Critical swelling of particle-encapsulating vesicles

TL;DR

This paper analyzes the critical swelling behavior of particle-encapsulating vesicles, revealing a continuous phase transition to maximum volume with implications for osmotic lysis.

Contribution

It introduces a theoretical framework describing the universal swelling transition in particle-encapsulating vesicles, highlighting their unique critical behavior.

Findings

Vesicles undergo a continuous phase transition during swelling.

Pressure difference and surface tension increase near maximum volume.

Swelling behavior is universal as vesicles approach their limiting volume.

Abstract

We consider a ubiquitous scenario where a fluctuating, semipermeable vesicle is embedded in solution while enclosing a fixed number of solute particles. The swelling with increasing number of particles or decreasing concentration of the outer solution exhibits a continuous phase transition from a fluctuating state to the maximum-volume configuration, whereupon appreciable pressure difference and surface tension build up. This criticality is unique to particle-encapsulating vesicles, whose volume and inner pressure both fluctuate. It implies a universal swelling behavior of such vesicles as they approach their limiting volume and osmotic lysis.