Bi2O3 gated Fe3O4@ZrO2 core/shell drug delivery system for chemo/ionic synergistic therapeutics

Magnetic mesoporous ZrO 2 (Fe 3 O 4 @ZrO 2 , MMZr) nanoparticles blocked by bismuth oxide (Bi 2 O 3 ) are presented and efficiently deliver chemotherapeutic agent daunomycin (DNM) to the targeted tumor cells. Bi 2 O 3 not only rapidly dissolves in the acidic condition of cancer cells to release the loaded chemotherapeutic drug but also enhances the anti-cancer effect through synergistic effects of the chemotherapy and Bi 3+ ions. By monitoring the treatment process, compared with the free drug DNM, the drug loaded DDS exhibit more significant suppression against cancerous cells growth such as A549 and MCF-7 cancer cells and lower cytotoxicity against normal Hacat cells. Mechanism research indicates that the drug loaded DDS can arrest the cell cycle at G0/G1 phase, change the mitochondrial membrane potential and finally induced the apoptosis of the cancerous cells. These results indicate that the Bi 2 O 3 -gated ZrO 2 platform is a promising approach to serve as a pH-sensitive DDS in the treatment of various cancers by chemo/ionic synergistic effects.