Research

The Mechanobiology & Soft Matter group seeks to understand the basic physical principles underlying force transmission and elucidating how cell mechanical properties regulate cellular functions. Our experimental approach of cell mechanics takes advantage of physical chemistry of soft condensed matter and engineering sciences to address physiological questions at single-cell and tissue levels. Here are some current research projects in the group:

 

#1- Cellular mechanotransduction

When endothelial cells are exposed to shear stress, they exhibit a marked elongation and orientation, together with the development of thick stress fibers. By using microcontact printing and confocal microscopy, we seek to understand how reorganization of cellular structures and coordinate remodeling of cell-cell and cell-substrate adhesion complexes drive these changes. We pay also attention to the internal orchestration between cell and nuclear shape with a specific attention to nuclear mechanics in pathological contexts.

 

#2- Neurons and glial cells

We use a magnetic micromanipulation technique to study force-regulated processes in primary nerve cells. By applying nano- to piconewton forces on micrometric paramagnetic beads bound to the cell cytoskeleton, we characterize mechanical and rheological properties of neuron and glial cells. This magnetic tweezer technique is developed in combination with surface functionalization tools to address physiological questions on individual cells and well-defined networks of nerve cells, especially to elucidate the molecular mechanisms of traumatic brain injury (TBI).

 

#3- Cell motility

ImageJ=1.46rCell migration requires temporal and spatial integration of multiple force-generating systems. Contractile forces generated by myosin II activity and by turnover of the elastic actin network are balanced by adhesions between the cell and the underlying substrate, enabling generation of traction force and net forward movement. These processes, which are complex and highly regulated, have been well characterized individually but the influence of the properties of the underlying substrate on these mechanisms are still not well understood. We use fish epithelial keratocytes, which are notoriously well coordinated cells, to elucidate the manner in which changes of the cell environment properties affect shape and movements of motile cells.