The structure-dynamics feedback mechanism governs the glassy dynamics in epithelial monolayers

Area of Science:

• Biophysics
• Cell Biology
• Soft Matter Physics

Background:

• Confluent epithelial monolayers display glass-like slow dynamics essential for biological processes like wound healing and cancer progression.
• Experimental observations show unique properties, including a strong correlation between static properties and glassiness, and sub-Arrhenius relaxation, deviating from ordinary glasses.

Purpose of the Study:

• To investigate the nature of slow dynamics in confluent epithelial monolayers.
• To determine if the observed dynamics are truly glassy and elucidate the underlying mechanism.
• To explore the relationship between static properties and dynamic behavior in cellular systems.

Main Methods:

• Analytical mode-coupling theory (MCT) was employed.
• Vertex model simulations were utilized.
• Experimental data from cellular systems were integrated.

Main Results:

• The study confirms that the slow dynamics in epithelial monolayers are glassy, but with a distinct mechanism compared to ordinary glasses.
• A structure-dynamics feedback mechanism, as described by MCT, dominates over barrier-crossing mechanisms.
• Relaxation time diverges with a power law exponent of 3/2, explaining the sub-Arrhenius relaxation observed experimentally.

Conclusions:

• The glassy dynamics in epithelial monolayers are driven by structure-dynamics feedback, not barrier-crossing.
• The findings suggest that static properties, such as cell shape and its variability, can predict complex biological processes like cell division and apoptosis.