| 摘要: | 熱塑性聚氨酯 (TPU) 因其卓越的機械性能和生物相容性而在醫療領域中被廣泛應用於導管、傷口護理和長期植入等方面。然而，由於TPU基材具有疏水表面特性，在長期植入人體時容易出現非特異性生物黏附的問題，進而引發人體免疫反應、細菌感染和功能喪失，因此對TPU表面進行修飾賦予其高親水性、潤滑性和防污性能具有重要意義。本研究重點在於開發一種用於修飾TPU表面的雙層塗層系統，該系統由基底層和功能性塗層組成。基底層由四種單體組成，包含帶有季銨陽離子的2-甲基丙烯醯氧基乙基三甲基氯化銨 (TMAEMA)、甲基丙烯酸十二烷基酯 (DMA) 之長碳鏈有利於基底層吸附在TPU表面、3-甲基丙烯醯氧基-2-羥丙基-4-氧基二苯甲酮 (MHPBP) 通過光誘導的烴基插入交聯反應 (CHic) 形成交聯層、乙烯基吡咯烷酮 (NVP) 作為除氧劑促進光交聯反應，合成之基底層即為隨機共聚物TMAEMA-r-DMA-r-MHPBP-r-NVP (TDMN)；功能性塗層為雙離子材料2-甲基丙烯醯氧基乙基磷醯膽鹼 (MPC) 和MHPBP合成之共聚物MPC-r-MHPBP (MPM) 以及商用之親水材料聚乙烯吡咯烷酮 (PVP)，作為親水性的防污塗層。本研究通過自由基聚合合成共聚物，並利用1H NMR和ATR-FTIR光譜進行官能基鑑定，通過GPC分析確定共聚物的分子量，並利用UV-Vis識別光誘導聚合物的吸收波長範圍。修飾溶液的測量包含表面張力及黏度，塗層則使用AFM觀察其表面形貌，通過水接觸角和摩擦力測試比較表面潤滑度及穩定性，並利用蛋白質和抗菌黏附試驗研究其防污性能。研究結果表明，TDMN適用於TPU表面改質雙塗層系統中的基底層，MPM和PVP兩種聚合物作為功能性塗層都具有良好的抗污性和潤滑性，未來有望將雙塗層系統應用於改進TPU在醫療領域的長期植入效果。;Thermoplastic polyurethane (TPU) is extensively utilized in medical applications such as catheters, wound care, and long-term implants due to its excellent mechanical properties and biocompatibility. However, the hydrophobic nature of TPU surfaces could lead to issues related to nonspecific bioadhesion during prolonged human implantation. Consequently, surface modification of TPU to enhance its hydrophilicity, lubricity, and antifouling properties holds significant importance.
This study focuses on the development of a two-layer coating system for surface modification of TPU, comprising a primer layer and a functional layer. The primer layer consists of four monomers. It incorporates the positively charged quaternary ammonium group from 2-trimethylammonioethyl methacrylate (TMAEMA) monomer, while the long carbon chain of dodeyl methacrylate (DMA) facilitates physical adsorption of layer onto the TPU surface. The cross-linking absorption is achieved through the light-induced C,H insertion crosslinking (CHic) reaction using 3-methacryloyloxy-2-hydroxypropyl-4-oxybenzophenone (MHPBP) as a photo-crosslinkable monomer. In addition, n-vinyl-2-pyrrolidone (NVP) acts as an oxygen scavenger to promote the photo-crosslinking reaction. The synthetic primer layer is random copolymer, TMAEMA-r-DMA-r-MHPBP-r-NVP (TDMN). As for the functional layer, the deposition of polyvinylpyrrolidone (PVP) is served as a hydrophilic antifouling coating. Another hydrophilic coating is MPM random copolymer, which consists of MHPBP and a zwitterionic monomer, 2-methacryloxyethylphosphorylcholine (MPC).
The copolymers were synthesized using free radical polymerization. Chemical structure characterization of the copolymers was conducted by 1H NMR and ATR-FTIR spectroscopy. The molecular weight was determined through GPC analysis. UV-Vis spectroscopy was employed to identify the absorption wavelength range of the photoinduced polymers. Besides, water contact angle and friction tests were conducted to compare surface wetting and lubricity, while AFM was used to observe the morphology of coatings. Protein and antibacterial adhesion tests were employed to evaluate the antifouling performance of the coatings.
According to the research, both MPM and PVP polymers exhibit excellent antifouling properties and high lubricity, making them suitable for the functional coatings in the double-layer coating system for TPU surface modification. This system shows great potential for improving the long-term implantation effectiveness of TPU in the medical field. Overall, this study provides valuable insights for the development of high-performance, biocompatible materials to address the demands in medical applications. |
