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Research and development of the small caliber artificial blood vessel with antithrombogenicity

具有抗血栓形成作用的小口径人工血管的研发

基本信息

批准号：
58870070
负责人：
SAKURAI Yasuhisa
金额：
$ 3.65万
依托单位：
Tokyo Women's Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1983
资助国家：
日本
起止时间：
1983 至 1985
项目状态：
已结题

项目摘要

The surface of block type copolymers having microphase separated structure of alternating lamellar type shows the excellent antithrombogenicity through the suppression of platelet adhesion and platelet activation. By using the microsphere-column method which was developed by us, adhesion of platelets on sample materials was examined in vitro. On the surface of homopolymer such as PHEMA or polystyrene, a large amount of platelets adhered, aggregated and extensively activated to form thrombus. On the contrary, platelet adhesion was significantly suppressed on the block type copolymer such as HEMA-St, FAA-St. It was indicated that the surface free energy gap between microdomains consisted of HEMA and St, or FAA and St was the determinant factor in formation of organized and stable layer of adsorbed proteins which gave intense influence to platelet adhesion and activation. In addition, prolonged platelet aggregation time (PAT) clearly indicates that the activation of adhered platelets was effectively inhibited on the surfaces with microphase separated structure.In ex vivo experiment (rabbit A-V shunt), duration of graft patency made of block type copolymers was distinguishably longer than of graft made of homopolymer. Time-course change in number and function of circulating platelets was remarkable in case of graft made of homopolymer. On the other hand, in case of block copolymer, the number and function of circulating platelets were maintained in the normal range after shunt formation. From these results, the excellent antithrombogenicity and hemocompatibility of the block type copolymers was confirmed. In coronary by-pass experiment in dogs, 1.5 mm internal diameter prosthetic tube coated with HEMA-St was kept it patency as long as four weeks.

具有微相分离交替层状结构的嵌段型共聚物表面通过抑制血小板粘附和血小板活化表现出优异的抗血栓性。采用自制的微球柱法，对血小板在样品材料上的粘附进行了体外检测。在PHEMA或聚苯乙烯等均聚物表面，大量血小板粘附、聚集并广泛活化形成血栓。相反，嵌段型共聚物（HEMA-St, fa - st）对血小板粘附有明显抑制作用。结果表明，由HEMA和St或FAA和St组成的微域之间的表面自由能间隙是形成有组织稳定的吸附蛋白层的决定因素，对血小板的粘附和活化有强烈的影响。此外，血小板聚集时间延长（PAT）清楚地表明，粘附血小板在微相分离结构表面的活化被有效抑制。在离体实验（兔A-V分流）中，嵌段型共聚物接枝的通畅时间明显长于均聚聚合物接枝。均聚物接枝后循环血小板数量和功能随时间变化显著。另一方面，嵌段共聚物在分流形成后，循环血小板数量和功能维持在正常范围内。结果表明，嵌段型共聚物具有良好的抗血栓性和血液相容性。在犬冠状动脉旁路实验中，将1.5 mm内径的假体管涂覆HEMA-St，保持通畅4周。