A General Strategy for Tumor-Specific In Situ Synthesis of Copper Sulfide for Gas Therapy and Surface Plasmon Resonance Enhanced Phototherapy

CuS nanomaterials have attracted much attention for tumor therapy because of their excellent photothermal and photodynamic properties. Notably, Cu 2 O can be converted in situ to CuS through sulfurization by H 2 S in tumor cells. However, this approach is currently limited to colon cancer because other tumors exhibit comparatively lower H 2 S concentrations. Herein, we reported a nanoplatform consisting of two key components, diallyl trisulfide (DATS) and Cu 2 O-coated nanogapped gold nanoparticle (AuNNP). DATS reacted with upregulated glutathione (GSH) in tumor cells to release H 2 S for gas therapy as well as the sulfurization of Cu 2 O. AuNNPs further enhanced the photothermal and photodynamic effect of the in situ-formed CuS via surface plasmon resonance effect. Both H 2 S-induced gas therapy and CuS-mediated photothermal/photodynamic therapy exhibited much higher toxicity to tumor cells than to normal cells. Given that GSH is typically overexpressed in cancer cells, the developed strategy is thus generally applicable for almost any tumors.