Fall issue: Microscopy Research & Technique

The work "Measuring (biological) materials mechanics with atomic force microscopy. 2. Influence of the loading rate and applied force (colloidal particles)" by Andreas Weber, Barbara Zbiral, Jagoba Iturri, Rafael Benitez and José L. Toca‐Herrera from Institute for Biophysics shows the non‐linear dependence of cell mechanical properties on loading rate when using atomic force microscopy.

Mechanical forces are ubiquitous in biological systems and it is therefore no surprise that cells can feel and respond to such forces. A deeper understanding of such processes is needed and in recent years a multitude of studies have been published concerned on the mechanical properties of cells. Elucidation of these properties will lead to novel understandings of the cell components important for cell mechanics, complex mechanotransduction pathways, identification of adhesion mechanisms and differentiation between healthy and cancerous cells. Of the techniques used to study cell mechanics, Atomic Force Microscopy (AFM) stands out as the most often used one.

AFM cell mechanical measurements can be made in many ways and it is known that the measured properties depend on how the measurement is performed. Therefore, we have investigated the influence of measurement settings such as loading rate, maximum force and particle size on cell mechanical measurements using AFM with colloidal particles as indenters. We report on the non-linear increase of apparent Young’s Modulus with indentation rate and provide evidence that cell mechanics can be described by power law behavior. Such results are then discussed with the aim to provide a framework of how to perform AFM measurements on cells as well as how to evaluate those measurements properly using “just” elastic theory.

Read more in: Measuring (biological) materials mechanics with atomic force microscopy. 2. Influence of the loading rate and applied force (colloidal particles), Microscopy Research and Technique, 12. November 2020, https://onlinelibrary.wiley.com/doi/10.1002/jemt.23643