Mechanical Criterion for the Rupture of a Cell Membrane under Compression.

We investigate the mechanical conditions leading to the rupture of the plasma membrane of an endothelial cell subjected to a local, compressive force. Membrane rupture is induced by tilted microindentation, a technique used to perform mechanical measurements on adherent cells. In this technique, the applied force can be deduced from the measured horizontal displacement of a microindenter's tip, as imaged with an inverted microscope and without the need for optical sensors to measure the microindenter's deflection. We show that plasma membrane rupture of endothelial cells occurs at a well-defined value of the applied compressive stress. As a point of reference, we use numerical simulations to estimate the magnitude of the compressive stresses exerted on endothelial cells during the deployment of a stent.