Platelet-rich Fibrin Promotes the Proliferation and Osteo-/odontoblastic Differentiation of Human Dental Pulp Stem Cells.

Abstract

Pulp regeneration is a promising strategy that promotes the continued development of young permanent teeth with immature apical foramen. Platelet-rich fibrin (PRF) was found to stimulate the proliferation and differentiation of osteoblasts, but its effects on osteoblast/odontoblast differentiation of human dental pulp stem cells (hDPSCs) are unknown. The hDPSCs were isolated and identified using known surface markers by flow cytometry. The CCK-8 assay and the expression of Ki67 and PCNA were used to examine hDPSC proliferation. After 7 days of culture in an osteo-/odontoblastic induction medium with various concentrations of liquid PRF (0, 10% and 20%), the early stage of osteogenesis-intracellular alkaline phosphatase (ALP) was checked. After 21 days of culture, matrix mineralization was checked using Alizarin Red S and quantified. The mRNA and protein levels of osteo-/odontoblastic genes, including RUNX2, DSPP, DMP1 and BSP, were measured by qRT-PCR. The notch signal was checked by Western blot to analyze three key proteins (Notch 1, Jagged 1 and Hes 1). PRF-treated groups showed higher expression of Ki-67 and PCNA, higher ALP activity, and the higher dose showed a stronger induction. PRF promoted osteo-/odontoblastic differentiation of hDPSCs indicated by elevated protein levels and mRNA levels of the expression of osteo-/odontoblastic markers. The three key proteins in Notch signaling showed an increase compared with the control group and increased as the PRF concentration increased. PRF can promote the proliferation and osteo-/odontoblastic differentiation of hDPSC, which may be through the Notch signaling pathway.