Probing single-cell mechanics with picosecond ultrasonics

Area of Science:

• Biophysics
• Cellular Mechanics
• Acoustic Microscopy

Background:

• Cellular mechanical properties are crucial for biological processes like migration, proliferation, differentiation, and tissue morphogenesis.
• Probing subcell-scale mechanics and adhesion requires non-invasive techniques due to cellular complexity and cell-substrate interactions.

Purpose of the Study:

• To review the application of picosecond ultrasonics (PU) for probing single-cell mechanical properties.
• To present an opto-acoustic bio-transducer for in vivo measurements.
• To demonstrate quantitative analysis of cell adhesion and mechanics.

Main Methods:

• Utilized laser-generated GHz acoustic waves (picosecond ultrasonics) for non-invasive cell analysis.
• Applied the technique to vegetal cells and biomimetic systems as models for complex animal cells.
• Developed and employed an opto-acoustic bio-transducer for in vivo measurements under physiological conditions.

Main Results:

• Successfully probed density and compressibility of Allium cepa cells using the bio-transducer.
• Quantified animal-cell adhesion on metallic surfaces by analyzing reflected acoustic pulses.
• Demonstrated the ability to investigate cell mechanics without fluorescent labels or direct mechanical contact.

Conclusions:

• Picosecond ultrasonics is an innovative, quantitative method for assessing cell mechanics and adhesion.
• The developed opto-acoustic transducer enables in vivo measurements in physiological environments.
• This label-free, contact-free approach provides new avenues for studying cell biophysics.