Void collapsing dynamics under alignment and motion polarizations of spindle-shaped fibroblast monolayer

Yun-Xuan Zhang^1*, Chun-Yu Liu¹, Hsiang-Ying Chen¹, Lin I¹

¹Department of Physics and Center for Complex Systems, National Central University, Jhongli, Taiwan

* Presenter:Yun-Xuan Zhang, email:yunxuanzhang1998@gmail.com

We experimentally investigate the void collapsing process in spindle-shaped fibroblast monolayer from the dilute state. The anisotropic cell shape leads to cell alignment and motion polarizations. It is found that, voids with various sizes are spontaneously formed after cells form a connected network. Void boundaries can be classified into convex and concave boundaries, where cell alignments and motions are aligned along and normal to the boundary, respectively. Convex boundaries mainly dominate for small voids, along which the successive stick-slip like void collapsing is achieved through cell structural rearrangements. For large voids, both kinds of boundaries exist. The transverse cell alignment at the cusp tip of concave boundary leads to follow-the-leader type cell motion toward the opposite side of the void, and splits a large void into smaller voids. The above void collapsing processes are different from the purse-string mechanism in the wound healing of endo- or epithelial cell monolayers with isotropic cell shapes.

Keywords: Cell Monolayer, Collective Motion, Active Nematics, Wound Healing