Mechanical behavior of multi-cellular spheroids under osmotic compression

The internal and external mechanical environment plays an important role in tumorogenesis. As a proxy of avascular early state tumor, we use multicellular spheroids, composite material made cells, extracellular matrix permeating fluid. We characterize its effective rheology at the timescale minutes to hours by compressing aggregates with osmotic shocks modeling experimental results active poroelastic that reproduces stress strain distributions aggregate. model also predicts how emergent bulk modulus aggregate as well hydraulic diffusion percolating interstitial fluid are modified preexisting within further show value these two phenomenological parameters can be rationalized considering that, our context, cells effectively impermeable incompressible inclusions nested compressible permeable matrix.