Dynamic Force Spectroscopy to Probe Adhesion Strength of Living Cells

We studied the mechanical strength of the adhesion of living cells to model membranes. The latter contained a RGD lipopeptide which is a high affinity binding site for a cell adhesion molecule (integrin [Formula presented]). Cells adhered specifically to the vesicles. We used micropipette aspiration for breaking this adhesion with well defined forces. Systematic variation of the rate of force application revealed pronounced kinetic effects. The dependence of the detachment forces on the loading rate was well described by a power law (exponent [Formula presented]), in agreement with recent theoretical work.