title: Antibacterial effects of zinc oxide nanorod surfaces.
abstract: Antibacterial coating approaches are being investigated to modify implants to reduce bacterial adhesion and viability in order to reduce implant-associated infection. Nanostructured materials possess unique surface properties, and nanotopographic surfaces have been reported to modulate bacterial adhesion. Zinc oxide (ZnO) films presenting well-controlled nanorod surface structures have recently been developed. To assess the efficacy of ZnO nanorod surfaces as an anti-bacterial coating, we evaluated bacterial adhesion and viability, compared to sputtered ZnO substrates (a relatively flat control) and glass substrates (as a reference). Common implant-associated pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis were investigated. The number of adherent P. aeruginosa on ZnO nanorod surfaces was found to be reduced compared to glass and sputtered ZnO, while the adherent number of S. epidermidis on the ZnO nanorods was equivalent to glass. Regarding bacteria viability, the ZnO nanorod and sputtered ZnO surfaces demonstrated a modest, but significant bactericidal effect on adherent P. aeruginosa, killing 2.5-fold and 1.7-fold more over the number of dead P. aeruginosa on glass, respectively. A greater bactericidal effect of ZnO substrates on S. epidermidis was found, with sputtered ZnO and ZnO nanorod substrates killing -20-fold and 30-fold more over the number of dead S. epidermidis on glass, respectively. These data support the further investigation and optimization of ZnO nanorod coatings with potential for bacterial adhesion resistance and bactericidal properties.
authors.affiliation: J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Jansson
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Clare-Salzler
authors.forename: Toral D
authors.initials: TD
authors.lastname: Zaveri
authors.forename: Shahil
authors.initials: S
authors.lastname: Mehta
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Dolgova
authors.forename: Byung-Hwan
authors.initials: BH
authors.lastname: Chu
authors.forename: Fan
authors.initials: F
authors.lastname: Ren
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Keselowsky
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D005453:Fluorescence; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes; D015034:Zinc Oxide / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015034:Zinc Oxide