Organ-Derived Extracellular Matrix (ECM) Hydrogels: Versatile Systems to Investigate the Impact of Biomechanics and Biochemistry on Cells in Disease Pathology

The extracellular matrix (ECM) provides instructive and constructive support to cells in all organs. The ECM’s composition and structure are organ-dependent. The adhesion of cells to ECM with, e.g., integrins triggers cellular mechanosignalling. The role of mechanical properties of ECM hydrogels in vivo remains scarce. To replicate the ECM-cell interactions requires organ and tissue-specific ECM hydrogels. Such 3D culture systems allow the monitoring of ECM dynamics, i.e., turnover and mechanical changes (stiffness and stress relaxation). Compression testing allows to determine stiffness and stress relaxation. Hydrogels’ stress relaxation is governed by displacement of water, large macromolecules, and cells in a time- and organ origin-dependent fashion. The ECM biochemistry also regulates cell fate and function, e.g., through integrin signalling and via small molecules like growth factors that bind to specific ECM components. Organ-derived ECM hydrogels gain increasing interest due to their promising prospects for clinical use to augment tissue regeneration.