Relaxation kinetics controls cell transport in crowded active monolayers

In a near-confluent active phase-field monolayer, slowing passive relaxation in a minority of soft cells more than doubles their transport and increases the untouched majority’s transport by half.

• Why it matters: Crowded active tissues show bursty migration, but prior work conflated deformation energy with the relaxation rate that controls how quickly cells recover shape against neighbors.
• What they did: The authors used an active phase-field model where relaxation rate and free energy were varied independently, then compared transport in mixtures with altered relaxation in only a subset of cells.
• The result: Crowding cancels propulsion mainly via relaxation of cell deformations; when soft-cell relaxation is fast, the soft-cell advantage disappears and reverses at high soft-cell fractions, with mixtures behaving like a uniform layer set by the geometric-mean interfacial tension.

AI summary of the abstract · may contain errors · not medical advice · read the paper.