Hydrodynamic tether extrusion from ``gelly'' vesicles

Extrusion of cell tethers requires the detachment of the plasma membrane and can be used to probe the strength of membrane-cytoskeleton adhesion. We have studied the hydrodynamic extrusion of tethers from red blood cells [1] and developed a theoretical model based on permeation of lipids through the network of membrane proteins linked to the cytoskeleton [2]. Our aim here is to probe the model on biomimetic systems, namely lipid vesicles filled with artificial cytoskeleton made of synthetic or biological gels, where we can adjust the membrane-cytoskeleton coupling. The properties of tubes extruded from these ``gelly'' vesicles will be compared to simple vesicles on one hand, and to red blood cells or human carcinoid BON cells on the other. [1] N. Borghi et al, Biophys. J. 93 (2007) [2] F. Brochard-Wyart, et al, Proc. Natl. Acad. Sci. USA, 103 (2006)