Sorafenib (SRF) is recognized as the primary treatment for hepatocellular carcinoma (HCC), yet the emergence of SRF resistance in many HCC patients results in unfavorable outcomes. Enhancing the efficacy of SRF in HCC remains a significant challenge. SRF works in inducing ferroptosis, a form of cell death, in cancer cells through the inhibition of glutathione peroxidase 4 (GPX4). The effectiveness of this process is limited by the low levels of cellular iron and reactive oxygen species (ROS). A promising approach to circumvent this limitation is the use of intracellular magnetic hyperthermia (MH) mediated by magnetic iron oxide nanomaterials (MIONs). When MIONs are subjected to an alternating magnetic field (AMF), they heat up, enhancing the Fenton reaction, which in turn significantly increases the production of ROS within cells. In this study, we explore the capability of MH facilitated by high-performance ferrimagnetic vortex-domain iron oxide nanoring (FVIO) to enhance the effectiveness of SRF treatment in HCC. The increased iron uptake facilitated by FVIO significantly enhances the sensitivity of HCC cells to SRF-induced ferroptosis. Moreover, the nanoheat generated by FVIO in response to an AMF further elevates ROS levels and stimulates lipid hydroperoxide (LPO) production and GPX4 inactivation, thereby intensifying ferroptosis. Both in vitro and in vivo animal studies demonstrate that combining FVIO-mediated MH with SRF significantly reduces cell viability and inhibits tumor growth, primarily through enhanced ferroptosis, with minimal side effects. The effectiveness of this combination therapy is affected by the ferroptosis inhibitor ferrostatin-1 (Fer-1) and the iron chelator deferoxamine (DFO). The combination treatment of FVIO-mediated MH and SRF offers a strategy for HCC treatment by promoting accelerated ferroptosis, presenting a different perspective for the development of ferroptosis-based anticancer therapies.
Keywords: ferrimagnetic vortex-domain iron oxide nanoring; ferroptosis; hepatocellular carcinoma; intracellular magnetic hyperthermia; sorafenib.