title: Flow-Driven Rapid Vesicle Fusion via Vortex Trapping.
abstract: Fusion between suspended lipid vesicles is difficult to achieve without membrane proteins or ions because the vesicles have extremely low equilibrium membrane tension and high poration energy. Nonetheless, vesicle fusion in the absence of mediators can also be achieved by mechanical forcing that is strong enough to induce membrane poration. Here, we employ a strong fluid shear stress to achieve vesicle fusion. By utilizing a unique vortex formation phenomenon in branched channels as a platform for capturing, stressing, and fusing the lipid vesicles, we directly visualize using high-speed imaging the vesicle fusion events, induced solely by shear, on the time scale of submilliseconds. We show that a large vesicle with a size of up to ∼10 μm can be achieved by the fusion of nanoscale vesicles. This technique has the potential to be utilized as a fast and simple way to produce giant unilamellar vesicles and to serve as a platform for visualizing vesicle interactions and fusions in the presence of shear.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors.forename: Jesse T
authors.initials: JT
authors.lastname: Ault
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone
mesh_terms: D057446:Hydrodynamics; D055595:Mechanical Phenomena; D013314:Stress, Mechanical; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D053835:Unilamellar Liposomes