Long-time fate of microphase separation in extensile–contractile mixtures

Determine whether microphase separation arrests at a finite cluster size or continues to coarsen at asymptotically long times in a phase-field model of a confluent monolayer composed of an equal mixture of extensile (positive intercellular dipolar activity) and contractile (negative intercellular dipolar activity) cells, as assessed by the segregation index and density autocorrelation metrics.

Background

The paper uses a multi-phase-field model to simulate a confluent epithelial monolayer containing equal numbers of extensile and contractile cells that differ only in their intercellular dipolar activity. The simulations show rapid initial sorting into elongated clusters followed by much slower evolution.

Quantitative measures, including the segregation index (SI) and the density autocorrelation length scale, indicate microphase separation with apparent saturation at late times within the simulation window. However, the authors explicitly note uncertainty about whether this reflects true arrest or simply very slow continued coarsening beyond accessible times.