Fig. 1: Nanovesicle formed by a lipid bilayer with purple headgroups and gray hydrocarbon chains.

The vesicle encloses the aqueous solution γ (blue) and interacts with the liquid nanodroplet α (green). Both the nanodroplet and the nanovesicle are immersed in the aqueous bulk phase β (white): a Initially, the droplet is well separated from the vesicle which implies that the outer leaflet of the bilayer is only in contact with the β phase. In this situation, both the nanodroplet and the nanovesicle have a spherical shape; b When the droplet is attracted towards the vesicle, it spreads onto the lipid bilayer, thereby forming an increasing contact area with the vesicle membrane; and c Partial engulfment of the droplet by the membrane after the vesicle–droplet couple has relaxed to a new stable state. The contact area between bilayer and α droplet defines the αγ segment of the bilayer membrane whereas the rest of the bilayer represents the βγ segment still in contact with the β phase. This engulfment process deforms both the nanovesicle and the nanodroplet into nonspherical shapes.