Figure 2.

(a) Wetting transition leading to inversion of liquid phases; (b) Wetting-induced budding, potentially leading to (c) complete vesicle fission. Note that in the presence of a heterogeneous membrane, the “red” lipid phase has an affinity for the dark blue liquid phase, and the two bud and separate from the mother vesicle together; (d) “Inward” budding induced by a dark blue liquid droplet external to the vesicle; (e) Raspberry-like vesicle morphology caused by several smaller droplets wetting the membrane; these droplets will coalesce to form a single bud; (f) During membrane engulfment of a nanodroplet, symmetry is broken; the line tension is negative so a long contact line minimizes line tension energy while the contact area between the separate liquid phases is reduced, creating a “lipped” membrane neck. The plane of the upper cross section is shown by the dotted line below and vice versa.