Lipid Segregation on Cylindrically and Spherically Curved Membranes

TL;DR

This paper explores how external curvature affects lipid segregation on membranes, revealing that curvature and bending-modulus contrast promote multi-domain formations similar to magnetic vortices, with specific criteria and domain sizes calculated.

Contribution

It introduces a novel mechanism linking membrane curvature and lipid phase separation, providing criteria and quantitative analysis for multi-domain formation.

Findings

Curvature reduces effective line tension between lipid phases.

Multi-domain states form on highly curved membranes.

Domain sizes depend on membrane geometry and curvature.

Abstract

We investigate how an externally imposed curvature influences lipid segregation on two-phase-coexistent membranes. We show that the bending-modulus contrast of the two phases and the curvature act together to yield a reduced effective line tension. On largely curved membranes, a state of multiple domains (or rafts) forms due to a mechanism analogous to that causing magnetic-vortex formation in type-II superconductors. We determine the criterion for such multi-domain state to occur; we then calculate respectively the size of the domains formed on cylindrically and spherically curved membranes.