Spatiotemporal Oscillation in Confined Epithelial Motion upon Fluid-to-Solid Transition

Fluid-to-solid phase transition in multicellular assembly is crucial many developmental biological processes, such as embryogenesis and morphogenesis. However, biomechanical studies this area are limited, little known about factors governing the how cell behaviors regulated. Due to different stresses present, cells could behave distinctively depending on nature of tissue. Here we report a fluid-to-solid geometrically confined assemblies. Under circular confinement, Madin-Darby canine kidney (MDCK) monolayers undergo spatiotemporally oscillatory motions that strongly dependent confinement size distance from periphery monolayers. Nanomechanical mapping reveals epithelial tensional stress traction forces substrate both size. The oscillation pattern cellular nanomechanics profile appear well correlated with fiber polarization. These experimental observations imply size-dependent surface tension regulates actin assembly, force generation, Our analyses further suggest characteristic (approximates MDCK's natural correlation length) below which sufficiently high triggers findings may shed light geometrical nanomechanical control tissue morphogenesis growth.