Applicability of human dental follicle cells to bone regeneration without dexamethasone: an in vivo pilot study

The aim of this study was to investigate the capacity of human dental follicle cells (hDFCs) for bone formation in vivo. hDFCs were obtained from wisdom teeth extracted from patients aged 14 and 22 years. hDFCs from the 5th to 8th passages were grown in three-dimensional (3D) culture using gelatin sponges. Cells were transplanted onto the calvaria of F344/NJcl-rnu/rnu male rats (immunodeficient rats). Haematoxylin and eosin (HE) staining and immunohistochemistry were performed, and newly formed bone was evaluated by micro-computed tomography (micro-CT). HE staining showed newly formed bone in 3D culture. Immunohistochemistry showed bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (RUNX2), and osterix staining in areas with newly formed bone. Furthermore, micro-CT showed that, in comparison to controls, transplanted hDFCs promoted better bone quality and bone mineral density (BMD 582 ± 131.1 vs. 300.5 ± 77.7 mg/cm3; P = 0.039), bone mineral content (BMC 5.6 ± 1.1 vs. 2.1 ± 0.4 mg; P = 0.006), bone volume (BV 9.7 ± 0.5 × 10−3 vs. 7.0 ± 0.4 × 10−3 cm3; P = 0.002), BMC/total volume (TV) (399.9 ± 76.3 vs. 147.7 ± 30.8 mg/cm3; P = 0.006), and BV/TV (69.1 ± 3.6% vs. 49.6 ± 3.1%; P = 0.002). This suggests that human dental follicles are potentially useful for regenerative therapy.