Slow and anomalous dynamics of an MCF-10A epithelial cell monolayer

Understanding the mechanics and dynamics of active matter at high density is indispensable to a range of physical and biological processes such as swarm dynamics, tissue formation and cancer metastasis. Here, we study the dynamics and mechanics of an MCF-10A epithelial cell monolayer on the multi-cellular and single-cell scales and over a wide density range. We show that the dynamics and Young's modulus of the monolayer are spatially heterogeneous on the multi-cellular scale. With increasing cell density, the monolayer approached kinetic arrest and the Young's modulus scaled critically. On the single-cell scale, as the cell density increased, cells were intermittently trapped in cages formed by their neighbors and their motion evolved from a ballistic motion to a sub-diffusive motion. Furthermore, the relaxation time and inverse self-diffusivity increased exponentially with the cell density. These findings provide a mechanism for long-ranged mechanical stress propagation, tissue remodeling and patterning at very high cell densities.