Viscoelastic Parameterization of Living Cells to Characterize Material Behavior at Multiple Characteristic Timescales Using Atomic Force Microscopy
 

Dr. Santiago D. Solares
St. Albert the Great Professor in Engineering
Department of Mechanical Engineering
The Catholic University of America

Wed, February 19, 2025 - 4:00 PM

A significant number of biophysical studies have sought distinct markers in the mechanical response of living cells that could be linked to specific pathological conditions, related to a variety of diseases. This presentation describes an iterative inversion methodology based on atomic force microscopy (AFM), which is used to investigate living cell viscoelastic behavior at multiple relaxation timescales. Past investigations have often involved parameterizing linear elastic relationships and assuming purely Hertzian contact mechanics. However, a linear elastic treatment fails to capture and properly account for the rich temporal information available in soft sample mechanical datasets. The application of the viscoelastic inversion method is illustrated for adherent metastatic melanoma cells, which respond with lower stiffness and greater fluidity at multiple relaxation timescales than their normal counterparts. This type of physical insight into the complex viscoelastic behavior of living metastatic melanoma cells can be useful for better understanding cancer metastasis and aggression. This type of methodology also shows promise for supporting a wide variety of applications at multiple length scales (from nano- to macroscales) in tissue engineering, medical diagnosis for diseases that bring about mechanical changes in the affected tissues, patient physical rehabilitation, and athletic performance.

References:
Parvini, C.H.; Cartagena-Rivera, A.X.; Solares, S.D.; “Viscoelastic parametrization of human skin cells characterize material behavior at multiple timescales,” Comm. Biology. 2022, 5, 17.

López-Guerra, E.A.; Shen, H.; Solares, S.D.; Shuai, D.; “Acquisition of time-frequency localized mechanical properties of biofilms and single cells with high spatial resolution,” Nanoscale 2019, 11, 8918-8929.

López-Guerra, E.A.; Eslami, B.; Solares, S.D.; “Calculation of standard viscoelastic responses with multiple retardation times through analysis of static force spectroscopy AFM data,” J. Pol. Sci. Part B 2017, 55, 804-813.

Solares, S.D.; Cartagena-Rivera, A.X.; “Frequency-dependent nanomechanical profiling for medical diagnosis,” Beilstein J. Nanotech. 2022, 13, 1483-1489.

Refreshments served at 3:45 PM

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