Unbiased High-Precision Cell Mechanical Measurements with Microconstrictions

Area of Science:

• Biophysics
• Cell Biology
• Microfluidics

Background:

• Measuring cell mechanical properties is crucial for understanding cell behavior.
• Existing methods often lack precision, throughput, or the ability to correlate mechanics with molecular expression.
• Cellular mechanics are influenced by various factors including cell state and protein expression.

Purpose of the Study:

• To develop a quantitative, high-precision, high-throughput microfluidic method for measuring cell mechanical properties.
• To relate cell mechanical responses to specific protein expression levels.
• To reduce measurement variability and enable reproducible detection of subtle mechanical differences.

Main Methods:

• Utilized a microfluidic device with microconstrictions and a high-speed camera (750 fps) to measure cell deformation under controlled pressure.
• Quantified elastic modulus (E) and fluidity (β) from pressure, deformation, and entry time data.
• Employed a histogram matching technique to normalize measurements based on pressure and strain, reducing variability.

Main Results:

• Cell elasticity increases with strain and applied pressure.
• Cell softening observed with increased time post-harvesting and from confluent cultures.
• Increased lamin A protein levels correlated with increased elastic modulus and decreased fluidity.
• Histogram matching significantly reduced measurement variability.

Conclusions:

• The developed microfluidic method offers a robust platform for high-throughput cell mechanics analysis.
• Histogram matching is effective in mitigating measurement variability, allowing for sensitive detection of mechanical changes.
• Cell mechanics are sensitive to harvesting conditions, culture density, and specific protein expression levels, such as lamin A.