Modelling the compression and reorganization of cell aggregates

Area of Science:

• Biophysics
• Materials Science
• Cellular Mechanics

Background:

• Multicellular aggregates exhibit complex mechanical behaviors influenced by cellular and interstitial components.
• Existing models often simplify the interplay between solid cellular structures and fluid phases within aggregates.
• Understanding these behaviors is crucial for fields like tissue engineering and developmental biology.

Purpose of the Study:

• To extend an existing elasto-visco-plastic model for multicellular aggregates.
• To incorporate the effects of a liquid constituent (water) within cellular spheroids.
• To accurately describe the mechanical responses of porous cellular materials under compression.

Main Methods:

• Developed an elasto-visco-plastic constitutive model for porous multicellular aggregates.
• Treated aggregates as composite materials with distinct elastic/plastic (cellular) and viscous (liquid) properties.
• Applied the model to simulate uniaxial homogeneous compression under constant load and fixed deformation conditions.

Main Results:

• The model successfully integrates elastic, plastic, and viscous behaviors of cell aggregates.
• Plasticity arises from cell-cell adhesion bond rearrangement, introducing a yield stress.
• The liquid phase contributes a viscous response, crucial for dynamic deformation.

Conclusions:

• The extended model provides a comprehensive framework for understanding the mechanical behavior of multicellular aggregates.
• Model predictions align well with experimental data on the dynamics of biological tissues under deformation.
• This approach enhances the predictive power for cellular material responses in various biological contexts.