Mon Htwe, Chang Yow-Ren, Ritter A L, Falkinham Joseph O, Ducker William A
Department of Chemical Engineering and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, United States.
Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, United States.
ACS Biomater Sci Eng. 2018 Jan 8;4(1):257-265. doi: 10.1021/acsbiomaterials.7b00799. Epub 2017 Dec 15.
We examined the effect of a crystalline layer of silica particles in the size range 0.5-4 μm on the adsorption and surface growth of . Growth on these colloidal crystal monolayers (CCMs) was compared to growth on a flat plate of silica. All surfaces were coated with a thin film of silica to provide chemical uniformity of the different topographies. The results showed that the CCM reduces the density of colony forming units (CFU) on the solid by 99-99.9% when the suspension load was 10 CFU. We also examined the interaction between the CCM and either antibiotics or a chemically bound antimicrobial. The addition of 20 μg/mL tobramycin after an initial 24 h growth period caused a further decrease in CFU counts of about 99-99.9% for all topographies. The percentage reduction as a result of the antibiotics was similar for all topographies, which suggested that there was no particular synergy between the topography and antibiotics. On the other hand, the additive nature of the two effects suggested promise for clinical studies: the large percentage reduction in CFU density on addition of the antibiotic to a flat surface was maintained on the topography, even starting from a much lower CFU density. A similar result was obtained for the combination of CCM and a covalently bound layer of antimicrobial poly(allylamine hydrochloride) (PAH). The PAH reduced the CFU, and the CCM caused a further reduction; the two factors behaved approximately independently. Overall the CCM was found to be very effective at reducing the density of adsorbed both with and without the additional reductions caused by antibiotics or surface-bound antimicrobials.
我们研究了粒径范围为0.5 - 4μm的二氧化硅颗粒结晶层对……吸附和表面生长的影响。将在这些胶体晶体单层（CCM）上的生长与在二氧化硅平板上的生长进行了比较。所有表面均涂覆有一层二氧化硅薄膜，以确保不同形貌具有化学均匀性。结果表明，当悬浮液负载为10个菌落形成单位（CFU）时，CCM可使固体上的CFU密度降低99% - 99.9%。我们还研究了CCM与抗生素或化学结合的抗菌剂之间的相互作用。在最初24小时的生长阶段后添加20μg/mL的妥布霉素，所有形貌的CFU计数进一步降低约99% - 99.9%。所有形貌因抗生素导致的降低百分比相似，这表明形貌与抗生素之间不存在特殊的协同作用。另一方面，这两种效应的相加性质为临床研究带来了希望：在平坦表面添加抗生素后CFU密度大幅降低的情况，在该形貌上也得以保持，即使起始CFU密度要低得多。对于CCM与共价结合的抗菌聚（烯丙胺盐酸盐）（PAH）层的组合也获得了类似结果。PAH降低了CFU，而CCM导致了进一步降低；这两个因素的作用大致相互独立。总体而言，发现CCM在降低吸附……的密度方面非常有效，无论是否存在抗生素或表面结合抗菌剂引起的额外降低。
