Synthesis of cobalt ferrite nanoparticles using spermine and their effect on death in human breast cancer cells under an alternating magnetic field

To compare heat generation under an AC magnetic field for inducing cancer cell death, CoFe₂O₄ and Fe₃O₄ nanoparticles with a diameter of ∼10 nm were synthesized by hydrolysis in an aqueous solution containing the metal chlorides iron(III) chloride and cobalt(II) or iron(II) chloride, with spermine or N,N'-bis(3-aminopropyl)butane-1,4-diamine, as a base and a protective reagent. Both CoFe₂O₄ and Fe₃O₄ nanoparticles were incorporated into human breast cancer MCF-7 cells; the nanoparticles exhibited little toxicity on the cells. When the cells containing nanoparticles were subjected to an AC magnetic field, MCF-7 cell death was induced by heat generated from ∼10-nm CoFe₂O₄ nanoparticles but not from ∼10-nm Fe₃O₄ nanoparticles. An increase in coercivity derived from the substitution of Fe²⁺ with Co²⁺ facilitated the ability of the nanoparticles to induce cell death in human breast cancer cells under an AC magnetic field.