The research comes from Chalmers University of Technology, Sweden and it shows how a minute layer of graphene flakes can reduce the risk of infections during surgical procedures like the fitting of implants. Examples of procedures include dentinal implants, or the fitting of new knee or hip replacements.
The risk with microbial infection stems from the way bacteria travel around the body in fluids like blood If bacteria succeed in adhering to a surface in sufficient numbers then a biofilm can develop. A biofilm is a special type of microbial community, within which bacteria communicate, and they are protected by a slime layer. Once a biofilm has formed, it constitutes a micro-niche that provides bacteria with an environment that is highly conducive to their survival while also protecting them from various types of aggression from outside.
To address this risk, the scientists from Chalmers University demonstrated how a thin layer (one thousandth of a millimeter) of vertical graphene flakes can be used to fashion a protective surface. This development also negates the need to administer antibodies and, based on successful trials, avoids the risk of implant rejection and further surgery. Moreover, the process of osseointegration, bone structures grow to attach the implant, is not disturbed.
Graphene, a one atom thick form of carbon, has been in a number of electronics applications due to its high conductivity and flexible nature, which makes it ideal for wearable devices. Graphene is also extremely sensitive to molecules, which allows it to be used in sensors. The biological applications have only recently emerged.
The graphene flakes are manufactured using a process called Plasma-Enhanced Chemical Vapor Deposition, which allows for a thin surface coating on a sample to be undertaken. This happens in a chamber as three gases – hydrogen, methane and argon – are released. The gases become ionized near the surface, to create the flakes.
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According to lead researcher, Professor Ivan Mijakovic: “We discovered that the key parameter is to orient the graphene vertically. If it is horizontal, the bacteria are not harmed.” Importantly, human cells are unaffected. Moreover, through this method of kill there is no known possibility of bacteria developing resistance to graphene.
He goes on to discuss future applications: “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.”
Further trials with graphene need to be undertaken, using animal cells, before the coating can be released for use in human surgery. These projects will be funded by Vinnova (a Swedish government agency).
The research has been published in the journal Advanced Materials Interfaces. The research paper is titled “Vertically Aligned Graphene Coating is Bactericidal and Prevents the Formation of Bacterial Biofilms.”
