對於生醫材料控制其表面達到抗非特異性生物分子吸附的特性是重要的一環，並且材料表面除了表現出優異的抗吸附能力還必須擁有長效的穩定性以提供更進一步的實際應用。 本研究選用[2-(Methacryloyloxy)ethyl]trimethylammonium (TMA) 和3-Sulfopropyl methacrylate potassium salt (SA)單體，在修飾有溴官能基的金膜表面聚合成混合電荷共聚刷狀高分子poly (TMA/SA)。在單體比例1:1總濃度1.2M室溫的高分子聚合條件下可以得到表面為電中性的混合電荷共聚刷狀高分子；三種蛋白質Human Serum Albumin (HSA)、γ-Globulin及Fibrinogen於不同表面的非特定吸附行為由表面電漿共振儀(surface plasma resonance, SPR)來檢測獲得。此外在本研究中三種完美覆蓋的表面CH3-SAM、OEG-SAM以及poly(SBMA)刷狀高分子表面其蛋白質吸附的行為也作為實驗數據上的比較對象。 在探討操作環境對poly (TMA/SA)抗蛋白質吸附的影響方面，本研究使用的環境變因包括：溫度、鹽濃度、鹽種類以及pH值。也發現在這些實驗操作條件下poly(TMA/SA)對三種指標性蛋白質展現良好的穩定性和抗吸附能力，展現了poly(TMA/SA)的使用穩定性。此外本研究除了使用單一蛋白質做吸附測試外，還做了人體血漿及血小板貼附測試，實驗結果顯示poly(TMA/SA)表現出近似poly(SBMA)刷狀高分子良好的抗血漿吸附能力，在血小板貼附的測試中，也未發現活化的血小板貼附於poly(TMA/SA)表面，顯示poly(TMA/SA)具有相當良好的血液相容性。 An ideal nonbiofouling surface for biomedical applications requires both high-efficient antifouling characteristics in relation to biological components and long-term material stability from biological systems. This work describes the performance of an antifouling surface with grafted mixed charge copolymer brushes. We form statistical copolymer brush coatings via surface-initiated atom transfer radical polymerization (ATRP) from the bromide-covered gold surface with a comonomer mixture of positively charged [2-(methacryloyloxy) ethyl]trimethylammonium chloride (TMA) and negatively charged 3-sulfopropyl methacrylate potassium salt (SA). The polymerization condition with the molar ratio (TMA:SA) of 1:1 and concentration of 1.2M in the reaction solution at 25oC allowed the formation of a neutral mixed charge polymer brush [poly(TMA/SA)], which was determined by electron spectroscopy for chemical analysis (ESCA). The nonspecific adsorption of fibrinogen,γ-globulin, and serum albumin from human plama was measured using a surface plasmon resonance (SPR) biosensor. Three controlled surfaces with methyl-terminated (CH3) self-assembled monolayers (SAMs), oligo(ethylene glycol)-terminated (OEG) SAMs and well-packed polyzwitterionic sulfobetaine methacrylate (polySBMA) brushes were also studied for comparison. It was found that excellent stable nonbiofouling surface with grafted poly(TMA/SA) can be performed with a cycling test of the three model protein adsorption and in a wide range of various salt types, buffer composition, solution pH, and temperature. It was further revealed that the poly(TMA/SA) grafted surface effectively reduces the plasma protein adsorption from platelet poor plasma solution to a level comparable to the well-packed polySBMA grafted surface but superior than that of adsorption on a surface terminated with tetra(ethylene glycol). The adhesion and activation of platelet from platelet rich plasma solution were not observed on the poly(TMA/SA) grafted surface. This work further concludes that a surface with good hemocompatibility can be simply achieved by the well-packed surface grafted neutral mixed charge poly(TMA/SA) brushes.
