Influence of Vanadium 4+ and 5+ Ions on the Differentiation and Activation of Human Osteoclasts

BACKGROUND: In the pathophysiology of implant failure, metal ions and inflammation-driven osteoclasts (OC) play a crucial role. The aim of this study was to investigate whether vanadium (V) ions induce differentiation of monocytic OC precursors into osteoresorptive multinucleated cells. In addition, the influence of V ions on the activation and function of in vitro generated OC was observed. METHODS: Human monocytes and osteoclasts were isolated from peripheral blood monocytic cells (PBMCs). Exposition with increasing concentrations (0–3 μM) of V4(+)/V5(+) ions for 7 days followed. Assessment of OC differentiation, cell viability, and resorptional ability was performed by standard colorimetric cell viability assay 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenil)-2H-tetrazolium (MTS), tartrate-resistant acid phosphatase (TRAP) expression, and functional resorption assays on bone slides during a period of 21 days. RESULTS: No significant differences were noted between V4(+)/V5(+) ions (p > 0.05). MTS showed significant reduction in cellular viability by V concentrations above 3 μM (p < 0.05). V concentrations above 0.5 μM showed negative effects on OC activation/differentiation. Higher V concentrations showed negative effects on resorptive function (all p < 0.05) without affecting cell viability. V4(+)/V5(+) concentrations below 3 μM have negative effects on OC differentiation/function without affecting cell survival. CONCLUSION: Vanadium-containing implants may reduce implant failure rate by influencing osteoclast activity at the bone-implant interface. V-ligand complexes might offer new treatment options by accumulating in the bone.