Klose Theresia, Welzel Petra B, Werner Carsten
Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials Dresden, Hohe Str. 6, 01069 Dresden, Germany.
Colloids Surf B Biointerfaces. 2006 Aug 1;51(1):1-9. doi: 10.1016/j.colsurfb.2006.04.019. Epub 2006 May 17.
The adsorption of human serum albumin (HSA) and lysozyme (LSZ) on pure as well as maleic acid (MA) copolymer coated spherical soda lime glass particles was investigated under flowing conditions. Coating the glass particles with two different maleic acid copolymers alters the properties of the particle surface concerning its charge and hydrophobicity in a well-defined gradation. Frontal chromatography was used to determine the surface concentration of the adsorbed proteins and to establish adsorption isotherms. The introduced methodology was demonstrated to provide a powerful means to study protein adsorption at solid/liquid interfaces. Investigations with virginal and protein-preadsorbed glass particles revealed that even under streaming conditions HSA is irreversibly adsorbed, whereas LSZ partially desorbs. For LSZ and HSA the adsorbed amounts and the isotherms strongly depend on the surface "history", i.e. the presence or absence of preadsorbed protein layers, and the kind of surface modification of the glass. Compared to the soda lime glass surface the adsorption of HSA was strongly increased on surfaces modified with a hydrophobic maleic acid copolymer indicating a strong hydrophobic protein-surface interaction. By coating the surface with a hydrophilic and more negatively charged maleic acid copolymer the adsorption of HSA to that surface was lower and comparable to the adsorption onto plain glass due to the electrostatic repulsion between HSA and the modified surface. In contrast the affinity to any of the investigated particle surfaces was generally higher for LSZ than for HSA which can be mainly attributed to the electrostatic attraction between LZS and the surface. The adsorbed amount of LSZ on the copolymer coated particle surfaces was much higher than on the pure soda lime glass particles indicating superposed hydrophobic interactions in the case of the hydrophobic MA copolymer layer and an increased density of anionic sites as well as interactions of LSZ within the three-dimensional (swollen), hydrophilic MA copolymer layer.
在流动条件下，研究了人血清白蛋白（HSA）和溶菌酶（LSZ）在纯的以及涂覆有马来酸（MA）共聚物的球形钠钙玻璃颗粒上的吸附情况。用两种不同的马来酸共聚物涂覆玻璃颗粒，会以明确的梯度改变颗粒表面的电荷和疏水性等性质。采用前沿色谱法测定吸附蛋白质的表面浓度并建立吸附等温线。结果表明，所引入的方法为研究固/液界面的蛋白质吸附提供了一种有力手段。对原始的和预吸附了蛋白质的玻璃颗粒的研究表明，即使在流动条件下，HSA也是不可逆吸附的，而LSZ会部分解吸。对于LSZ和HSA，吸附量和等温线强烈依赖于表面“历史”，即预吸附蛋白质层的存在与否以及玻璃的表面改性种类。与钠钙玻璃表面相比，HSA在疏水性马来酸共聚物改性的表面上的吸附显著增加，这表明蛋白质与表面之间存在强烈的疏水相互作用。通过用亲水性更强且带更多负电荷的马来酸共聚物涂覆表面，由于HSA与改性表面之间的静电排斥，HSA在该表面上的吸附较低，且与在普通玻璃上的吸附相当。相比之下，LSZ对任何所研究颗粒表面的亲和力通常都高于HSA，这主要归因于LZS与表面之间的静电吸引。LSZ在共聚物涂覆颗粒表面上的吸附量远高于在纯钠钙玻璃颗粒上的吸附量，这表明在疏水性MA共聚物层的情况下存在叠加的疏水相互作用，以及在三维（溶胀的）亲水性MA共聚物层中阴离子位点密度增加以及LSZ的相互作用。
