Effect of different calcium-magnesium ratios on the properties of amorphous calcium pyrophosphate.

• Mg-doped ACPPs with different Ca/Mg molar ratios are achieved. • Ca-Mg = 2 owns the best release of Ca2+ and Mg2+. • When Ca/Mg is 2, it can realize better osteogenic bioactivity. In this paper, the property effect of different calcium-magnesium ratios on amorphous calcium pyrophosphate (ACPP) was studied. Three calcium-magnesium ratios (Ca-Mg = 1–2, Ca-Mg = 2, Mg = 0) was selected to prepare ACPP. To compare the changes in morphology, microstructure, phase and component, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) were carried out. Then, Inductively Coupled Plasma (ICP) was conducted to investigate the ion release. Finally, to compare the osteogenic activity, cell proliferation, adhesion, migration and osteogenic differentiation experiments were performed. The results showed that Mg2+ was inserted into the particle and adsorbed on the surface at Ca-Mg = 2. For Ca-Mg = 1–2, Mg2+ was mainly in a form of Mg-O-P. As a result, Ca-Mg = 2 had denser microstructure and better Ca2+ and Mg2+ release. Thus, Ca-Mg = 2 behaved superior osteogenic activity and differentiation ability. [ABSTRACT FROM AUTHOR]