Simultaneous near infrared photothermal therapy and temperature mapping by magnetic resonance in 3D cell aggregates loaded with Fe3Se4 nanoparticles

Control over temperature in space and time is of utmost importance in many contexts, including photothermal therapies, where a good temperature monitoring and control is expected to improve their clinical outcome. One of the most promising techniques involves the use of magnetic resonance imaging, exploring the temperature change of proton relaxometric properties or exploring the temperature change of contrast agents. In real applications, the use of contrast agents for thermometry is much better justified if thermometry comes as an added value of a photothermal agent. Here we show iron selenide nanoparticles (NPs) that are able to work simultaneously as efficient near infrared photothermal and thermometry agents embedded in cellular models at concentrations where their toxicity is low. The simultaneous heat generation and temperature mapping around these NPs allow the control over the depth achieved by the therapy and detection and control of hot spots that would be otherwise overlooked, for instance.