Attractive instability of oppositely charged membranes induced by charge density fluctuations

TL;DR

This paper predicts how charge density fluctuations can cause an attractive instability in oppositely charged membranes, potentially leading to fusion, with the instability's characteristics controlled by charge and viscosity parameters.

Contribution

It introduces a theoretical framework for understanding dynamic charge density fluctuations as a mechanism for membrane fusion in charged systems.

Findings

Charge density fluctuations induce attractive instability.

Instability modes and timescales depend on charge and viscosity.

Dynamic instabilities may precede membrane fusion.

Abstract

We predict the conditions under which two oppositely charged membranes show a dynamic, attractive instability. Two layers with unequal charges of opposite sign can repel or be stable when in close proximity. However, dynamic charge density fluctuations can induce an attractive instability and thus facilitate fusion. We predict the dominant instability modes and timescales and show how these are controlled by the relative charge and membrane viscosities. These dynamic instabilities may be the precursors of membrane fusion in systems where artificial vesicles are engulfed by biological cells of opposite charge.