Light-Enhanced O2-Evolving Nanoparticles Boost Photodynamic Therapy To Elicit Antitumor Immunity

Breast cancer remains to show high mortality and poor prognosis in women despite of significant progress in recent diagnosis and treatment. Herein, we report the rational design of a highly efficient ultrasmall nanotheranostic agent with excellent photodynamic therapy (PDT) performance to against breast cancer and its metastasis by eliciting antitumor immunity. The ultrasmall nanoagent (3.1 ± 0.4 nm) was fabricated from polyethylene glycol modified Cu2–xSe nanoparticles, β-cyclodextrin, and chlorin e6 under ambient conditions. The resultant nanoplatform (CS–CD–Ce6 NPs) can be passively accumulated into the tumor to exhibit dramatic antitumor efficacy through the excellent PDT effect under near-infrared irradiation. The excellent PDT performance of this nanoplatform is owing to its role as a Fenton-like Haber–Weiss catalyst for the efficient degradation of H2O2 within the tumor to release hydroxyl radicals (·OH) and very toxic singlet oxygen (1O2) under irradiation. The generated vast amounts of reactive o...