R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Jhong-Li, Taoyuan 320, Taiwan.
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Jhong-Li, Taoyuan 320, Taiwan.
Colloids Surf B Biointerfaces. 2014 Jun 1;118:254-60. doi: 10.1016/j.colsurfb.2014.03.051. Epub 2014 Apr 6.
Three well-defined diblock copolymers made of poly(sulfobetaine methacrylate) (poly(SBMA)) and poly(propylene oxide) (PPO) groups were synthesized by atom transfer radical polymerization (ATRP) method. They were physically adsorbed onto three types of surfaces having different topography, including smooth flat surface, convex surface, and indented surface. Chemical state of surfaces was characterized by XPS while the various topographies were examined by SEM and AFM. Hydrophilicity of surfaces was dependent on both the surface chemistry and the surface topography, suggesting that orientation of copolymer brushes can be tuned in the design of surfaces aimed at resisting bacterial attachment. Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans and Escherichia coli with green fluorescent protein (E. coli GFP) were used in bacterial tests to assess the resistance to bacterial attachment of poly(SBMA)-covered surfaces. Results highlighted a drastic improvement of resistance to bacterial adhesion with the increasing of poly(SBMA) to PPO ratio, as well as an important effect of surface topography. The chemical effect was directly related to the length of the hydrophilic moieties. When longer, more water could be entrapped, leading to improved anti-bacterial properties. The physical effect impacted on the orientation of the copolymer brushes, as well as on the surface contact area available. Convex surfaces as well as indented surfaces wafer presented the best resistance to bacterial adhesion. Indeed, bacterial attachment was more importantly reduced on these surfaces compared with smooth surfaces. It was explained by the non-orthogonal orientation of copolymer brushes, resulting in a more efficient surface coverage of zwitterionic molecules. This work suggests that not only the control of surface chemistry is essential in the preparation of surfaces resisting bacterial attachment, but also the control of surface topography and orientation of antifouling moieties.
三种由聚（磺酸甜菜碱甲基丙烯酸酯）（poly(SBMA))和聚（环氧丙烷）（PPO）组成的嵌段共聚物通过原子转移自由基聚合（ATRP）方法合成。它们通过物理吸附在具有不同形貌的三种类型的表面上，包括光滑的平面、凸面和凹面。通过 XPS 对表面的化学状态进行了表征，通过 SEM 和 AFM 对各种形貌进行了检测。表面的亲水性取决于表面化学和表面形貌，这表明在设计旨在抵抗细菌附着的表面时，可以调整共聚物刷的取向。大肠杆菌、表皮葡萄球菌、变形链球菌和带有绿色荧光蛋白（E. coli GFP）的大肠杆菌用于细菌测试，以评估聚（SBMA）覆盖表面对细菌附着的抵抗力。结果突出表明，随着聚（SBMA）与 PPO 比例的增加，抵抗细菌附着的能力有了显著提高，表面形貌也有重要影响。化学效应直接与亲水部分的长度有关。亲水部分越长，可以困住更多的水，从而提高抗菌性能。物理效应影响共聚物刷的取向以及可用的表面接触面积。凸面和凹面晶圆呈现出最好的抗细菌附着能力。事实上，与光滑表面相比，这些表面上的细菌附着量明显减少。这可以通过共聚物刷的非正交取向来解释，这导致了更有效的两性离子分子表面覆盖。这项工作表明，在制备抗细菌附着的表面时，不仅要控制表面化学，还要控制表面形貌和抗污分子的取向。
