RESUMO
BACKGROUND:Al oying is a convenient and effective method to alter the microstructure and control the corrosion behavior of magnesium al oy. OBJECTIVE:To explore the in vitro and in vivo degradation of Mg-Nd-Zn-Zr al oy as a degradable medical biomaterial. METHODS:(1) In vitro static immersion test:The immersion tests were carried out at (37.0±0.5) thermostatic bath. Six Mg-Nd-Zn-Zr al oy samples and six pure magnesium samples were immersed in the 250 mL simulated body fluid and vibrated without agitation during immersion. After 3, 7 and 30 days static immersion, the samples were taken out from the simulated body fluid. Then the in vitro corrosion properties were evaluated using scanning electron microscope and energy dispersive spectrometer analysis. (2) In vivo animal experiment:After bone tunnel was established in the left femur of adult New Zealand rabbits, the Mg-Nd-Zn-Zr al oy rods were embedded in the Mg-Nd-Zn-Zr al oy group, titanium al oy rods were embedded in the titanium al oy group, and only bone tunnel was established in the sham-operated group. At 1, 2, 4, 8 weeks after implantation, an X-ray of the implanted region was taken to determine the location and the degradation behavior℃in a of Mg-Nd-Zn-Zr al oy. At 4, 8 weeks after implantation, the corrosion product and its element composition were observed using scanning electron microscope with an energy dispersive spectroscopy system.