Porous calcite CaCO₃ microspheres: Preparation, characterization and release behavior as doxorubicin carrier

Porous CaCO₃ microspheres are nowadays extensively used as a drug delivery system due to their excellent biocompatibility and degradability. However, the stability of vaterite CaCO₃ microspheres is a major problem as a drug carrier. In this work, porous calcite CaCO₃ microspheres are fabricated by calcination of gelatin-CaCO₃ composite microspheres at 550 °C in air. The size and morphology of CaCO₃ microspheres could be well regulated by the addition of gelatin. The structure of the as-prepared porous calcite CaCO₃ microspheres is characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Compared with vaterite CaCO₃ microspheres, porous calcite CaCO₃ microspheres are more stable and exhibit good drug-loading and drug release properties for doxorubicin (DOX), an effective anticancer agent. This study provides an easy and novel approach to prepare stable porous calcite CaCO₃ microspheres, which show promising potential as a carrier for DOX.