Shape Deformation and Phase Separation Dynamics of Two-Component Vesicles

Abstract

We numerically study dynamics of shape deformations of vesicles resulting from intramembrane phase separation. At off-critical compositions resultant vesicle shapes closely resemble the echinocytosis of red blood cells, while at the critical composition a bicontinuous domain structure emerges. The coarsening process of domain structures on such a deformable surface is considerably slower than that on a rigid surface. The total length of domain boundaries ${N}_{\mathrm{DB}}$ decreases as ${t}^{\ensuremath{-}1/3}$ for the rigid sphere, whereas in the present system ${N}_{\mathrm{DB}}\ensuremath{\simeq}{t}^{\ensuremath{-}z}$ $(z\ensuremath{\simeq}0.1)$ at the late stage due to the coupling between the shape and the phase separation.