雷帕霉素联合CD34抗体复合支架快速捕获外周血中内皮祖细胞

Specificity to capture endothelial progenitor cells in the peripheral blood by CD34 antibody applied on a rapamycin eluting stent

背景:临床用于治疗血管狭窄疾病的药物洗脱支架和单纯内皮修复型支架存在内皮化延迟和植入后再狭窄的问题。雷帕霉素联合CD34抗体复合支架可协同抵消抗增殖药物的内皮化延迟和内膜的过度增生,目前尚处于实验研究阶段。目的:观察雷帕霉素联合CD34抗体复合支架捕获内皮祖细胞能力及其所捕获内皮祖细胞的分化特征。方法:通过扫描电镜及间接免疫荧光观察雷帕霉素联合CD34抗体复合支架体外捕获外周血内皮祖细胞形态及其分化特征。通过荧光显微镜观察雷帕霉素联合CD34抗体复合支架植入兔耳动脉后捕获内皮祖细胞情况及支架片段的内皮化程度。结果与结论:扫描电镜观察到CD34抗体涂层支架可捕获直径6-8μm的纺锤状细胞,24 h时细胞变得充盈饱满。所捕获细胞具有内皮祖细胞的外形特征。间接免疫荧光观察CD34抗体支架表面可见大量血管内皮生长因子受体2阳性细胞黏附的红色荧光斑点。免疫荧光观察到CD34抗体涂层支架植入兔耳动脉24 h大部分被血管内皮细胞所覆盖,48 h达到完全覆盖,未见细胞异常聚集。结果表明雷帕霉素联合CD34抗体复合支架能特异性快速捕获外周血液中的血管内皮祖细胞,植入体内48 h即可完成血管内皮细胞覆盖,实现了支架快速内皮化,可促进内皮细胞修复。

BACKGROUND： Drug eluting stents and endothelium stents for clinical treatment of vascular stenosis can lead to delayed endothelialization and restenosis. A rapamycin eluting stent combined with CD34 antibody can play a synergistic role to offset delayed endothelialization and intimal hyperplasia due to antiproliferative drugs, but it is still in the pilot phase. OBJECTIVE： To observe the ability of rapamycin eluting stent combined with CD34 antibody to capture endothelial progenitor cells, and to observe the differentiation characteristics of the captured cells. METHODS： Scanning electron microscope and indirect immunofluorescence were used to observe the morphology and differentiation characteristics of captured endothelial progenitor cells. Under a fluorescence microscope, we observed the captured endothelial progenitor cells and the degree of endothelialization after implantation of the rapamycin eluting stent combined with CD34 antibody into rabbit ear vein.RESULTS AND CONCLUSION： Under the scanning electron microscope, fusiform-like cells with a diameter of 6-8 μm were captured by the composite stent, and 24 hours later, the cells became full-shaped. The captured cells had the appearance characteristics of endothelial progenitor cells. Results from indirect immunofluorescence observation showed that there were a lot of red fluorescent spots on the coating which represented adherent cells positive for vascular endothelial growth factor receptor-2; the composite stent was largely covered with vascular endothelial cells at 24 hours after stent implantation, and fully covered at 48 hours, but there was no abnormal cell cluster. These findings indicate that the rapamycin eluting stent combined with CD34 antibody can be specific to rapidly capture endothelial progenitor cells in the peripheral blood, and the stent can be completely covered with vascular endothelial cells at 48 hours after stent implantation, thereby achieving rapid endothelialization and promoting the repair of endothelial cells.