Hydrodynamics and multiscale order in confluent epithelia.

Area of Science:

• Biophysics
• Soft Matter Physics
• Cell Biology

Background:

• Confluent epithelia, or cell layers without gaps, are crucial in development and disease.
• Understanding collective cell migration is key to tissue dynamics.

Purpose of the Study:

• To develop a hydrodynamic theory for confluent epithelia.
• To investigate the multiscale liquid crystal order in migrating epithelia.

Main Methods:

• Formulation of a hydrodynamic theory based on p-atic liquid crystals.
• Analysis of the system's structure factor.
• Cell-resolved modeling using the self-propelled Voronoi and multiphase field models.

Main Results:

• Epithelia display both nematic (p=2) and hexatic (p=6) orders, dominant at large and small scales, respectively.
• The structure factor shows two power-law scaling regimes reflecting cell geometry and flow.
• Momentum dissipation and noise impact fluctuations and cell cooperativity.

Conclusions:

• The study provides a theoretical framework for multiscale order in epithelia.
• This framework can explain recent experimental observations in kidney cell layers.
• It opens avenues for further theoretical and experimental investigations into collective cell behavior.