Core/Shell Superparamagnetic Nanoparticles and their Potential for Magnetic Hyperthermia Cancer Therapy*

Due to the side effects produced by radiotherapy and chemotherapy on cancer patients, there has been a need in the world of biomedicine for an alternative option. Superparamagnetic nanoparticles (SMNPs) have been sought out due to their potential for hyperthermia treatment in which a magnetic field is applied to to heat up injected nanoparticles causing them to heat up. To be successful, magnetic nanoparticles must display high magnetism and good dispersion to allow for the heating potential of the nanoparticles to be reached and effectively kill cancer cells. Iron-oxide has been utilized thus far due to the cost efficiancy of the materials and the success in reaching their heating potential. One complication that arises with iron oxides in hyperthermia treatment is their lower magnetization levels which means there is difficulty at times to reach the optimized specific absorption rate (SAR) needed to effectively treat cancer using hyperthermia. In this work, we use a "bottom-up" approach where we use iron precursors to synthesize pure iron nanoparticles (FeNP's) with a gold core-shell surrounding the nanoparticle (Au@FeNP's). We used VSM, XRD, and SEM devices to assess the magnetization and structure of these nanoparticles. Due to the high magnetization and SAR of the superparamagnetic nanoparticles, as well as the x-ray diffraction values, there are indications of pure iron nanoparticles mixed with iron-oxide nanoparticles being produced. the results yielded varying magnetizations based on many factors such as nucleation times, chemical ratios, and the use of the pressure reactor. The most promising of our results show a high magnetization of 175.13 emu/g, while still remaining superparamagnetic. Through XRD analysis we have confirmed that our samples are composed of pure iron and gold with little impurities allowing for potential use in-vitro and in-vivo studies.