Developing novel small-molecule-based probes with both deep tissue imaging and therapeutic functions is highly significant in cancer diagnosis and treatment. Herein, we report a novel second near-infrared (NIR-II) fluorescent probe QT-RGD constructed with a NIR-II emissive organic fluorophore and two cyclic-(arginine-glycine-aspartic acid) (cRGD) peptides that can specifically bind to the tumor-associated α_vβ₃ integrin for accurate tumor diagnosis and targeting therapy. The isotopic ¹²⁵I-labeled probe exhibited great tumor targeting ability and emitted intensive NIR-II/photoacoustic (PA)/single-photon emission computed tomography (SPECT) signals, which allows specific and sensitive multimodal visualization of tumors in vivo. More notably, this probe could also be applied for effective imaging-guided photothermal therapy (PTT) of tumors in mouse models owing to its prominent photothermal conversion efficiency and excellent photothermal stability. We thus envision that our work which unveils a combination of NIR-II/PA/SPECT imaging and PTT would offer a valuable means of improving tumor diagnostic accuracy as well as therapeutic efficacy.

中文翻译：

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新型αvβ3整合素靶向NIR-II纳米探针，用于体内多模态成像引导光热疗法

开发具有深层组织成像和治疗功能的新型基于小分子的探针在癌症的诊断和治疗中具有重要意义。本文中，我们报道了一种新型的第二近红外（NIR-II）荧光探针QT-RGD，该探针由NIR-II发光有机荧光团和两个可以特异性结合至的环-（精氨酸-甘氨酸-天冬氨酸）（cRGD）肽构建肿瘤相关α _v β ₃整联准确肿瘤的诊断和靶向治疗。同位素¹²⁵ I标记的探针显示出强大的肿瘤靶向能力，并发射出密集的NIR-II /光声（PA）/单光子发射计算机断层扫描（SPECT）信号，从而可以在体内对肿瘤进行特异性和灵敏的多模式可视化。更值得注意的是，由于其出色的光热转换效率和出色的光热稳定性，该探针还可用于对小鼠模型中的肿瘤进行有效的成像引导光热疗法（PTT）。因此，我们认为我们的工作揭示了NIR-II / PA / SPECT成像与PTT的结合，将为提高肿瘤的诊断准确性和治疗效果提供有价值的手段。