title: Dual-action hygienic coatings: benefits of hydrophobicity and silver ion release for protection of environmental and clinical surfaces.
abstract: Coatings that demonstrate reduced attachment of crystalline precipitates and the medical device colonising Staphylococcus epidermidis were prepared by the immobilisation of silver doped perfluoropolyether-urethane siloxane thin films on glass substrates. The presence of stratified hydrophobic perfluoropolyether groups protects the coating surface from the attachment of crystalline hydrophilic species such as chlorides and phosphates, whilst silver ion release inhibited attachment of S. epidermidis and subsequent biofilm formation in vitro. The release of silver ions protects the perfluoro groups from the hydrophobic interactions of S. epidermidis cells, which can reduce the hydrophobicity of the protective coating. These coatings also exhibited significant antibacterial activity against planktonic Acinetobacter baumannii and S. epidermidis bacterial strains. Detailed elemental and chemical surface analysis obtained using X-ray photoelectron spectroscopy (XPS) provided useful information on the effect of bacterial incubation on key indicator hydrophobic and hydrophilic functional groups. XPS analysis indicated preferential adsorption of S. epidermidis cells at the hydrophobic sites along the polymeric chain. These dual-action hygienic coatings can be employed to protect against contamination environmental surfaces and bacterial colonisation on implanted medical devices.
authors.affiliation: School of Chemical and Pharmaceutical Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland. niall.stobie@dit.ie
authors.forename: Niall
authors.initials: N
authors.lastname: Stobie
authors.forename: Brendan
authors.initials: B
authors.lastname: Duffy
authors.forename: John
authors.initials: J
authors.lastname: Colreavy
authors.forename: Patrick
authors.initials: P
authors.lastname: McHale
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Hinder
authors.forename: Declan E
authors.initials: DE
authors.lastname: McCormack
mesh_terms: D040981:Acinetobacter baumannii / Q000254:growth & development*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D004866:Equipment Contamination / Q000517:prevention & control*; D004987:Ethers / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D012833:Siloxanes / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013212:Staphylococcus epidermidis / Q000254:growth & development*; D014520:Urethane / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D004987:Ethers; D005466:Fluorocarbons; D012833:Siloxanes; C078113:perfluoropolyether; D014520:Urethane; D012834:Silver