Microwave-Assisted Hydrothermal Rapid Synthesis of Amorphous Calcium Phosphate Mesoporous Microspheres Using Adenosine 5′-Diphosphate and Application in pH-Responsive Drug Delivery

Graphical Amorphous calcium phosphate mesoporous microspheres (ACP-MSs) have been synthesized using adenosine 5′-diphosphate disodium salt as an organic phosphorus source by a rapid microwave-assisted hydrothermal method. The ACP-MSs drug delivery system shows a pH-responsive drug release behavior and a high ability to damage cancer cells after loading doxorubicin. Herein we report a rapid and green strategy for the preparation of amorphous calcium phosphate mesoporous microspheres (ACP-MSs) using adenosine 5′-diphosphate disodium salt (ADP) as an organic phosphorus source by a microwave-assisted hydrothermal method. The effects of the pH value, the reaction time, and temperature on the crystal phase and morphology of the product are investigated. The ADP biomolecules used in this strategy play an important role in the formation of ACP-MSs. The as-prepared ACP-MSs are efficient for anticancer drug delivery by using doxorubicin (Dox) as a model drug, and the Dox-loaded ACP-MSs show a high ability to damage cancer cells. Moreover, the ACP-MSs drug delivery system exhibits a pH-responsive drug-release behavior due to the degradation of ACP-MSs at a low pH value, thus, it is promising for applications in pH-responsive drug delivery.