Verification of Microphase-Separated Hypothesis of Blood Compatibility Utilizing Precisely Designed Polymer Surfaces

以正十八烷基三氯硅烷（OTS, CH_3(CH_2)_<17>SiCl_3）、18-十二烷基三氯硅烷（NTS, CH_2=CH(CH_2)_<17>SiCl_3）、[2-（全氟辛基）乙基]三氯硅烷（FOETS, CF_3(CF_2)_7CH_2CH_2SiCl_3）单层膜及其混合单层膜为模型表面，研究蛋白质吸附机理。采用表面等离子体共振（SPR）光谱分析了蛋白质在单层表面的吸附行为。原子力显微镜（AFM）观察了这些单层膜暴露于牛血清白蛋白（BSA）和γ-球蛋白（IgG）溶液后的表面。原子力显微镜观察发现，pI以下或pI以上的带电蛋白优先吸附在相分离（OTS/FOETS）混合单层的FOETS相上。对BSA溶液中单层表面的AFM原位观察也显示了BSA在疏水FOETS表面的优先吸附。SPR结果表明，在带电状态下吸附蛋白的量比在中性状态下要少1…在吸附了BSA的混合单层FOETS相中，测量了带负电荷的HOOC(CH_2)_9SH化学吸附悬臂端与OTS相之间的力距曲线，没有检测到附着力。这些结果表明，无论在pI以下还是pI以上，混合单层体系中蛋白质在FOETS相上的优先吸附是由于(1)单层表面与缓冲溶液之间的界面自由能最小，以及(2)带电荷的蛋白质分子之间的静电排斥。采用真空紫外分步光分解和化学吸附工艺，在硅衬底上成功制备了多组分有机硅烷微图纹单层膜。通过x射线光电子能谱（XPS）证实了不同有机硅烷分子的区域特异性引入。AFM和LFM观测表明，微图纹表面的线宽与掩膜的线宽一致。官能团的微图案化影响了表面自由能的大小。观察到该多组分表面对蛋白质的选择性吸附。少

The n-octadecyltrichlorosilane (OTS, CH_3(CH_2)_<17>SiCl_3), 18-nonadecenyltrichlorosilane (NTS, CH_2=CH(CH_2)_<17>SiCl_3), [2-(perfluorooctyl)ethyl]trichlorosilane (FOETS, CF_3(CF_2)_7CH_2CH_2SiCl_3) monolayers, and their mixed monolayers were used as model surfaces for the study of protein adsorption mechanism. Surface plasmon resonance (SPR) spectroscopy was applied to analyze the protein adsorption behavior onto the monolayer surfaces. The surfaces after exposure of these monolayers to bovine serum albumin (BSA) and γ-globulin(IgG) solutions were observed with atomic force microscope(AFM). AFM observation revealed that the charged protein either below or above pI was preferentially adsorbed onto the FOETS phase of the phase-separated (OTS/FOETS) mixed monolayer. in situ AFM observation of monolayer surfaces in BSA solution also revealed the preferential adsorption of BSA onto the hydrophobic FOETS surface. SPR clarified that the amount of adsorbed protein in the charged state was l … More ower than that in the neutral state. Adhesion force was not detected in the force-distance curve measurement between negatively-charged HOOC(CH_2)_9SH chemisorbed cantilever tip and the OTS phase in the presence of adsorbed BSA on FOETS phase of mixed monolayer. These results indicate that the preferential adsorption of protein onto the FOETS phase for the mixed monolayer systems at either below or above pI is due to (1) the minimization of interfacial free energy between the monolayer surface and the buffer solution, and (2) the electrostatic repulsion among protein molecules bearing charges.Multi-component micropatterned organosilane monolayers were successfully fabricated on Si substrate by stepwise vacuum ultraviolet-ray (VUV) photodecomposition and chemisorption process. The area-specific introduction of different organosilane molecules was confirmed by X-ray photoelectron spectroscopy (XPS). AFM and LFM observations revealed that the line-widths of micropatterned surface corresponded to those of photomask. Micropatterning of the functional groups influenced the magnitudes of surface free energy. Selective adsorption of protein was observed for this multicomponent surface. Less