Laboratoire Matière et Systèmes Complexes

MSC : Atef Asnacios, François Gallet, Florence Gazeau, Sylvie Hénon, Benoît Ladoux, Nathalie Luciani, Alain Richert, Claire Wilhelm.

A living cell is a mechanosensitive system, which detects mechanical informations from its environment and translates them into biological signals, in order to better adapt to external conditions. For instance, the adhesive contacts of a cell cultivated on a stiff substrate are reinforced as compared to a soft substrate; cell migration is oriented in the direction of rigidity gradient (durotaxis) ; applying an external stress may induce cell polarization, migration, division, and even stem cell differentiation, through the expression of mechanosensitive genes. In the biophysics group, we adopted an approach between physics and biology, in order to understand some of these mechanotransduction phenomena. We have developed a set of complementary techniques, allowing us to control the mechanical stresses exerted on single cultivated cells or cell aggregates (optical tweezers, magnetic nanoparticles, single cell rheometer, arrays of force sensors, nanopatterned substrates). We use them to observe the structure and the remodelling of the cytoskeleton submitted to a stress, to measure the activity of molecular motors, to analyze the dynamics of the formation of cell- cell or cell-matrix adhesive contacts, in 2D or 3D environments, to study cell migration in confined structures… etc.

See also the following items:

• Mechanics of a single living cell
• Microfabrication and cell adhesion
• Distribution of active forces in a living system
• Tissue engineering