Injectable biomaterials such as cryogels that allow controlled delivery of therapeutic agents or cell therapies could minimize complications associated with surgical implantation. Bencherif et al. describe a strategy that enabled the delivery of loaded cryogels using conventional needle and syringe injection. Injection of cryogels to mice enabled sustained release of granulocyte–macrophage colony-stimulating factor, and cryogels loaded with cells and a cell adhesion peptide (as a model for cell transplantation) promoted cell survival, local retention and engraftment of transplanted cells.