A study of brushite crystallization from calcium-phosphate solution in the presence of magnesium under the action of a low magnetic field

The paper discusses the crystallization of dicalcium phosphate dehydrate (DCPD) with subsequent transformation to nanocrystalline hydroxyapatite (НA) under the permanent magnetic field in the presence of magnesium. It was found that the presence of magnesium in the initial solution in concentrations of 0.01–0.03 g/l decreased the crystallinity of calcium-phosphates. The precipitation of DCPD under the magnetic field of 0.3 T was carried out in proximity of the north and south magnetic poles. The differences in the particle morphology and structure of precipitates with the same phase composition (DCPD) were observed in the neighborhood of the north and the south pole. Lattice parameters of DCPD precipitates obtained biomimetically near opposite magnet poles were calculated using XRD results. It was found that the increased crystallization time (more than 3 days) leads to a complete attenuation of DCPD peaks, whereas НА peaks are still present.

► Brushite (DCPD) exists as an intermediate in the precipitation of hydroxyapatite (HA).
► The presence of Mg in the initial solution lowers crystallinity of DCPD and HA.
► DCPD is substituted by HA after 3 days of immersion in solution with Ca/P ratio = 10/6.
► Particle morphology of precipitates varies near different magnet poles.
► A difference in crystal texture of DCPD is also found near different magnet poles.