Immunostimulatory multi-interfacial bimetallic phosphide nanoparticles as photo-enhanced cascade nanozyme for cancer therapy

Nanozyme has been widely explored for tumor catalytic therapy. Nevertheless, highly efficient and specific cancer therapy with nanozyme is still challenging under the strict condition of tumor microenvironment (TME). Herein, we fabricate a bimetallic phosphide nanoparticle (CuFeP) with multiphase interfaces as a photo-enhanced cascade nanozyme for efficient immunostimulatory cancer therapy. The CuFeP has structural, atomic and electric coupling with multi-interfacial heterojunction to promote the interfacial electron transfer, and the bimetallic redox couple of Cu+/2+ and Fe0/2+/3+ to synergistically improve the cascade catalysis of peroxidase (POD) and glutathione peroxidase (GPX), thereby inducing lethal cellular oxidative damage. Moreover, the excellent photothermal efficiency of 66.9% assists in catalysis in view of thermodynamics. Finally, the synergetic catalysis triggers immune cell death (ICD) process, which promotes maturation of dendritic cells (DCs), activation of cytotoxic and helper T cells, and excretion of proinflammatory cytokines to boost antitumor immunity in vivo. This study provides an enlightenment for the design of efficient therapeutic nanozyme to conquer cancer.