Single-cell mechanical analysis and tension quantification via electrodeformation relaxation.

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Understanding cellular mechanical properties is crucial for cell mechanics and biomechanics.
• The cell cortex, a network of proteins beneath the plasma membrane, plays a key role in cell mechanics.
• Quantifying cortical tension is essential for understanding cell behavior and disease states.

Purpose of the Study:

• To analyze the mechanical behavior and cortical tension of single cells using electrodeformation relaxation.
• To investigate the relationship between pulse duration and cellular mechanical response.
• To extract quantitative measurements of cortical tension in different cell types.

Main Methods:

• Electrodeformation relaxation technique applied to single cells.
• Utilizing pulse durations from 0.01 to 10 seconds.
• Employing a mathematical model with analytical solutions for ellipsoidal geometry.

Main Results:

• Cellular mechanical response exhibits power-law behavior in the long-pulse regime, consistent with soft glassy rheology.
• A single timescale characterizes the short-pulse regime, indicating a prestressed cortical state.
• Cortical tensions for MCF-10A, MCF-7, MDA-MB-231, and GBM cells are approximately 10⁻² N/m at 0.01 s pulse duration.

Conclusions:

• Electrodeformation relaxation is an effective method for measuring single-cell cortical tension.
• Cellular mechanics are dependent on the timescale of applied force, revealing distinct regimes of behavior.
• The study provides quantitative insights into the mechanical properties of the cell cortex in various cell lines.