Bistratal Au@Bi2S3 nanobones for excellent NIR-triggered/multimodal imaging-guided synergistic therapy for liver cancer

Abstract

To fabricate a highly biocompatible nanoplatform enabling synergistic therapy and real-time imaging, novel Au@Bi₂S₃ core shell nanobones (NBs) (Au@Bi₂S₃ NBs) with Au nanorods as cores were synthesized. The combination of Au nanorods with Bi₂S₃ film made the Au@Bi₂S₃ NBs exhibit ultrahigh photothermal (PT) conversion efficiency, remarkable photoacoustic (PA) imaging and high computed tomography (CT) performance; these Au@Bi₂S₃ NBs thus are a promising nanotheranostic agent for PT/PA/CT imaging. Subsequently, poly(N-vinylpyrrolidone)-modified Au@Bi₂S₃ NBs (Au@Bi₂S₃-PVP NBs) were successfully loaded with the anticancer drug doxorubicin (DOX), and a satisfactory pH sensitive release profile was achieved, thus revealing the great potential of Au@Bi₂S₃-PVP NBs in chemotherapy as a drug carrier to deliver DOX into cancer cells. Both <i>in vitro</i> and <i>in vivo</i> investigations demonstrated that the Au@Bi₂S₃-PVP NBs possessed multiple desired features for cancer therapy, including extremely low toxicity, good biocompatibility, high drug loading ability, precise tumor targeting and effective accumulation. Highly efficient ablation of the human liver cancer cell HepG2 was achieved through Au@Bi₂S₃-PVP NB-mediated photothermal therapy (PTT). As both a contrast enhancement probe and therapeutic agent, Au@Bi₂S₃-PVP NBs provided outstanding NIR-triggered multi-modal PT/PA/CT imaging-guided PTT and effectively inhibited the growth of HepG2 liver cancer cells <i>via</i> synergistic chemo/PT therapy.