Department of Chemical Engineering, University of Washington-Seattle, United States.
Department of Bioengineering, University of Washington-Seattle, United States.
Acta Biomater. 2018 Sep 15;78:23-35. doi: 10.1016/j.actbio.2018.07.042. Epub 2018 Jul 21.
Surface-induced thrombosis is still a significant clinical concern for many types of blood-contacting medical devices. In particular, protein adsorption and platelet adhesion are important events due to their ability to trigger the coagulation cascade and initiate thrombosis. Poly(lactic acid) (PLA) has been the predominant polymer used for making bioresorbable stents. Despite long-term advantages, these stents are associated with higher rates of early thrombosis compared with permanent metallic stents. To address this issue, we modified the surface of PLA with a perfluoro compound facilitated by surface activation using radio frequency (RF) plasma. Fluoropolymers have been extensively used in blood contacting materials, such as blood vessel replacements due to their reduced thrombogenicity and reduced platelet reactivity. The compositions of plasma-treated surfaces were determined by electron spectroscopy for chemical analysis (ESCA). Also, contact angle measurements, cell cytotoxicity and the degradation profile of the treated polymers are presented. Finally, relevant blood compatibility parameters, including plasma protein adsorption, platelet adhesion and morphology, were evaluated. We hypothesized that tight binding of adsorbed albumin by fluoropolymers enhances its potential for blood-contacting applications.
Although bioresorbable stents made from poly(lactic acid) (PLA) may have long-term clinical advantages, they have shown higher rates of early thrombosis as compared with permanent metallic stents. To improve the thromboresistance of PLA, we developed a novel method for surface fluorination of this polymer with a perfluoro compound. Fluoropolymers (e.g., expanded polytetrafluoroethylene) have long been used in blood-contacting applications due to their satisfactory clinical performance. This is the first report of PLA surface fluorination which might be applied to the fabrication of a new generation of fluorinated PLA stents with improved platelet interaction, tunable degradability and drug release capabilities. Also, we describe a general strategy for improving the platelet interactions with biomaterials based on albumin retention.
表面诱导的血栓形成仍然是许多类型的与血液接触的医疗设备的一个重要临床问题。特别是，由于蛋白质吸附和血小板黏附的能力能够触发凝血级联反应并引发血栓形成，因此这两个事件是重要的。聚乳酸（PLA）一直是用于制造可生物吸收支架的主要聚合物。尽管具有长期优势，但与永久性金属支架相比，这些支架与更高的早期血栓形成率有关。为了解决这个问题，我们使用射频（RF）等离子体对 PLA 表面进行了氟化改性，这得益于表面的激活。由于其较低的血栓形成性和较低的血小板反应性，氟聚合物已广泛应用于与血液接触的材料中，如血管替代品。经等离子体处理的表面的组成通过电子能谱化学分析（ESCA）确定。此外，还介绍了接触角测量、细胞细胞毒性和处理聚合物的降解情况。最后，评估了相关的血液相容性参数，包括血浆蛋白吸附、血小板黏附和形态。我们假设氟聚合物对吸附白蛋白的紧密结合增强了其在与血液接触应用中的潜力。
尽管由聚乳酸（PLA）制成的可生物吸收支架可能具有长期的临床优势，但与永久性金属支架相比，它们显示出更高的早期血栓形成率。为了提高 PLA 的抗血栓性，我们开发了一种用全氟化合物对该聚合物进行表面氟化的新方法。氟聚合物（如膨体聚四氟乙烯）由于其令人满意的临床性能，长期以来一直用于与血液接触的应用中。这是 PLA 表面氟化的首次报道，这可能会应用于制造新一代具有改善的血小板相互作用、可调降解性和药物释放能力的氟化 PLA 支架。此外，我们描述了一种基于白蛋白保留来改善与生物材料血小板相互作用的通用策略。
