How cells feel viscoelasticity and why this is important in health and disease

Viscoelasticity is a ubiquitous mechanical property of living systems. It means that our tissues and organs—some more than others, with the brain being the most viscoelastic tissue in the body—do not behave like simple springs. Instead, when forces are applied to them, their deformation lags behind the applied force; conversely, when the force is removed, it takes time for the tissue to recover its original shape.Viscoelasticity is also present in many other aspects of everyday life. It is the property that allows running shoes to dissipate impact with the ground, and it is also what makes Blandiblu (or Silly Putty in other countries) so attractive to children.Importantly, viscoelasticity is also relevant for cells. In our tissues, cells are mechanically active entities that pull on and apply forces to their environment. In response to these forces, they activate internal biochemical reactions that determine a range of behaviours—ultimately, whether they remain healthy or become diseased.In this work, we demonstrate that cells require Piezo1—a Nobel Prize–winning ion channel involved in sensing pressure and temperature—to sense viscoelasticity, particularly in soft tissues. This finding is important because it will help us design new biomaterials that underpin in vitro models to study health and disease or to test drugs without using animals. It is also significant because it can support the development of new treatments based not on the biochemical behaviour of cells, but on their mechanical sensing of their environment, laying the foundations for mechanomedicine.