Kargar Mehdi, Chang Yow-Ren, Khalili Hoseinabad Hamoun, Pruden Amy, Ducker William A
Department of Mechanical Engineering, ‡Via Department of Civil and Environmental Engineering, and §Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia United States.
Department of Mechanical Engineering, Via Department of Civil and Environmental Engineering, and §Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia United States.
ACS Biomater Sci Eng. 2016 Jun 13;2(6):1039-1048. doi: 10.1021/acsbiomaterials.6b00163. Epub 2016 May 18.
The objective of this work was to examine whether close-packed spheres of polystyrene (colloidal crystals) could be used to delay the development of biofilms. We examined early stage biofilm formation of after 2 days on a flat sheet of polystyrene and on the same solid coated in polystyrene spheres of 450 or 1500 nm diameter. All materials were coated in fetal bovine serum to enable comparison of the effects of different surface curvature while maintaining constant surface chemistry. After 2 days, fluorescence imaging showed that the volume of bacterial colonies was much smaller on the 1500 nm colloidal crystals than on the flat film. In addition, electron microscopy showed that the area covered by structures containing more than one layer of bacteria was significantly reduced on both the 450 and 1500 nm colloidal crystals compared to the flat sheet. This provides proof of concept of biofilm inhibition of a pathogen by a simple nonchemical coating that may find future application in reducing the incidence of infections. Even though the density of adhered bacteria on 450 and 1500 nm was similar after 1 day, biofilm formation after 2 days was delayed more on the 1500 nm spheres than on the 450 nm spheres. We also observed that bacteria have preferred adsorption sites on the 1500 nm colloidal crystals and that cell bodies were often separated. This leads us to hypothesize that the greater spacing between favorable sites on the 1500 nm colloidal crystal hindered the early stage biofilm formation by separation of cell bodies.
这项工作的目的是研究聚苯乙烯紧密堆积球体（胶体晶体）是否可用于延缓生物膜的形成。我们在聚苯乙烯平板以及涂覆有直径为450或1500 nm聚苯乙烯球体的同一固体表面上，观察了2天后生物膜的早期形成情况。所有材料均涂有胎牛血清，以便在保持表面化学性质恒定的同时，比较不同表面曲率的影响。2天后，荧光成像显示，1500 nm胶体晶体上细菌菌落的体积比平板上小得多。此外，电子显微镜显示，与平板相比，在450和1500 nm胶体晶体上，被含有多层细菌的结构覆盖的面积显著减少。这为一种简单的非化学涂层抑制病原体生物膜提供了概念验证，该涂层未来可能在降低感染发生率方面得到应用。尽管在1天后，450和1500 nm上附着细菌的密度相似，但在2天后，1500 nm球体上生物膜的形成比450 nm球体上延迟得更多。我们还观察到，细菌在1500 nm胶体晶体上有优先吸附位点，且细胞体常常分离。这使我们推测，1500 nm胶体晶体上有利位点之间更大的间距通过细胞体的分离阻碍了生物膜的早期形成。
