Photoactivation-Triggered in Situ Self-Supplied H2o2 for Boosting Chemodynamic Therapy Via Nanosheet-Mediated Catalytic Cascade Reaction

Chemodynamic therapy (CDT), which is featured with high tumor specificity and selectivity, has aroused extensive interest as an advanced anti-cancer approach. However, chemodynamic therapeutic efficacy heavily relies on the level of endogenous hydrogen peroxide (H 2 O 2 ) that is intrinsically heterogenous and insufficient. Herein, a self-supplied H 2 O 2 enhanced chemodynamic therapeutic strategy was developed by constructing a 2-demensional (2D) sheet-like nanocatalyst to induce catalytic cascade reactions. The cascade nanocatalyst was fabricated by integrating photosensitizer indocyanine green (ICG) and Fenton catalyst Fe 2+ ions into a 2D ultrathin layered double hydroxide nanoparticle. Under near infrared light irradiation, ICG in the nanocatalyst produced cytotoxic singlet oxygen ( 1 O 2 ) to damage tumor cells, and meanwhile generated superoxide radical (O 2 ·- ) that was subsequently converted into H 2 O 2 by reacting with intracellular superoxide dismutase. A considerable amount of in situ self-supplied H 2 O 2 , together with endogenous H 2 O 2 , was catalyzed by Fe 2+ in the nanocatalyst to produce abundant, highly cytotoxic hydroxyl radicals ( · OH) to trigger apoptosis and death of tumor cells. I n vitro and in vivo evaluations manifest the cascade nanocatalyst-mediated remarkably enhanced chemodynamic therapeutic performance. This work has therefore demonstrated a cascade catalytic therapeutic nanoplatform enabling photoactivation-triggered H 2 O 2 self-supplied synergistic strategy for safe and efficacious tumor treatment