The synthesis of core–shell Cu9S5@mSiO2–ICG@PEG–LA for photothermal and photodynamic therapy

Abstract

Recently, with strong NIR absorption, CuS_x nanomaterials have been considered as potential photothermal and photodynamic anticancer agents. Herein, Cu₉S₅ nanoparticles were synthesized as the core and coated with mesoporous silica to construct the core–shell nanostructure (Cu₉S₅@mSiO₂). The as-synthesized Cu₉S₅@mSiO₂ nanomaterial possesses uniform sphere morphology, about 50 nm in size. Considering its ample porous structure, Cu₉S₅@mSiO₂–NH₂ was used as a nanocarrier to demonstrate the high loading efficiency of the photosensitizer indocyanine green (ICG). Under 808 nm NIR light illumination, the temperature rises to 55.8 °C (3 W cm⁻²), and the high photo-thermal converter is ascribed the combined action of Cu₉S₅ and ICG. Moreover, Cu₉S₅@mSiO₂–ICG also reveals the illumination-dependent ROS generation. In addition, polyethylene glycol (PEG) and lactose acid (PEG–LA) was prepared and grafted outside Cu₉S₅@mSiO₂–ICG to further guarantee the targeting and cell uptake performance. Under the synergistic effect of PTT and PDT, the Cu₉S₅@mSiO₂–ICG@PEG–LA nanocomposite shows enhanced cytotoxicity to human hepatoma cells (HepG2), making it a promising candidate in nanomedicine as an antitumor agent.