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 physiological fluids, thus reducing the bioactivity of the coating. In this work, we report the biofilm inhibition of Staphylococcus epidermidis using a room temperature processed silver doped perfluoropolyether-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.