Thermodynamics and dynamics of the formation of spherical lipidic vesicles

TL;DR

This paper models the thermodynamics and dynamics of spherical vesicle formation from lipid membranes, deriving equations to describe the process and identifying different formation mechanisms based on membrane size.

Contribution

It introduces a free energy model and a Fokker-Planck equation to analyze vesicle formation dynamics, providing explicit transition rates and times.

Findings

Vesicle formation can be an activated process for small membranes.

For large membranes, formation occurs as a transport process.

Explicit expressions for transition rates and formation times are provided.

Abstract

We propose a free energy expression accounting for the formation of spherical vesicles from planar lipidic membranes and derive a Fokker-Planck equation for the probability distribution describing the dynamics of vesicle formation. We found that formation may occur as an activated process for small membranes and as a transport process for sufficiently large membranes. We give explicit expressions for the transition rates and the characteristic time of vesicle formation in terms of the relevant physical parameters.