Human periodontal ligament stem cells with distinct osteogenic potential induce bone formation in rat calvaria defects

Plain language summary Bone is one of the most transplanted tissues worldwide and cell-based therapies has been investigated as an alternative for the treatment of bone defects. Dental tissues have been investigated as sources of stem cells and the periodontal ligament has been shown to be a viable source of these cells. Stem cells from periodontal ligament induce significant bone formation in rat calvaria defects and are safe for cell-based therapies, as the cells remain at the bone defect site for up to 4 weeks and do not migrate to vital organs, such as brain, heart, lungs, spleen, kidneys, and liver in the same period. In addition, immune responses were not detected. Considering that, stem cells from periodontal ligament can be useful in cell therapy strategies to induce bone regeneration. Aim: This study aimed to evaluate the ability of human periodontal ligament stem cells (PDLSCs) with high (HP-PDLSCs) and low (LP-PDLSCs) osteogenic potential, in addition to mixed cells, to repair bone tissue. Methods: Cell phenotype, proliferation and differentiation were evaluated. Undifferentiated PDLSCs were injected into rat calvarial defects and the new bone was evaluated by mu CT, histology and real-time PCR. Results: PDLSCs exhibited a typical mesenchymal stem cell phenotype and HP-PDLSCs showed lower proliferative and higher osteogenic potential than LP-PDLSCs. PDLSCs induced similar bone formation and histological analysis suggests a remodeling process, confirmed by osteogenic and osteoclastogenic markers, especially in tissues derived from defects treated with HP-PDLSCs. Conclusion: PDLSCs induced similar bone formation irrespective of their in vitro osteogenic potential.