抗凝血功能化修饰的聚己内酯/壳聚糖复合小口径人工血管研究

抗凝血功能化修饰的聚己内酯/壳聚糖复合小口径人工血管研究
姚瑶，孔德领，崔云，赵强
基金项目：高等学校博士学科点专项科研基金（新教师类）（20100031120021）；天津市应用基础与前沿技术研究计划（自然科学基金）青年项目资金 （12JCQNJC09300） 作者简介：姚瑶，1988，女，硕士研究生，小口径人工血管 通信联系人：赵强，1978，男，副教授，生物活性材料.

（南开大学生命科学学院生物活性材料教育部重点实验室，天津 300071） 
摘要：小口径人工血管移植（直径小于6mm）是治疗心血管疾病的有效手段之一，但目前还没有商品化的产品成功应用于临床。其主要原因是血栓形成以及由此导致的血管狭窄。在本研究中，我们设计并构建了一种由合成可降解聚合物—聚（ε-己内酯）和天然聚合物—壳聚糖组成的具有复合纤维结构的小口径人工血管（内径2mm）。进一步，通过静电相互作用将具有抗凝血功能的肝素分子固定在壳聚糖纤维上，从而赋予人工血管抗凝血功能。人工血管上所结合的肝素分子具有一定的稳定性，并能保持缓释一个月以上。通过体外血小板粘附实验、凝血实验、考察了其血液相容性。肝素功能化修饰能够显著降低材料表面的血小板粘附，延长凝血时间（活化部分凝血活酶时间，APTT、血浆凝血酶原时间，PT和血浆凝血酶时间，TT），展现出良好的血液相容性。 
关键词：功能高分子，小口径人工血管；肝素；缓释；抗凝血。
中图分类号：063-0
Anti-thrombogenic property of PCL/Chitosan hybrid small-diameter

Yao Yao, Kong Deling, Cui Yun, Zhao Qiang
(Key Laboratory of Bioactive Materials,College of Life Science, Nankai University, Tianjin,300071)
Abstract: Nowadays, vascular transplantation by using small-diameter vascular grafts is an effective strategy for the treatment of cardiovascular diseases. In clinic, no commercial product  has been successfully utilized, because the thrombus formation and the subsequent occlusion. In this study, we developed a hybrid small-diameter vascular graft from synthetic polymer poly(ε-caprolactone) (PCL) and natural polymer chitosan by co-electrospinning technique (Dinner= 2mm). Heparin was immobilized onto the grafts through ionic bonding between heparin and chitosan fibers, thus introducing anti-thrombogenic function. The immobilization was relatively stable and heparin could continuously release from the grafts for more than one month. Heparin functionalization evidently improved the haemocompatibility of the PCL/CS vascular grafts, which was illustrated by the reduced platelet adhesion and prolonged coagulation time (APTT, PT, and TT) as shown in human plasma assay.
Key words: functional polymer;Small-diameter vascular grafts; Heparin; Controlled release;  Anti-thrombogenicity