Rattle-type Fe(3)O(4)@SiO(2) hollow mesoporous spheres as carriers for drug delivery.

Rattle-type Fe(3)O(4)@SiO(2) hollow mesoporous spheres with different particle sizes, different mesoporous shell thicknesses, and different levels of Fe(3)O(4) content are prepared by using carbon spheres as templates. The effects of particle size and concentration of Fe(3)O(4)@SiO(2) hollow mesoporous spheres on cell uptake and their in vitro cytotoxicity to HeLa cells are evaluated. The spheres exhibit relatively fast cell uptake. Concentrations of up to 150 microg mL(-1) show no cytotoxicity, whereas a concentration of 200 microg mL(-1) shows a small amount of cytotoxicity after 48 h of incubation. Doxorubicin hydrochloride (DOX), an anticancer drug, is loaded into the Fe(3)O(4)@SiO(2) hollow mesoporous spheres, and the DOX-loaded spheres exhibit a somewhat higher cytotoxicity than free DOX. These results indicate the potential of Fe(3)O(4)@SiO(2) hollow mesoporous spheres for drug loading and delivery into cancer cells to induce cell death.