Selective monitoring and treatment of neuroblastoma cells with hydrogen sulfide activatable phototheranostic agent

Abstract

Activity-based photosensitizers (aPSs) are highly attractive as they offer improved selectivity and better therapeutic outcome in the scope of photodynamic therapy (PDT). Here, a hydrogen sulfide (H2S) responsive iodinated resorufin-based PS (RHS) was developed to treat neuroblastoma cancer cells selectively. RHS was shown to be a phototheranostic agent as it turned on its fluorescence signal and singlet oxygen (O-1(2)) generation capability after reacting with H2S. RHS exhibited remarkable sensitivity towards H2S and proved to be highly cytotoxic in H2S rich SH-SY5Y human neuroblastoma cells upon light irradiation. In contrast, no photocytotoxicity was observed in H2S deficient nonmalignant fibroblast L929 cells. RHS marks the first example of a resorufin-based H2S activatable photo-theranostic agent, which paves the way for effective treatment of neuroblastoma through PDT modality.