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BP: Fachverband Biologische Physik
BP 20: Poster IIIa
BP 20.27: Poster
Wednesday, March 20, 2024, 11:00–14:30, Poster B
Tangential diffusion and motility-induced mixing transition in growing spheroidal cell colonies — •Torben Sunkel1,2, Lukas Hupe1,2, and Philip Bittihn1,2 — 1MPI for Dynamics and Self-Organization, Göttingen, Germany — 2Institute for the Dynamics of Complex Systems, Göttingen University, Göttingen, Germany
Growth is a known driver of cellular dynamics in a range of dense aggregates from bacterial colonies to developing tissues to tumors. Hence, universal physical principles underlying these dynamics are of great interdisciplinary interest. Here, we study the emergent dynamics arising from the interplay of growth, steric repulsion and motility in a minimal agent-based model of exponentially growing three-dimensional spheroids. Our results show that, without cell motility, deterministic motion caused by overall volume expansion dominates the dynamics of individual cells in the radial direction, while growth and division lead to cellular-scale diffusive motion in the tangential direction, whose magnitude is largely independent of expansion velocity. Despite this small-scale diffusion, we show that cell lineages are subject to confinement in their local environment, quenching weak cell motility. At higher motility, we find a transient regime of tangential superdiffusivity, accompanied by global mixing of cells. Reminiscent of glassy dynamics, we find a diverging mixing time scale at the transition. We also explore the influence of passive components like extracellular matrix. Our observations highlight the complex mechanical interaction between global expansion and local cell activity and may serve as a baseline to identify additional biological mechanisms in experiments.
Keywords: proliferating active matter; multicellular spheroids; agent-based model; mean squared displacement; glassy dynamics