Engineering a Wnt-activated osteomimetic microenvironment with iPSC-derived MSCs for synergistic bone regeneration, angiogenesis, and neurogenesis.

To advance the bioactivity of artificial bone grafts, human induced pluripotent stem cell (hiPSC)-derived mesenchymal stem cells (iMSCs) are ideal seed cells. However, the instability in iMSC generation and their limited osteogenic capacity challenge their clinical application. In this study, we applied a novel strategy that combines a stable iMSC induction method that mimics the developmental process with an osteocytic Wnt-based osteogenic microenvironment, with the aim of creating a scalable, mechanistically defined platform to enhance bone regenerative efficiency. The small-molecule Wnt activator SKL2001-treated osteocyte osteogenic microenvironment (SOOME) substantially enhanced the osteogenic differentiation of iMSCs and promoted iMSCs-mediated bone defect repair in a rat femoral condyle defect model. Moreover, the SOOME-iMSC composite demonstrated its ability to promote angiogenesis and neurogenesis both in vitro and in vivo, and also enhanced osteoclast activity at the regeneration site. These findings suggest that the SOOME-treated iMSCs create a native-like osteomimetic microenvironment, which improves implant integration and bone tissue regeneration. This approach introduces a novel strategy for the standardized fabrication of seed cells with enhanced osteogenic potential, offering a promising solution for the fabrication and clinical application of bioactive bone graft materials.