一种新型具有内皮祖细胞捕获能力的冠状动脉支架涂层材料体外血液相容性研究

目的：研究冠状动脉支架材料表面RGD修饰PEG-PLA-PGL共聚物涂层体外血液相容性，为该聚合物作为冠状动脉内支架涂层材料的临床应用提供实验依据。方法以裸钢片、PEG-PLA-PGL聚合物涂层钢片为对照组，通过体外溶血实验、血小板吸附数量测定、抗凝血时间测定及蛋白吸附评价RGD修饰PEG-PLA-PGL共聚物（PEG-PLA-PGL/RGD）涂层钢片的体外血液相容性。结果裸钢片、PEG-PLA-PGL组、PEG-PLA-PGL/RGD组三组钢片溶血率均＜5%，无溶血作用；与标本血比较，三组钢片APTT均表现出明显差异（P＝0.047、0.044、0.036），均能改善标本血抗凝血性能；PEG-PLA-PGL涂层与裸钢片相比，在各项所测指标中未表现出明显差异；接枝 RGD 后 PEG-PLA-PGL/RGD 涂层在血小板吸附及白蛋白吸附方面优于裸钢片，有统计学差异（P＝0.046、0.043），一定程度上提高了裸钢片的血液相容性。结论与裸钢片相比，RGD在聚合物表面的接枝提高了其血液相容性，PEG-PLA-PGL/RGD有望成为广阔发展前景的EPC捕获支架生物活性涂层材料。

Blood compatibility of a new type of EPC capture coronary stent coating in vitro

Objective To investigate the blood compatibility of PEG-PLA-PGL/RGD on 316L stainless steel surface in vitro so as to provide further experimental reference for its clinical application. Methods The blood compatibility was evaluated by hemolysis assay, platelet adhesion experiments, anticoagulant time measurement and protein adsorption test. Results The hemolysis rate of each group was less than 5%, which suggested they were all avirulent;APTT remarkable prolonged compared with plasma sample, showed anti-coagulant property of steel in three groups（P=0.047, 0.044, 0.036）. Compared with bare steel, PEG-PLA-PGL steel had no apparent differences in any tests, meanwhile, PEG-PLA-PGL/RGD steel adsorbed less platelets but larger amount of albumin（P=0.046, 0.043）. Conclusion Blood compatibility of PEG-PLA-PGL/RGD steel has been improved compared with PEG-PLA-PGL steel and bare steel. PEG-PLA-PGL/RGD might be a potential appropriate material for coronary stent.