Abstract The formation of biofilms on the surface of some biomaterials causes problems that can have a negative impact on human health. Various studies have been carried out for the modification of polymeric biomaterials; however, with conventional methods of modifying surfaces with radiation-induced grafts, obtaining uniformly distributed grafts over the entire surface is not facilitated, so the mechanical properties are strongly affected by the modification. In this study, silicone rubber (SR) films were modified with 2-hydroxyethyl methacrylate (HEMA) and with oligo(ethylene glycol) methyl ether methacrylate, Mn = 300 g mol−1 (OEGMA300) using the oxidative pre-irradiation method with gamma-irradiation followed by reversible addition-fragmentation chain transfer (RAFT) grafting polymerization. The copolymers of SR-g-PHEMA and SR-g-poly(HEMA-co-OEGMA300) were synthesized with various grafting percentages and these could be adjusted to obtain a thin grafted layer. The grafted samples were characterized by FTIR-ATR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), light microscopy, swelling in water, contact angle, and dynamic mechanical analysis (DMA); in addition, the non-grafted polymer formed in the RAFT copolymerization reactions was analyzed by gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (NMR). The results confirmed the presence of PHEMA and poly(HEMA-co-OEGMA300) on the surface of SR films, uniformly grafted by the use of a chain transfer agent (CTA). The uniform layer of hydrophilic grafts in the SR films generates a surface capable of forming a water barrier on the surface, without significantly compromising the elastic properties of the SR; furthermore, the grafted thin layer was capable of loading biologically active molecules like curcumin. Modified SR films loaded with curcumin may decrease the possibility of biofilm formation. The described approach of oxidative gamma pre-irradiation followed by RAFT controlled grafting may be of interest for the modification of biomaterials in a controlled way, in the case of silicone for instance for catheters or aesthetic implants.

中文翻译：

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伽马辐照和 RAFT 接枝聚合控制硅橡胶表面改性

摘要 在某些生物材料表面形成生物膜会引起一些问题，对人类健康产生负面影响。已经对聚合物生物材料的改性进行了各种研究；然而，使用辐射诱导移植物对表面进行改性的传统方法，无法获得在整个表面上均匀分布的移植物，因此改性会严重影响机械性能。在这项研究中，硅橡胶 (SR) 薄膜用 2-羟乙基甲基丙烯酸酯 (HEMA) 和低聚（乙二醇）甲基醚甲基丙烯酸酯，Mn = 300 g mol−1 (OEGMA300) 使用氧化预辐照方法与 γ -辐照，然后是可逆加成-断裂链转移 (RAFT) 接枝聚合。SR-g-PHEMA 和 SR-g-poly(HEMA-co-OEGMA300) 的共聚物以不同的接枝百分比合成，这些可以调整以获得薄的接枝层。通过FTIR-ATR光谱、热重分析(TGA)、扫描电子显微镜(SEM)、光学显微镜、水溶胀、接触角和动态力学分析(DMA)对接枝样品进行表征；此外，在 RAFT 共聚反应中形成的未接枝聚合物通过凝胶渗透色谱 (GPC) 和核磁共振光谱 (NMR) 进行分析。结果证实了 PHEMA 和聚 (HEMA-co-OEGMA300) 存在于 SR 膜的表面，通过使用链转移剂 (CTA) 均匀接枝。SR 薄膜中亲水接枝的均匀层产生的表面能够在表面形成水屏障，而不会显着损害 SR 的弹性；此外，接枝的薄层能够加载姜黄素等生物活性分子。装载姜黄素的改性 SR 膜可能会降低生物膜形成的可能性。所描述的氧化伽马预辐照和 RAFT 控制移植的方法可能对以受控方式改性生物材料感兴趣，例如在硅胶的情况下，用于导管或美学植入物。装载姜黄素的改性 SR 膜可能会降低生物膜形成的可能性。所描述的氧化伽马预辐照和 RAFT 控制移植的方法可能对以受控方式改性生物材料感兴趣，例如在硅胶的情况下，用于导管或美学植入物。装载姜黄素的改性 SR 膜可能会降低生物膜形成的可能性。所描述的氧化伽马预辐照和 RAFT 控制移植的方法可能对以受控方式改性生物材料感兴趣，例如在硅胶的情况下，用于导管或美学植入物。