Enhanced osteogenic activities of magnesium-containing nanowire modified-titanium surface via macrophage immunomodulation

We aimed to synthesize modified magnesium nanowire (Ti-NW-Mg) on the surface of titanium implants and to investigate its effects on bone binding by regulating macrophage polarization in vitro. The Ti-NW-Mg was synthesized from smooth titanium (CP-Ti) by hydrofluoric acid etching and high temperature alkalization, and then through the displacement reaction of magnesium sulfate solution with the titanium surface. The control groups were CP-Ti, sandblasted and etched with acid titanium (Ti-SLA), and only for micro/nano-modified titanium surfaces (Ti-NW). The physicochemical properties of the Ti-NW-Mg surface were examined. The biological effects of materials on RAW264.7 cells were compared, and the effects on osteogenesis by mediating RAW264.7 polarization were discussed. We observed the effect of the materials on osteogenesis through immunohistochemistry. In this experiment, the Ti-NW-Mg surface was interwoven into a nanotopological network, which released a specific concentration of magnesium ions and had good hydrophilicity. Compared to CP-Ti, Ti-SLA, and Ti-NW, Ti-NW-Mg reduced the proliferation of macrophages on the surface, inhibited inflammation, regulated macrophage polarization, and promoted bone formation. Ti-NW-Mg reduced the proliferation and adhesion of macrophages and decreased the release of inflammatory factors from macrophages. These results provide an essential experimental basis for the effect of Ti-NW-Mg on improving implant osteogenesis and increasing the implant success rate.