Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/80489

Title

The influence of nano-scale surface roughness on bacterial adhesion to ultrafine-grained titanium

Author(s)

Truong, Vi K.;  Lapovok, Rimma;  Estrin, Yuri S.;  Rundell, Stuart;  Wang, James Y.;  Fluke, Christopher J.;  Crawford, Russell J.;  Ivanova, Elena P.

Abstract

We discuss the effect of extreme grain refinement in the bulk of commercial purity titanium (CP, Grade-2) on bacterial attachment to the mechano-chemically polished surfaces of the material. The ultrafine crystallinity of the bulk was achieved by severe plastic deformation by means of equal channel angular pressing (ECAP). The chemical composition, wettability, surface topography and roughness of titanium surfaces were characterized using X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurements, as well as atomic force microscopy (AFM) with 3D interactive visualization of the titanium surface morphology. It was found that physico-chemical surface characteristics of the as-received and the ECAP-modified CP titanium did not differ in any significant way, while the surface roughness at the nano-scale did. Optical profilometry performed on large scanning areas of approximately 225 μm × 300 μm showed that there was no significant difference between the roughness parameters Ra and Rq for surfaces in the two conditions, the overall level of roughness being lower for the ECAP-processed one. By contrast, topographic profile analysis at the nano-scale by AFM did reveal a difference in these parameters. This difference was sensitive to the size of the scanned surface area. A further two surface roughness parameters, skewness (Rskw) and kurtosis (Rkur), were also used to describe the morphology of titanium surfaces. It was found that the bacterial strains used in this study as adsorbates, viz. Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9025, showed preference for surfaces of ECAP-processed titanium. S. aureus cells were found to have a greater propensity for attachment to surfaces of ECAP-modified titanium, while the attachment of P. aeruginosa, while also showing some preference for the ECAP-processed material, was less sensitive to the ECAP processing.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Life and Social Sciences

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Industrial Research Institute Swinburne

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Biomaterials, Vol. 31, no. 13 (May 2010), pp. 3674-3683

Publication year

2010

FOR Code(s)

0903 Biomedical Engineering;  0904 Chemical Engineering;  0912 Materials Engineering

Keyword(s)

Bacterial adhesion;  Bioimplant materials;  ECAP;  Equal channel angular pressing;  Pseudomonas aeruginosa;  Staphylococcus aureus;  Titanium surfaces

Publisher

Elsevier

ISSN

0142-9612

Publisher URL

http://dx.doi.org/10.1016/j.biomaterials.2010.01.071

Copyright

Copyright © 2010 Elsevier Ltd. All rights reserved.

Peer reviewed