Fabrication of PEGylated Fe@Bi2S3 nanocomposites for dual-mode imaging and synergistic thermoradiotherapy

Abstract

Nanocomposites for integrating imaging and therapy have attracted tremendous attention for biomedical applications. Herein, Fe@Bi₂S₃ nanocomposites modified with polyethylene glycol (PEG) molecules are fabricated for synergistic thermoradiotherapy. For such nanocomposites, Bi₂S₃ exhibits a strong absorbance in the near-infrared (NIR) region, which allows Bi₂S₃ to convert energy from light into heat for effective photothermal therapy (PTT), whereas Bi can also significantly enhance radio-mediated cell death induction as a radiotherapy sensitizer due to its high atomic number (high-Z). Most importantly, it is found that the combination of PTT and radiation therapy (RT), using PEGylated Fe@Bi₂S₃ nanocomposites, can bring a strong synergistic effect for the tumor treatment in in vitro and in vivo experiments. Besides, the magnetic Fe core and the Bi₂S₃ shell components endow this nanocomposite with an ability to serve as both a magnetic resonance imaging (MRI) and computed tomography (CT) contrast agent. Therefore, our work presents a new type of multifunctional nanocomposite with the potential for synergistic thermoradiotherapy and simultaneously MRI/CT imaging.