%0 Journal Article
%T Sedimentation of vesicles: from pear-like shapes to microtether extrusion
%+ Adhésion et Inflammation (LAI)
%+ Laboratoire Charles Coulomb (L2C)
%A Zen-Hong, Huang
%A Abkarian, Manouk
%A Viallat, Annie
%Z 16 pages
%< avec comité de lecture
%@ 1367-2630
%J New Journal of Physics
%I Institute of Physics: Open Access Journals
%V 13
%P 035026
%8 2011-03-29
%D 2011
%R 10.1088/1367-2630/13/3/035026
%K vesicles
%K sedimentation
%K tether
%K GUV
%Z 87.16.D-
%Z Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph]Journal articles
%X We study the sedimentation of buoyant giant lipid vesicles in a quiescent fluid at velocities ranging from 5 to 20 μm/s. Floppy vesicles are deformed by the flow. Their bottom (upstream) part remains spherical while their top (downstream) part narrows down and elongates along the direction of motion, resulting in pear-like shapes or in the reversible formation of a micron-size tube at the vesicle top. The sedimentation velocity of vesicle is very similar to that of a rigid sphere. Using a thermodynamic approach, we show that the hydrodynamic force acting at the top of a floppy vesicle can exceed the critical force needed to draw a membrane tube. We predict that the tube radius scales as the power 1/3 of the ratio of the bending energy to the typical hydrodynamic stress, ηU/R where η is the fluid viscosity, U is the sedimentation velocity and R the vesicle radius. This result is consistent with the reported experimental data. The tensions of vesicles exhibiting a tube and of pear-like shape are deduced from the thermodynamic approach
%G English
%2 https://hal.science/hal-00583690/document
%2 https://hal.science/hal-00583690/file/viallatvesicles.pdf
%L hal-00583690
%U https://hal.science/hal-00583690
%~ INSERM
%~ CNRS
%~ UNIV-AMU
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021