The importance of mechanics in biology has been established more than a century ago, but the development of reliable methods for measuring forces in living systems is only recent. Calibrated single molecule force spectroscopy methods have elevated our understanding of the mechanics of biomolecules; however, accuracy and precision are still limited in the characterization of mechanics at the cellular scale. Traction force microscopy (TFM), an imaging-based method for the measurement of forces exerted on soft substrates, is the state-of-the-art tool to quantify forces generated by living systems (Toyjanova et al.). It is however limited in accuracy and precision as it relies on bulk mechanical properties that overlook the microscale environments a cell experiences, and does not intrinsically control for sample-to-sample variability in the polymeric substrate. In this project researchers propose to connect imaging and mechanical measurements in a set of hardware and software tools they call HookeUp. This tool is a novel, unbiased and precise approach for the measurement of microscale 3D force fields and surface stresses.
HookeUp will be applied to the field of mechanobiology of bacterial pathogens. Specifically, we will measure the forces exerted by single bacterial cells and multicellular structures called biofilms. These forces span a wide range of magnitudes, from 100 Pa generated by single cells on surfaces to MPa by biofilm growth and expansion. Altogether, HookeUp will constitute a milestone in mechanobiology, contributing to our understanding of the functions of forces in the physiology of biological systems, and will be widely applicable in other fields such as microscale mechanics and soft matter.
