Mapping heterogeneity of cellular mechanics by multi-harmonic atomic force microscopy

Area of Science:

• Mechanobiology
• Cellular Biophysics
• Biomaterials Science

Background:

• Mechanobiology investigates the physical properties of cells in health and disease.
• Conventional atomic force microscopy (AFM) offers pointwise force curves but is slow for dynamic cellular processes.
• Dynamic AFM (dAFM) is faster but requires complex conversion of observables to mechanical maps.

Purpose of the Study:

• To present a novel technique for quantitative mapping of live cell viscoelastic properties.
• To enable fast, high-resolution mechanical measurements at the cellular level.
• To provide detailed protocols for implementing this technique.

Main Methods:

• Utilizing commercial AFM systems with direct cantilever excitation.
• Quantitative mapping of viscoelastic properties at multiple frequencies.
• Achieving nanometer spatial resolution and acquisition times of tens of seconds.

Main Results:

• Successful quantitative mapping of viscoelastic properties in live cells.
• Demonstrated nanometer-scale resolution and rapid image acquisition.
• Protocol applicable to various biological samples like cells and viruses.

Conclusions:

• The developed technique allows for efficient and quantitative mechanical property mapping of live cells.
• This method bridges the gap between dAFM imaging speed and quantitative force curve analysis.
• The protocol is accessible to experienced AFM users, facilitating broader adoption in mechanobiology research.