title: Thermal-driven domain and cargo transport in lipid membranes.
abstract: Domain migration is observed on the surface of ternary giant unilamellar vesicles held in a temperature gradient in conditions where they exhibit coexistence of two liquid phases. The migration localizes domains to the hot side of the vesicle, regardless of whether the domain is composed of the more ordered or disordered phase and regardless of the proximity to chamber boundaries. The distribution of domains is explored for domains that coarsen and for those held apart due to long-range repulsions. After considering several potential mechanisms for the migration, including the temperature preferences for each lipid, the favored curvature for each phase, and the thermophoretic flow around the vesicle, we show that observations are consistent with the general process of minimizing the system's line tension energy, because of the lowering of line interface energy closer to mixing. DNA strands, attached to the lipid bilayer with cholesterol anchors, act as an exemplar "cargo," demonstrating that the directed motion of domains toward higher temperatures provides a route to relocate species that preferentially reside in the domains.
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Talbot
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Lucia
authors.initials: L
authors.lastname: Parolini
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Jurij
authors.initials: J
authors.lastname: Kotar
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Di Michele
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom pc245@cam.ac.uk.
authors.forename: Pietro
authors.identifier: 0000-0002-9193-8496
authors.initials: P
authors.lastname: Cicuta
mesh_terms: D001692:Biological Transport; D004247:DNA / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D013696:Temperature; D053835:Unilamellar Liposomes / Q000378:metabolism*
chemical_list: D008563:Membrane Lipids; D053835:Unilamellar Liposomes; D004247:DNA
keywords: DNA; lipid bilayers; lipid phase separation; thermophoresis; vesicles