Rhodes Nicholas P, Wilson Darren J, Williams Rachel L
Clinical Engineering, School of Clinical Sciences, University of Liverpool, Daulby Street, Liverpool L69 3GA, UK.
Biomaterials. 2007 Nov;28(31):4561-70. doi: 10.1016/j.biomaterials.2007.07.008. Epub 2007 Jul 31.
Medical-grade polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS), polyetherurethane (PEU) and ultrahigh molecular weight polyethylene (UHMWPE) were plasma treated with O2, Ar, N2 and NH3. Their surface properties were characterised using X-ray photoelectron spectroscopy (XPS), static secondary ion mass spectroscopy (SSIMS), atomic force microscopy (AFM) and dynamic contact angle (DCA) analysis. Platelet adhesion, aggregation, activation and release of microparticles were determined after contact with whole blood in a cone and plate viscometer. Activation of the coagulation system was quantified in a static environment using a partial thromboplastin time (PTT) assay. The chemical compositions of the untreated surfaces were found to be very similar to those of the bulk material except for PEU, whose surface was comprised almost entirely of soft ether segments. For all materials, the different plasma treatments resulted in moderate etching with the incorporation of functional groups and removal of side groups: defluorination, dehydrogenation, cleavage of methyl side groups and soft segments for PTFE, UHMWPE, PDMS and PEU, respectively. Consequently, plasma treatment resulted in increased wettability in all cases. Blood contact with the virgin materials resulted in activation of platelets and the clotting cascade. Plasma treatment resulted in a significant reduction in platelet adhesion for all materials and all treatments. In the case of PTFE and PEU, the activation status of these cells was also reduced. Plasma treatment of all materials reduced fluid-phase CD62P expression. Platelet aggregate size correlated well with degree of aggregate formation, but many treatments increased the degree of aggregation, as was the case for microparticle shedding. There was no correlation between CD62P expression, aggregate formation and platelet microparticle (PMP) shedding. It is concluded that despite incorporation of the same chemical groups, the pattern of response to blood in vitro is not the same across different polymers.
医疗级聚四氟乙烯（PTFE）、聚二甲基硅氧烷（PDMS）、聚醚聚氨酯（PEU）和超高分子量聚乙烯（UHMWPE）用氧气、氩气、氮气和氨气进行了等离子体处理。使用X射线光电子能谱（XPS）、静态二次离子质谱（SSIMS）、原子力显微镜（AFM）和动态接触角（DCA）分析对其表面性质进行了表征。在锥板粘度计中与全血接触后，测定血小板的粘附、聚集、活化和微粒释放情况。使用部分凝血活酶时间（PTT）测定法在静态环境中对凝血系统的活化进行定量。发现除PEU外，未处理表面的化学成分与块状材料非常相似，PEU的表面几乎完全由软醚链段组成。对于所有材料，不同的等离子体处理导致适度蚀刻，同时引入官能团并去除侧基：分别对PTFE、UHMWPE、PDMS和PEU进行脱氟、脱氢、甲基侧基和软链段的裂解。因此，等离子体处理在所有情况下均导致润湿性增加。与原始材料的血液接触导致血小板活化和凝血级联反应。等离子体处理导致所有材料和所有处理的血小板粘附显著减少。对于PTFE和PEU而言，这些细胞的活化状态也有所降低。所有材料的等离子体处理均降低了液相CD62P表达。血小板聚集体大小与聚集形成程度密切相关，但许多处理增加了聚集程度，微粒脱落情况也是如此。CD62P表达、聚集形成与血小板微粒（PMP）脱落之间没有相关性。得出的结论是，尽管引入了相同的化学基团，但不同聚合物在体外对血液的反应模式并不相同。
