AbstractPhotoacoustic (PA) imaging is emerging as one of the important non‐invasive imaging techniques in biomedical research. Small molecule‐ second near‐infrared window (NIR‐II) PA dyes combined with imaging data can provide comprehensive and in‐depth in vivo physiological and pathological information. However, the NIR‐II PA dyes usually exhibit “always‐on” properties due to the lack of a readily optically tunable group, which hinders the further applications in vivo. Herein, a novel class of dyes GX have been designed and synthesized as an activatable NIR‐II PA platform, in which the absorption/emission wavelength of GX‐5 extends up to 1082/1360 nm. Importantly, the GX dyes have a strong tissue penetration depth and high‐resolution for the mouse vasculature structures in NIR‐II PA 3D imaging and high signal‐to‐noise ratio in NIR‐II fluorescence (FL) imaging. Furthermore, to demonstrate the applicability of GX dyes, the first NIR‐II PA probe GX‐5‐CO activated by carbon monoxide (CO) was engineered and employed to reveal the enhancement of the CO levels in the hypertensive mice by high‐contrast NIR‐II PA and FL imaging. We expect that many derivatives of GX dyes will be developed to afford versatile NIR‐II PA platforms for designing a wide variety activatable NIR‐II PA probes as biomedical tools.
摘要光声(PA)成像正在成为生物医学研究中重要的无创成像技术之一。小分子-第二近红外窗口(NIR-II)PA 染料与成像数据相结合,可提供全面而深入的体内生理和病理信息。然而,由于缺乏易于光学调谐的基团,NIR-II PA 染料通常表现出 "始终开启 "的特性,这阻碍了其在体内的进一步应用。在此,我们设计并合成了一类新型染料 GX,作为可激活的近红外-II PA 平台,其中 GX-5 的吸收/发射波长可达 1082/1360 nm。重要的是,GX 染料具有很强的组织穿透深度,在近红外-II PA 三维成像中对小鼠血管结构具有高分辨率,在近红外-II 荧光(FL)成像中具有高信噪比。此外,为了证明 GX 染料的适用性,我们设计并使用了第一个由一氧化碳(CO)激活的近红外-II PA 探针 GX-5-CO,通过高对比度近红外-II PA 和荧光成像揭示了高血压小鼠体内 CO 水平的增强。我们期望开发出许多 GX 染料的衍生物,以提供多功能近红外-II PA 平台,从而设计出多种可激活的近红外-II PA 探针作为生物医学工具。