Visualization of membrane loss during the shrinkage of giant vesicles under electropulsation

TL;DR

This study visualizes how giant vesicles lose lipids and shrink when exposed to electric fields, revealing mechanisms like pore, vesicle, and tubule formation that cause membrane permeabilization.

Contribution

It provides direct visual evidence of lipid loss mechanisms during electric field-induced permeabilization of giant vesicles, linking size decrease to lipid area loss.

Findings

Lipid loss correlates with vesicle size decrease.

Three mechanisms observed: pore, vesicle, and tubule formation.

Lipid loss is proportional to permeabilized area.

Abstract

We study the effect of permeabilizing electric fields applied to two different types of giant unilamellar vesicles, the first formed from EggPC lipids and the second formed from DOPC lipids. Experiments on vesicles of both lipid types show a decrease in vesicle radius which is interpreted as being due to lipid loss during the permeabilization process. We show that the decrease in size can be qualitatively explained as a loss of lipid area which is proportional to the area of the vesicle which is permeabilized. Three possible mechanisms responsible for lipid loss were directly observed: pore formation, vesicle formation and tubule formation.