Protein and Cell Adhesion on Novel PTFE Nanostructures

描述（由申请人提供）：我们提出，通过新型喷吹工艺制备的纳米纤维/纳米结构PTFE将表现出有用的生物医学特性，特别是对于心血管应用，如血管移植物。 在这项研究中要回答的一个基本问题是，与蛋白质相同长度尺度的纳米结构是否会导致迄今为止传统表面改性策略无法获得的有益医疗结果。为了回答这个问题，我们提出了以下工作假设：（1）由于在喷吹过程中形成的聚四氟乙烯独特的纳米形貌/纳米形态，血小板将不会粘附并被激活，并且依赖于锚定的哺乳动物细胞如内皮细胞将不会粘附到这些未修饰的表面。(2)纳米纤维/纳米结构PTFE和相关复合材料的表面可以被工程化/化学官能化以允许靶细胞类型（例如内皮细胞）的选择性粘附和适当表型行为的发展。 为了验证这些假设，拟议的研究分为三个具体目标，旨在开发能够防止医疗器械生物污染的独特纳米结构PTFE材料和复合材料。由于血管移植物设计中涉及复杂的宿主-材料相互作用，我们将集中精力研究这些材料上的内皮细胞增殖，因为移植物管腔表面的完全内皮化是非常需要的。与体内血小板粘附、补体激活、血栓形成、栓子形成相关的问题将成为未来提案的主题（使用从该R21收集的数据作为初步数据）。这里提出的研究具有高风险，几乎没有医学初步数据描述这些纳米材料在心血管应用中的性能。然而，这些纳米材料可能具有独特的生物材料特性，这是由于它们的纳米形态和设计的表面功能化，因此回报可能很高。 这项研究将导致医疗设备的改进，特别是用于治疗心血管疾病。

DESCRIPTION (provided by applicant): We propose that nanofibrous/nanostructured PTFE prepared by a novel jet-blowing process will exhibit useful biomedical properties, especially for cardiovascular applications such as vascular grafts. A fundamental question to be answered in this study is whether nanoarchitecture at the same length scale as proteins will lead beneficial medical outcomes thus far inaccessible to conventional surface modification strategies. To answer this question we have formulated the following working hypotheses: (1) Because of the unique nanotopography/nanomorphology of polytetrafluoroethylene formed during the jet-blowing process, platelets will not adhere and become activated and anchorage-dependent mammalian cells such as endothelial cells will not adhere to these unmodified surfaces. (2) The surface of nanofibrous/nanostructured PTFE and related composites may be engineered/chemically functionalized to permit the selective adhesion of target cell types (e.g. endothelial cells) and development of appropriate phenotypic behavior. To test these hypotheses, the proposed research is divided into three specific aims directed toward the goal of developing unique nanostructured PTFE materials and composites capable of preventing the biofouling of medical devices. Because of the complex host-material interactions involved in vascular graft design, we will focus our efforts here on the study of endothelial cell proliferation on these materials since complete endothelialization of the lumen surface of a graft is highly desired. Issues related to in vivo platelet adhesion, complement activation, thrombogenesis, emboli formation will be the subject of future proposals (using the data gathered from this R21 as preliminary data). The research proposed here is of high risk, with little medical preliminary data describing the performance of these nanomaterials in cardiovascular applications. However, these nanomaterials may possess unique biomaterials properties resulting from their nanomorphology and designed surface functionalization and thus the reward may be high. This research will lead to improved medical devices, especially for treatment of cardiovascular disease.