Synthesis and Properties of Manganese-Containing Calcium Phosphate Materials

We have studied manganese-containing calcium phosphates differing in manganese content and phase composition. At a manganese content of 0.15 wt %, the whitlockite content is similar to 90 wt % and the calcium pyrophosphate content is similar to 10 wt %. Increasing the manganese content to 1.49 wt % reduces the whitlockite content to similar to 70 wt % and increases the calcium pyrophosphate content to similar to 30 wt %. IR spectroscopy results show that the samples calcined at 400 degrees C have the apatite structure, whereas raising the calcination temperature to 900 degrees C leads to the formation of the whitlockite structure and calcium pyrophosphate. Active sintering begins in the range 920-1050 degrees C. Raising the firing temperature to 1200 degrees C leads to the formation of a densely sintered structure, with melted regions and an average grain size from 15 to 25 mu m. With increasing manganese content, the grain size of the ceramics decreases. Our results on cytotoxic properties demonstrate that the samples are not cytotoxic and maintain cell proliferation and spreading. The cytotoxicity of the samples is insensitive to the calcium pyrophosphate and manganese concentrations. The powders and ceramics prepared in this study can be used as key components of novel materials for bone tissue engineering.