A few weeks ago, I wrote a post about extra-strong graphene. After reading it, you may think that its applications are limited to new technology, but US and Chinese scientists have now revealed a new unexpected property for this versatile material – it can be used as a plaster to disinfect cuts and bruises.
It turns out that graphene can kill bacteria by disrupting its cellular membrane. The researchers believe this material can open the membrane due to strong repulsive interactions between the two compounds: graphene and lipids. Once the disruption is initiated, the cellular contents are inevitably spilled, signalling the end for the bacteria!
Further research needed
Researchers are convinced this can be used to develop new antibiotics with an added bonus – bacteria can never become resistant to it. As this is a physical rather than chemical process, bacteria do not have the ability to evolve and become resistant to this type of antibiotic. One of their ideas is to create graphene-based plasters for easy application in small cuts and cruises, but the team still need to study any potential side-effects to human cells. It would be slightly worrying if this mechanism would equally affect skin cells the same manner, or in other words, if it cannot differentiate between “good” and “bad” cells. In theory, this would not happen as the material can “recognise” different cellular structures and composition, but further research is needed. Future plans also include the assessment of other types of bacteria, to complement current work with E. Coli.
How does it work?
It cannot be argued that graphene is lethal for bacteria, but the exact mechanisms involved in the process have not been clearly identified yet. Some ideas are based on the unusual conductivity properties of graphene or its strange crystalline arrangement, but all this needs to be verified in the lab. So far, most of the work has relied quite heavily on computer-generated membrane models and may not take into account surrounding particles that interfere with the membrane and how it reacts to the presence of graphene. The answer, according to the authors, is to prepare experiments using real lipid membranes in direct contact with graphene and observe what happens.
I wonder if we will ever be able to buy graphene plasters in our local pharmacy …
Yusong Tu, Min Lv, Peng Xiu, Tien Huynh, Meng Zhang, Matteo Castelli, Zengrong Liu, Qing Huang, Chunhai Fan, Haiping Fang & Ruhong Zhou. Destructive extraction of phospholipids from Escherichia coli membranes by graphene nanosheets. Nature Nanotechnology (2013) doi:10.1038/nnano.2013.125