Synthetic Bone-Like Structures Through Omnidirectional Ceramic Bioprinting In Cell Suspensions

The integration of hierarchical structure, chemistry, and functional activity within tissue-engineered scaffolds is of great importance in mimicking native bone tissue. Bone is a highly mineralized tissue which forms at ambient conditions by continuous crystallization of the mineral phase within an organic matrix in the presence of bone residing cells. Despite recent advances in the biofabrication of complex engineered tissues, replication of the heterogeneity of bone microenvironments has been a major challenge in constructing biomimetic bone scaffolds. Herein, inspired by the bone biomineralization process, the first example of bone mimicking constructs by 3D writing of a novel apatite-transforming ink in a supportive microgel matrix with living cells is demonstrated. Using this technique, complex bone-mimicked constructs are made at room temperature without requiring invasive chemicals, radiation, or postprocessing steps. This study demonstrates that mineralized constructs can be deposited within a high density of stem cells, directing the cellular organization, and promoting osteogenesis in vitro. These findings offer a new strategy for fabrication of bone mimicking constructs for bone tissue regeneration with scope to generate custom bone microenvironments for disease modeling, multicellular delivery, and in vivo bone repair.