title: Effect of ultrafine-grained titanium surfaces on adhesion of bacteria.
abstract: The influence of the ultrafine crystallinity of commercial purity grade 2 (as-received) titanium and titanium modified by equal channel angular pressing (modified titanium) on bacterial attachment was studied. A topographic profile analysis of the surface of the modified titanium revealed a complex morphology of the surface. Its prominent micro- and nano-scale features were 100-200-nm-scale undulations with 10-15 microm spacing. The undulating surfaces were nano-smooth, with height variations not exceeding 5-10 nm. These surface topography characteristics were distinctly different from those of the as-received samples, where broad valleys (up to 40-60 microm) were detected, whose inner surfaces exhibited asperities approximately 100 nm in height spaced at 1-2 microm. It was found that each of the three bacteria strains used in this study as adsorbates, viz. Staphylococcus aureus CIP 68.5, Pseudomonas aeruginosa ATCC 9025 and Escherichia coli K12, responded differently to the two types of titanium surfaces. Extreme grain refinement by ECAP resulted in substantially increased numbers of cells attached to the surface compared to as-received titanium. This enhanced degree of attachment was accompanied with an increased level of extracellular polymeric substances (EPS) production by the bacteria.
authors.affiliation: Swinburne University of Technology, Hawthorn, Victoria, Australia.
authors.forename: Vi Khanh
authors.initials: VK
authors.lastname: Truong
authors.forename: Stuart
authors.initials: S
authors.lastname: Rundell
authors.forename: Rimma
authors.initials: R
authors.lastname: Lapovok
authors.forename: Yuri
authors.initials: Y
authors.lastname: Estrin
authors.forename: James Y
authors.initials: JY
authors.lastname: Wang
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Berndt
authors.forename: David G
authors.initials: DG
authors.lastname: Barnes
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Fluke
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Crawford
authors.forename: Elena P
authors.initials: EP
authors.lastname: Ivanova
mesh_terms: D001422:Bacterial Adhesion; D048168:Escherichia coli K12 / Q000502:physiology*; D052638:Particulate Matter; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D012828:Silicones / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000502:physiology*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D052638:Particulate Matter; D012828:Silicones; D014025:Titanium