Mechanical properties and microdomain separation of fluid membranes with anchored polymers

TL;DR

This study investigates how anchored polymers influence the mechanical properties and domain formation in fluid membranes through simulations and theoretical modeling.

Contribution

It introduces a combined simulation and mean field theory approach to understand the effects of anchored polymers on membrane rigidity and domain stabilization.

Findings

Anchored polymers reduce line tension at membrane edges and interfaces.

Densely anchored polymers stabilize small membrane domains.

Simulation results align with theoretical predictions.

Abstract

The entropic effects of anchored polymers on biomembranes are studied using simulations of a meshless membrane model combined with anchored linear polymer chains. The bending rigidity and spontaneous curvature are investigated for anchored ideal and excluded-volume polymer chains. Our results are in good agreement with the previous theoretical predictions. It is found that the polymer reduces the line tension of membrane edges, as well as the interfacial line tension between membrane domains, leading to microdomain formation. Instead of the mixing of two phases as observed in typical binary fluids, densely anchored polymers stabilize small domains. A mean field theory is proposed for the edge line tension reduced by anchored ideal chains, which reproduces our simulation results well.