Onsager's irreversible thermodynamics of the dynamics of transient pores in spherical lipid vesicles

TL;DR

This paper applies Onsager's irreversible thermodynamics to derive kinetic equations for transient pore dynamics in spherical lipid vesicles, revealing the roles of surface tension, pressure, and viscosity in pore opening and collapse.

Contribution

It systematically deduces pore kinetic equations using thermodynamics, highlighting the importance of initial conditions and nonlinear effects in pore dynamics.

Findings

Edge tension determined from initial pore relaxation

Surface tension and pressure are about 25% of initial values at final state

Pore lifetime controlled by solution viscosity

Abstract

Onsager's irreversible thermodynamics is used to perform a systematic deduction of the kinetic equations governing the opening and collapse of transient pores in spherical vesicles. We show that the edge tension has to be determined from the initial stage of the pore relaxation and that in the final state the vesicle membrane is not completely relaxed, since the surface tension and the pressure difference are about $25\%$ of its initial value. We also show that the pore life-time is controlled by the solution viscosity and its opening is driven by the solution leak-out and the surface tension drop. The final collapse is due to a non-linear interplay between the edge and the surface tensions together with the pressure difference. Also, we discuss the connection with previous models.