21 November 2018 A Review on Mechanobiology in Nature Reviews in Physics

The review presented by ICFO Prof. Michael Krieg, in collaboration with an international team of researchers, provides an in-depth view and current status of the field of study Mechanobiology is an emerging field of science that intertwines biology, biophysics, medicine with engineering. It aims to describe how the proteins, cells, tissues and organ mechanical variations trigger development, differentiation, physiology and disease. The grand challenge in mechanobiology is to quantify how biological systems sense, transduce, respond and apply mechanical signals.

During these past decades, atomic force microscopy (AFM) has become the enabling platform for mechanobiology in order to study these biological systems and their behaviours. It is a type of scanning probe microscopy that provides provides microscopy-based mechanical mapping with a piconewton to nanonewton force resolution and with a nanometer spatial precision. It is 1000 times better than optical scanning techniques because it does not use lenses and thus, it can surpass the optical diffraction limit. This technique uses a probe to scan the surfaces of samples by touching the surface with a mechanical probe and converting the forces sensed by this probe into electrical signals. Its integration as a nanotool with cutting edge microscopy and physiological recordings enables researchers to gain a wide range of the cells’ functionalities.

Thus, in a recent study published in Nature Reviews Physics, ICFO Prof. Michael Krieg, in collaboration with researchers from ETH (Zurich), the Université catholique de Louvain (Louvain), the Zernike Instituut (Groningen), Vrije Universiteit Amsterdam (Amsterdam), Ludwig- Maximilians Universität (Munich), and the Swiss Nanoscience Institute (Basel), provide an in-depth overview of the basic principles, advantages and limitations of the most common AFM modalities used to map the dynamic mechanical properties of complex biological samples to their morphology.

They have discussed how mechanical properties can be directly linked to cell function, which so far has been a matter poorly addressed. They have also made emphasis on the potential of combining AFM with complementary techniques, including optical microscopy and spectroscopy (flourescence spectroscopy), super-resolution microscopy, optical tweezers to investigate the response of cells to mechanical stress.

They summarize by stating that the application of these novel force spectroscopic techniques to biological systems will certainly require the development of complementary theories and mathematical models to guide the comprehensive analysis of experimental data and thus understand how biological systems sense, transduce and regulate responses to mechanical triggers.