Truong Vi Khanh, Pham Vy T H, Medvedev Alexander, Lapovok Rimma, Estrin Yuri, Lowe Terry C, Baulin Vladimir, Boshkovikj Veselin, Fluke Christopher J, Crawford Russell J, Ivanova Elena P
School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia.
Appl Microbiol Biotechnol. 2015 Aug;99(16):6831-40. doi: 10.1007/s00253-015-6572-7. Epub 2015 Apr 17.
The surface nanotopography and architecture of medical implant devices are important factors that can control the extent of bacterial attachment. The ability to prevent bacterial attachment substantially reduces the possibility of a patient receiving an implant contracting an implant-borne infection. We now demonstrated that two bacterial strains, Staphylococcus aureus and Pseudomonas aeruginosa, exhibited different attachment affinities towards two types of molecularly smooth titanium surfaces each possessing a different nanoarchitecture. It was found that the attachment of S. aureus cells was not restricted on surfaces that had an average roughness (S a) less than 0.5 nm. In contrast, P. aeruginosa cells were found to be unable to colonise surfaces possessing an average roughness below 1 nm, unless sharp nanoprotrusions of approximately 20 nm in size and spaced 35.0 nm apart were present. It is postulated that the enhanced attachment of P. aeruginosa onto the surfaces possessing these nanoprotrusions was facilitated by the ability of the cell membrane to stretch over the tips of the nanoprotrusions as confirmed through computer simulation, together with a concomitant increase in the level of extracellular polymeric substance (EPS) being produced by the bacterial cells.
医用植入装置的表面纳米形貌和结构是能够控制细菌附着程度的重要因素。防止细菌附着的能力可大幅降低接受植入手术的患者感染植入物相关感染的可能性。我们现已证明，金黄色葡萄球菌和铜绿假单胞菌这两种细菌菌株，对两种具有不同纳米结构的分子光滑钛表面表现出不同的附着亲和力。研究发现，在平均粗糙度（Sa）小于0.5纳米的表面上，金黄色葡萄球菌细胞的附着不受限制。相比之下，除非存在尺寸约为20纳米且间距为35.0纳米的尖锐纳米突起，否则铜绿假单胞菌细胞无法在平均粗糙度低于1纳米的表面上定殖。据推测，通过计算机模拟证实，细胞膜能够在纳米突起的尖端伸展，以及细菌细胞产生的胞外聚合物（EPS）水平随之增加，促进了铜绿假单胞菌在具有这些纳米突起的表面上的附着增强。
