  The growth and reconfiguration of polymer networks such as the cytoskeleton
can generate forces that move objects and deform materials and membranes, even
in the absence of molecular motors. Taking inspiration from this, we ask
whether a dynamic polymer system can generate deformation forces by merely
controlling the monomer structure and interactions, and the temporal schedule
of monomer release, which can be considered a "molecular program" directing
polymer assembly. Using simulations of patchy particles that are released into
the interior of a vesicle at a given rate, we ask which molecular programs are
most proficient at generating forces. We show that stiff polymers induce
deformation by spontaneously bundling, and deforming the vesicle axially. The
rate at which monomers are released controls whether the polymers can generate
forces quickly, or deform the vesicle more slowly but with a larger maximal
force. For softer polymers, which cannot ordinarily deform the vesicle, we
demonstrate that introducing crosslinkers can be enough to promote the bundling
of polymers required to deform vesicles, but that the details of how this
crosslinking is implemented can significantly affect the outcome. Finally, we
show that dynamic release of monomers and crosslinkers can increase the
variance of this process, and that by making the polymers polar filaments one
can obtain better force generation by suppressing nucleation. Our results
provide a blueprint for the experimental realization of molecular programs that
could produce nanoscale forces using synthetic biopolymers.
