Medical Coatings
In-dwelling medical devices are a crucial lifeline for patients in hospital. The devices, often in the form of tubes, provide access to the body for the delivery of fluids, drugs, and even nutrition and air (Endotracheal tubes). They also provide a means of removing unwanted substances from the body through urinary catheters, kidney dialysis, and wound drains. The insertion of such devices, as well as other tubes, for example urinary (Foley) catheters into the body provide a conduit for skin bacteria and yeast to gain entry into the body and cause infection. Infections arising from the use of in-dwelling biomedical devices, especially catheters, are associated with increased morbidity and mortality, prolonged hospitalization, patient discomfort and increased medical costs. Urinary tract infections (UTIs) caused by Foley catheters are among the most prevalent type of hospital acquired infections as noted below:
- UTIs account for 40% of HAIs
- Foley catheter use causes 80-90% of UTIs
- 15-50% of hospitalized patients with a urinary catheter experience UTI from urinary catheterization
- Infection risk increases by 5% each day of catheterization
- Bacteremia (bacteria in the blood) occurs in up to 4% of cases
- 1-3.8 extra hospital days are due to UTI and $680-$3,800 per patient/episode of UTI added to the healthcare system
- UTIs increase the costs associated with treatment by more than US$1.8 billion per year in the USA
In order to reduce the potential for HAI infections from medical devices, manufacturers have added various coatings to the surface of catheters. Ionic silver is well accepted as an antiseptic and is a proven broad-spectrum antimicrobial agent that eradicates gram positive bacteria, gram negative bacteria as well as antibiotic-resistant bacteria like methicillin-resistant Staphylococus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE). Ionic silver also kills moulds (fungi) including yeast such as Candida albicans. Covalon has developed a proprietary coating that is applicable to a wide variety of medical devices that include dialysis lines, PICC lines, and various catheters.
Covalon technology applies a covalently bonded, stable, high-quality hydrophilic polymer coating on the surface of invasive medical devices yielding products with improved biocompatibility and functionality. The coatings enhance medical device service by reducing the coefficient of static friction of surfaces including silicone, polyurethane, and polyvinyl chloride medical devices. Examples include, Foley catheters, central venous lines, silicone films and polyurethane films. The surface coating acts as a repository for the controlled efflux of therapeutics at the site of device insertion or application. Once the coating has been applied various therapeutics of varying molecular structure may be introduced into the surface matrix. Customers receive thin, uniform, molecular coating with pre-determined properties and, if required, controlled, site-specific therapeutic delivery to enhance therapeutic effect while reducing detrimental effects. Covalon technology allows us to deliver silver ions from medical device surfaces for extended periods thereby creating an antimicrobial surface coating. The coatings can be applied to Foley catheters, peritoneal dialysis catheters, hemodialysis catheters, wound drains, central venous lines and other tubular medical devices, and various wound dressings and skin coverings. The coating can be formulated to provide controlled delivery of various therapeutics for a range of applications.
Please also see:
Medical Devices' Silver Bullet - Antimicrobial coatings for preventing infections are becoming indispensable components of implantable medical devices. Read the whole story at www.devicelink.com/mpmn/archive/09/07/012.html
Finelli, A., Burrows, L., DiCosmo, F., DiTizio, V., Sinnadurai, S., Oreopoulos, D.G., and Khoury, A.E. 2002. Colonization resistant antimicrobial coated peritoneal dialysis catheters: Evaluation in a newly developed rat model of persistent Pseudomonas aeruginosa peritonitis. Peritoneal Dialysis International 22: 27-31.
