| 摘要: | 熱塑型聚氨酯(Thermoplastic polyurethane, TPU)具有優異機械性質，被廣泛應用於各種用途，如:鞋墊、油漆塗料及手機保護殼等，而此材料亦具有良好生物相容性，因此可應用於醫療器材，例如:心導管、尿導管等等。但是聚氨酯導管具有一項缺陷，即是其表面的疏水性質，可能會造成蛋白質或是細菌的貼附，更進一步導致血栓，甚至是造成病患受到感染，因此熱塑形聚氨酯的表面修飾是一個令人重視的議題，主要目標是將表面修飾為親水性表面，並同時具有對抗蛋白質及細菌貼附的能力。在植入性的醫療器材中，器材的使用壽命也是十分重要的，所以必須利用化學性修飾使功能性高分子穩固地鍵結於表面。在此研究中，我們利用三種嵌段組成醫療性塗層: 其一，疏水性單體丙烯酸丁酯(BMA)與甲基丙烯酸月桂酯(DMA)能夠使共聚高分子物理吸附於聚胺酯表面；其二，光起始交聯單體3-甲基丙烯醯氧基-2-羥丙基-4-氧化二苯甲酮(MHPBP)；其三，親水性雙離子單體2-甲基丙烯醯氧乙基磷酸膽鹼(MPC)，其擁有優異的抗沾黏及生物相容性質，因此被廣泛使用。我們的表面修飾是建構在雙層塗層的架構上，含有MHPBP之高分子透過光起始之烴基插入交聯反應，扮演聚氨酯基材和MPC共聚物間的橋接夾層；第二層修飾層為功能性塗層，共聚中的主要成分MPC賦予此塗層抗沾黏特性以及潤滑度。以上提及的兩種高分子皆是透過傳統的自由基聚合反應合成，反應後之產物利用核磁共振光譜儀以及紫外光¬-可見光光譜儀進行特性分析。使用接觸角測量儀量測修飾塗層的潤濕特性；X射線光電子能譜儀及衰減全反射傅立葉轉換紅外光譜儀分析修飾塗層表面組成及接枝情形；原子力顯微鏡及掃瞄電子顯微鏡檢測塗層表面粗糙度、表面形貌及修飾厚度；拉伸測試機透過摩擦力測試量測修飾後導管之潤滑度；蛋白質及細菌貼附測試檢測塗層的抗沾黏特性。在初步的實驗中，我們調整塗層配方以及探討操作參數對塗層的影響，例如:MHPBP在PX共聚物中所佔的莫耳比例、MPC在MPC共聚物中所的莫耳比例、PX共聚物的溶解度、共聚物濃度、紫外光曝照時間以及紫外光曝照波長。以上所提及之變因會藉由改變塗層之穩定性、抗沾黏特性及潤滑度，進而影響醫療塗層的品質。因為研究中所使用塗層是透過化學鍵結進行修飾，相較於物理吸附，化學鍵結具有較良好的穩定性，因此希望此塗層在未來能夠被應用於醫療器材的製造中。;Thermoplastic polyurethane (TPU) is a widely used biomaterial. It was found to have some serious problems, such as thrombosis and bacterial or protein adsorption that will cause the infection of the patients due to its hydrophobic properties. Therefore, it is an important issue to modify the TPU surface with hydrophilic properties, and the properties to prevent the adsorption of bacteria and proteins. Chemical modification of functional polymers is crucial for long-term and indwelling applications for medical devices. In this work, we applied three building blocks for constructing medical coatings: First, hydrophobic monomers, butyl methacrylate (BMA), and dodecyl methacrylate (DMA), for physical adsorption of polymers on TPU. Second, photo-crosslinkable benzophenone monomer, 3-methacryloyloxy-2-hydroxypropyl-4-oxybenzophenone (MHPBP). Third, hydrophilic 2-methacryloyloxyethyl phosphorylcholine (MPC), which is a widely applied zwitterionic monomer, due to its outstanding antifouling and biocompatibility. The coating strategy was established based on a two-layer scheme. The first layer as a mediate layer containing MHBPB to serve as a crosslinking adlayer between MPC copolymer and TPU through photo-induced C,H insertion crosslinking (CHic). The second layer as a functional layer with the major component of MPC for fouling resistance and high lubrication. Two polymers were synthesized by conventional free radical polymerization and characterized by Nuclear Magnetic Resonance spectroscopy (NMR) and Ultraviolet–visible spectroscopy (UV-Vis). The wettability of the coatings was tested by the contact angle goniometer. The immobilization of the layers was examined by X-ray photoelectron spectroscopy (XPS) and Attenuated total reflectance-Fourier transform infrared spectra (ATR-FTIR) measurement. The roughness and the morphology of the coating layers on TPU were examined by Atomic Force Microscope (AFM). The thickness of the coating layers was analyzed by Scanning Electron Microscope (SEM). Lubrication of the coating was characterized by friction tests with the universal test machine. The antifouling properties of the coated TPU tubes were studied by protein and bacterial adsorption tests. In preliminary data, we formulated the coating solutions and discovered some key operation parameters, the molar ratio of MHBPB in the copolymer of the first layer, the solubility of co-polymers, co-polymer concentration, UV time, and UV wavelength. Those can considerably affect the quality of medical coatings in terms of stability, antifouling properties, and lubrication. In the future, due to the stability of the chemical modification, hoping that the coating process can be applied to the manufacturing of medical devices. |
