Controlled preparation of giant vesicles from uniform water droplets obtained by microchannel emulsification with bilayer-forming lipids as emulsifiers

Abstract

We investigated a preparation method of giant vesicles using monodisperse water-in-oil (W/O) emulsions stabilized by bilayer-forming emulsifiers. A mixture of phosphatidylcholine, cholesterol and stearylamine was used both to stabilize the water droplets formed in the emulsion and to form the vesicles. Using this lipid mixture, we obtained monodisperse W/O emulsions with mean droplet diameters of 10–40 μm and coefficients of variation as small as ca 5% by means of the microchannel (MC) emulsification technique. Utilization of an asymmetric straight-through MC array device enabled a monodisperse droplet productivity of up to 80 ml/h. The obtained water droplets were converted to giant vesicles via evaporative removal of the continuous-phase solvent followed by addition of an aqueous buffer solution. The resulting vesicles were similar in size to their starting water droplets, and a hydrophilic fluorescent marker was entrapped inside the vesicles.