Procedures such as dental implant or knee replacement surgery always carry a risk of bacterial infection. Bacteria that enter the body circulate in fluids such as the blood, and find surfaces to cling to.
Once attached, they multiply to form a protective “biofilm” that can sometimes stop an implant attaching to bone, meaning it has to be removed.
As reported in the journal Advanced Materials Interfaces, researchers at Chalmers were able to demonstrate that a layer of vertical graphene flakes can form a protective layer across the surface of the implant, inhibiting bacterial attachment.
The sharp graphene flakes slice the bacteria apart and destroy them. Coating implants with this protective layer could therefore prevent infection, eliminate the need for antibiotics and reduce the risk of implant rejection.
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.”
Santosh Pandit, Co-Author
The flakes do not damage human cells because those cells are so much larger (25 µm in diameter) than bacterial cells (1 µm in diameter). The effect on human cells is therefore the equivalent of a tiny scratch, as opposed to a deadly attack.
Beneficial bacteria are destroyed by the flakes, but this is not a problem because the effect is localized and the balance of microflora in the body is not disturbed.
Study author Jie Sun said: "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.”
The researchers will now study the effect on animal cells when implants are coated with the protective flake layer.