A novel near-infrared fluorescent probe for real-time monitoring of leucine aminopeptidase activity and metastatic tumor progression

This article discusses the importance of early tumor detection, particularly in liver cancer, and the role of leucine aminopeptidase (LAP) as a potential marker for liver cancer diagnosis and prognosis assessment. The article highlights the limitations of current tumor markers and the need for new markers and multi-marker approaches to improve accuracy. The authors introduce a novel near-infrared fluorescent probe, NTAP, designed for LAP detection. They describe the synthesis of the probe and evaluate its spectral properties, including the LOD was 0.0038 U/mL, and QY was 0.32 %. The kinetic properties of NTAP, such as the relationship between LAP concentration (0-0.08 U/mL), reaction time (3 min), and fluorescence excitation spectra (475 nm) and emission spectra (715 nm) are investigated. The article also discusses the stability and selectivity of the probe and its ability to detect LAP in complex samples. Cellular imaging experiments demonstrate the NATP specificity and selectivity in detecting LAP activity and its inhibition. Animal models of liver and lung metastasis are used to evaluate the probe's imaging capabilities, showing its ability to accurately locate and detect metastatic lesions. The article concludes by emphasizing the potential applications of the NTAP probe in early tumor diagnosis, treatment monitoring, and the study of tumor metastasis mechanisms.