Carrier-free GSH-responsive in situ nanoreactor for copper-overload augment cuproptosis/chemodynamic therapy

Recently, copper (Cu)-based cancer therapy, an intracellular Cu-dependent process, has received tremendous attention because of the emergence of cuproptosis. However, the inherent regulatory mechanism limits intracellular Cu accumulation. Herein, a carrier-free GSH-responsive in situ nanoreactor (TECJ) is fabricated, of which Cu ionophore elesclomol (ES), GSH-responsive nitric oxide (NO) donor O₂-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1,2-diolate (JSK) and Cu²⁺ are integrated via self-assembly and coated with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS). TECJ enhances the systemic stability and tumor accumulation of ES and JSK through both the coating function and the additional inner force provided by TPGS. After internalization, TECJ specifically releases the cargoes via GSH-responsive dissociation. Then, ES efficiently transports extracellular Cu²⁺ into the cytoplasm for Cu influx, while NO released from JSK aggravates mitochondrial dysfunction and blocks adenosine triphosphate supply to inhibit ATP7A expression and reduce Cu efflux, therefore dually resulting in Cu-overload and amplifying cuproptosis. Furthermore, Cu-induced Fenton-like reaction together with TPGS-mediated ROS generation triggers chemodynamic therapy (CDT), and NO transfers ROS into more toxic ONOO^- for accelerating tumor death while reducing tumor self-alleviation by inhibiting DNA repair. Afterwards, the process above synergistically activates immunogenic cell death and cascades immunotherapy. Finally, TECJ successfully suppresses tumor growth and prevents tumor metastasis.