Dissipative particle dynamics simulation of critical pore size in a lipid bilayer membrane

TL;DR

This study uses dissipative particle dynamics simulations to identify the critical pore size in lipid bilayer membranes, revealing how pore stability depends on membrane parameters and differs from polymer film behavior.

Contribution

It introduces a simulation approach to determine critical pore size in lipid membranes and explores conditions affecting pore stability, highlighting differences from polymer films.

Findings

Pores larger than critical radius grow, smaller ones close.

Pore stability varies with system parameters.

Lipid membranes behave differently from polymer films.

Abstract

We investigate with computer simulations the critical radius of pores in a lipid bilayer membrane. Ilton et al. (2016) recently showed that nucleated pores in a homopolymer film can increase or decrease in size, depending on whether they are larger or smaller than a critical size which scales linearly with film thickness. Using dissipative particle dynamics, a particle-based simulation method, we investigate the same scenario for a lipid bilayer membrane whose structure is determined by lipid-water interactions. We simulate a perforated membrane in which holes larger than a critical radius grow, while holes smaller than the critical radius close, as in the experiment of Ilton et al. (2016). By altering system parameters such as the number of particles per lipid and the periodicity, we also describe scenarios in which pores of any initial size can seal or even remain stable, showing a fundamental difference in the behavior of lipid membranes from polymer films.