In article number 1901239 by Wenguo Cui, Hélder A. Santos, Qin Shi, and co-workers, a photo-crosslinked osteogenic growth peptide is constructed by solid-state synthesis, and then co-crosslinked with photo-crosslinked gelatin by UV-radiation to create a novel osteogenic polypeptide hydrogel to promote long term bone regeneration. The co-crosslinked polypeptide can strengthen the mechanical property of the defect bone and avoid burst osteogenic peptides, releasing during the bone defect healing period.