UBC researchers discover 'silver bullet' for protecting medical devices from infection

Two catheters, one with a silver coating designed to kill bacteria, are seen in an image provided by the University of British Columbia. (Credit: Kizhakkedathu Lab)

A team of researchers from the University of British Columbia and Vancouver Coastal Health has discovered a “silver bullet” that kills bacteria and prevents them from infecting patients with implanted medical devices.

While devices such as stents and feeding tubes can save lives, the researchers noted they can also pose a significant risk of infection, particularly if there’s any contamination during the implant procedure. 

The team’s solution is a silver-based coating that can be applied to a variety of medical devices, including catheters – which are associated with 95 per cent of urinary tract infections, according to a study from the Infectious Diseases Society of America.

“This is a highly effective coating that won’t harm human tissues and could potentially eliminate implant-associated infections. It could be very cost-effective and could also be applicable to many different products,” said Dr. Jayachandran Kishakkedathu, a professor in UBC’s pathology department, in a news release.

Although silver is an effective antimicrobial, it has a toxic effect when used in implants and medical devices. The new coating technology has solved that issue and led to a new method of preventing bacteria from adhering to the devices, researchers explained to CTV News. 

The coating was tested for one month in an environment with a high concentration of various bacteria known to cause infection. The device came away with “no bacteria attached,” according to UBC. A seven-day test with live rats showed the same results and no damage to the rats’ tissues.

“We’re preventing that by keeping bacteria off the surface in the first place and then killing them with the release of silver. Since we prevent attachment of both live and dead bacteria, this coating has significant potential to maintain a clean surface for any device or material for an extended period of time, which is something we haven’t seen so far,” said Dr. Dirk Lange, the associate professor in UBC’s department of Urologic Sciences, in the release.

Researchers suggest the “silver bullet” would add about 50 cents to the cost of a catheter, and it works on different materials.

According to the team, the silver-based coating can be applied to:

• central venous catheters
• urethral catheters
• peritoneal catheters
• feeding tubes
• vascular grafts
• ureteral stents or orthopaedic implants.

The study is currently in the proof-of-concept phase, and it might take five to 10 years to complete the clinical evaluation.