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.

中文翻译：

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PEG化Fe @ Bi ₂ S ₃纳米复合材料的制备，用于双模式成像和协同热放射疗法†

集成成像和治疗的纳米复合材料已引起生物医学应用的极大关注。本文中，制备了用聚乙二醇（PEG）分子修饰的Fe @ Bi ₂ S ₃纳米复合材料，用于协同热放射疗法。对于此类纳米复合材料，Bi ₂ S ₃在近红外（NIR）区域具有很强的吸光度，这使得Bi ₂ S ₃可以将光能转换为热能以进行有效的光热疗法（PTT），而Bi由于其高原子数（高Z），也可以显着增强作为放射疗法敏化剂的放射介导的细胞死亡诱导。最重要的是，发现使用PEG化Fe @ Bi ₂ S ₃纳米复合材料的PTT和放射疗法（RT）的组合可以在体内和体外实验中为肿瘤治疗带来强大的协同作用。此外，磁性铁芯和Bi ₂ S ₃壳成分赋予了这种纳米复合材料以磁共振成像（MRI）和计算机断层扫描（CT）造影剂的能力。因此，我们的工作提出了一种新型的多功能纳米复合材料，具有协同热放射疗法和同时进行MRI / CT成像的潜力。