Figure 2:

Designing hydrogels for temporal control of cell-driven processes. a. The components of these hydrogel systems include single cells or multicellular aggregates, signaling ligands and other biochemical groups, and a 3D polymer network with chemically reactive functionalities. b. Networks can be engineered to have dynamic crosslinks that break when cells apply forces locally and reform when forces relax (top panel), or have crosslinks that degrade through the action of cell-secreted proteases such as MMPs (bottom panel). c. These engineered hydrogels permit studies of cellular processes for example with single cells that spread and deposit native ECM (top panel), stem cell clusters that mature into tissue-mimetic organoids (middle panel), and homogenously distributed cells that remodel local microenvironments and undergo self-assembly and morphogenesis (bottom panel).