對於生醫材料，控制其表面以達到抗非特異性生物分子吸附的特性是重要的一環，尤其材料必須表現出優異的抗吸附能力以及長效的穩定性。吾人選用sulfobetaine methacrylate(SBMA)單體，在修飾有溴官能基的金膜表面聚合成刷狀高分子poly(SBMA)。本研究主要利用表面電漿共振感測儀探討其循環抗蛋白質吸附之穩定性，以及在不同的操作環境下poly (SBMA)抗人體血漿蛋白質和血小板吸附的能力。此外，本研究使用兩種常見的材料為比較對象，其一是末端具有乙二烯乙二醇寡聚體的自組裝單層膜(OEG-SAM)，另一個是末端為甲基的自組裝單層膜(CH3-SAM)。 單一蛋白質吸附測試的結果顯示，poly (SBMA)具有優異的抗蛋白質吸附特性，從SPR的共振頻率位移判斷，poly(SBMA)幾乎完全不吸附Human Serum Albumin (HSA)、γ-Globulin及Fibrinogen這三種人體血漿蛋白質，抗蛋白質吸附能力更勝於OEG-SAM。使用同一片樣品，經過三次重複吸附、脫附的測試發現，三種蛋白質依然不會吸附到poly (SBMA)的表面上，顯見此材料的使用穩定性。 在探討操作環境對poly(SBMA)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。首先從溫度變因的結果來看，具有疏水表面的CH3-SAM 在溫度提高時疏水作用力變強，表面吸附上的蛋白質有略為增加，相對於CH3-SAM，親水的poly(SBMA)表面在22℃到37℃的範圍間，皆不吸附蛋白質；在改變環境鹽濃度及鹽種類的實驗結果，也發現儘管置於搶水環境，poly (SBMA)依舊能表現出優異的抗蛋白質吸附能力；而控制環境pH值在pH = 3到pH = 11的範圍做蛋白質吸附測試的實驗中，結果顯示poly(SBMA)在中性環境或鹼性環境可抗蛋白質吸附，不過從pH = 5的時候開始，poly (SBMA)表面會吸附蛋白質，甚至在pH = 3時的酸性環境中，蛋白質在poly(SBMA)表面接近單層或多層吸附。 本研究除了使用單一蛋白質做吸附測試外，另外還做了人體血漿及血小板的吸附測試。相對於OEG-SAM，實驗結果顯示poly(SBMA)表現出更佳的抗生物分子吸附能力。 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. In this study we demonstrate the performance and stability of an antifouling surface with grafted zwitterionic sulfobetaine methacrylate(SBMA). The SBMA was grafted from a bromide-coated gold surface via surface-initiated atom transfer radical polymerization to form well-packed polymer brushes. Plasma protein adsorption on poly(sulfobetaine methacrylate) [poly(SBMA)] grafted surfaces was measured with a surface plasmon resonance sensor. It is revealed that an excellent stable nonbiofouling surface with grafted poly(SBMA) can be performed with a cycling test of the adsorption of three model proteins in a wide range of various salt types, buffer compositions, solution pH levels, and temperatures. This work also demonstrates the adsorption of plasma proteins and the adhesion of platelets from human blood plasma on the polySBMA grafted surface. It was found that the poly(SBMA) grafted surface effectively reduces the plasma protein adsorption from platelet-poor plasma solution to a level superior to that of adsorption on a surface terminated with tetra(ethylene glycol). The adhesion and activation of platelets from platelet-rich plasma solution were not observed on the poly(SBMA) grafted surface. This work further concludes that a surface with good hemocompatibility can be achieved by the well-packed surface-grafted poly(SBMA) brushes.
