Osteocyte-Inspired Microenvironment Engineering for hiPSC-MSC-Based 3D Biomanufacturing of Bone Regeneration

Large bone defects remain difficult to regenerate because successful skeletal reconstruction requires more than bone formation alone; it depends on the coordinated restoration of osteogenic, vascular, neural, and immune functions. For 3D bone biomanufacturing, this places increasing emphasis on the development of microenvironments that are not only printable and cell-compatible, but also biologically instructive and capable of directing regenerative cell fate. Human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs, iMSCs) provide a scalable cell source with strong osteogenic potential, yet their regenerative performance is highly dependent on the surrounding niche. We have therefore focused on the osteocyte microenvironment as an engineering platform for skeletal regeneration. By modulating osteocyte state through Wnt activation and selective small-molecule regulation, we established that the osteocyte niche can be functionally programmed to enhance osteogenic instruction while coordinating angiogenic, neurogenic, and bone remodeling-associated activities. This concept was further extended from a living-cell microenvironment to a materialized regenerative niche. Decellularization of engineered osteocyte matrices enabled the development of GC-ink, a bioink that retained osteocyte-derived biological information within the extracellular matrix and transferred these cues to recipient iMSCs. GC-ink promoted osteogenic commitment through TGF-β-associated signaling, reshaped the osteoimmune microenvironment, and thereby converted an engineered osteocyte state into a stable and transferable material function. Integration of GC-ink with hard material–living cell 3D bioprinting generated anatomically adaptable bone constructs with enhanced osteogenesis, vascularization, and neural integration in vivo. Collectively, these studies define a continuous strategy of osteocyte microenvironment engineering, in which regenerative function is progressively programmed at the cellular level, preserved within extracellular matrices, and incorporated into 3D biomanufactured constructs. This framework provides a route toward more instructive and functionally integrated systems for bone regeneration.

Chengzhu Zhao, PhD, is an Associate Professor at the Laboratory of Skeletal Development and Regeneration, College of Laboratory Medicine, Chongqing Medical University. She received her PhD from Kyoto University and completed her postdoctoral training at the Center for iPS Cell Research and Application (CiRA), Kyoto University. Her research bridges iPSC biology, biomaterials, and biofabrication, with a focus on engineering osteocyte-inspired microenvironments to direct the fate and regenerative functions of hiPSC-derived mesenchymal stem cells. By integrating cell-state engineering, decellularized extracellular matrix bioinks, and 3D bioprinting, she develops functionally integrated bone constructs designed to coordinate osteogenesis with vascular, neural, and immune remodeling. Her work has been published in Biomaterials, Materials Today Bio, and EMBO Molecular Medicine, and has been supported by the Japan Society for the Promotion of Science and the National Natural Science Foundation of China.