Bio3D graft engineered from human mesenchymal stromal cells/extracellular complexes facilitate periodontal tissue regeneration

Periodontitis, a chronic inflammatory disease leading to irreversible loss of tooth-supporting tissues, remains a major unmet clinical challenge despite advances in biomaterial-based cell therapies. Scaffold-free regenerative strategies that fully rely on cellular and extracellular matrix (ECM) components may overcome the limitations of artificial scaffolds. Here, we developed a human Bio3D graft fabricated from clumps of mesenchymal stromal cells and their self-produced ECM (C-MSCs) using a Bio3D printer. When transplanted into a critical-size periodontal defect in immunodeficient rats, the Bio3D graft achieved safe and reproducible regeneration of cementum, periodontal ligament, and alveolar bone without ectopic or excessive bone formation. Transcriptomic and histological analyses revealed enhanced YAP/TAZ signaling in the Bio3D graft compared with C-MSCs, and functional inhibition of YAP/TAZ abolished periodontal reconstruction, demonstrating its essential role. These findings establish a foundation for next-generation, scaffold-free cell therapies capable of reconstructing complex periodontal structures.