Abstract
Giant vesicle (GV), which is a compartment composed of lipid bilayer of amphipathic molecules with the diameter above 1µm, is applied as model for artificial cell membrane and expected as microreactor. GVs are generally prepared by electroformation method. However, there is no method to prepare GVs with controlled size and high entrapment yield. Microchannel (MC) emulsification is known as the method to prepare monodispersed water-in-oil (W/O) emulsions in the range from a micrometer to tens micrometers. In this study, in order to prepare GVs with high entrapment yields, we applied MC emulsification. Firstly, MC emulsification was carried out to prepare W/O emulsion using hexane as continuous phase, tris-HCl buffer as dispersed phase, and sorbitan monooleate (Span 80) as surfactant. Monodispersed W/O emulsion with the size of 4.0 µm was successfully prepared. Secondly, Span 80 was replaced with lipids mixtures consisted of phosphatidylcholine, cholesterol and stearylamine (5:5:1) as component of lipid bilayer. The substitution process was performed at -10 Celsius degree with water phase droplet frozen to avoid coalescence of emulsion droplets. With keeping water frozen, hexane was evaporated and tris-HCl buffer was added as external water phase. Using this procedure, GVs were successfully prepared with entrapment yield of 11%. The final size of the prepared GVs reflected the original emulsion droplet size.
