NIR/Tumor-microenvironment dual-activatable nanorods for concomitant photothermal/photodynamic therapy and hypoxia-amplified chemotherapy

To overcome challenges in cancer treatment, non-invasive photothermal therapy (PTT) andphotodynamic therapy (PDT) hold significant promise. In this study, we designed a type of amino-modifiedSiO2-coated bismuth sulfide nanorods serving (Bi2S3) and used amide reaction to couple with 3-(4-carboxyphenoxy) phthalocyanine zinc (ZnPc-COOH) to form a porous nanorods material, resulting in aBi2S3@SiO2-Pc/TPZ anti-cancer nanorod loaded with tirapazamine (TPZ), which synergistically combinesPTT, PDT and chemotherapy. Notably, this multifunctional nano-platform exhibits excellent photothermalproperties (η = 31.1%) under 808 nm laser irradiation, facilitating the uptake of Bi2S3@SiO2-Pc/TPZ andpromoting the generation of effective reactive oxygen species. Moreover, the synergistic interplay betweenPTT and PDT significantly enhanced the chemotherapeutic efficacy of hypoxia-activated TPZ. Thisapproach confirmed the potent synergistic anticancer effects of combined PDT, PTT, and chemotherapy.KEYWORDS: photothermal therapy, photodynamic therapy, bismuth sulfide (Bi2S3) nanorods, zincphthalocyanine, tirapazamine, combined therapy.