A large-scale balloon model of confluent cells validates stress inference from geometry

Area of Science:

• Cellular mechanics
• Biophysics
• Quantitative biology

Background:

• Cellular mechanical environment significantly impacts cell behavior.
• Existing methods for measuring cell mechanics are often invasive.
• Stress inference (SI) is a non-invasive, image-based technique to estimate cell mechanics from cell geometry.

Purpose of the Study:

• To validate the stress inference (SI) method using a direct physical measurement.
• To develop an improved SI method with reduced noise sensitivity.
• To demonstrate the utility of SI in biological systems.

Main Methods:

• Developed a large-scale physical model of confluent cells using densely-packed balloons equipped with pressure sensors.
• Simultaneously measured balloon geometry and internal pressure.
• Developed a novel stress inference (SI) algorithm and applied it to the balloon model and biological cell data.

Main Results:

• The new SI method showed a correlation coefficient >0.8 with direct pressure measurements from the balloon model.
• The developed SI method exhibited reduced sensitivity to noise in computational models.
• Successfully measured pressure changes in red onion epithelial cells, demonstrating real-world applicability.

Conclusions:

• The study validates stress inference (SI) as a reliable method for measuring cell mechanics.
• The improved SI method offers enhanced accuracy and robustness for both physical and computational applications.
• Validated SI is a powerful tool for studying cell mechanics across various scales.