Near-Infrared Driven Gold Nanoparticles-Decorated g-C3N4/SnS2 Heterostructure through Photodynamic and Photothermal Therapy for Cancer Treatment.

Background: Phototherapy based on photocatalytic semiconductor nanomaterials has received considerable attention for the cancer treatment. Nonetheless, intense efficacy for in vivo treatment is restricted by inadequate photocatalytic activity and visible light response.

Methods: In this study, we designed a photocatalytic heterostructure using graphitic carbon nitride (g-C₃N₄) and tin disulfide (SnS₂) to synthesize g-C₃N₄/SnS₂ heterostructure through hydrothermal process. Furthermore, Au nanoparticles were decorated in situ deposition on the surface of the g-C₃N₄/SnS₂ heterostructure to form g-C₃N₄/SnS₂@Au nanoparticles.

Results: The g-C₃N₄/SnS₂@Au nanoparticles generated intense reactive oxygen species radicals under near-infrared (NIR) laser irradiation through photodynamic therapy (PDT) pathways (Type-I and Type-II). These nanoparticles exhibited enhanced photothermal therapy (PTT) efficacy with high photothermal conversion efficiency (41%) when subjected to 808 nm laser light, owing to the presence of Au nanoparticles. The in vitro studies have indicated that these nanoparticles can induce human liver carcinoma cancer cell (HepG2) apoptosis (approximately 80% cell death) through the synergistic therapeutic effects of PDT and PTT. The in vivo results demonstrated that these nanoparticles exhibited enhanced efficient antitumor effects based on the combined effects of PDT and PTT.

Conclusion: The g-C₃N₄/SnS₂@Au nanoparticles possessed enhanced photothermal properties and PDT effect, good biocompatibility and intense antitumor efficacy. Therefore, these nanoparticles could be considered promising candidates through synergistic PDT/PTT effects upon irradiation with NIR laser for cancer treatment.