Nosocomial (hospital acquired) infections represent one of the most severe problems facing the health care industry. Of the approximately two million hospital acquired infections reported annually in this country, about half are associated with catheters, ureteral stents, central lines and other percutaneous devices that provide a support surface for organisms to track into deeper tissue. A typical infection can cost as much as $47,000 per patient to treat. Although invasive medical devices such as stents and catheters are pre-sterilized and inserted or implanted under the most sterile conditions available; biofilm growth, encrustation, and subsequent infection are the most common mode of failure. Coatings that could render these devices inherently resistant to biofilm formation and encrustation could significantly reduce the incidence of infections and unnecessary illness, allow better use of health care resources, reduce healthcare costs, and save lives. Encrustation results from mineral incorporation into biofilms on device surfaces. These deposits inhibit drainage; are virulent bacterial reservoirs; and increase susceptibility of the local tissues to infection. Antibiotic strategies have proven to be of little value in preventing biofilm formation and encrustation of stents and catheters. One technique for producing antimicrobial surfaces is to apply a coating which is capable of releasing metal ions when exposed to moisture. Antimicrobial silver ions are particularly useful for in vivo use due to the fact that they are not substantially absorbed into the body. In Phase I, Brighton Technologies Group developed and characterized a novel antimicrobial nanocoating (AMNC) based on gas-phase deposition of a silver salt-containing polymer that effectively inhibits biofilm formation for a wide range of microorganisms. Phase II will extend these results to create an antimicrobial surface that will inhibit biofilm formation and encrustation on medical devices such as stents and indwelling catheters through: 1. Developing techniques for depositing these films on urinary devices such as ureteral stents, Foley catheters, and ureteral catheters. 2. Evaluating important AMNC characteristics such as hydrophobicity/hydrophilicity, coefficient of friction, adhesion and wear resistance. 3. Developing predictive knowledge of activity and effective lifetime of AMNC's as a function of structure and composition. 4. Initiating in vivo performance and biocompatibility evaluations.
