  The study of the ability of drug molecules to enter cells through the
membrane is of vital importance in the field of drug delivery. In cases where
the transport of the drug molecules through the membrane is not easily
accomplishable, other carrier molecules are used. Spherical fullerene molecules
have been postulated as potential carriers of highly hydrophilic drugs across
the plasma membrane. Here we report the coarse-grain molecular dynamics study
of the translocation of C60 fullerene and its derivatives across a cell
membrane modeled as a 1, 2-distearoyl-sn-glycero-3-phosphocholine (DSPC)
bilayer. Simulation results indicate that pristine fullerene molecules enter
the bilayer quickly and reside within it. The addition of polar functionalized
groups makes the fullerenes less likely to reside within the bilayer but
increases their residence time in bulk water. Addition of polar functional
groups to one half of the fullerene surface, in effect creating a Janus
particle, offers the most promise in developing fullerene models that can
achieve complete translocation through the membrane bilayer.
