Abstract
OBJECTIVES: To develop a hollow Cu(9)S(8)-based nanoparticles loaded with the photosensitizer IR780, investigate its photothermal and photodynamic (PTT-PDT) effects against esophageal cancer cells and analyze the underlying mechanisms. METHODS: Hollow Cu(9)S(8) nanoparticles were synthesized using a sacrificial-template strategy, and IR780 was encapsulated within a lauric acid matrix to serve as a phase-change material for preparing IR780@Cu(9)S(8) composite nanoparticles. The composite nanoparticles were characterized for morphology and structural attributes using transmission electron microscopy, X-ray diffraction, and UV-visible spectroscopy. The effects of IR780@Cu(9)S(8) on proliferation, invasion, and migration of esophageal cancer cells under near-infrared (NIR) irradiation (808 nm, 1.5 W/cm², 5 min) were assessed using CCK-8 assay, live/dead staining, reactive oxygen species, mitochondrial membrane potential assay, wound-healing assay, and Transwell assay. The in vivo PTT-PDT therapeutic efficacy and biosafety of IR780@Cu(9)S(8) was evaluated in a mouse model bearing subcutaneous esophageal cancer xenografts. RESULTS: The synthesized IR780@Cu(9)S(8) nanoparticles exhibited a uniform quasi-spherical morphology with a photothermal conversion efficiency of 44.0%. Under NIR irradiation, IR780@Cu(9)S(8) produced pronounced synergistic PTT-PDT effects against KYSE150 cells, causing a significant reduction of cell viability and marked suppression of cell proliferation, migration, and invasion. In the tumor-bearing mice, IR780@Cu(9)S(8) and 808 nm laser irradiation exhibited strong synergistic PTT-PDT effects and significantly inhibited tumor growth with a good biocompatibility. CONCLUSIONS: The IR780@Cu(9)S(8) composite nanoparticles achieve synergistic PTT-PDT antitumor activity in esophageal cancer cells which can be a promising strategy for combined therapy and targeted drug delivery for esophageal cancer.