Confinement-induced shape transitions in multilamellar vesicles

TL;DR

This study investigates how confinement within spherical vesicles induces novel inner vesicle shapes, combining experimental confocal microscopy and numerical modeling to reveal new morphologies and transitions.

Contribution

It introduces a combined experimental and numerical approach to discover and explain confinement-induced shape transitions in multilamellar vesicles.

Findings

Confinement induces novel vesicle shapes like double and quadruple stomatocytes.

Numerical simulations accurately reproduce experimental morphologies.

Some shape transitions can be explained by a simple theoretical model.

Abstract

Morphologies of a vesicle confined in a spherical vesicle were explored experimentally by fast confocal laser microscopy and numerically by a dynamically-triangulated membrane model with area-difference elasticity. The confinement was found to induce several novel shapes of the inner vesicles, that had been never observed in unilamellar vesicles: double and quadruple stomatocytes, slit vesicle, and vesicles of two or three compartments with various shapes. The simulations reproduced the experimental results very well and some of the shape transitions can be understood by a simple theoretical model for axisymmetric shapes.