The influence of non-anchored polymers on the curvature of vesicles¶

Abstract

The influence of non-anchored polymers on the membrane curvature of vesicles is studied theoretically. The interaction between polymer and membrane consists of a hard-wall contribution, which prevents the polymer from penetrating the membrane, and an additional attractive potential which can lead to polymer adsorption onto the membrane surface. The vesicle membrane divides space into an interior and an exterior compartment. These two compartments are taken to be osmotically balanced but may contain different polymer species. The polymer-induced curvature of the vesicle membrane is calculated as a function of the adsorption strength which is described by the inverse extrapolation length. For strong adsorption, the membrane bends away from the adsorbed polymers whereas it bends towards the polymers for complete desorption. The polymer-induced curvature changes its sign at a characteristic adsorption strength below the adsorption transition which corresponds to a positive value of the inverse extrapolation length.