The origin of yield-stress and plasticity in tissue monolayers

An intriguing and crucial feature of confluent tissue monolayers lies in their capacity to endure significant deformations without compromising either their epithelial integrity or mechanical resilience. Viewed through the lens of material science, these tissue monolayers can be conceptualized as yield-stress materials. Below the yield stress, they exhibit solid-like behavior, while above this threshold, they undergo plastic flow. As such, gaining insights into the factors that determine a tissue's yield stress is essential for understanding both tissue development and the onset of tumorigenesis. To investigate this, we employed a multifaceted approach that combines agent-based computational simulations with mean-field theoretical models. This allowed us to explore the origins of yield stress in a representative tissue model, as well as to elucidate the mechanisms underlying plasticity when the tissue exceeds its yield stress.