Model for curvature-driven pearling instability in membranes

TL;DR

This paper introduces a phase-field model to study curvature-driven pearling instability in membranes, successfully reproducing experimental morphologies and revealing energetic preferences for inhomogeneous structures at high anchor concentrations.

Contribution

It presents a novel phase-field model for membrane instabilities and demonstrates its ability to replicate experimental observations and predict energetic favorability of different shapes.

Findings

Homogeneous pearled structures form from cylindrical tubes.

High anchor concentration favors inhomogeneous shapes with large and small spheres.

The model reproduces morphological changes observed in experiments.

Abstract

A phase-field model for dealing with dynamic instabilities in membranes is presented. We use it to study curvature-driven pearling instability in vesicles induced by the anchorage of amphiphilic polymers on the membrane. Within this model, we obtain the morphological changes reported in recent experiments. The formation of a homogeneous pearled structure is achieved by consequent pearling of an initial cylindrical tube from the tip. For high enough concentration of anchors, we show theoretically that the homogeneous pearled shape is energetically less favorable than an inhomogeneous one, with a large sphere connected to an array of smaller spheres.