Geometric pinning and antimixing in scaffolded lipid vesicles

TL;DR

This study introduces a new model of multicomponent vesicles with controlled shape, revealing how membrane domains adapt to curvature and form an 'antimixed' state, advancing understanding of membrane organization.

Contribution

The paper presents a novel vesicle model with controlled shape and composition, demonstrating curvature-induced domain pinning and antimixing phenomena.

Findings

Domains adapt to vesicle geometry

Identification of antimixed state in lipid domains

Link between curvature pinning and membrane parameters

Abstract

Unravelling the physical mechanisms behind the organisation of lipid domains is a central goal in cell biology and membrane biophysics. Previous studies on cells and model lipid bilayers featuring phase-separated domains found an intricate interplay between the membrane geometry and its chemical composition. However, the lack of a model system with simultaneous control over the membrane shape and conservation of its composition precluded a fundamental understanding of curvature-induced effects. Here, we present a new class of multicomponent vesicles supported by colloidal scaffolds of designed shape. We find that the domain composition adapts to the geometry, giving rise to a novel "antimixed" state. Theoretical modelling allowed us to link the pinning of domains by regions of high curvature to the material parameters of the membrane. Our results provide key insights into the phase separation of cellular membranes and on curved surfaces in general.