Comprehensive Characterization of Grafted Expanded Poly(tetrafluoroethylene) for Medical Applications
Comprehensive Characterization of Grafted Expanded Poly(tetrafluoroethylene) for Medical Applications
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DOI：
10.1021/la1010677
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发表时间：
2010-10-05
期刊：
影响因子：
3.9
通讯作者：
Grondahl, Lisbeth
中科院分区：
文献类型：
--
作者：
Chandler-Temple, Adrienne F.;Wentrup-Byrne, Edeline;Grondahl, Lisbeth
任何生物材料的成功植入都取决于其机械、结构和表面特性。具有良好整体特性的材料很少具有所需的适当表面特性或良好的生物整合性。本研究调查了高度多孔、全氟化聚合物基材膨体聚四氟乙烯（ePTFE）的表面改性结果，以提高表面生物活性，从而最终提高其生物整合性。改性涉及在各种溶剂系统（水、甲醇、甲乙酮及其混合物）中用单体磷酸单丙烯酰氧基乙酯（MAEP）和磷酸甲基丙烯酰氧基乙酯（MOEP）进行γ辐射诱导的接枝共聚。为了确定接枝共聚物进入 ePTFE 膜的孔和/或主体的渗透深度，使用了角度依赖性 X 射线光电子能谱 (XPS) 和磁共振成像 (MRI)。研究发现，渗透深度受到单体和溶剂的选择以及用于从接枝混合物中去除溶解氧的技术（氮气脱气与真空）的严重影响。通过结合微衰减全反射傅立叶变换红外 (mu-ATR-FTIR) 测绘和飞行时间二次离子质谱 (ToF-SIMS) 成像的数据，很大程度上克服了由于膜的多孔性质而确定接枝共聚物横向位置的困难。结果表明，不同样品之间接枝异质性的巨大差异很大程度上是底层基材和单体选择的影响。这项研究的结果为控制这些多孔 ePTFE 膜中接枝共聚物的横向位置和渗透深度提供了必要的知识和实验数据。
Successful implantation of any biomaterial depends on its mechanical, architectural, and surface properties. Materials with good bulk properties seldom possess the appropriate surface characteristics required or good biointegration. The present study investigates the results of surface modification of a highly porous, fully fluorinated polymeric substrate, expanded poly(tetrafluoroethylene)(ePTFE), with a view to improving the surface bioactivity and hence ultimately its biointegration. Modification involved gamma irradiation-induced graft copolymerization with the monomers monoacryloxyethyl phosphate (MAEP) and methacryloxyethyl phosphate (MOEP) in various solvent systems (water, methanol, methyl ethyl ketone, and mixtures thereof). In order to determine the penetration depth of the graft copolymer into the pores and/or the bulk of the ePTFE membranes, angle-dependent X-ray photoelectron spectroscopy (XPS) and magnetic resonance imaging (M RI) were used. It was found that the penetration depth was critically affected by the choice of monomer and solvent as well as by the technique used to remove dissolved oxygen from the grafting mixture: nitrogen degassing versus vacuum. Difficulties due to the porous nature of the membranes in establishing the lateral position of the graft copolymers were largely overcome by combining data from microattenuated total reflectance Fourier transfer infrared (mu-ATR-FTIR) mapping and time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging. Results show that the large variation in graft heterogeneity found between different samples is largely an effect of the underlying substrate and choice of monomer. The results from this study provide the necessary knowledge and experimental data to control both the graft copolymer lateral position and depth of penetration in these porous ePTFE membranes.