  We investigate the influence of a non-ionic surfactant like polymer on
phospholipid vesicles. Our results from cryogenic transmission electron
microscopy (cryo-TEM), dynamic light scattering (DLS), small angle neutron and
X-ray scattering (SANS/SAXS), identifies the existence of multilayer vesicles
and an increase in size of the vesicles in presence of the polymers. We present
a generalized model to obtain the bending rigidity from neutron spin echo
spectroscopy (NSE) data for multilayer vesicles. We demonstrated that polymers
are trapped in the lipid bilayer, causing a partial disruption in the vesicle,
which is attributed to the reduction in bending rigidity per unit bilayer. We
also observed substantial dampening of the trapped lipid tail motion in
presence of the polymer. Our results highlighted the possibilities of using
specialized polymers that can disrupt membrane and control their dynamics with
possible application in topical drug or nutraceutical formulations.
