Supplementary Information

Transcription

1 Supplementary Information Differential attraction and repulsion of Staphylococcus aureus and Pseudomonas aeruginosa on molecularly smooth titanium films Elena P. Ivanova 1*, Vi Khanh Truong 1, Hayden Webb 1, Vladimir A. Baulin 2,3, James Y. Wang 4, Narges Mohammodi 1, Feng Wang 1, Christopher Fluke 5, and Russell J. Crawford 1 1 Faculty Life and Social Sciences, 4 Faculty of Engineering and Industrial Sciences, IRIS, and 5 Centre for Astrophysics and Supercomputing Swinburne University of Technology, PO BOX 218, Hawthorn, Victoria, 3122, Australia 2 ICREA, 23 Passeig Lluis Companys, Barcelona, Spain and 3 Departament d'enginyeria Quimica, Universitat Rovira i Virgili 26 Avenue dels Paisos Catalans, Tarragona, Spain.

2 Supplementary Table S1 Comparative evaluation of physicochemical characteristics of titanium surfaces Ti film Contact angle θ ( ) a Surface free energy components [mn m -1 ] b thickness [nm] θ W θ F θ Di Interfacial tension (IFT) γ TOT Dispersive γ LW Polar γ AB Acid γ + Base γ ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± a θ W, θ F and θ D : water, formamide and diidomethane contact angles respectively. b Surface free energies components: Lifshitz-van der Waals (γ LW ), acid/base (γ AB ), electron acceptor (γ + ) and electron donor (γ - ) components

3 Supplementary Table S2 Atomic fractions a of elements b detected on the surfaces studied Ti film O Ti N C Si thickness [nm] <dl <dl a It is conventional to list surface compositions obtained from XPS analyses as atomic fractions (or concentrations), rather than as mass fractions. b The uncertainty in the elemental atomic fractions in each value is at best 5%, so only the first decimal place is retained. c < dl, less than the detection limit (ca. 0.1 at%)

4 Supplementary Table S3 Bacterial cell surface characteristics a and numbers of retained cells on titanium surfaces Bacterial strain Water contact angle θ [ ] Zeta potenti al ζ [mv] Initial cell density 10 6 [number of cells per mm 2 ] Percentage of attached cells [%] Retained cells a 10 5 [number of cells per mm 2 ] Ti film thickness [nm] P aeruginosa ± 8 ± 0.7 ± 1.5 ± 0.11 ± 0.12 ± 0.07 ± 0.14 ± 0.16 ± 0.09 S. aureus ± 8 ± 1.0 ± 1.7 ± 1.63 ± 2.24 ± 0.74 ± 3.40 ± 4.66 ± 1.54 a Data from Ivanova et al., b Cell densities have estimated errors of approximately 15-20% due to local variability in the surface coverage.

5 Supplementary Figure Legends Figure S1 A: XPS wide spectra of silicon wafer substratum (a) and titanium thin film surfaces: 3 nm (b); 12 nm (c); 150 nm (d) thickness. B: Typical XPS spectra of Si and Ti2p and O1s onto titanium thin film surfaces of 3 nm, 12 nm and 150 nm thickness. Figure S2 Typical 2D AFM images and surface profiles of silicon wafer (a) and titanium thin film (b, c, d respectively for 3 nm, 12 nm and 150 nm titanium thin films) surfaces from approximately 10 μm 10 μm scanned areas. Figure S3 Correlation between the retained bacterial cells (left column) and biovolume (right column). P. aeruginosa ( ) and S. aureus ( ) on 3 nm, 12 nm and 150 nm titanium surfaces. The corresponding distribution maps (top images) of P. aeruginosa (a) and S. aureus (b) biofilm on 3 nm (1), 12 nm (2) and 150 nm (3) titanium surfaces. Figure S4 Interactive, 3-dimensional views of the AFM images of silicon wafer (a) and titanium thin film (b, c, d respectively for 3 nm, 12 nm and 150 nm Ti thin films) surfaces from approximately 5 μm 5 μm scanned areas. Readers using version 8.0 or higher of Acrobat Reader can enable interactive views by clicking on the figure panels. Once enabled, 3-d mode allows the reader to rotate and zoom the view using the computer mouse.

6 Supplementary Fig. S1A 6

7 Supplementary Fig S1B. 7

8 Fig S2. 8

9 Fig S3. 9

10 (a) (b) (c) (d)