title: A liposomal hydrogel for the prevention of bacterial adhesion to catheters.
abstract: The adhesion of bacteria to medical implants and the subsequent development of a biofilm frequently results in the infection of surrounding tissue and may require removal of the device. We have developed a liposomal hydrogel system that significantly reduces bacterial adhesion to silicone catheter material. The system consists of a poly (ethylene glycol)-gelatin hydrogel in which liposomes containing the antibiotic ciprofloxacin are sequestered. A poly (ethylene glycol)-gelatin-liposome mixture was applied to a silicone surface that had been pre-treated with phenylazido-modified gelatin. Hydrogel cross-linking and attachment to surface-immobilized gelatin was accomplished through the formation of urethane bonds between gelatin and nitrophenyl carbonate-activated poly (ethylene glycol). Liposomal hydrogel-coated catheters were shown to have an initial ciprofloxacin content of 185+/-16 microg cm(-2). Ciprofloxacin was released over seven days with an average release rate of 1.9+/-0.2 microg cm(-2) h(-1) for the first 94 h. In vitro assays using a clinical isolate of Pseudomonas aeruginosa established the antimicrobial efficacy of the liposomal hydrogel. A modified Kirby-Bauer assay produced growth-inhibition zone diameters of 39+/-1 mm, while bacterial adhesion was completely inhibited on catheter surfaces throughout a seven-day in vitro adhesion assay. This new antimicrobial coating shows promise as a prophylactic and/or treatment for catheter-related infection.
authors.affiliation: Institute of Biomedical Engineering, Department of Botany, University of Toronto, ON, Canada.
authors.forename: V
authors.initials: V
authors.lastname: DiTizio
authors.forename: G W
authors.initials: GW
authors.lastname: Ferguson
authors.forename: M W
authors.initials: MW
authors.lastname: Mittelman
authors.forename: A E
authors.initials: AE
authors.lastname: Khoury
authors.forename: A W
authors.initials: AW
authors.lastname: Bruce
authors.forename: F
authors.initials: F
authors.lastname: DiCosmo
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage*; D001422:Bacterial Adhesion; D001424:Bacterial Infections / Q000517:prevention & control*; D001672:Biocompatible Materials / Q000008:administration & dosage*; D018441:Biofilms; D002404:Catheterization; D002939:Ciprofloxacin / Q000008:administration & dosage*; D020100:Hydrogels / Q000008:administration & dosage*; D008081:Liposomes; D011092:Polyethylene Glycols; D011552:Pseudomonas Infections / Q000517:prevention & control; D011550:Pseudomonas aeruginosa; D012828:Silicones; D014466:Ultraviolet Rays
chemical_list: D000890:Anti-Infective Agents; D001672:Biocompatible Materials; D020100:Hydrogels; D008081:Liposomes; D012828:Silicones; D011092:Polyethylene Glycols; D002939:Ciprofloxacin