层层自组装壳聚糖/肝素复合涂层膜对支架血栓形成的影响

目的:观察层层自组装壳聚糖/肝素复合涂层膜对支架血栓形成的影响.方法:通过逐层自组装的方式将壳聚糖和肝素逐层结合在316L不锈钢槽内,制成不同层数的涂层膜,以凝固法测定健康人血液在聚合物膜和不锈钢上作用2 h后的部分凝血活酶时间(APTT)、凝血酶原时间(PT)和凝血酶时间(TT),并检测其抗凝血功能的稳定性.制备壳聚糖/肝素复合涂层膜支架,研究复合涂层膜支架在猪动静脉分流血栓模型中对支架血栓形成的影响.结果:备组复合涂层膜APTT和TT均较316L不锈钢组极显著延长(P<0.01),并且APTT和TT延长和复合涂层膜层数增加相关.复合涂层膜在2周内上述凝血功能无显著差异(P>0.05).在猪动静脉分流血栓模型中,复合膜涂布的金属支架形成的血栓重量极显著低于316L裸支架(P<0.001).结论:层层自组装壳聚糖/肝素复合涂层膜具有极显著的抗支架血栓作用,而且具有良好的稳定性.

Effects of composite Chitosan/Heparin coated membrane through a layer by layer self-assemble technique on stent thrombosis

Objective:To investigate the influence of the composite chitosan/heparin coated membrane through a layer-by-layer self-assemble technique on stent thrombosis.Methods: The composite chitosan/heparin coated membrane,which was assembled through a layer-by-layer technique,was attached to the inside surface of cylinder made from 316L stainless steel flake to form membranes of different layers of chitosan/heparin.The activated partial thromboplastin time (APTT),prothrombin time (PT) and thrombin time (TT) of the whole blood samples of healthy controls were examined by clotting method; and the stability of its anticoagulation effect was also examined.The influence of the prepared composite chitosan/heparin coated membrane on coronary stent thrombosis was investigated using swine model of arteriovenous shunt thrombus.Results: The APTT and TT were significantly longer in the composite coated membrane group compared with those of 316L stainless steel group (P<0.01).Moreover,the prolongation of APTT and TT was correlated with the increase of coated layers.The anticoagulant function of chitosan/heparin coated membrane was stable for two weeks(P>0.05).The weight of thrombus was significantly lower in the coated stent group than that in 316L stainless steel group(P<0.001).Conclusion: The composite chitosan /heparin coated membrane made by layer-by-layer self-assemble has effective and stable anti-thrombotic function.