The formation of epithelial tubes takes place during organogenesis and this structural feature is then maintained in several organs. For instance, during neurulation, epithelial tissue deforms in tubular shape, as an intermediate process at the origin of the central nervous system. Then, in the gut, this tubular geometry is essential to transport gases and liquids in the body. These shape changes at the tissue level involve processes at the cellular scale, like cell shape changes, rearrangement and proliferation. Today, for example, the understanding of the mechanisms underlying epithelial tube formation remains elusive due to the complexity to access to both the tissue and the cellular scale observation in 3D environments.
Our goal is to better understand the coupling between cellular processes and tissue folding at different temporal and spatial scales. We developed a technique to fast fold an initial flat tissue in a given curvature. Its principle is to generate a differential stress in a bilayer film of PDMS (polydimethylsiloxane) that allows us to obtain an out-of-plane curvature in self-rolling substrates [Tomba et al., Dev Cell 2022]. For example, we showed that epithelia, to comply with curvature, transiently and actively swell while adapting to large curvature induction.