當生醫材料置入人體時，最先靠近基材表面是水分子，再來蛋白質會吸附在基材上，最後細胞才貼附上來，所以細胞與基材間蛋白質的吸附量以及其形態是影響細胞貼附的重要因素。
自組裝單分子層(SAMs)具有緻密、排列良好之特性，且製備容易，所以在許多研究中藉由改變硫醇末端官能基，將基材修飾成具有各種不同性質的表面。在本研究中將模仿肝素結構，以磺酸根硫醇(10-mercaptodecanesulfonic acid, 10-MDS)為主，搭配氫氧根硫醇(11-hydroxy-1-undecanthiol, 11-HUT)、甲烷基硫醇(1-decanthiol, 1-DT)，製出不同親疏水性質的混合自組裝單分子層，進行SAMs表面性質分析及蛋白質吸附分析。
本實驗以靜態接觸角、循環伏安法及交流阻抗分析、紅外線光譜對SAMs表面做分析。再使用表面電漿共振儀，分析SAMs與白蛋白及纖維蛋白原間吸附狀況。表面親水之氫氧根硫醇(11-HUT)SAM不論吸附何種蛋白質其吸附量為都最低；表面疏水之甲烷基硫醇(1-DT)SAM則吸附量都較高；而表面帶負電之磺酸根硫醇(10-MDS)SAM會因不同蛋白質溶液而有不同程度吸附；若是混合自組裝單分子層，則與吸附蛋白質溶液不同及表面組成的不同，有不同吸附情形。最後在吸附混合蛋白質溶液時，則會產生不同競爭吸附情形。

As the biomaterials were implanted into the human body, water molecules were first absorbed onto the materials surface, followed by the protein and cells, sequentially. Therefore, the interactions between the cell and material surface are believed to be influenced by the amount of protein adsorbed as well as the conformation of the adsorbed protein.
Due to its ease of preparation as well as a densely-packed and well-defined structure, self-assembled monolayer (SAM) prepared by alkanethiol has been utilized as a model surface with a wide variety of surface property by simply changing the terminal functionality of alkanethiol. In this investigation, heparin-like SAMs with different surface hydrophilicity were prepared by mixing 10-mercaptodecanesulfonic acid (10-MDS) with 1-decanthiol (1-DT) or 11-hydroxy-1-undecanthiol (11-HUT). Protein adsorption characteristic as well as surface properties on these SAMs were evaluated by different techniques.
The surface properties of these SAMs were determined by contact angle, cyclic voltammetry, electrochemical impedance spectroscopy and infrared reflection absorption spectroscopy. Protein adsorption for bovine serum albumin and bovine fibrinogen was determined by surface plasmon resonance spectroscopy. No matter of what kind of protein used, the amount of protein adsorbed was lowest on the SAMs prepared by the pure –OH terminated alkanethiol (11-HUT). In contrast, the hydrophobic SAMs prepared by the –CH3 terminated alkanethiol (1-DT) adsorbed the largest amount of protein; albumin and fibrinogen. For the SAM prepared by the negative-charged sulfonic acid-terminated alkanethiol (10-MDS), the amount of protein adsorbed was influenced by the type of protein used. For the SAMs made by the mixtures of 10-MDS and 11-HUT or 1-DT, protein adsorption characteristic was not only determined by the type of protein used but also by the surface characteristics. Competition in protein adsorption was also noted when protein mixture solutions or protein adsorption sequence were used.

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