Shape change and physical properties of giant phospholipid vesicles prepared in the presence of an AC electric field

摘要: Giant unilamellar vesicles with diameters ranging from 10 to 60 microns were obtained by the swelling of phospholipid bilayers in water presence an AC electric field. This technique leads a homogeneous population perfectly spherical and vesicles, as revealed phase-contrast optical microscopy freeze-fracture electron microscopy. Freshly prepared had high surface tension no visible undulations. Undulations started spontaneously after several hours incubation or triggered application small osmotic pressure. Partially deflated giant could undergo further shape change if asymmetrical formed adding lyso compounds external leaflet imposing transmembrane pH gradient that selectively accumulates on one phosphatidylglycerol. Fluorescence photobleaching 7-nitrobenz-2-oxa-1,3-diazol-4-yl-labeled phospholipids labeled dextran trapped within enabled measurement membrane continuity dumbbell-shaped vesicles. In all instances diffused lobe other, but soluble sometimes was unable traverse neck. suggests diameter connecting neck may be variable.