Folate-Conjugated Fe3O4@SiO2 Hollow Mesoporous Spheres for Targeted Anticancer Drug Delivery

Herein we developed a targeted anticancer drug delivery system based on folate-conjugated rattle-type Fe3O4@SiO2 hollow mesoporous spheres combining receptor-mediated targeting and magnetic targeting. Folic acid (FA) ligands were successfully grafted onto rattle-type Fe3O4@SiO2 hollow mesoporous spheres via amide reaction. The magnetization saturation value of folate-conjugated Fe3O4@SiO2 spheres (Fe3O4@ SiO2-FA) was about 1.6 emu/g, and these spheres could be targeted under an external magnetic field. On the other hand, in vitro cytotoxicity and cell uptake of these Fe3O4@SiO2-FA spheres to Hela cells were evaluated. These Fe3O4@SiO2-FA spheres were nontoxic up to a concentration of 150 mu g/mL, and further can be specifically taken up by Hela cells via FA receptor-mediated endocytosis. Doxorubicin hydrochloride (DOX), an anticancer drug, was introduced into Fe3O4@SiO2-FA spheres. The release of DOX from Fe3O4@SiO2-FA spheres had a sustained release pattern, and the DOX-loaded Fe3O4@SiO2-FA spheres exhibited greater cytotoxicity than free DOX and DOX-loaded Fe3O4@SiO2 spheres due to the increase of cell uptake of anticancer drug delivery vehicles mediated by the FA receptor. Therefore, we conclude that folate-conjugated Fe3O4@SiO2 hollow mesoporous spheres have potential for targeted anticancer drug delivery for cancer therapy.