Abstract: Objective: To culture human dental pulp stem cells (hDPSCs) in vitro by using platelet-rich fibrin extract (PRFe) with serum-free medium, and analyze their proliferation and differentiation. Methods: hDPSCs were isolated from impacted third molars of young healthy donors and identified by stem cell surface marker expression using flow cytometry. Experimental group used α-minimal essential medium containing PRFe without fetal bovine serum, while control group used the α-MEM with 10%FBS. The two groups were analyzed for: morphology, growth characteristics, alkaline phosphatase activity using ALP staining, and the gene expression of BMP2, RUNX-2, OCN, and ALP using real-time PCR. Results: hDPSCs had high expression of markers CD44, CD90, CD105, and low expression of markers CD34 and CD45. hDPSCs cultured in the experimental group showed a similar morphology as cultured in the control group but more thin, long and stereoscopic. Under osteogenesis induction, the osteogenic differentiation ability of two groups significantly increased (P<0.05). However, the expression of experimental group was higher than that of control group (P<0.05). Conclusion: PRFe can support the proliferation and osteogenic differentiation of hDPSCs in vitro.

Key words: Blood platelet, Fibrin, Dental pulp stem cells, Osteogenic differentiation