Further, the magnitude and distribution of cellular forces are impacted by the conditions of the microenvironment such as ECM composition, geometry, substrate stiffness, and the presence of other ligands or drugs ( The signaling associated with the transduction of these forces plays an important role in the regulation of proliferation, differentiation, morphogenesis, and homeostasis. By combining microarrays with a semi-automated implementation of TFM analysis, this protocol enables evaluation of the impact of substrate stiffness, matrix composition, and tissue geometry on cellular mechanical behavior in high throughput.Ĭellular generated forces are transmitted to the extracellular matrix (ECM) through integrins, and to surrounding cells by cadherins.
These images are analyzed in a semi-automated fashion using a series of MATLAB scripts which produce the displacement and traction fields, and summary data. A microscope with an automated stage is used to image each of the cellular islands before and after lysing cells with a detergent. Here we describe a TFM system using polyacrylamide substrates and a microarray spotter to fabricate arrays of multicellular islands on various combinations of extra cellular matrix (ECM) proteins or other biomolecules. From these images, a displacement field is calculated, and from the displacement field, a traction field. Broadly, these involve culturing cells on a flexible substrate with embedded fluorescent markers which are imaged before and after relaxion of cell forces. Numerous TFM systems have been described in literature. Traction Force Microscopy (TFM) provides a method to measure the forces applied to a surface by adherent cells. The composition and mechanical properties of the cellular microenvironment along with the resulting distribution of cellular devolved forces can affect cellular function and behavior.