Sharp corners and jagged edges on graphene sheets enable them to puncture cell membranes. Researchers from Brown University have shown how tiny graphene microsheets — ultra-thin materials with a number of commercial applications — could be big trouble for human cells. The research shows that sharp corners and jagged protrusions along the edges of graphene sheets can easily pierce cell membranes. After the membrane is pierced, an entire graphene sheet can be pulled inside the cell where it may disrupt normal function. The new insight may be helpful in finding ways to minimize the potential toxicity of graphene, said...