A unified rheological model for cells and cellularised materials

Area of Science:

• Biophysics
• Materials Science
• Rheology

Background:

• Cellular and tissue mechanics display diverse timescales, leading to power-law rheology.
• Traditional rheological models struggle to capture this complex behavior, hindering material characterization and predictive modeling.

Purpose of the Study:

• To develop a novel model integrating viscoelastic elements and fractional calculus for epithelial monolayers.
• To accurately capture the macroscopic relaxation response and predict mechanical behaviors like stretch and creep.

Main Methods:

• Developed a new rheological model incorporating fractional calculus with conventional viscoelastic elements.
• Fitted the model to experimental data of epithelial monolayer relaxation modulus.
• Used model parameters to predict responses to slow stretch and creep tests.

Main Results:

• The novel model successfully captured the macroscopic relaxation response of epithelial monolayers.
• Model parameters accurately predicted material responses to slow stretch and creep.
• Identified two characteristic times defining distinct material response regimes.

Conclusions:

• The unified model provides a robust mathematical framework for analyzing biological material mechanics.
• Linked epithelial power-law behavior to cell cortex dynamics, unifying single cell and tissue responses.
• Establishes a foundation for improved computational models in tissue mechanics.