Effects of titanium allov particles on cell Proliferation and expression of receptor activator of nuclear factor-κB ligand gene in osteoblasts of mice

Objective To observe the effect of titanium alloy particles on the cell proliferation and the expression of gene receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) in osteoblasts of mice,and to investigate the mechanism of periprosthetic osteolysis.Methods Osteoblasts were cultured in 10％ serum medium containing different concentrations of titanium alloy particles.The cells were randomly divided into four groups.In the experimental groups A,B and C,osteoblasts were cultured with 0.01％,0.10％ and 1.00％ concentrations of titanium alloy particles,respectively; in the control group,no titanium alloy particles were given.Cell Counting Kit-8 (CCK-8) test was used to assess the cell proliferation at 24,48,96,168 h,respectively.At 24 and 48 h,reverse transcription-polymerase chain reaction (RTPCR) and enzyme linked immunosorbent assay (ELISA) were performed to detect the RANKL expression in osteoblasts and the intensity of the concentrations of RANKL in the supernatant of medium,respectively.Results The proliferation of osteoblasts had no differences between experimental groups A or B and control group at 48 h (P ＞ 0.05).The proliferation of osteoblasts in the experimental group C was significantly reduced as compared with other groups at 48 h (P ＜ 0.01 ).Meanwhile the titanium alloy particles up-regulated the mRNA and protein expression of RANKL ( P ＜ 0.01 ).Conclusion The proliferation of osteoblasts is decreased with exposure to titanium particles and different concentrations of titanium alloy particles could up-regulate the mRNA and protein expression of RANKL,which may be one of the mechamisms for the periprosthetic osteolysis. Key words: Titanium alloy particles;  Osteoblast;  Nuclear factor-κB;  Osteolysis