功能性聚對二甲苯之物理特性及鍍膜基材選擇性

Abstract

藉由化學氣相層積技術所製備之聚對二甲苯高分子鍍膜，提供了良好的表面特性，創造了生物相容性，也提供選擇性改質的應用。這樣子的鍍膜技術，除了有強韌的附著性之外，更可以應用於各種不同的物質材料以及生醫裝置上。我們也透過相關的生物測試，證實此鍍膜技術在生醫領域上的應用。最後，透過表面能量的改變，讓聚對二甲苯高分子鍍膜具備選擇性表面改質的特性。 在這篇研究中，一開始我們使用了功能性聚對二甲苯高分子作為作為鍍膜，設計具有各種生醫功能的材料。研究的材料除了平面的基材外，也使用了立體結構的骨釘、骨板。這些材料進行了熱穩定測試以及機械強度測試，來證明以聚對二甲苯高分子作為生醫材料鍍膜的穩定特性。更進一步的，透過在鍍膜表面修飾蛋白質分子，給予這些材料良好的生物相容性。這些具有不同尾端的蛋白質分子，在表面造成了不同的特性，可以用來控制蛋白質貼附及細胞的吸附。透過上述的鍍膜技術應用於生醫材料，除了擁有強韌的物理特性及穩定性，更是一個很好的界面，在生物環境中控制不同的生物反應。 在了解優異的表面物理特性後，進一步的，我們透過由下而上 (bottom-up) 的表面圖樣 (patterning) 技術，發揮聚對二甲苯高分子在表面改質精準度上的的優點。然而在過去，這樣的技術受限於基材的選擇。在這篇研究的第二部分，我們研究了一個可以被廣泛運用的技術，讓聚對二甲苯高分子可以選擇性的層積在表面上。在進行化學氣相層積的過程中，透過電場在基材的表面提供高能量，成功的抑制聚對二甲苯高分子在特定位置的層積。這樣子的技術，克服了過去在基材以及官能基上的限制，為聚對二甲苯高分子在由下而上選擇性表面改質上，提供了更廣泛的應用。

Poly-para-xylylene coatings prepared by chemical vapor deposition can tailor surface properties through specific conjugation reactions, create effective biological functions, and provide selective surface modification. The coating technology gives a robust adherent property to a variety of substrate materials, allowing for facile and versatile application, as well as contributing a precise selective surface modification in next-generation implantable devices, cellular assays, tissue engineering, and regenerative medicine applications. In this present study, we have used functionalized poly-para-xylylene polymers as coatings for the design of biological functions on various substrates. A thermal stability test against elevated temperature was used to test these coatings on selected substrates, and mechanical stability against harsh scratch test was also tested on flat substrates as well as on a bone plate/screw device. Furthermore, biofunctional activities are performed via immobilization of PEG and functional peptides based on specific conjugation using functional sites of the coatings. Tailored surface functions are created using these coatings as a result of their antifouling properties and ability to control cell attachment. The coatings reported herein provide (i) robust coating stability on a wide range of substrate materials that are commonly used in biomedical applications and (ii) designable interfaces to mimic biological environments for controlled biological responses. After the important interface material of poly-para-xylylenes has been demonstrated to be a robust tool to modify material surfaces to impart precise surface properties, with the bottom-up patterning approach, poly-para-xylylenes coatings provides intrinsic advantages associated with unlimited resolution but is limited by the materials available for selection. A general and simple approach towards the selective deposition of poly-para-xylylenes is introduced in this research. The chemical vapour deposition (CVD) of poly-para-xylylenes is inhibited on the high-energy surfaces of electrically charged conducting substrates. This technology provides an approach to selectively deposit poly-para-xylylenes irrespective of the substituted functionality and to pattern these polymer thin films from the bottom up.