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.

Imaging of a novel ratio γ-glutamyl transpeptidase fluorescent probe in living cells and biopsies.

Herein, a novel fluorescent probe, GTP, was developed for monitoring the GGT (γ-glutamyl transpeptidase) level in living cells and biopsies. It consisted of the typical recognition group γ-Glu (γ-Glutamylcysteine) and the fluorophore (E)-4-(4-aminostyryl)-1-methylpyridin-1-ium iodide. With a ratio response between the signal intensity at 560 nm and 500 nm (RI560/I500), it could be important complement for the turn-on ones. With the linear range of 0-50 U/L, the limit of detection was calculated as 0.23 µM. The detection system showed the strongest response near pH 7.4, and exhibited steady fluorescence signals for at least 48 h. With high selectivity, good anti-interference and low cytotoxicity, GTP was suitable for physiological applications. By monitoring the GGT level with the ratio values in the green and blue channels, the probe GTP could distinguish cancer cells from normal cells. Furthermore, in the mouse tissues and humanization tissue samples, the probe GTP could also recognize the tumor tissues from the normal ones.

Mitochondrial targeted fluorescent nitrite peroxide probe for dynamic monitoring of cellular lung injury.

Herein, a mitochondrial targeted fluorescent nitrite peroxide probe CHP for dynamic monitoring of cellular lung injury was developed. For the practical delivery and selectivity, the structural features including pyridine head and borate recognition group were selected. CHP could respond to ONOO- with the 585 nm fluorescence signal. The detecting system indicated advantages such as wide linear range (0.0-30 µM), high sensitivity (LOD = 0.18 µM), high selectivity and steadiness under different environmental conditions including pH (3.0-10.0), time (48 h) and medium. In living A549 cells, the response of CHP towards ONOO- showed dose-dependent and time-dependent tendencies. The co-localization suggested that CHP could achieve mitochondrial targeting. Moreover, CHP could monitor the variation of endogenous ONOO- level and the cellular lung injury induced by LPS.