Urethral catheters are essential in the management of many diseases and conditions yet often result in catheter associated urinary tract infections. The use of sterile closed systems, advanced infection control protocols, and antimicrobial parts has not prevented infection or the associated morbidity increase. Additionally, direct patient care costs for these infections exceed $0.5billion annually. Our novel ironically bonded antimicrobial coating shows promise for the long-term prevention of infection in urethral catheters. This research will establish that unlike conventional systems where the antimicrobial agent is entrapped in a matrix and acts through diffusion, our antimicrobial agents are ionically bonded to a polymeric backbone. The release mechanism is one of ion exchange and is not purely diffusional. The effectiveness is thus sustainable for a long period. Initial work will establish antimicrobial activity as a function of time against four organisms characteristic of nosocomial urinary tract infections. The method of release will be established by comparing the results of three different measures of antimicrobial activity, namely, the zone of inhibition and bacterial adherence tests. Preliminary biocompatibility tests and coating integrity will be conducted as well. Coating effectiveness greater than 1 week will justify further in vivo investigations.
Urethral catheters that effectively reduce the incidence of infection in long-term use have great market potential due to the reduction in mortality, morbidity, and direct patient costs. For instance, the direct patient costs associated with the treatment of catheter associated urinary tract infections exceeds $0.5 billion annually. The success of Bard's hydrogel/silver Foley catheter demonstrates that the medical and insurance communities would be highly receptive to reasonably priced products that significantly reduces the incidence of nosocomial urinary tract infections. While advances in infection control procedures and medical devices have reduced the overall incidence of catheter associated urinary tract infections, in long term (> one week) catheterizations there is a greater than 50% chance that those patients will acquire a sometimes anti-biotic resistant infection. There are no products that are effective for more than 1 week. Preliminary results have shown that our antimicrobial coating is effective for as long as 30 days, a four-fold increase over any other commercially available product. Since our coating does not alter the physical characteristics of the base material or product, acceptance by the medical device community once safety and efficacy is established should be achievable with appropriate business development efforts.
