Localized cancer treatment by radio-frequency hyperthermia using magnetic nanoparticles immobilized on graphene oxide: from novel synthesis to in vitro studies.

We have produced an innovative, theranostic hybrid nanocomposite of graphene oxide and iron oxide (GO-Fe3O4) for radio-frequency hyperthermia therapy. A new electrochemical synthesis route for the GO-Fe3O4 nanocomposite is employed. Superparamagnetic nanoparticles used for magnetic hyperthermia for biomedical application face longstanding obstacles, including the large number of nanoparticles required to achieve the desired therapeutic temperature, poor colloidal stability in aqueous suspension or physiological media, poor biocompatibility and, most importantly, low specific absorption rate (SAR). To limit the dosage of nanoparticles for therapeutic use, efforts are being made to increase the heating efficiency of nanoparticles. We have introduced an alternative way to increase the SAR value by improving the colloidal stability of magnetic nanoparticles. It is necessary to immobilize these nanoparticles on a support to prevent their agglomeration and precipitation in aqueous suspension. To address these issues, we report a reproducible electrochemical synthesis route for the GO-Fe3O4 nanocomposite. Our nanocomposite demonstrated good colloidal stability and low cytotoxicity in vitro. Due to its good colloidal stability, the nanocomposite had a high SAR of 543 W g-1 and corresponding intrinsic loss power of 5.98 nH m2 kg-1, which is 46% better than the best commercial equivalents. In vitro cytotoxicity studies demonstrated almost 70% cell viability at 200 μg mL-1 GO-Fe3O4 nanocomposite, a comparable concentration for clinical use according to FDA standards. We also showed the therapeutic potential of the nanocomposite using magnetic hyperthermia. We observed cancer cell (A549 human lung epithelial adenocarcinoma) ablation at 41, 42 and 43 °C for 30, 45, and 60 min. A maximum cancer cell death rate of 80.5% was observed at 43 °C for 60 min under alternating magnetic field exposure. Thus, the nanocomposites could be used in the efficient treatment of cancer.