Department of Chemistry, Surface and Corrosion Science, Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden.
J Colloid Interface Sci. 2010 Sep 1;349(1):265-74. doi: 10.1016/j.jcis.2010.05.061. Epub 2010 May 21.
Silica surfaces were coated with a range of cationic bottle-brush polymers with 45 units long poly(ethylene oxide) side chains, and their efficiency in reducing protein adsorption was probed by QCM-D, reflectometry and AFM. Preadsorbed layers formed by bottle-brush polymers with different side chain to charge ratio was exposed to two proteins with different net charge, lysozyme and BSA. The reduction in protein adsorption was found to depend on both the type of protein and on the nature of the polyelectrolyte layer. The most pronounced reduction in protein adsorption was achieved when the fraction of charged backbone segments was in the range 0.25-0.5 equivalent to a fraction of poly(ethylene oxide) side chains of 0.75-0.5. It was concluded that these polymers have enough electrostatic attachment points to ensure a strong binding to the surface, and at the same time a sufficient amount of poly(ethylene oxide) side chains to counteract protein adsorption. In contrast, a layer formed by a highly charged polyelectrolyte without side chains was unable to resists protein adsorption. On such a layer the adsorption of negatively charged BSA was strongly enhanced, and positively charged lysozyme adsorbed to a similar extent as to bare silica. AFM colloidal probe force measurement between silica surfaces with preadsorbed layers of bottle-brush polymers were conducted before and after exposure to BSA and lysozyme to gain insight into how proteins were incorporated in the bottle-brush polymer layers.
硅烷表面涂覆有一系列具有 45 个单位长聚（氧化乙烯）侧链的阳离子刷状聚合物，通过 QCM-D、反射计和 AFM 研究了其减少蛋白质吸附的效率。将具有不同侧链电荷比的刷状聚合物预先吸附的层暴露于两种具有不同净电荷的蛋白质（溶菌酶和 BSA）。发现蛋白质吸附的减少取决于蛋白质的类型和聚电解质层的性质。当带电荷的主链段的分数在 0.25-0.5 范围内（相当于聚（氧化乙烯）侧链的分数为 0.75-0.5）时，蛋白质吸附的减少最为显著。结论是这些聚合物具有足够的静电附着点以确保与表面的强结合，同时具有足够数量的聚（氧化乙烯）侧链以抵消蛋白质吸附。相比之下，没有侧链的高电荷聚电解质形成的层无法抵抗蛋白质吸附。在这样的层上，带负电荷的 BSA 的吸附被强烈增强，而带正电荷的溶菌酶的吸附程度与裸露的硅相同。在暴露于 BSA 和溶菌酶前后，在涂覆有刷状聚合物预吸附层的硅烷表面之间进行了 AFM 胶体探针力测量，以深入了解蛋白质如何掺入刷状聚合物层中。
