Three-dimensional traction force microscopy of engineered epithelial tissues.

Several biological processes, including cell migration, tissue morphogenesis, and cancer metastasis, are fundamentally physical in nature; each implicitly involves deformations driven by mechanical forces. Traction force microscopy (TFM) was initially developed to quantify the forces exerted by individual isolated cells in two-dimensional (2D) culture. Here, we extend this technique to estimate the traction forces generated by engineered three-dimensional (3D) epithelial tissues embedded within a surrounding extracellular matrix (ECM). This technique provides insight into the physical mechanisms that underlie tissue morphogenesis in 3D.