Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, 3122, Australia.
Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, 11031, Taiwan.
Small. 2018 Apr;14(14):e1703574. doi: 10.1002/smll.201703574. Epub 2018 Feb 27.
Micro- and nanotopographies can interfere with bacteria attachment, however, the interplay existing between surface chemistry and topography remains unclear. Here, self-assembled spherical micrometer- silica and nanometer poly(methyl methacrylate) (PMMA)-sized particles are used to make binary colloidal crystal (BCC) topographical patterns to study bacterial attachment. A uniform surface chemistry of allylamine plasma polymer (AAMpp) is coated on the top of the BCCs to study only the topography effects. The uncoated and coated BCCs are exposed to Pseudomonas aeruginosa, and the surfaces and bacteria are characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and fluorescence microscopy. It is found that bacteria attachment to the uncoated BCCs is delayed and individual cells are attracted to the small particle regions of the patterns. Surprisingly, this phenomenon is also observed for the AAMpp-coated BCCs, with bacteria attaching to the small particle regions of the pattern, in stark contrast to uniform flat films of AAMpp that are highly adhesive toward P. aeruginosa. Also, the overall levels of bacterial attachment are significantly reduced by the BCC patterns compared to controls. Thus, there is a trade-off that exists between chemistry and topography that can be exploited to delay the onset of P. aeruginosa biofilm formation on surfaces.
微观和纳米形貌可以干扰细菌附着，然而，表面化学和形貌之间的相互作用尚不清楚。在这里，自组装的球形微米级二氧化硅和纳米级聚甲基丙烯酸甲酯（PMMA）大小的颗粒被用于制造二元胶体晶体（BCC）形貌图案，以研究细菌附着。在 BCC 的顶部涂覆一层均匀的丙烯胺等离子体聚合物（AAMpp）表面化学物质，以仅研究形貌效应。将未涂层和涂层的 BCC 暴露于铜绿假单胞菌，并使用扫描电子显微镜（SEM）、X 射线光电子能谱（XPS）和荧光显微镜对表面和细菌进行表征。结果发现，未涂层 BCC 上的细菌附着被延迟，并且单个细胞被吸引到图案的小颗粒区域。令人惊讶的是，这种现象也在 AAMpp 涂层的 BCC 上观察到，细菌附着在图案的小颗粒区域，与对铜绿假单胞菌具有高粘附性的均匀 AAMpp 平板形成鲜明对比。此外，与对照相比，BCC 图案显著降低了细菌附着的总体水平。因此，在化学和形貌之间存在一种权衡，可以利用这种权衡来延迟铜绿假单胞菌生物膜在表面上的形成。
