Fluidization and anomalous density fluctuations in 2D Voronoi cell tissues with pulsating activity

Area of Science:

• Cellular dynamics
• Biophysics
• Tissue engineering

Background:

• Cells exhibit active motions beyond crawling, including nonmotile contractions and pulsations.
• Understanding these active motions is crucial for comprehending tissue structure and dynamics.

Purpose of the Study:

• To investigate the impact of nonmotile cell pulsation on cellular monolayers.
• To model how random and synchronized cell pulsations affect tissue fluidity, structure, and density fluctuations.

Main Methods:

• Utilized a Voronoi cell model to simulate cellular monolayers.
• Analyzed the effects of random and synchronized cell pulsation on tissue properties.

Main Results:

• Random cell pulsation was shown to fluidize solid epithelial tissues into a hyperuniform fluid state.
• Synchronized cell pulsation inhibited fluidity, inducing solidification through a Berezinskii-Kosterlitz-Thouless-type transition.
• Observed strong density and dynamic heterogeneity, with fluctuations diverging with pulsation period, leading to anti-hyperuniformity.

Conclusions:

• Cellular nonmotile activity significantly alters tissue states, from hyperuniform fluids to solid-like structures.
• The study proposes a unified fluctuating hydrodynamic theory for anomalous density fluctuations.
• Findings provide insights into experimental observations of Madin-Darby canine kidney cell monolayers.