A tumor microenvironment-responsive Co/ZIF-8/ICG/Pt nanoplatform for chemodynamic and enhanced photodynamic antitumor therapy.

Hypoxia and the overexpression of hydrogen peroxide (H 2 O 2 ) in the tumor microenvironment (TME) are conducive to cancer cell proliferation, which greatly hinders cancer treatment. Here, we design a novel TME-responsive therapeutic nanoplatform Co/ZIF-8/ICG/Pt (CZIP) to achieve chemodynamic therapy (CDT) and enhanced photodynamic therapy (PDT). In this nanoplatform, under near-infrared light (NIR) irradiation, the photosensitizer indocyanine green (ICG) can generate singlet oxygen ( 1 O 2 ) for cancer cell apoptosis. Meanwhile, overexpressed H 2 O 2 in the TME could be catalyzed to generate O 2 by the loaded Pt to relieve tumor hypoxia and promote the PDT-induced 1 O 2 production. In addition, the doped Co 2+ could react with H 2 O 2 to produce hydroxyl radicals (˙OH) for CDT. The multifunctional nanoplatform CZIP showed high biosafety and a good antitumor effect, which would provide a new route for cancer therapy.