Traction Force Microscopy for Noninvasive Imaging of Cell Forces

Abstract

The forces exerted by cells on their surroundings play an integral role in both physiological processes and disease progression. Traction force microscopy is a noninvasive technique that enables the in vitro imaging and quantification of cell forces. Utilizing expertise from a variety of disciplines, recent developments in traction force microscopy are enhancing the study of cell forces in physiologically relevant model systems, and hold promise for further advancing knowledge in mechanobiology. In this chapter, we discuss the methods, capabilities, and limitations of modern approaches for traction force microscopy, and highlight ongoing efforts and challenges underlying future innovations.

Integration of Magnetic Tweezers and Traction Force Microscopy for the Exploration of Matrix Rheology and Keratinocyte Mechanobiology: Model Force- and Displacement-Controlled Experiments

“…Excellent reviews of TFM and the various analytical and numerical approaches used to calculate stress traction vector fields, ( * , * , ), from observed substrate displacement fields, ( * , * , ), can be found elsewhere 39,46,47 . In brief, we computed the inverse solution for ( * , * , ) using data sets where…”

Three-dimensional traction microscopy accounting for cell-induced matrix degradation

“…Next, we model the process of ECM relaxation after cell lysis. This process typically takes ∼ 45 mins [18,34], and is commonly assumed to be quasi-static (e.g., [15,17]). We further assume that ECM degradation mainly occurs during cell culturing (∼ 3 days [18]) before cell lysis, and that ECM properties do not vary significantly during the short period of ECM relaxation.…”

“…This is because the relaxed state is typically achieved by lysing the cell, which makes it difficult to locate the cell surface after cell lysis. It is possible to remove tractions while preserving cell integrity by using cellcontractility inhibitor (e.g., myosin inhibitor blebbistatin) [15]. In that case, the cell-ECM interface in the relaxed state can be measured, but the effectiveness of traction inhibition must be established to ensure complete stress relaxation.…”

“…Over the years, several methods have been developed to estimate tractions imparted by cells. Interested readers are referred to several comprehensive review articles on traction measurements [9,10,14,15,16,17]. Among various techniques, three-dimensional traction microscopy 1 (3DTM) has the distinguishing feature that it can be used to quantify cellular tractions in 3D settings that are similar to the in vivo cell environment [18].…”

“…The direct method has also been used to compute cellular tractions [15,17,36,37,32]. In this method, the measured discrete displacements are interpolated and extrapolated onto a continuous displacement field, which is differentiated to compute the strain field.…”