Protein interactions with poly(ethylene glycol) self-assembled monolayers on glass substrates: Diffusion and adsorption
Protein interactions with poly(ethylene glycol) self-assembled monolayers on glass substrates: Diffusion and adsorption
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作者：
Yang, ZH;Galloway, JA;Yu, HU
通过用（omega-甲氧基封端的 PEG）三甲氧基硅烷将玻璃表面上的硅烷醇基团进行甲硅烷基化，将亲水性聚合物链聚乙二醇 (PEG) 连接到玻璃表面。我们认为这些束缚的聚合物链类似于 PEG 的自组装单层 (SAM)，因为接枝过程完全是自发的。它们表现出优异的生物相容性，并代表了研究蛋白质与聚合物表面相互作用的模型系统。 PEG SAM 由两种不同分子量的聚合物（MW = 750 和 5000）制备，并通过角度依赖性 X 射线光电子能谱和原子力显微镜技术进行表征。对于低分子量样品，聚合物链倾向于延伸，形成刷状单层，而对于大分子量样品，较长的聚合物链倾向于相互渗透，在表面形成蘑菇状PEG单层。通过光漂白后的荧光恢复技术，从蛋白质吸附和扩散的角度研究血浆蛋白、牛血清白蛋白和 PEG SAM 之间的相互作用。尽管吸附和解吸行为相似，但发现蛋白质在两个单层上的扩散和聚集行为有很大不同。利用水合表面动力学的假设对结果进行分析。
Hydrophilic polymer chains, poly(ethylene glycol) (PEG), are attached to glass surfaces by silylation of the silanol groups on glass surfaces with (omega-methoxy-terminated PEG)trimethoxysilanes. We consider these tethered polymer chains to resemble self-assembled monolayers (SAMs) of PEG since the grafting process is entirely spontaneous. They are shown to exhibit excellent biocompatibility and represent a model system for studying the interactions of proteins with polymer surfaces. The PEG SAMs are prepared with two different molecular weight polymers (MW = 750 and 5000) and characterized with the techniques of angular-dependent X-ray photoelectron spectroscopy and atomic force microscopy. For the low molecular weight sample, the polymer chains tend to extend, forming a brush-like monolayer, whereas for the large molecular weight sample, the longer polymer chains tend to interpenetrate each other, forming a mushroom-like PEG monolayer on the surface. Interactions between a plasma protein, bovine serum albumin, and the PEG SAMs are investigated in terms of protein adsorption and diffusion on the surfaces by the technique of fluorescence recovery after photobleaching. The diffusion and aggregation behaviors of the protein on the two monolayers are found to be quite different despite the similarities in adsorption and desorption behaviors. The results are analyzed with a hypothesis of the hydrated surface dynamics.