Cell adhesion as wetting transition?

Cell adhesion is controlled by a complex interplay of short range (lock-and-key) forces mediated by cell surface receptors, a phalanx of (short and long range) nonspecific (generic) interactions, and last but not least membrane elasticity. The physical basis of cell adhesion is explored by the design of simplified model systems, mimicking cell and tissue surfaces, enabling local measurements of cellular shape changes and adhesion forces by microinterferometry. Cell adhesion can be understood as first-order dewetting transition that results in the formation of adhesion plaques, such as focal adhesion sites of cells, which allow cell adhesion at astonishingly low receptor densities. The repeller molecules of the glycocalix play a key role for the control of the adhesion transition and the mechanical stability of the adhering cells by relaxing the strength of the binding forces. Stress fibers are postulated to be essential for the stabilization of adhesion domains against leverage through bending moments enforced by hydrodynamic shear forces.