Control of Budded Domains in Amphiphilic Bilayer Membranes

Phase separated domains in multicomponent vesicles form spherical buds to reduce interfacial energy. We study the response of a multicomponent budded vesicle to an imposed shear flow with dissipative particle dynamics. We find that shear can either act to stretch the bud open or separate the bud from the vesicle, depending on bud orientation. We examine the interplay of interfacial tension, bending energy, and shear in determining the behavior of the vesicle, and provide criteria for the design of vesicles for controlled bud release.The neck connecting the budded domain with the bulk vesicle assumes a catenoid shape to minimize bending energy. We model the mechanism for pinch-off of catenoid necks with continuum elastic theory and dissipative particle dynamics. We examine pore nucleation and growth driven by Gaussian energy, by the adhesion energy of an encapsulated particle, and by the line energy of an interface between two amphiphile species, aiming to provide principles for the design of vesicles for biomimetic phagocytosis