[Image from Chalmers University]
Bacteria moves around the body in fluids like blood looking for an area to stick to. Once they find a place, the bacteria starts to grow and form a protective layer called a biofilm.
Surgical implant procedures like hip and knee replacements and dental implants have a risk of bacterial infection. Sometimes, this causes the implant to not be able to attach to the skeleton, causing the implant to have to be removed. Most prosthetic joint infections (PJI) require surgery and medical therapy to treat the resulting joint pain. The cost to treat PJI in the U.S. was $566M in 2009 and is expected to more than double to $1.62B by 2020, according to a 2014 Clinical Microbiology Reviews article relayed by the National Institutes of Health.
Researchers at Chalmers University have recently shown that a layer of vertical graphene flakes acts as a protective surface that bacteria can’t attach to. Rather than sticking to the surface, the bacteria is cut apart by the flakes and dies. The graphene layers do not interfere with the bone structure’s ability to attach to an implant.
The researchers suggest that coating implants with the graphene flakes can protect patients from infection, eliminate the need for antibiotic treatment and reduce implant rejections.
“We discovered that the key parameter is to orient the graphene vertically. If it is horizontal, the bacteria are not harmed” said Ivan Mijakovic, professor in the department of biology and biological engineering at Chalmers University, in a press release.
The spikes of graphene do not affect human cells because human cells are significantly larger than bacteria. One bacteria measures one micrometer while one human cell measure 25 micrometers.
“Graphene has high potential for health applications. But more research is needed before we can claim it is entirely safe. Among other things, we know that graphene does not degrade easily” said Jie Sun, one of the researchers on the study.
The researchers also note that good bacteria are killed by the graphene spikes, but since it is localized, the microflora balance in the body is unaffected.
“We want to prevent bacteria from creating an infection. Otherwise, you may need antibiotics, which could disrupt the balance of normal bacteria and also enhance the risk of antimicrobial resistance by pathogens” said Santosh Pandit, one of the researchers.
The researchers hope to further their use of graphene spikes by coating implant surfaces and studying the effect of them on animal cells.
