Silver Doped Perfluoropolyether-Urethane Coatings: Antibacterial Activity and Surface Analysis

The colonisation of clinical and industrial surfaces with pathogenic microorganisms has prompted increased research into the development of effective antibacterial and antifouling coatings. There is evidence that implanted biomedical surfaces coated with metallic silver can be inactivated by hysiological fluids, thus reducing the bioactivity of the coating. In this work, we report the biofilm inhibition of Staphylococcus epidermidis using a roomtemperatureprocessedsilver dopedperfluoropolyether-urethane coating. The release of silver ions from these fluoropolymers over a six-day period inhibited bacterial encrustation – as observed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analysis indicated differences in carbon, fluorine and sodium surface composition between silver doped and undoped fluoropolymers after exposure to nutrient rich media. These silver doped perfluoropolyether coatings also exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii; suggesting potential use in preventing transmission of pathogenic and opportunistic microbes on environmental surfaces in healthcare facilities. The broad-spectrum antibacterial activity of these silver release coatings may be exploited on biomaterials surfaces to combat the development of resistant Gram-negative Enterobacteriaceae that can occur during prophylactic treatment for urinary tract infections

Enhancement of the Antibacterial Properties of Silver Nanoparticles Using Beta-Cyclodextrin as a Capping Agent

Silver nanoparticles (AgNPs) were synthesized by reducing silver salts using NaBH4 followed by capping with varying concentrations of β-cyclodextrin (β-CD) and were physically characterised. Antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was determined by a microtitre well method. The AgNPs were spherical under TEM while DLS showed average diameters of capped particles to be smaller (4-7 nm) than their uncapped equivalents (17 nm). Capped particles demonstrated superior photostability when exposed to intense UV radiation for 4 hours and a significantly (

Silver Doped Perfluoropolyether-Urethane Coatings: Antibacterial Activity and Surface Analysis

The colonisation of clinical and industrial surfaces with pathogenic microorganisms has prompted increased research into the development of effective antibacterial and antifouling coatings. There is evidence that implanted biomedical surfaces coated with metallic silver can be inactivated by hysiological fluids, thus reducing the bioactivity of the coating. In this work, we report the biofilm inhibition of Staphylococcus epidermidis using a roomtemperatureprocessedsilver dopedperfluoropolyether-urethane coating. The release of silver ions from these fluoropolymers over a six-day period inhibited bacterial encrustation – as observed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analysis indicated differences in carbon, fluorine and sodium surface composition between silver doped and undoped fluoropolymers after exposure to nutrient rich media. These silver doped perfluoropolyether coatings also exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii; suggesting potential use in preventing transmission of pathogenic and opportunistic microbes on environmental surfaces in healthcare facilities. The broad-spectrum antibacterial activity of these silver release coatings may be exploited on biomaterials surfaces to combat the development of resistant Gram-negative Enterobacteriaceae that can occur during prophylactic treatment for urinary tract infections

Dual-Action Hygienic Coatings: Benefits of Hydrophobicity and Silver Ion Release and Surface Analysis

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