Selective radiofrequency ablation of tumor by magnetically targeting of multifunctional iron oxide-gold nanohybrid

Radiofrequency (RF) ablation therapy is of great interest in cancer therapy as it is non-ionizing radiation and can effectively penetrate into the tissue. However, the current RF ablation technique is invasive that requires RF probe insertion into the tissue and generates a non-specific heating. Recently, RF-responsive nanomaterials such as gold nanoparticles (AuNPs) and iron oxide nanoparticles (IONPs) have led to tremendous progress in this area. They have been found to be able to absorb the RF field and induce a localized heating within the target, thereby affording a non-invasive and tumor-specific RF ablation strategy. In the present study, for the first time, we used a hybrid core-shell nanostructure comprising IONPs as the core and AuNPs as the shell (IO@Au) for targeted RF ablation therapy. Due to the magnetic core, the nanohybrid can be directed toward the tumor through a magnet. Moreover, IONPs enable the nanohybrid to be used as a magnetic resonance imaging (MRI) contrast agent. In vitro cytotoxicity experiment showed that the combination of IO@Au and 13.56-MHz RF field significantly reduced the viability of cancer cells. Next, during an in vivo experiment, we demonstrated that magnetically targeting of IO@Au to the tumor and subsequent RF exposure dramatically suppressed the tumor growth. Therefore, the integration of targeting, imaging, and therapeutic performances into IO@Au nanohybrid could afford the promise to improve the effectiveness of RF ablation therapy.