title: Dynamics of coarsening in multicomponent lipid vesicles with non-uniform mechanical properties.
abstract: Multicomponent lipid vesicles are commonly used as a model system for the complex plasma membrane. One phenomenon that is studied using such model systems is phase separation. Vesicles composed of simple lipid mixtures can phase-separate into liquid-ordered and liquid-disordered phases, and since these phases can have different mechanical properties, this separation can lead to changes in the shape of the vesicle. In this work, we investigate the dynamics of phase separation in multicomponent lipid vesicles, using a model that couples composition to mechanical properties such as bending rigidity and spontaneous curvature. The model allows the vesicle surface to deform while conserving surface area and composition. For vesicles initialized as spheres, we study the effects of phase fraction and spontaneous curvature. We additionally initialize two systems with elongated, spheroidal shapes. Dynamic behavior is contrasted in systems where only one phase has a spontaneous curvature similar to the overall vesicle surface curvature and systems where the spontaneous curvatures of both phases are similar to the overall curvature. The bending energy contribution is typically found to slow the dynamics by stabilizing configurations with multiple domains. Such multiple-domain configurations are found more often in vesicles with spheroidal shapes than in nearly spherical vesicles.
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Chloe M
authors.initials: CM
authors.lastname: Funkhouser
authors.affiliation: Department of Integrated Natural Sciences, Arizona State University, Glendale, Arizona 85069, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Solis
authors.affiliation: Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: K
authors.initials: K
authors.lastname: Thornton
mesh_terms: D002462:Cell Membrane / Q000737:chemistry*; D003198:Computer Simulation; D004548:Elasticity; D008055:Lipids / Q000737:chemistry*; D008560:Membrane Fluidity
chemical_list: D008055:Lipids