Bates Novella M, Heidenreich Heather E, Fallon Meghan E, Yao Yuan, Yim Evelyn K F, Hinds Monica T, Anderson Deirdre E J
Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, United States.
Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada.
Front Bioeng Biotechnol. 2020 Dec 18;8:621768. doi: 10.3389/fbioe.2020.621768. eCollection 2020.
Poly(vinyl alcohol) hydrogel, PVA, is a suitable material for small-diameter vascular grafting. However, the bioinert properties of the material do not allow for endothelialization, which is needed to combat common graft failure mechanisms, such as intimal hyperplasia and thrombosis. In this work, the surface of planar and tubular PVA was covalently modified with a collagen-mimicking peptide, GFPGER. The surface of modified PVA was characterized by measuring contact angle and x-ray photoelectron spectroscopy. Endothelial cell attachment to GFPGER-modified PVA was quantified and qualitatively examined using immunohistochemical staining. Then, hemocompatibility testing was performed by quantifying platelet attachment, coagulation factor XII activation, and initiation of fibrin formation. Finally, an established , non-human primate model was employed to examine platelet attachment and fibrin formation under non-anticoagulated, whole blood flow conditions. GFPGER-modified PVA supported increased EC attachment. initiation of fibrin formation on the modified material was significantly delayed. thrombosis assessment showed a reduction in platelet attachment and fibrin formation on GFPGER-modified PVA. Overall, GFPGER-modified PVA encouraged cell attachment while maintaining the material's hemocompatibility. This work is a significant step toward the development and characterization of a modified-hydrogel surface to improve endothelialization while reducing platelet attachment.
聚乙烯醇水凝胶（PVA）是一种适用于小口径血管移植的材料。然而，该材料的生物惰性特性不利于内皮化，而内皮化是对抗常见移植物失效机制（如内膜增生和血栓形成）所必需的。在这项工作中，平面和管状PVA的表面用一种模拟胶原蛋白的肽GFPGER进行了共价修饰。通过测量接触角和X射线光电子能谱对修饰后的PVA表面进行了表征。使用免疫组织化学染色对内皮细胞在GFPGER修饰的PVA上的附着进行了定量和定性检测。然后，通过定量血小板附着、凝血因子XII激活和纤维蛋白形成的起始来进行血液相容性测试。最后，采用一个成熟的非人类灵长类动物模型，在非抗凝全血流条件下检测血小板附着和纤维蛋白形成。GFPGER修饰的PVA支持增加的内皮细胞附着。修饰材料上纤维蛋白形成的起始明显延迟。血栓形成评估显示，GFPGER修饰的PVA上的血小板附着和纤维蛋白形成减少。总体而言，GFPGER修饰的PVA在保持材料血液相容性的同时促进了细胞附着。这项工作是朝着开发和表征一种修饰水凝胶表面迈出的重要一步，以改善内皮化同时减少血小板附着。
