title: Stretching and relaxation of vesicles.
abstract: We study the shape relaxation of spherical giant unilamellar vesicles which have been deformed far from equilibrium into ellipsoids using optical tweezers. The relaxation back to a sphere is determined by elastic constants of the vesicles, and their excess area, parameters that are obtained for each stretched vesicle from shape fluctuations in thermal equilibrium, as well as low Reynolds number fluid flow. The relaxation time could be compared favorably to a simple formula which encompasses the joint effect of membrane rigidity and fluid flow. The time constant of the stretched vesicle is slower than that of its thermal fluctuations, which agrees with a recent theory; however, it is one order of magnitude faster than predicted.
authors.affiliation: Physics Department, Eindhoven University of Technology, Eindhoven, the Netherlands.
authors.forename: Hernan
authors.initials: H
authors.lastname: Zhou
authors.forename: Beatriz Burrola
authors.initials: BB
authors.lastname: Gabilondo
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Losert
authors.forename: Willem
authors.initials: W
authors.lastname: van de Water
mesh_terms: D057446:Hydrodynamics; D055620:Optical Phenomena; D010713:Phosphatidylcholines / Q000737:chemistry; D013997:Time Factors; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D010713:Phosphatidylcholines; D053835:Unilamellar Liposomes; C017251:1,2-oleoylphosphatidylcholine