Rapid microwave synthesis of size-controllable assembled hydroxyapatite microspheres

Abstract

Porous hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂, HA) microspheres have gained extensive interest in fields such as drug carriers and ion adsorption due to their special morphology, decent flowability, and large specific surface area along with other advantages. However, conventional methods for preparing HA microspheres have drawbacks such as complexity, time-consuming procedures, and a single structure. In this study, flower-shaped HA microspheres assembled from nanoscale structural units were rapidly prepared by means of a microwave hydrothermal method, and the influences of different synthesis conditions on sample morphology, size, and phase were studied. The results showed that the three-dimensional structure of HA microspheres could be well regulated through modifying the microwave reaction temperature, reaction time, and reactant concentration. HA microspheres, whose average diameter is approximately 19 μm, could be synthesized by reacting the reactants for 30 min at 150 °C. In addition, the synthesized HA microspheres exhibited good biodegradability and biocompatibility. This study provides a simple and efficient synthesis method for preparing HA microspheres with uniform size, controllable microstructure, and interconnected pore structures. These HA microspheres can be used as effective carriers for tissue engineering and as ion-adsorption materials.