Confocal Images (20X) of S. Aureus Bacteria trapped in Graphene Oxide Aggregates formed after incubation in Saline Solution. Bacteria are labeled in red and GO in green.

Scientists at the Università Cattolica del Sacro Cuore in Rome are studying graphene oxide in the hopes of creating bacteria-killing catheters and medical devices. Coating surgical tools with this carbon-based compound could kill bacteria, reducing the need for antibiotics, decreasing the rates of post-operative infections, and speeding recovery times.

"We want to make materials that will help patients and medical professionals," said Valentina Palmieri, a biotechnologist at the Università Cattolica del Sacro Cuore.

Graphene oxide, a form of graphene with molecular oxygen incorporated into it, protects against infection by destroying bacteria before it gets inside the body. The graphene oxide wraps around the bacteria, puncturing its membrane. A broken membrane prevents the bacteria from growing and often kills it. "The bacteria lose their complex structure and die," Palmieri added. "And since graphene is just carbon (a building block of life) its cytotoxicity against human cells is much lower compared to any drug-based antimicrobial therapy."

Researchers decided to use graphene oxide because it is very stable in a water solution, making it safe to interact with human cells. Graphene specifically attacks bacterial cells, while sparing human cells, and the mechanism behind this specificity is still unclear, Palmieri said. Current theories include that the material interacts more favorably with the bacterial cell wall or that mammalian cells have evolved multiple repair mechanisms to survive the chemical oxidation damage that graphene induces.

Graphene is also more eco-friendly. Traditional methods of preventing infection include antibiotic therapy and tools coated with silver, both of which are toxic to the environment, Palmieri said.