Effect of different Doses of titanium on gene expression of osteoprotegerin/osteoprotegerin ligand in MG-63 osteoblast-like cells

Objective: To explore the mechanism of periprosthetic osteolysis caused by wear particles in order to find a new way in the prophylaxis of aseptic loosening of implants. Method:Cultured MG-63 osteoblasts were treated by different doses of phagocytosable titanium particles (less than 3μm in diameter) for 24 hours. A semi-quantitative RT-PCR was taken to observe the gene expression of osteoprotegerin(OPG) and osteoprotegerin ligand (OPG-L).Result:The titanium particles induced a constant and varying increases in the OPG and OPG-L,and the up-regulated mRNA level of OPG-L was higher than that of OPG.Conclusion:The OPG-L/OPG ratio is in accordance with dose-increase of the titanium particles, which can induce more osteolysis than osteogenesis.This may be an crucial mechanism in the particle-induced periprosthetic aseptic loosening.The finding indicates that reducing the ratio may reverse or prevent the pathologic procedure of the osteolysis.