Make or break for cellular tissues

Thanks to the analogy between the cellular layer examined and the well-understood behaviour of thin liquid films, the scientists Stéphane Douezan and Françoise Brochard-Nyart devised a model of the layer's evolution. They considered it as an active, amorphous material made of a continuum of cells. Because it is subject to a constant competition between neighbouring cell-cell and cell-substrate adhesion, it can either maintain its contiguous structure or break.The authors investigated the layer's stability when subjected to chemical and physical disturbances.

In particular, they scrutinised how the cellular layer reacted to a non-adhesive substrate with little chemical affinity with the cells. They also subjected the cells to a physical disturbance by laying them in substrates with low stiffness, such as soft gels.The researchers observed what is known as the dewetting phenomenon, whereby the cellular layer is ruptured leading to islands of cells interspersed with dry patches. Dewetting is normally observed in viscous polymer films on slippery surfaces. They concluded that the dewetting phenomenon is due to the cells' distinctive sensitivity to the nature of its substrate, particularly to its decreased stiffness. This means that active, living cells remain governed by the laws of physics.