An international team, led by the University of Sydney, have developed a new bone implant that reduces the chance of infection and consequently, the risk of implant failure.
Implants for hip and knee replacements which are currently used in Australia have a significant failure rate of around 20%, which can result in unnecessary pain for patients. It can also be costly for the healthcare system, the patient and their family, if revision surgery is needed.
Implant failure can be caused by a build up of biofilm (a layer microorganisms that can trigger infection). However, the new implant would help to reduce this build up, due to the presence of gallium and defensin (a naturally occurring antimicrobial biomolecule in our body) within. Both the gallium and defensin mixed together helped to reduce the rate of surface bacteria on the bone by almost 90%, compared to a control. The reduction of 90% therefore significantly reduces the risk of implant failure.
“Gallium is an undercover agent that can be used to combat infection,” said lead author, Professor Wojciech Chrzanowski, from the University of Sydney Nano Institute and head of nanomedicine research at the Faculty of Medicine and Health. “Gallium looks like iron and can exploit bacteria’s need for iron to trick them into taking it up. Once inside bacterial cells, gallium destroys them. So, in the case of bone implants, which are highly susceptible to infection as foreign substances are introduced into the body, gallium is a superhero substance. Defensin, a kind of protein, is also active against bacteria (as well as fungi and some viruses) and is a natural part of our immune systems,” he said.
The researchers also found that the new implant reduced long-term inflammation by 45%, by decreasing immune cells reaction to the implant.