The Acute Effects of Graphene Nanoflakes on Whole-Cell Cholesterol

Graphene is a novel nanomaterial with great potential in biomedicine owing to its high electron mobility, thermal conductivity, and mechanical strength. In biological applications, graphene often makes direct contact with the plasma membrane and likely affects cellular function. The lack of understanding about graphene-plasmalemma interaction inspired this mechanistic study. Based on published work from our lab about graphene’s chronic effects on cell growth, we used graphene nanoflakes (GNFs) and examined their acute effects in astrocytes. Our tests show that GNFs readily insert into the plasmalemma, focally enrich membrane cholesterol (mChol), stabilize surrounding membrane, and promote membrane protein activity and transmembrane signaling. More importantly, GNFs’ interplay with mChol stimulates cellular cholesterol production, leading to a long-lasting functional impact. In summary, these results advocate for novel and broad applications of GNFs, such as allosteric modulation of cell signaling pathways and active control of sterol metabolism, both of which have promising therapeutic implications.