Self-Propelled Janus Nanocatalytic Robots Guided by Magnetic Resonance Imaging for Enhanced Tumor Penetration and Therapy

Biomedical micro/nanorobots as active delivery systemswith thefeatures of self-propulsion and controllable navigation have madetremendous progress in disease therapy and diagnosis, detection, andbiodetoxification. However, existing micro/nanorobots are still sufferingfrom complex drug loading, physiological drug stability, and uncontrollabledrug release. To solve these problems, micro/nanorobots and nanocatalyticmedicine as two independent research fields were integrated in thisstudy to achieve self-propulsion-induced deeper tumor penetrationand catalytic reaction-initiated tumor therapy in vivo. We presentedself-propelled Janus nanocatalytic robots (JNCRs) guided by magneticresonance imaging (MRI) for in vivo enhanced tumor therapy. TheseJNCRs exhibited active movement in H2O2 solution,and their migration in the tumor tissue could be tracked by non-invasiveMRI in real time. Both increased temperature and reactive oxygen speciesproduction were induced by near-infrared light irradiation and iron-mediatedFenton reaction, showing great potential for tumor photothermal andchemodynamic therapy. In comparison with passive nanoparticles, theseself-propelled JNCRs enabled deeper tumor penetration and enhancedtumor therapy after intratumoral injection. Importantly, these robotswith biocompatible components and byproducts exhibited biosecurityin the mouse model. It is expected that our work could promote thecombination of micro/nanorobots and nanocatalytic medicine, resultingin improved tumor therapy and potential clinical transformations.

Automated summary

In this study, the integration of micro/nanorobots and nanocatalytic medicine was used to achieve self-propulsion-induced deeper tumor penetration and catalytic reaction-initiated tumor therapy in vivo. The self-propelled Janus nanocatalytic robots (JNCRs) were guided by magnetic resonance imaging (MRI) for active movement and their migration in the tumor tissue could be tracked by non-invasive MRI in real time. These JNCRs showed great potential for tumor photothermal and chemodynamic therapy through near-infrared light irradiation and iron-mediated Fenton reaction.