NBIA Colloquium by Jacques Prost

A physical approach to cells and tissues

There is now growing evidence on the significant role of mechanical forces in shaping the behavior of cells in tissues and in tumors. However, fundamental questions such as how one defines mechanical pressure in such non-equilibrium systems that continuously move, divide and die, remains elusive. In the first part of the talk I shall discuss this problem through a theoretical model in connection with experiments on tumor spheroids. Next, I shall describe a novel type of phase transition in cellular layers based on the theory of active gels. When an assembly of cells is confined into stripes, the system switches from a perfectly quiescent state to a spontaneously shearing state, simply by changing the stripe width. Finally, I shall talk about recent non-intuitive results on the interaction of applied electric fields with cellular tissues.

Over the past forty years, Jacques Prost has made remarkable contributions to our understanding of soft and biological matter. He was a pioneer in studying liquid crystals, which led to his lasting contribution, together with Pierre-Gilles de Gennes, of their classic book  "The Physics of Liquid Crystals". Subsequently, he moved towards  biophysics.   He is a member of the French and European Academies of Sciences and has been awarded the 2007 Del Duca European Grand Prix and the 2016 Beverly and Raymond Sackler Prize in Biophysics.

All are welcome!  Refreshments as usual after the talk in the NBIA lounge.