A motility-induced mixing transition in growing spheroids
How do cells mix inside a growing tissue? Motility competes with two effects of growth — the mechanical pressure it generates and the expansion it drives: Below a critical motility, these keep cell lineages confined and the tissue stays unmixed; above it, cells overcome the confinement, disperse, and the tissue mixes. Right at the transition, the time needed to mix diverges as a power law — a critical slowing-down reminiscent of glassy dynamics. Combining large-scale agent-based simulations with an effective model, we pinned down the mechanism behind this transition and how it depends on motility and growth. Whether a tissue sits in the mixed or the confined regime has direct implications for tumor invasion, therapeutic access, and the design of cell therapies.
Huge congratulations to Torben, together with co-author Lukas — a great piece of work!