Asymmetric Bilayers by Hemifusion: Method and Leaflet Behaviors

We describe a new method to prepare asymmetric giant unilamellar vesicles (aGUVs) via hemifusion. Hemifusion of giant unilamellar vesicles and a supported lipid bilayer, triggered by calcium, promotes the lipid exchange of the fused outer leaflets mediated by lipid diffusion. We used different fluorescent dyes to monitor the inner and the outer leaflets of the unsupported aGUVs. We confirmed that almost all newly exchanged lipids in the aGUVs...