Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

• Effect of MPS concentration and solvents during HA silanization was studied.
• Silanization rendered HA has lower crystallinity compared to untreated HA.
• Silicon concentration was higher for acetone than that obtained using methanol.
• Methanol–water system containing MPS at 3 wt.% provides the better results.

The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA.