Infrared‐Emitting Multimodal Nanostructures for Controlled In Vivo Magnetic Hyperthermia

Abstract

Deliberate and local increase of the temperature within solid tumors represents an effective therapeutic approach. Thermal therapies embrace this concept leveraging the capability of some species to convert the absorbed energy into heat. To that end, magnetic hyperthermia (MHT) uses magnetic nanoparticles (MNPs) that can effectively dissipate the energy absorbed under alternating magnetic fields. However, MNPs fail to provide real‐time thermal feedback with the risk of unwanted overheating and impeding on‐the‐fly adjustment of the therapeutic parameters. Localization of MNPs within a tissue in an accurate, rapid, and cost‐effective way represents another challenge for increasing the efficacy of MHT. In this work, MNPs are combined with state‐of‐the‐art infrared luminescent nanothermometers (LNTh; Ag2S nanoparticles) in a nanocapsule that simultaneously overcomes these limitations. The novel optomagnetic nanocapsule acts as multimodal contrast agents for different imaging techniques (magnetic resonance, photoacoustic and near‐infrared fluorescence imaging, optical and X‐ray computed tomography). Most crucially, these nanocapsules provide accurate (0.2 °C resolution) and real‐time subcutaneous thermal feedback during in vivo MHT, also enabling the attainment of thermal maps of the area of interest. These findings are a milestone on the road toward controlled magnetothermal therapies with minimal side effects.

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“…68–70 Shen et al 71 functionalized MnFe 2 O 4 NPs with Ir( iii ) complexes to construct Ir@MnFe 2 O 4 nanoparticles to elevate the local temperature and induce mitochondrial damage and cell death upon exposure to AMF, during which Fe( iii ) was reduced to Fe( ii ) by the overexpressed GSH in the mitochondria of tumor cells, hence offering precise and effective treatment against cancer. Significantly, to address the failure of magnetic nanoparticles in providing real-time thermal feedback in MHT, Erving Ximendes and coworkers 72 integrated magnetic nanoparticles with infrared luminescent nanothermometers (LNTh; Ag 2 S nanoparticles) in optomagnetic nanocapsules. In this strategy, the novel nanocapsules acted as multimodal CAs, providing accurate and real-time thermal feedback during in vivo controllable MHT and avoiding the collateral damage caused by overheating.…”

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