Abstract

We present a mechanical model to describe the growth of healthy and cancerous tissues.

We first show that because of the coupling between cell division and the local stress, a tissue can be considered as a visco-elastic liquid with a relaxation time smaller than the cell division time. We give examples of the liquid behavior related to the competition for space between two tissues and discuss the stability of the interface between two tissues. We then present numerical simulations of tissues based on a dissipative particle dynamics algorithm. The simulations confirm the liquid-like behavior of the tissue and have been used to study the rheology of the tissue. Finally, we discuss the steady state structure of villis which are the protrusions of the surface of the intestine or the colon. We describe the formation of villis as a buckling instability of a polar cell monolayer. The polarity of the layer does not seem to play a role in the intestine where the villis are arranged in a square array but it is important in the colon where they are organized in a hexagonal array.