Evaluation of bone regeneration potential of dental follicle stem cells for treatment of craniofacial defects.

Background Aims: Stem cell-based tissue regeneration offers potential for treatment of craniofacial bone defects. The dental follicle, a loose connective tissue surrounding the unerupted tooth, has been shown to contain progenitor/stem cells. Dental follicle stem cells (DFSCs) have strong osteogenesis capability, which makes them suitable for repairing skeletal defects. The objective of this study was to evaluate bone regeneration capability of DFSCs loaded into polycaprolactone (PCL) scaffold for treatment of craniofacial defects.

Methods: DFSCs were isolated from the first mandibular molars of postnatal Sprague-Dawley rats and seeded into the PCL scaffold. Cell attachment and cell viability on the scaffold were examined with the use of scanning electron microscopy and alamar blue reduction assay. For in vivo transplantation, critical-size defects were created on the skulls of 5-month-old immunocompetent rats, and the cell-scaffold constructs were transplanted into the defects.

Results: Skulls were collected at 4 and 8 weeks after transplantation, and bone regeneration in the defects was evaluated with the use of micro-computed tomography and histological analysis. Scanning electron microscopy and Alamar blue assay demonstrated attachment and proliferation of DFSCs in the PCL scaffold. Bone regeneration was observed in the defects treated with DFSC transplantation but not in the controls without DFSC transplant. Transplanting DFSC-PCL with or without osteogenic induction before transplantation achieved approximately 50% bone regeneration at 8 weeks. Formation of woven bone was observed in the DFSC-PCL treatment group. Similar results were seen when osteogenic-induced DFSC-PCL was transplanted to the critical-size defects.

Conclusions: This study demonstrated that transplantation of DFSCs seeded into PCL scaffolds can be used to repair craniofacial defects.