Combining photothermal therapy (PTT) and multimodality molecular imaging into one nanotheranostic can improve the diagnostics and therapeutics outcome of malignant tumors significantly. Herein, a heteronanostructure (named Au-Fe₃O₄@PDA-PEG-DTPA-Gd) has been synthesized for multimodality molecular imaging-guided PTT by conjugation of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) on a polydopamine (PDA) coated Au-Fe₃O₄ heterodimeric via a polyethylene glycol (PEG) crosslinker. Au-Fe₃O₄@PDA-PEG-DTPA-Gd exhibits reasonable biocompatibility, high photothermal conversion efficiency (η = 41.3%), integration of excellent T₁-/T₂-weighted magnetic resonance imaging (MRI, the molar longitudinal relaxivity rate (r₁) = 6.14 mM⁻¹ s⁻¹/transverse relaxation rate (r₂) = 71.88 mM⁻¹ s⁻¹) and X-ray computed tomography imaging (CT, approximately 1.94 times higher than that of the commercial CT contrast agent ioversol) contrast functionality. The theranostic capability of Au-Fe₃O₄@PDA-PEG-DTPA-Gd has been verified on the triple negative breast tumor cell (MDA-MB-231 cell) and MDA-MB-231 tumor-bearing mouse model. From MR/CT imaging, Au-Fe₃O₄@PDA-PEG-DTPA-Gd shows remarkable PTT efficacy, which completely inhibits MDA-MB-231 tumor growth in vivo with a single treatment.

中文翻译：

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用于多模态分子成像引导光热疗法的异质结构的合成

将光热疗法（PTT）和多模态分子成像相结合成一种纳米热疗法可以显着改善恶性肿瘤的诊断和治疗效果。在这里，杂多结构（命名为Au-Fe ₃ O ₄ @ PDA-PEG-DTPA-Gd）已经合成，用于多模态分子成像指导的PTT，方法是在涂有聚多巴胺（PDA）的g-二亚乙基三胺五乙酸（Gd-DTPA）上偶联。通过聚乙二醇（PEG）交联剂形成Au-Fe ₃ O ₄异二聚体。Au-Fe ₃ O ₄ @ PDA-PEG-DTPA-Gd表现出合理的生物相容性，高的光热转化效率（η = 41.3％），优异的集成度T _1- / T ₂加权磁共振成像（MRI，摩尔纵向弛豫率（r ₁）= 6.14 mM ^-1 s ^-1 /横向弛豫率（r ₂）= 71.88 mM ^-1 s ^-1）和X射线计算机断层扫描成像（CT，比市售CT造影剂ioversol的约高1.94倍）造影功能。已在三阴性乳腺肿瘤细胞（MDA-MB-231细胞）和MDA-MB-231荷瘤小鼠模型上验证了Au-Fe ₃ O ₄ @ PDA-PEG-DTPA-Gd的治疗能力。通过MR / CT成像获得Au-Fe ₃ O₄ @ PDA-PEG-DTPA-Gd显示出显着的PTT功效，只需一次治疗即可在体内完全抑制MDA-MB-231肿瘤的生长。