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 65.8^T 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 R_q 0.14 nm, 0.38 nm and 5.55 nm (1 μm × 1 μm scanning area). Analysis of bacterial retention profiles showed that the bacteria responded differently changes in the R_a and R_q (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 (R_q) roughness.