Integrating Periosteum Derived Organoids and 3D Printed Scaffolds for Enhanced Craniofacial Bone Regeneration

Craniofacial bone defects, particularly those of substantial size, require a significant quantity of cells for effective regeneration. Although developmental engineering strategies using bone mesenchymal stem cells (BMSCs) aggregates have demonstrated potential, they do not fully replicate natural cellular processes. In contrast, periosteal mesenchymal stem cells (PMSCs) exhibit superior efficacy for craniofacial bone regeneration compared to BMSCs. This study aims to engineer periosteum-derived organoids (PDOs) by integrating PMSCs with osteogenic induction centers in 3D-printed polycaprolactone (PCL) scaffolds. Cell condensation was initiated with fibroblast growth factor 8b (FGF8b) and Vitamin C (Vc) to develop a high-density bioink possessing strong osteogenic differentiation capabilities, thereby mimicking osteoblast condensation integral to craniofacial bone repair. Composite scaffolds comprising PCL/β-TCP and naringin-loaded GelMA hydrogel bio-ink were fabricated, successfully forming calcification centers. Transcriptomic analysis revealed the molecular mechanisms underlying the formation and osteogenic differentiation of PDOs in vitro. This study presents a novel approach to biomimetic periosteum-based bone regeneration in vitro and highlights a promising strategy for scaffold fabrication incorporating calcified centers. These innovations contribute to the ongoing efforts to address the clinical challenge of repairing large craniofacial bone defects, offer valuable insights into the potential of 3D bioprinting for creating biomimetic bone structures, and explore the incorporation of traditional Chinese medicine compounds into bone tissue engineering.