gene) wrapped with liposome was'injected into the flaps in experimental group(n= 40). The flaps in the two control groups were injected with PcDNA (n = 40) or saline( n = 40). 1,3,5,7days after injection, 10 rats in each group were randomly selected to performed pedicle division. 7 days after pedicle division, the rats were killed to measure the flap survival rate. The microvessels was studied by histologic examination. The expression of VEGF was assessed by imunohistpchemical staining. The flaps were also examined under the electron uhrastrueture microscopy. Results ①Flap survival rote after pedicle division in experimental group at 1 day,3 days,5 days,7 days after injection,were (45.45 ±12.24)% ,(82.95± 3.81)% ,(85.00± 3.38) %, (85.96±3.25) %, respectively. The flap survival rates were significant different between experimental group and the control groups at 3, 5, 7 days after injection (P<0.05), but not at I days after injection (P> 0.05).② The average microvascular diameter and number in experimental group were significantly higher than those in control groups(P<0.05). ③The expression of VEGF in experimental group was significantly higher than that in the two control groups(P<0.05).④Ultrastrcture study showed more angiogenesis in experimental group. Conclusions Subcutaneous injection of liposome-mediated VEGF gene can increase the survival rate of flap with early pedicle division. It is a simple, efficient, economic, and the relatively safe gene therapy.