On the synthesis of nanostructured akermanite scaffolds via space holder method: The effect of the spacer size on the porosity and mechanical properties.

In the present study, for the first time, the space holder method was used to prepare akermanite scaffolds with high porous structures, high interconnectivity, and high compressive strength, while the role of different spacer sizes on the akermanite scaffold properties was also evaluated. The results showed that the increase in the NaCl particle size which was used as spacer leads to an increase of the pore size and interconnectivity and a decrease of compressive strength. When the size of the spacer was 420-600µm and more than 600µm, a total porosity of 82 and 83% and a compressive strength of 0.86 and 0.82MPa were obtained, respectively. These values are higher than those reported in previously studies and provide a great potential for akermanite to be used as bone substitute in tissue engineering. The in vitro bioactivity of the obtained akermanite scaffolds was also investigated.

A comparative study on the synthesis mechanism, bioactivity and mechanical properties of three silicate bioceramics.

In the present study three akermanite (Ca2MgSi2O7), diopside (CaMgSi2O6) and baghdadite (Ca3ZrSi2O9) applicable bioceramics were synthesized via a sol-gel based method. The combination of sol-gel method and the raw materials used in this study presents a new route for the synthesis of the mentioned bioceramics. By the use of thermal analysis, the mechanisms occurred during the synthesis of these bioceramics were investigated. The differences in the structural density and their relation with the degradation rate and mechanical properties of all three ceramics were studied. In vitro bioactivity and apatite formation mechanisms of the samples soaked in the simulated body fluid were considered. The results showed that baghdadite as a Zr-containing material has a more dense structure in comparison with the other ceramics, which leads to a lower degradation rate and also lower bioactivity. There were also main differences between akermanite and diopside as Mg-containing ceramics. Diopside showed a structure with lower porosity content compared to the akermanite samples which resulted in the lower degradation rate and higher compressive strength.