High-efficiency and Safe Sulfur-Doped Iron Oxides for Magnetic Resonance Imaging Guided Photothermal/Magnetic Hyperthermia Therapy
Heat therapy is a promising therapeutic modality for cancer treatments due to selective local hyperthermia with minimum adverse effects but the low heating efficiency under the safe condition is an issue for its bioapplication. Here, we report on the synthesis of water-dispersible sulfur doped iron oxides (SDIOs) with different phase structure and exploration of the relation between different SDIOs and their induction heating capacities as a guideline to obtain a photo-magnetic hyperthermia agent. The agent exhibits good biocompatibility, excellent photothermal conversion efficiency (55.8 %) and great T2 weighted magnetic resonance imaging (63.7 mM-1 S-1). Significantly, the SDIOs effectively eliminate the tumour under a biological safe range of AC magnetic field (H·f =4.3 < 5.0 × 106 kA m−1 s−1) and an 808 nm laser irradiation at the safe density of 0.33 W cm-2, which can be chiefly metabolized from the body after one month. This work presented here adopts anion doped iron oxides to dramatically improve photo-magnetic hyperthermia effect and may provide a further exploration in the thermotherapeutic research.