PEGylated Cu3BiS3 hollow nanospheres as a new photothermal agent for 980 nm-laser-driven photothermochemotherapy and a contrast agent for X-ray computed tomography imaging

Abstract

Developing multifunctional near-infrared (NIR) light-driven photothermal agents is in high demand for efficient cancer therapy. Herein, PEGylated Cu₃BiS₃ hollow nanospheres (HNSs) with an average diameter of 80 nm were synthesized through a facile ethylene glycol-mediated solvothermal route. The obtained PEGylated Cu₃BiS₃ HNSs exhibited strong NIR optical absorption with a large molar extinction coefficient of 4.1 × 10⁹ cm⁻¹ M⁻¹ at 980 nm. Under the irradiation of a 980 nm laser with a safe power density of 0.72 W cm⁻², Cu₃BiS₃ HNSs produced significant photothermal heating with a photothermal transduction efficiency of 27.5%. The Cu₃BiS₃ HNSs also showed a good antitumoral drug doxorubicin (DOX) loading capacity and pH- and NIR-responsive DOX release behaviors. At a low dosage of 10 μg mL⁻¹, HeLa cells could be efficiently killed through a synergistic effect of chemo- and photothermo-therapy respectively based on the DOX release and the photothermal effect of Cu₃BiS₃ HNSs. In addition, Cu₃BiS₃ HNSs displayed a good X-ray computed tomography (CT) imaging capability. Furthermore, Cu₃BiS₃ HNSs could be used for efficient in vivo photothermochemotherapy and X-ray CT imaging of mice bearing melanoma skin cancer. This multifunctional theranostic nanomaterial shows potential promise for cancer therapy.