Biodegradable CoS2 nanoclusters for photothermal-enhanced chemodynamic therapy

Abstract Retaining in tumors for cancer diagnosis/treatment with sequential elimination from body is crucial to the clinical translation of inorganic medicaments. Herein, monodispersed CoS2 nanoclusters (CoS2 NCs) assembled from ultrasmall nanocrystals oligomerization via the La Mer scheme were successfully developed for chemodynamic therapy (CDT) of cancer cells due to the Fenton-like catalytic activity. Owing to their excellent photothermal conversion ability, both in vitro and in vivo cancer cell-killing efficacy of CoS2 NCs could be greatly enhanced upon near infrared (NIR) light irradiation, suggesting that generated heat would accelerate the Fenton-like catalytic reaction rate. Moreover, the structure of loosely stacking of CoS2 nanocrystals not only endowed CoS2 NCs more catalytic reaction sites to convert endogenous H2O2 into cytotoxic OH in tumor region, but also facilitated them degrading into ions in vivo and rapidly excreting from body by feces and urine through the reticuloendothelial systems, without causing any appreciable toxicity confirmed by systematic toxicological evaluation. Thus, our study demonstrated that these CoS2 NCs with biodegradable behaviors and highly integrated properties might have broad applications for cancer treatment.