Effect Of Transforming Growth Factor–β₃ And Dexamethasone On The Osteogenic Differentiation Of Dental Pulp Cells In Vitro

Objective : To evaluate the role of recombinant human transforming growth factor（TGF-β₃） and Dexamethasone（DEX） to induce rabbit dental pulp progenitor cells into osteoblasts.Method : Multilineage differentiation capability of enzymatically Isolated dental pulp stem cells were evaluated after 3 weeks of in vitro culture with oil red staining and Toluidine blue staining. the proliferative effect of different concentration of each TGF-β₃（2.5,5,10,20ng/ml）,and DEX（10nM,100 nM,1μM） was assessed by MTT. DPSCs of third passage were divided into for groups : A served as control group,culture media containing TGF-β₃ was added to group B, DEX in group C,B+C in group D. after 14 days of intervention,alizarin red S staining for mineralized nodules was performed.Osteoblast markers of Osteocalcin and Runx-2 were identified with immunocytochemical staining,and genetic expression of osteoblast related genes（octeocalcin, ALP, Runx-2,COL-1） were quantitativelyevaluated using real-time PCR. Result : no significant difference was found on A490 value of different concentrations of TGF-β₃ added groups.DEX has a bi-directional regulatory role on the Proliferation and differentiation of DPSCs and the effect of DEX is more obvious at100 nM. The number of positive cells of the osteogenic markers,and the expression ofosteoblast related genes were lower than those of group D（P<0.05）。Conclusion: Combination of rhTGF-β₃ and DEX could provide a ideal osteogenic induction medium for tissue engineering.