Ultrasmall AgBiSe2 nanodots for CT/thermal imaging-guided photothermal tumor therapy in the NIR-II biowindow

"Spark" PtMnIr Nanozymes for Electrodynamic-Boosted Multienzymatic Tumor Immunotherapy

Multienzyme-mimicking redox nanozymes capable of efficient reactive oxygen species (ROS) generation and cellular homeostasis disruption are highly pursued for cancer therapy. However, it still faces challenges from the complicate tumor microenvironment (TME) and high chance for tumor metastasis. Herein, well-dispersed PtMnIr nanozymes are designed with multiple enzymatic activities, including catalase (CAT), oxidase (OXD), superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPx), which continuously produce ROS and deplete glutathione (GSH) concurrently in an "inner catalytic loop" way. With the help of electrodynamic stimulus, highly active "spark" species (Ir3+ and Mn3+ ) are significantly increased, resulting in an effective cascade enzymatic and electrodynamic therapy. Moreover, the cyclic generation of ROS can also facilitate ferroptosis and apoptosis in tumor cells, boosting synergistic therapy. Importantly, lung metastasis inhibition is found, which confirms efficient immunotherapy by the combined effect of immunogenic cell death (ICD) and Mn2+ -induced cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (cGAS-STING) pathway, contributing great potential in the treatment of malignant tumors.

Dual enzyme-like Co-FeSe2 nanoflowers with GSH degradation capability for NIR II-enhanced catalytic tumor therapy

Nanozymes mediated catalytic therapy can produce toxic reactive oxygen species (ROS) and destroy the metabolic balance of tumor cells, providing a new direction for cancer treatment. However, the catalytic efficiency of a single nanozyme is limited by the complexity of the tumor microenvironment (hypoxia, GSH overexpression, etc.). In order to overcome these problems, we designed flower-like Co-doped FeSe₂ (Co-FeSe₂) nanozymes by a simple wet chemistry method. Co-FeSe₂ nanozymes not only exhibit high POD and OXD-mimicking activities for facile kinetics, but also effectively consume over-expressed glutathione (GSH), inhibiting the consumption of generated ROS and destroying the metabolic balance of the tumor microenvironment. These catalytic reactions trigger cell death through apoptosis and ferroptosis dual pathways. More importantly, under the NIR II laser irradiation, the catalytic activities of Co-FeSe₂ nanozymes are boosted, confirming the photothermal and catalytic synergistic tumor therapy. This study takes advantage of self-cascading engineering that offers new ideas for designing efficient redox nanozymes and promoting their clinical translation.