Chemodynamic therapy (CDT) is a highly tumor-specific and minimally invasive treatment that is widely used in cancer therapy. However, its therapeutic effect is limited by the poor efficiency of hydroxyl radical generation. In colon cancer in particular, the high expression of hydrogen sulfide (H2S), which has strong reducibility, results in the consumption of generated hydroxyl radicals, further weakening the efficacy of CDT. To overcome this problem, we developed a novel two-dimensional (2D) Cu-bipyridine metal-organic framework (MOF) nanosheet [Cu(bpy)2(OTf)2] for colon cancer CDT. The therapeutic effect of Cu(bpy)2(OTf)2 is enhanced based on three factors. First, the developed 2D Cu-MOF rapidly consumes H2S to inhibit the consumption of generated hydroxyl radicals. Second, the ultrasmall CuS generated after H2S depletion facilitates Fenton-like reactions. Third, the generated CuS exhibits good photothermal performance in the second near-infrared window, allowing for photothermal-enhanced CDT. The ability of Cu(bpy)2(OTf)2 to improve the CDT effect was demonstrated through both in vitro and in vivo experiments. This work demonstrates the applicability of 2D Cu-MOF in the CDT of colon cancer and provides a novel strategy for constructing CDT agents for colon cancer.
Keywords: 2D Cu-bipyridine MOF; chemodynamic therapy; photothermal-enhanced CDT; second near-infrared window; ultrasmall CuS.