Bacterial attachment response to nanostructured titanium surfaces

The effect of sub-nanometric surface roughness of Ti thin films surfaces on the attachment of two human pathogenic bacteria, Staphylococcus aureus CIP 65.8T and Pseudomonas aeruginosa ATCC 9027, was studied. A magnetron sputtering thin film deposition system was used to control the titanium thin film thicknesses of 3 nm, 12 nm and 150 nm on silicon wafers with corresponding surface roughness parameters of Rq 0.14 nm, 0.38 nm and 5.55 nm (1 m 1 m scanning area). Analysis of bacterial retention profiles showed that the bacteria responded differently changes in the Ra and Rq (Ti thin film) surface roughness parameters of a less than 1 nm, with up to 2-3 times: more cells being retained on the surface, and elevated levels of extracellular polymeric substances being secreted on the Ti thin films, in particular on the surfaces with 0.14 nm (Rq) roughness.