posted on 2024-01-31, 12:05authored byYaling Wang, Yong Zhang, Mingrui Li, Xueyun Gao, Dongdong Su
Activatable
near-infrared (NIR) fluorescent probes possess advantages
of high selectivity, sensitivity, and deep imaging depth, holding
great potential in the early diagnosis and prognosis assessment of
tumors. However, small-molecule fluorescent probes are largely limited
due to the rapid diffusion and metabolic clearance of activated fluorophores in vivo. Herein, we propose an efficient and reproducible
novel strategy to construct activatable fluorescent nanoprobes through
bioorthogonal reactions and the strong gold–sulfur (Au–S)
interactions to achieve an enhanced permeability and retention (EPR)
effect, thereby achieving prolonged and high-contrast tumor imaging in vivo. To demonstrate the merits of this strategy, we
prepared an activatable nanoprobe, hCy-ALP@AuNP, for
imaging alkaline phosphatase (ALP) activity in vivo, whose nanoscale properties facilitate accumulation and long-term
retention in tumor lesions. Tumor-overexpressed ALP significantly
increased the fluorescence signal of hCy-ALP@AuNP in
the NIR region. More importantly, compared with the small-molecule
probe hCy-ALP-N3, the nanoprobe hCy-ALP@AuNP significantly improved the distribution and retention
time in the tumor, thus improving the imaging window and accuracy.
Therefore, this nanoprobe platform has great potential in the efficient
construction of biomarker-responsive fluorescent nanoprobes to realize
precise tumor diagnosis in vivo.