Weakly adhering vesicles in shear flow: Tanktreading and anomalous lift force

Abstract

We report the deformation and unbinding of weakly adhering giant vesicles under hydrodynamic shear forces. Linear shear fields are generated in a flat cell and vesicle adhesion onto a supported membrane is generated by electrostatic forces between oppositely charged lipids. The hydrodynamic flow in the aqueous medium near the outer side of the vesicle, within the vesicle and the tanktreading motion in the membrane are observed by tracing small markers attached to the vesicles or suspended in the medium by confocal laser scanning microscopy. The lift force generated by the rotational flow in the vesicle was estimated to be at least two orders of magnitude larger than predicted by the simple theory.

Hydrodynamic mechanisms of cell and particle trapping in microfluidics

“…This phenomenon was first demonstrated theoretically for droplets, 40,106 and later was numerically and experimentally observed for bubbles, vesicles, and viscous capsules. [107][108][109][110][111][112][113] The essential factor responsible for the deformation and consequent lateral migration of droplets is found to be stress matching type of boundary conditions at the corresponding interface instead of no-slip condition at the boundary of a rigid wall. 109 Various studies 40,114,115 assert the point that the direction of migration depends on the type of deformable particle and its relative viscosity with respect to the surrounding fluid.…”

Influence of shear flow on vesicles near a wall: A numerical study

“…In the experiment [7], this is done by choosing iso-osmolar but different buffers for swelling the vesicle and suspending the vesicle. The threshold velocity at which unbinding of the vesicle from the substrate occurs allows to estimate the lift force.…”

“…We are also motivated by recent experiments on weakly adhering vesicles in shear flow [7]. These investigations reveal the lipid flow within the vesicle membrane and the flow field within the vesicle and near its outer surface.…”

Biomimetic study of rolling transport through smooth muscle contraction

“…While it is clear that the transport of oosperm involves smooth muscle contraction [1,2], the detailed mechanism still remains elusive [1][2][3][4][5][6][7], due in part to the complexity of cellsubstrate interactions via receptor-ligand binding as well as various physical forces inside and outside of the cytoskeleton [8][9][10][11][12]. Cells are known to respond to mechanical forces exerted through surrounding fluid, adhering beads or substrates [9,[12][13][14], and they could detach, slip or roll on a substrate in response to these forces [15][16][17][18][19][20][21][22]. For example, cells on a cyclically stretched substrate tend to reorient themselves away from the stretching direction [23][24][25][26][27], and cells migrate along a substrate with rigidity gradient (durotaxis) [18].…”

“…For example, cells on a cyclically stretched substrate tend to reorient themselves away from the stretching direction [23][24][25][26][27], and cells migrate along a substrate with rigidity gradient (durotaxis) [18]. Blood cells are found to undergo a transition from rolling to translational motion on a blood vessel wall under increasing hydrodynamic shear forces [19], exemplifying a general fact that it takes less effort for a round object to roll than to slip on a substrate [28,29].…”