Preventing infection with an improved silver coating for medical devices

According to folklore, silver bullets kill werewolves, but in the real world, researchers want to harness this metal to fight another deadly foe:bacteria. Scientists have tried to develop a silver coating for medical devices to protect against infections, but they have had limited success. In a study in Central Science, one team describes a silver-ion releasing coating that prevents rats from adhering to implants and then killing them.

Sometimes surgeons need to implant a device, such as a tube to drain a wound, or deliver medication directly into the blood, in order to provide medical care. There is a risk of infections on the surfaces of these devices. Silver is known to kill microbes and researchers are working to develop a silver-based coating. Their efforts have faced many challenges, including that silver can be toxic to human cells and that it is difficult to make a coating that releases small amounts of the metal over long periods. They wanted to find a formula that could overcome these difficulties.

To develop a simple-to-use coating, the team screened many sets of ingredients that they could apply to a surface in a single step. The formula that worked the best included silver nitrate. This silver-based film-forming antibacterial engineered (SAFE) coating formed stable, silver- containing assemblies, which gradually released silver ion in lab tests.

The new coating recipe was effective in keeping the most common types ofbacteria at bay. It did so by repelling thebacteria from the surface and then killing them with silver ion. They put a titanium implant under the skin of rats to see if SAFE worked. The researchers found that implants with the coating had a lower number ofbacteria than those without it. There were no signs of toxicity to the rats tissues. The coating appeared tough after being rubbed and sterilized. The researchers say that the combination of attributes will make the coating useful in many types of medical devices and implants to preventbacterial infections over the long-term.

More information: Durable Surfaces from Film-forming Silver Assemblies for Long-term Zero Bacterial Adhesion without Toxicity, ACS Central Science (2022). DOI: 10.1021/acscentsci.1c01556 Journal information: ACS Central Science Citation: Preventing infection with an improved silver coating for medical devices (2022, April 27) retrieved 27 April 2022 from https://phys.org/news/2022-04-infection-silver-coating-medical-devices.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.