Porous hollow microspheres of amorphous calcium phosphate: soybean lecithin templated microwave-assisted hydrothermal synthesis and application in drug delivery.

Calcium phosphate biomaterials are very promising for various biomedical applications owing to their excellent biocompatibility and biodegradability. Calcium phosphate nanostructured materials with a porous and hollow structure are excellent drug carriers due to their advantages such as high biocompatibility, large specific surface area, nanosized channels for drug loading and release, high drug loading capacity and pH-responsive drug release behavior. In this work, porous hollow microspheres of amorphous calcium phosphate have been successfully prepared by the microwave-assisted hydrothermal method using adenosine triphosphate disodium salt, CaCl and soybean lecithin in aqueous solution. This preparation method is facile, rapid, energy-saving and environment friendly. The effects of microwave hydrothermal temperature and concentrations of the reactants on the morphology and structure of the product were investigated. The as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The as-prepared porous hollow microspheres of amorphous calcium phosphate are efficient for drug loading and release, and the drug delivery system shows a pH-responsive drug release behavior and high ability to damage tumor cells. Thus, the as-prepared porous hollow microspheres of amorphous calcium phosphate are promising for the applications in various biomedical fields.