Wan Jiandi, Thomas Marlon S, Guthrie Sean, Vullev Valentine I
Department of Bioengineering, University of California, Riverside, A-220 Bourns Hall, Riverside, CA 92521, USA.
Ann Biomed Eng. 2009 Jun;37(6):1190-205. doi: 10.1007/s10439-009-9673-6. Epub 2009 Mar 24.
Biocompatibility of materials strongly depends on their surface properties. Therefore, surface derivatization in a controllable manner provides means for achieving interfaces essential for a broad range of chemical, biological, and medical applications. Bioactive interfaces, while manifesting the activity for which they are designed, should suppress all nonspecific interaction between the supporting substrates and the surrounding media. This article describes a procedure for chemical derivatization of glass and silicon surfaces with polyethylene glycol (PEG) layers covalently functionalized with proteins. While the proteins introduce the functionality to the surfaces, the PEGs provide resistance against nonspecific interactions. For formation of aldehyde-functionalized surfaces, we coated the substrates with acetals (i.e., protected aldehydes). To avoid deterioration of the surfaces, we did not use strong mineral acids for the deprotection of the aldehydes. Instead, we used a relatively weak Lewis acid for conversion of the acetals into aldehydes. Introduction of alpha,omega-bifunctional polymers into the PEG layers, bound to the aldehydes, allowed us to covalently attach green fluorescent protein and bovine carbonic anhydrase to the surfaces. Spectroscopic studies indicated that the surface-bound proteins preserve their functionalities. The surface concentrations of the proteins, however, did not manifest linear proportionality to the molar fractions of the bifunctional PEGs used for the coatings. This finding suggests that surface-loading ratios cannot be directly predicted from the compositions of the solutions of competing reagents used for chemical derivatization.
材料的生物相容性很大程度上取决于其表面性质。因此，以可控方式进行表面衍生化提供了实现广泛化学、生物和医学应用所必需的界面的手段。生物活性界面在展现其设计活性的同时，应抑制支撑底物与周围介质之间的所有非特异性相互作用。本文描述了一种用蛋白质共价功能化的聚乙二醇（PEG）层对玻璃和硅表面进行化学衍生化的方法。虽然蛋白质为表面引入了功能，但聚乙二醇提供了抗非特异性相互作用的能力。为了形成醛功能化表面，我们用缩醛（即受保护的醛）涂覆底物。为避免表面劣化，我们未使用强无机酸对醛进行脱保护。相反，我们使用了一种相对较弱的路易斯酸将缩醛转化为醛。将α,ω - 双功能聚合物引入与醛结合的聚乙二醇层中，使我们能够将绿色荧光蛋白和牛碳酸酐酶共价连接到表面。光谱研究表明表面结合的蛋白质保留了其功能。然而，蛋白质的表面浓度与用于涂层的双功能聚乙二醇的摩尔分数并不呈线性比例关系。这一发现表明，表面负载率不能直接从用于化学衍生化的竞争试剂溶液的组成来预测。
