Wehmeyer Jennifer L, Synowicki Ron, Bizios Rena, García Carlos D
Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249.
Mater Sci Eng C Mater Biol Appl. 2010 Jan 30;30(2):277-282. doi: 10.1016/j.msec.2009.11.002.
Spectroscopic ellipsometry was used to characterize the optical properties of thin (<5 nm) films of nanostructured titanium dioxide (TiO(2)). These films were then used to investigate the dynamic adsorption of bovine serum albumin (BSA, a model protein), as a function of protein concentration, pH, and ionic strength. Experimental results were analyzed by an optical model and revealed that hydrophobic interactions were the main driving force behind the adsorption process, resulting in up to 3.5 mg/m(2) of albumin adsorbed to nanostructured TiO(2). The measured thickness of the adsorbed BSA layer (less than 4 nm) supports the possibility that spreading of the protein molecules on the material surface occurred. Conformational changes of adsorbed proteins are important because they may subsequently lead to either accessibility or inaccessibility of bioactive sites which are ligands for cell interaction and function relevant to physiology and pathology.
采用光谱椭偏仪对纳米结构二氧化钛（TiO₂）薄膜（厚度小于5纳米）的光学性质进行了表征。然后用这些薄膜研究了牛血清白蛋白（BSA，一种模型蛋白）的动态吸附情况，该吸附情况是蛋白质浓度、pH值和离子强度的函数。通过光学模型对实验结果进行了分析，结果表明疏水相互作用是吸附过程背后的主要驱动力，导致纳米结构TiO₂表面吸附的白蛋白量高达3.5毫克/平方米。所测得的吸附BSA层厚度（小于4纳米）支持蛋白质分子在材料表面发生铺展的可能性。吸附蛋白质的构象变化很重要，因为它们随后可能导致生物活性位点可及或不可及，而这些生物活性位点是与生理和病理相关的细胞相互作用及功能的配体。
