Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran; Department of Mechanical Engineering, University College London, London, UK
Andrea Malandrino
Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Engineering, Universitat Politècnica de Catalunya, Barcelona, Spain; Corresponding author
Ali Akbar Alemrajabi
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
Graham K. Sheridan
School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, UK
Guillaume Charras
London Centre for Nanotechnology, University College London, London, UK; Department of Cell and Developmental Biology, University College London, London, UK; Institute for the Physics of Living Systems, University College London, London, UK
Emad Moeendarbary
Department of Mechanical Engineering, University College London, London, UK; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Corresponding author
Summary: Cells maintain their volume through fine intracellular osmolarity regulation. Osmotic challenges drive fluid into or out of cells causing swelling or shrinkage, respectively. The dynamics of cell volume changes depending on the rheology of the cellular constituents and on how fast the fluid permeates through the membrane and cytoplasm. We investigated whether and how poroelasticity can describe volume dynamics in response to osmotic shocks. We exposed cells to osmotic perturbations and used defocusing epifluorescence microscopy on membrane-attached fluorescent nanospheres to track volume dynamics with high spatiotemporal resolution. We found that a poroelastic model that considers both geometrical and pressurization rates captures fluid-cytoskeleton interactions, which are rate-limiting factors in controlling volume changes at short timescales. Linking cellular responses to osmotic shocks and cell mechanics through poroelasticity can predict the cell state in health, disease, or in response to novel therapeutics.
