南京大学叶德举团队报道了能量转移过程中基质金属蛋白酶-2活性的比率余辉成像。相关研究成果发表在2024年4月19日出版的《德国应用化学》。

比率余辉发光（AGL）探针由于其高灵敏度和信号自校准功能而对体内成像具有吸引力。然而，目前很少有比率AGL探针可用于活生物体中的酶活性成像。

该文中，研究人员提出了一种能量转移（ED）策略，该策略能够设计用于体内余辉成像的酶激活比率AGL探针（RAG-RGD）。ED过程为RAG-RGD提供了“常开”520 nm AGL信号（AGL520）的辐射跃迁，并为响应特定酶的“关断”710 nm AGL（AGL710）提供了级联三步能量转移（ET）过程。

以基质金属蛋白酶-2（MMP-2）为例，RAG-RGD显示AGL710/AGL520向MMP-2显著增加约11倍。这可以通过MMP-2活性的比率余辉成像灵敏地检测U87MG脑肿瘤，具有高的信底比和深度成像。此外，通过利用比率成像的自校准效应，RAG-RGD显示了AGL710/AGL520值与原位U87MG肿瘤大小之间的强负相关，从而能够在体内准确监测原位神经胶质瘤的生长。

该ED工艺可用于设计用于灵敏余辉成像的其他酶激活比率余辉探针。

附：英文原文

Title: Ratiometric Afterglow Luminescent Imaging of Matrix Metalloproteinase-2 Activity via an Energy Diversion Process

Author: Weijing Huang, Wenhui Zeng, Zheng Huang, Daqing Fang, Hong Liu, Min Feng, Liang Mao, Deju Ye

Issue&Volume: 2024-04-19

Abstract: Ratiometric afterglow luminescent (AGL) probes are attractive for in vivo imaging due to their high sensitivity and signal self-calibration function. However, there are currently few ratiometric AGL probes available for imaging enzymatic activity in living organisms. Here, we present an energy diversion (ED) strategy that enables the design of an enzyme-activated ratiometric AGL probe (RAG-RGD) for in vivo afterglow imaging. The ED process provides RAG-RGD with a radiative transition for an ‘always on’ 520-nm AGL signal (AGL520) and a cascade three-step energy transfer (ET) process for an ‘off-on’ 710-nm AGL signal (AGL710) in response to a specific enzyme. Using matrix metalloproteinase-2 (MMP-2) as an example, RAG-RGD shows a significant ~11-fold increase in AGL710/AGL520 toward MMP-2. This can sensitively detect U87MG brain tumors through ratiometric afterglow imaging of MMP-2 activity, with a high signal-to-background ratio and deep imaging depth. Furthermore, by utilizing the self-calibration effect of ratiometric imaging, RAG-RGD demonstrated a strong negative correlation between the AGL710/AGL520 value and the size of orthotopic U87MG tumor, enabling accurate monitoring of orthotopic glioma growth in vivo. This ED process may be applied for the design of other enzyme-activated ratiometric afterglow probes for sensitive afterglow imaging.

DOI: 10.1002/anie.202404244

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202404244