01740nas a2200229   4500000000100000000000100001008004100002260001500043653002700058653002900085100001600114700002100130700003000151700001800181700002000199245005900219856005500278300000900333490000700342520114700349022001401496       2024                            d  c2024-04-0510aBiomedical Engineering10aPermeation and transport1 aGawoon Shim1 aIsaac B. Breinyn1 aAlejandro Martínez-Calvo1 aSameeksha Rao1 aDaniel J. Cohen00aBioelectric stimulation controls tissue shape and size  uhttps://www.nature.com/articles/s41467-024-47079-w  a29380 v153 aEpithelial tissues sheath organs and electro-mechanically regulate ion and water transport to regulate development, homeostasis, and hydrostatic organ pressure. Here, we demonstrate how external electrical stimulation allows us to control these processes in living tissues. Specifically, we electrically stimulate hollow, 3D kidneyoids and gut organoids and find that physiological-strength electrical stimulation of ∼ 5 - 10 V/cm powerfully inflates hollow tissues; a process we call electro-inflation. Electro-inflation is mediated by increased ion flux through ion channels/transporters and triggers subsequent osmotic water flow into the lumen, generating hydrostatic pressure that competes against cytoskeletal tension. Our computational studies suggest that electro-inflation is strongly driven by field-induced ion crowding on the outer surface of the tissue. Electrically stimulated tissues also break symmetry in 3D resulting from electrotaxis and affecting tissue shape. The ability of electrical cues to regulate tissue size and shape emphasizes the role and importance of the electrical micro-environment for living tissues.  a2041-1723