Mechanism study of how lipid vesicle electroformation is suppressed by the presence of sodium chloride.

Giant lipid vesicles (GLVs) are usually adopted as models of cell membranes and electroformation is the most commonly used method for GLV formation. However, GLV electroformation are known to be suppressed by the presence of salt and the mechanism is not clear so far. In this paper, the lipid hydration and GLV electroformation were investigated as a function of the concentration of sodium chloride by depositing the lipids on the bottom substrates and top substrates. In addition, the electrohydrodynamic force generated by the electroosmotic flow (EOF) on the lipid phase was calculated with COMSOL Multiphysics. It was found that the mechanisms for the failure of GLV electroformation in salt solutions are: 1) the presence of sodium chloride decreases the membrane permeability to aqueous solution by accelerating the formation of well-packed membranes, suppressing the swelling and detachment of the lipid membranes; 2) the presence of sodium chloride decreased the electrohydrodynamic force by increasing the medium conductivity.