Whenever a medical implant is introduced to the human body, there's a chance that its surface will be colonized by bacteria. In some cases, such infections require the implant to be removed. It's recently been discovered, however, that coating implants with vertical graphene flakes could help keep that from happening.
Graphene is composed of a one-atom-thick layer of linked carbon atoms. Using a technique known as Plasma-Enhanced Chemical Vapor Deposition, scientists at Sweden's Chalmers University of Technology have deposited microscopic vertically-protruding flakes of the material on a horizontal substrate – this means that the flakes essentially became tiny spikes.
In lab tests, any bacteria that came into contact with those graphene spikes were sliced apart by them, and killed. This did include so-called "good" bacteria, although in the body this probably wouldn't matter, as the amount of good bacteria killed on implant surfaces wouldn't be enough to disrupt the patient's overall balance of microflora.
Also importantly, bacteria aren't able to develop a resistance to the graphene, plus the spikes don't harm human cells, as an individual cell is much larger than an individual bacterium – 25 micrometers in diameter, as opposed to just one. And as an added benefit, the structure of the graphene should help with osseointegration, which is the process by which the body's adjacent bone structure grows to attach to an implant.
The researchers now plan on coating actual implants with the graphene flakes, and testing them in animal models.
"Graphene has high potential for health applications," says Chalmers' associate professor Jie Sun. "But more research is needed before we can claim it is entirely safe. Among other things, we know that graphene does not degrade easily."
A paper on the research was recently published in the journal Advanced Materials Interfaces.
