Bacterial colonization of medical implants poses serious risks, often resulting in infections that require device removal. Biomedical designers may soon have a new weapon in their antibacterial arsenal: graphene.
Researchers from Chalmers University of Technology, Sweden, have demonstrated that a layer of vertical graphene flakes forms a protective surface, preventing bacterial attachment. The microbial invaders are instead sliced apart by the sharp, 60-100 nm high graphene flakes and killed. Coating implants with a layer of graphene flakes can help protect the patient against infection, eliminate the need for antibiotic treatment and reduce the risk of implant rejection.
Vertical flakes of graphene are not a new invention, but the researchers are the first to use the material in this way. Osseointegration — the process by which the bone structure grows to attach to the implant — is not disturbed, and the sharp flakes do not damage human cells.
The key parameter for this effect is the orientation of graphene with respect to the coated surface. The researchers observed that chemical vapor deposition (CVD) graphene, deposited horizontally on the surface, exhibits no antibacterial effect. However, an array of graphene flakes grown perpendicularly to the surface by a plasma‐enhanced CVD process prevents biofilm formation. Bacteria do not develop resistance to this killing mechanism during multiple exposures.
The next step will be to continue testing the graphene flakes by coating implant surfaces and studying the effect on animal cells.