Robert Hurt, Ph.D., Agnes Kane, Ph.D., M.D.
NIEHS Grant P42ES013660
NIEHS grantees report that graphene materials with micrometer-scale dimensions, known as graphene microsheets, can enter cells when their sharp protrusions pierce the cell membrane. Understanding how these graphene sheets interact with cells can help scientists develop materials that are not harmful to the body.
The researchers’ initial simulations suggested that a microsheet would rarely pierce a cell because the energy barrier required for a sheet to cut the membrane was too high. However, when these simulations took into account the rough edges commonly found on the edges of graphene sheets, the sheets more easily pierced the membrane.
Confocal fluorescence and electron microscopy confirmed that graphene’s rough edges and corners could pierce primary human keratinocytes, human lung epithelial cells, and murine macrophages. The imaging also showed that cells could completely internalize graphene sheets with lateral dimensions of .5 to 10 micrometers. More research is needed to understand how the microsheets affect cells, but the researchers say that microsheets might disrupt cytoskeleton and cell motility and cause problems with epithelial barriers.
Citation: Li Y, Yuan H, von dem Bussche A, Creighton M, Hurt RH, Kane AB, Gao H. 2013. Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites. Proc Natl Acad Sci U S A 110(30):12295-12300.