The morphology of bone repair materials, such as particle size and roughness of the materials surface, can affect the adsorption of protein molecules. The effects of surface morphology on the absorption of proteins with different charges were studied. Submicron and nano hydroxyapatite (HA) powders prepared by the chemical precipitation method were coated on the surface of a gold sheet by electrophoretic deposition. Various hydroxyapatite coating morphologies were obtained by controlling the powder particle size and the deposition time. The coating surface morphology was analyzed by Atomic Force Microscopy (AFM), and the adsorption behavior of differently charged proteins on the surface was dynamically monitored by Quartz Crystal Microbalance with Dissipation (QCM-D). The adsorption dependence of two proteins with different charges upon hydroxyapatite coating surface morphology was investigated. Results show that coating surfaces with smaller deposited particle sizes are favorable for the adsorption of negatively-charged bovine albumin, while with larger deposited particles facilitate the adsorption of positively-charged lysozyme. This may be because that the negatively-charged hydroxyapatite coating exhibits stronger electrostatic effect as the increase in the coating particle size, which facilitates the adsorption of positively-charged proteins and hinders the adsorption of negatively-charged proteins. Increasing coating surface roughness facilitates protein adsorption, though the particle size exhibits a dominant influence. These results are significant for selective adsorption of proteins on material surfaces.

中文翻译：

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羟基磷灰石涂层表面形态对不同电荷蛋白质吸附行为的影响

骨修复材料的形态，例如材料表面的粒径和粗糙度，会影响蛋白质分子的吸附。研究了表面形态对不同电荷蛋白质吸收的影响。通过化学沉淀法制备的亚微米和纳米羟基磷灰石（HA）粉末通过电泳沉积法涂覆在金片的表面上。通过控制粉末粒度和沉积时间，可以获得各种羟基磷灰石涂层形态。通过原子力显微镜（AFM）分析了涂层的表面形态，并通过带耗散的石英晶体微量天平（QCM-D）动态监测了带电不同的蛋白质在表面上的吸附行为。研究了两种不同电荷的蛋白对羟基磷灰石涂层表面形貌的吸附依赖性。结果表明，具有较小沉积颗粒尺寸的涂层表面有利于吸附带负电荷的牛白蛋白，而具有较大沉积颗粒的涂层表面则有助于吸附带正电荷的溶菌酶。这可能是因为带负电的羟基磷灰石涂层随着涂层粒径的增加而表现出更强的静电作用，这有利于带正电的蛋白质的吸附并阻碍带负电的蛋白质的吸附。涂层表面粗糙度的增加有利于蛋白质的吸附，尽管粒径显示出主要的影响。