Jawbone-like organoids generated from human pluripotent stem cells

Engineering jawbone tissues from pluripotent stem cells presents a challenge owing to the lack of protocols for selectively inducing the jawbone progenitor, the first pharyngeal arch (PA1) ectomesenchyme, and for recapitulating three-dimensional osteocyte networks. Here we present a method for generating jawbone-like organoids from human induced pluripotent stem cells through PA1 ectomesenchyme of the mandibular prominence (mdEM). A three-dimensional culture system enables sequential differentiation of induced pluripotent stem cells into neural crest cells and mdEM. The mdEM exhibits proximal–distal patterning from the centre outwards, mirroring mandibular development. The introduction of exogenous pharyngeal epithelial signals induces mandibular prominence-specific regional patterning in the mdEM. When cultured under osteogenic conditions, the mdEM forms jawbone-like organoids comprising osteoblasts and network-forming osteocytes embedded in self-produced mineralized bone matrices. Moreover, these organoids promote bone regeneration when transplanted into jaws containing bone defects and recapitulate phenotypes of osteogenesis imperfecta, a genetic disorder characterized by fragile bones, using patient-derived induced pluripotent stem cells. Our protocols establish a foundation for investigating human jaw embryology and pathophysiology.