Biodegradable magnetic calcium phosphate nanoformulation for cancer therapy.

We fabricated a magnetic calcium phosphate nanoformulation by the biomineralization of calcium phosphate on the surface of magnetic nanoparticles with abundant amino groups, and thus the inorganic layer of calcium phosphate can improve the biocompatibility and simultaneously the magnetic iron oxide can maintain the magnetic targeting function. Two types of anticancer drug models, doxorubicin hydrochloride and DNA, were entrapped in these nanocarriers, respectively. This delivery system displayed high pH sensitivity in drug-controlled release profile as the dissolution of CaP under acid pH condition. Magnetofection was performed to investigate the intracellular uptake and the anti-proliferative effect of tumor cells in the presence of an external magnet. The transfection of the DNA-loaded magnetic system in A549 and HepG2 tumor cells demonstrated that the magnetic nanoformulation could enhance the transfection efficiency to 30% with an applied external magnetic field.