| dc.description.abstract | Through the interplay of mutual coupling and self-propelling, coupled many-body active systems can exhibit collective motions, especially in biological systems such as fish schools, flocking birds, dense bacteria, confluent cells. In the systems of 2D confluent cells on the substrate, cells are strongly coupled with their neighbors through cell junctions. The highly deformable cell boundary contains a large number of degrees of freedom. Therefore, the confluent epithelial and endothelial cell monolayers have been used as model systems to investigate the
intriguing cell collective motion. Nevertheless, unlike the studies on collective motion of the single type cell monolayers mainly exhibit liquid or solid-like
collective motions, the dynamics of mixtures of two different types of cells remain elusive. In this work, we experimentally study the dynamical evolutions of a confluent
endothelial cell (EC) monolayer and a cancer cell (CC)/ EC mixture after the invasion of more motile CCs into a confluent EC monolayer. We demonstrate that slowed down the vortex like coherent motion of EC only monolayer, and the
rejuvenation of aged motion after the invasion of a small fraction of CCs. It is found that, the slowed down collective motion in EC only monolayer is due to the gradual structure relaxation and increasing EC density through
proliferation. CC invasion is associated with opening EC cell-cell junctions. With increasing time, CCs tend to gradually aggregate and form larger clusters.
Interaction with ECs through the confining fluctuating irregular EC boundary without EC-CC junction, more CCs in the larger clusters exhibit stronger turbulent motion with power law scaling extending to the lower frequency modes. It also leads to longer trajectory persistent length. The speeded up CC dynamics in turn enhances the turbulent like motion of surrounding ECs and awakes their slowed down dynamics. | en_US |