血管内皮细胞生长因子基因涂布支架预防门腔静脉分流支架狭窄的实验研究

phVEGF165 gene transfer for prevention of stent restenosis after TIPSS

目的 通过转染人血管内皮细胞生长因子 (phVEGF)基因促使血管内支架处内皮细胞生长以预防支架内再狭窄的发生。方法 将 phVEGF基因局部涂布于由多聚赖氨酸包被的血管内支架上 ,采用介入方法经颈静脉插管至 6只狗的右肝静脉 ,同时以置入裸支架为对照组。结果 支架置入后第 1周 ,在转染 phVEGF基因组局部血管组织内 ,RT PCR法检测到 phVEGF的表达 ;荧光显微镜下观察到部分血管内皮细胞发出黄绿色荧光 ;扫描电镜显示支架腔内皮分化程度较对照组高。置入后第 8周 ,转染 phVEGF基因组 (n =6 )血管造影显示支架通畅 ,而对照组 (n =5 )则均发生再狭窄 ;支架端肝静脉血管平均新生内膜厚度 ,平均新生内膜面积 ,百分狭窄面积均明显小于对照组 [(0 .16 7± 0 .10 3)mm比 (1.96 5± 0 .72 5 )mm ,(2 .5 6 8± 1.5 2 6 )mm2 比 (17.5 96± 7.939)mm2 ,(11.46 2± 5 .42 3) %比 (6 8.5 0 5± 2 4.0 0 3) %,P <0 .0 5 ];免疫组化显示平滑肌细胞增殖程度 (PLI)也显著高于对照组 [(0 .0 30± 0 .0 0 2 )比 (0 .0 42± 0 .0 0 3) ,P <0 .0 5 ) ]。结论 phVEGF基因涂布支架可加速支架内皮化的形成 ,进而抑制血管内支架置入术后血栓形成和内膜增殖引起的再狭窄发生。

Objective To test the hypothesis that locally direct gene transfer of human vascular endothelial growth factor(phVEGF) 165 could passivate hepatic venous metallic stents by accelerating endothelialization and augmenting biocompatibility of endovascular stent. Methods The complexes of pAdTrackCMV and lipofectamine was smeared homogeneously to the surface of stent coating with poly-1-lysine. Bare stainless steel stents were used as controls. All stents were implanted into the hepatic right vein by the procedure of transjugular intrahepatic venous stent deployment. Results At the end of 1 week after implantation, the site -specific expression of phVEGF was detected by RT-PCR. Green fluorescence and the expression of phVEGF gene were detected in the transfered stented vessel of the treatment group. These phenomena were not observed in the control group. Scanning electron microscopy revealed that the endothelialization of stent was more pronounced in the treatment group than that in control group. At the end of 8 weeks after implantation, quantitative angiography analysis showed the degree of internal diameter stenosis was less severe in the treatment group compared with the control group. Mean neointima thickness, mean neointima areas and percent cross-sectional area narrowing in treatment group was significantly fewer than that in the control group, respectively. Immunohistochemistry analysis revealed that the proliferation of vascular smooth muscle cells was more active in control group than that in the treatment group. Conclusions Local gene transfer of phVEGF165 can passivate endovascular stents by accelerating stents endothelization and enhancing their biocompatibility in hepatic vein, resulting in reducing thrombus formation and attenuating intimal hyperplasia.