Biocompatible Exchange-Coupled Magnetic Nanoparticles for Advanced Hyperthermia*

Exchange-coupled bimagnetic nanoparticles describe a potential for advanced hyperthermia treatment of cancer with an increased heating capability. The feasibility of magnetic hyperthermia in humans warrants magnetic nanoparticles (MNPs) with an Fe₃O₄ shell to meet biocompatibility standards. In our study, we compare the heating efficiency and magnetic properties of CoFe₂O₄@ Fe₃O₄ MNPs with the inverse system, Fe₃O₄@ CoFe₂O₄. We calculate the Specific Absorption Rate (SAR) values of both nanoparticle systems when dispersed in hexane, water, and agar in addition to proper morphological and magnetic characterization using TEM, XRD, and DC Magnetometry. At 80mT, we report SAR values of our CoFe₂O₄@ Fe₃O₄ MNPs to be 62% greater in water and 2% greater in agar than the inverse MNPs. We observe a significant coercive field of the CoFe₂O₄@ Fe₃O₄ MNPs when taking DC Magnetometry measurements at 10K, to which we attribute its superior heating power over the inverse system in media that limit Brownian movement. We anticipate an increase in saturation magnetization of the CoFe₂O₄@ Fe₃O₄ system with negligible effect on coercive field with increased Fe₃O₄ shell thickness.