Two-dimensional graphene may be poised to revolutionize much of materials science, but a recent study has shown that this one-atom-thick material could present some serious health risks inside the human body. The problem? It's so thin that it can slice directly into our cells.
Graphene was discovered about a decade ago. It's incredibly strong, flexible, stretchy, conductive, and self-cooling. Eventually, it'll be used in small electronic devices, solar cells, batteries, and medical devices. But not much is known about what effect these materials might have if they get inside the human body.
And indeed, these materials could be ingested during the manufacturing process, during a product's lifecycle, or through other environmental channels. Graphene could be inhaled unintentionally, or deliberately injected or implanted as components of new biomedical technologies.
And troublingly, as the new study from Brown University researchers suggests, graphene does indeed appear to exhibit toxic qualities.
The scientists discovered that graphene features jagged edges that can easily pierce cell membranes, allowing it to enter into the cell and disrupt normal function. Previous computer models had discounted the possibility — but the models assumed perfectly square pieces of graphite. But in reality, after the exfoliation process, they come off in oddly shaped flakes with jagged protrusions called asperities.
To prove it experimentally, the researchers placed human lung, skin, and immune cells in petri dishes along with graphene microsheets. Then, after looking at the interactions with an electron microscope, they could see the graphene piercing into the cells with its rough edges and corners. Sheets of up to 10 micrometers could be gobbled up by a cell.
This is not good news, obviously. But now materials scientists can set about the task of finding a way to create cleaner cuts of graphite.
Read the entire study at PNAS: "Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites."