16 April 2018: Bacteria Beaten by Graphene Blades

The US, France and the UK have bombed Syria. UK PM Teresa May says it was all legal and morally sound. It’s legally questionable, and Macron says he convinced Trump to do it. It’s morally dubious, and sacked FBI director James Comey says Trump is morally unfit to lead anyway. 

So, you know, sounds legit.
[Sigh.]

Look, turn off the news about dubious airstrikes, here’s a happier story about warfare, this time on a microscopic scale in the medical battle against surgical infections. 

Material science researchers in Sweden have used Graphene, the world’s thinnest substance, to fight bacterial infections in surgical implants, such as hip and knee replacements. The material’s antibacterial effect isn’t because it’s acting as a drug: the researchers created a layer of tiny graphene blades to slice open and destroy invading bacteria.

When bacteria infect a surgical implant, they first form a skin at the surface of the implant known as a biofilm. In a paper published in the journal Advanced Materials Interfaces this week, researchers from Chalmers University of Technology in Sweden reported that a layer of tiny graphene spikes at the implant surface stopped the formation of a biofilm by slice through the invading bacterial cells’ outer membranes. 

Graphene is a form of carbon in which the atoms join together into a two-dimensional sheet, just one atom thick. Sheets of graphene have a suite of unique electrical and structural properties; in this case, however, the antibacterial value of graphene comes from its single-atom width: layers of graphene are the sharpest blades ever created.

The material scientists used a method known as plasma-enhanced chemical vapour deposition to grow a layer of tiny graphene spikes about 100 nm high — long enough to be deadly to tiny bacteria cells, but harmless to the much larger human cells. 

Importantly, the bacteria did not seem to develop resistance to the graphene blades over time. Because the graphene is only used locally at the site of the surgical implant, it has no broader impact on the vital friendly bacteria throughout the body.

Thin layers of Graphene have been trialled before as a barrier against surgical infections, with mixed results. The Chalmers team realised that the key to graphene’s potency is the angle of the flakes: when the graphene layers grow parallel to the surface or at a low angle, bacteria can easily attach and infect the site. 

But when the graphene is deposited as flakes perpendicular to the surface, the array of atom-thick knives easily slices through any bacteria cells that come too close.