title: Shape recovery of an optically trapped vesicle: effect of flow velocity and temperature.
abstract: A new biophysical approach based on optical tweezers is developed to measure the time-dependent shape transformation and recovery of a single liposome, which is induced by the sudden stop of a moving liposome from various flow velocities at constant temperature. A simple viscoelastic model has been applied to correlate the temporal geometric parameter of the deformed liposome with a characteristic time constant, i.e., the ratio of membrane viscosity to elasticity. Our results show that membrane viscosity becomes dominant in governing the shape recovery rate when sample temperature goes beyond the main phase transition temperature of the phospholipid bilayer. More importantly, flow speed and vesicle size are demonstrated as key physical determinants for the shape recovery of liposome.
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany. foo@mpi-cbg.de
authors.forename: Ji-Jinn
authors.initials: JJ
authors.lastname: Foo
authors.forename: Vincent
authors.initials: V
authors.lastname: Chan
authors.forename: Kuo-Kang
authors.initials: KK
authors.lastname: Liu
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D003198:Computer Simulation; D004548:Elasticity; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000737:chemistry*; D044085:Microfluidics / Q000379:methods*; D008846:Micromanipulation / Q000379:methods*; D008956:Models, Chemical; D009038:Motion; D055095:Optics and Photonics; D033081:Shear Strength; D013696:Temperature; D014783:Viscosity
chemical_list: D008081:Liposomes; D008563:Membrane Lipids; D015060:1,2-Dipalmitoylphosphatidylcholine