Droplet-Induced Budding Transitions of Membranes

TL;DR

This paper theoretically investigates how liquid droplets induce budding transitions in membranes, revealing conditions under which membranes partially or fully wrap droplets, with implications for biomimetic membrane behavior.

Contribution

It introduces a theoretical model for droplet-induced membrane budding, highlighting the role of membrane tension, contact angle, and volume in morphological transitions.

Findings

Budding transition occurs at a critical droplet volume.

Membrane tension and contact angle determine budding stability.

Discontinuous transition from partial to full wrapping is predicted.

Abstract

Motivated by recent experiments on biomimetic membranes exposed to several aqueous phases, we theoretically study the morphology of a membrane in contact with a liquid droplet formed via aqueous phase separation. We concentrate on membranes with negligible spontaneous curvature. At small droplet volume, bending energy dominates and the droplet is only partially wrapped by the membrane. At large volume, this configuration can become unstable and undergo a discontinuous transition to a state, in which the droplet is (almost) completely wrapped by the membrane. A morphology diagram, showing the parameter region where such budding transition occurs, is constructed as a function of the membrane tension and the intrinsic contact angle of the liquid with the membrane. The effects of spontaneous curvature are discussed qualitatively.