2 Mechanism of permeation of fullerene through a lipid membrane. a, Monomeric fullerene rapidly crosses the lipid head group region, then diffuses
more slowly in the membrane interior. Fullerene is shown in red, the lipids in cyan with blue head groups (phosphodiester groups), and water is yellow. The
simulation time is indicated in each snapshot. b, Penetration of a cluster of ten fullerenes. Lipid phosphodiester groups are shown as blue spheres, lipid tails as
cyan lines; water is not represented. The permeation of fullerene clusters is much slower than for monomers, and starts with the insertion of a single fullerene in the
lipid head group region. The simulation time is indicated in each snapshot.