AbstractTo realize sensing and labeling biomarkers is quite challenging in terms of designing multimodal imaging probes. In this study, we developed a novel β‐galactosidase (β‐gal) activated bimodal imaging probe that combines near‐infrared (NIR) fluorescence and magnetic resonance imaging (MRI) to enable real‐time visualization of activity in living organisms. Upon β‐gal activation, Gal‐Cy‐Gd‐1 exhibits a remarkable 42‐fold increase in NIR fluorescence intensity at 717 nm, allowing covalent labeling of adjacent target enzymes or proteins and avoiding molecular escape to promote probe accumulation at the tumor site. This fluorescence reaction enhances the longitudinal relaxivity by approximately 1.9 times, facilitating high‐resolution MRI. The unique features of Gal‐Cy‐Gd‐1 enable real‐time and precise visualization of β‐gal activity in live tumor cells and mice. The probe's utilization aids in identifying in situ ovarian tumors, offering valuable assistance in the precise removal of tumor tissue during surgical procedures in mice. The fusion of NIR fluorescence and MRI activation through self‐immobilizing target enzymes or proteins provides a robust approach for visualizing β‐gal activity. Moreover, this approach sets the groundwork for developing other activatable bimodal probes, allowing real‐time in vivo imaging of enzyme activity and localization.
摘要 要实现对生物标记物的传感和标记,在设计多模态成像探针方面具有相当大的挑战性。在这项研究中,我们开发了一种新型的β-半乳糖苷酶(β-gal)激活双模成像探针,它结合了近红外(NIR)荧光和磁共振成像(MRI)技术,可实现生物体内活动的实时可视化。β-gal激活后,Gal-Cy-Gd-1在717 nm波长处的近红外荧光强度显著增加42倍,可共价标记邻近的靶酶或蛋白质,避免分子逃逸,促进探针在肿瘤部位聚集。这种荧光反应将纵向弛豫性提高了约 1.9 倍,从而促进了高分辨率磁共振成像。Gal-Cy-Gd-1 的独特功能可以实时、精确地观察活体肿瘤细胞和小鼠体内的 β-gal 活性。探针的使用有助于识别原位卵巢肿瘤,为小鼠手术过程中精确切除肿瘤组织提供了宝贵的帮助。通过自固定靶酶或蛋白质将近红外荧光和核磁共振成像激活融合在一起,为β-gal活性的可视化提供了一种强有力的方法。此外,这种方法还为开发其他可激活的双模探针奠定了基础,从而可对酶的活性和定位进行实时体内成像。