|Schematic illustration shows E. coli exposed to graphene nanosheets. (Image by Chunhai Fan, Shanghai Institute of Applied Physics)|
While silver-based antibacterial coatings have become a common feature of many medical implantable devices, the material raises cytotoxicty and biocompatibility concerns. In the search for antibacterial materials that do not have cytotoxic properties, researchers are exploring the use of graphene, a monolayer of tightly packed carbon atoms that has been shown to effectively inhibit the growth of E. coli bacteria while producing minimal cytotoxicity.
As reported in Nanowerk, Qing Huang and Chunhai Fan, professors in the laboratory of physical biology at the Shanghai Institute of Applied Physics, have found that graphene derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), can inhibit bacterial growth. Because it exhibits antibacterial properties and can be mass-produced and easily processed to make freestanding and flexible paper at a low cost, GO could have important environmental and clinical applications, according to the scientists.
Fabricating water-dispersible GO and rGO nanosheets from their suspension using simple vacuum filtration, the scientists have learned that single-layer GO nanosheets with a thickness of approximately 1 nm and reduced graphene oxide sheets can be made into macroscopic, freestanding, robust, and flexible paper with a thickness between 1.5 and 4.6 µm. Evaluating the cellular uptake and cytotoxicity of the graphene oxide nanosheets with a mammalian cell line, the researchers have established that the sheets exhibt biocompatibility and only mild cytotoxicity.
"This is a significant finding, as both previous and our own studies have proven that graphene, particularly graphene oxide, is biocompatible and cells can grow well on graphene substrates, Fan remarks. "Furthermore, while silver and silver nanoparticles have been well known to be antibacterial, they and other nanomaterials are often cytotoxic."
The scientists' work, "Graphene-Based Antibacterial Paper," is published in the journal ACS Nano.