Comparative evaluation of the osteogenic capacity of second-generation platelet concentrates on dental pulp stem cells – An ex vivo study

Abstract

Introduction: Clinical evidence of platelet-rich fibrin (PRF) benefits on bone repair is still emerging, prompting researchers to experiment with different PRF formulations as osteoconductive scaffolds. Aims: This study compared the osteoconductive effects of injectable PRF (i-PRF) and leukocyte-rich PRF (L-PRF) on the differentiation of dental pulp stem cells (DPSCs) into osteoblasts. Materials and Methods: Blood samples were collected from the volunteers to prepare L-PRF and i-PRF conditioned media (CM) by centrifugation. DPSCs were isolated from impacted third molars and cultured. Proliferation of DPSCs in response to L-PRF and i-PRF was assessed by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Osteoinductive potential was evaluated through alkaline phosphatase (ALP) activity, alizarin red S (ARS) staining, growth factor levels (vascular endothelial growth factor [VEGF], transforming growth factor [TGF-beta]), and cytokine expression (interleukin 6 [IL-6], IL-8) after 7 days. Results: MTT assay results showed that both L-PRF and i-PRF increased DPSC proliferation relative to the control group. After 7 days in L-PRF and i-PRF CM, DPSCs exhibited increased ALP activity, higher red-colored calcium deposits with ARS staining, and elevated levels of VEGF and TGF-beta. In addition, higher concentrations of inflammatory cytokines IL-6 and IL-8 were observed in both L-PRF and i-PRF compared to the control. Conclusions: Using both L-PRF and i-PRF as scaffolds can enhance the osteoinductive ability of stem cells, offering a potential strategy for regenerative therapies.