Enhancement of cumulative photoirradiated and ac magnetic-field induced cancer (HeLa) cell killing efficacy of mixed α and γ-Fe2O3 magnetic nanoparticles

Abstract

In this current study we synthesized mixed α and γ-Fe₂O₃ nanoparticles and their synergistic toxic effect against HeLa cells was investigated under ac (alternating current) magnetic-field induction and photoirradiation conditions at room temperature. The experiment was designed to find out the cancer cell killing efficacy of as-synthesized bare γ-Fe₂O₃, bare α-Fe₂O₃ and mixed α and γ-Fe₂O₃ nanoparticles under combined ac magnetic-field induction and photoirradiation conditions. The toxic effect of nanoparticles was obtained by counting the percentage of viable cells after all the treatments were completed using various concentrations. The results revealed that the highest toxic effect was obtained using mixed α and γ-Fe₂O₃ nanoparticles under combined ac magnetic-field induction and photoirradiation conditions at a dose of 60 μg mL⁻¹ MEM (minimum essential medium), i.e., approximately 98% cancer cells were killed, whereas under only ac magnetic-field induction or only photoirradiation conditions, only 89% and 66% cancer cells were destroyed using the same dose of same nanomaterials, respectively. We also noticed that 55% and 79% cancer cells were destroyed using bare α-Fe₂O₃ and bare γ-Fe₂O₃ nanoparticles, respectively, under combined ac magnetic-field induction and photoirradiation conditions using the same dose. To the best of our understanding, the mechanism or reason for almost 100% HeLa cell killing under the combined conditions can be ascribed to the combined or additive effect of ac magnetic-field induced hyperthermia and photocatalytic cytotoxicity.