|Photo of a coated versus an uncoated catheter. |
Credit: Kizhakkedathu Lab
University of British Columbia researchers have found a ‘silver bullet’ to kill bacteria and keep them from infecting patients who have medical devices implanted.
The team from UBC and the Vancouver Coastal Health Research Institute has developed a silver-based coating that can easily be applied to devices such as catheters and stents. Their novel formulation, discovered by screening dozens of chemical components, overcomes the complications of silver that have challenged scientists for years.
|Dr. Jayachandran Kizhakkedathu|
Implanted medical devices can save lives, but they carry a great risk of infection which usually arises from contamination as the device is being implanted. Urinary tract infections from catheters, for example, are among the most common hospital-acquired infections.
Silver has long been viewed as a potential solution because of its ability to kill bacteria, but its use on implanted devices poses several challenges that have stumped researchers until now. The main challenge is its toxicity. Too much of the poison that kills bacteria can also be bad for human cells and tissues.
Coatings incorporating silver have also proven overly complicated to make, lacked durability, became easily gummed up with proteins or crystals, or simply didn’t adhere well to the surface of devices and implants.
|Dr. Hossein Yazdani-Ahmadabadi|
It also maintains its killing activity for longer than has been achieved by other coatings.
The researchers tested it for 30 days in an environment with a high concentration of diverse and resilient bacteria known to cause infections. Their device came away with no bacteria attached. In a seven-day test with live rats, it performed the same way and did not harm the rats’ tissues.
|Dr. Dirk Lange|
The coating could be applied to almost any material without pre-treatment used to make medical devices such as central venous catheters, urethral catheters, peritoneal catheters, feeding tubes, vascular grafts, ureteral stents or orthopedic implants.
Silver is a precious metal, but the amount required is so small that it would add only about 50 cents to the cost of a catheter.
The research team looks forward to seeing how the coating performs in clinical trials, and is optimistic that their discovery could be of wide use to prevent infections in patients within the next decade.
Their work was funded by Canadian Institutes of Health Research, the Natural Sciences and Engineering Council of Canada, the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund and the Michael Smith Foundation for Health Research.
Source/Credit: University of British Columbia | Erik Rolfsen