A near-infrared fluorescent probe that can image endogenous hydrogen polysulfides in vivo in tumour-bearing mice.

Hydrogen polysulfides (H2Sn, n > 1), which are important reactive sulfur species, play crucial roles in H2S-related bioactivities, including antioxidation, cytoprotection, activation of ion channels, transcription factor functions and tumour suppression. Monitoring H2Snin vivo is of significant interest for exploring the physiological roles of H2Sn and the exact mechanisms of H2Sn-related diseases. Herein, we conceive a novel near-infrared fluorescent probe, NIR-CPS, that is used to detect H2Sn in living cells and in vivo. With the advantages of high sensitivity, good selectivity and a remarkably large Stokes shift (100 nm), NIR-CPS was successfully applied in visualizing H2Sn in living cells and mice. More importantly, NIR-CPS monitored H2Sn stimulated by lipopolysaccharide in tumour-bearing mice. These results demonstrate that the NIR-CPS probe is a potentially powerful tool for the detection of H2Snin vivo, thus providing a valuable approach in H2Sn-related medical research.

A reaction-based near-infrared fluorescent probe that can visualize endogenous selenocysteine in vivo in tumor-bearing mice.

Monitoring the fluctuations of endogenous selenocysteine (Sec) in vivo is of significant interest to understand the physiological roles of Sec and the mechanisms of Sec-relevant diseases. Herein, a new near-infrared fluorescent probe, Fsec-1, has been developed for the determination of endogenous Sec in living cells and in vivo. Fsec-1 exhibits large fluorescence enhancement (136-fold) and a remarkably large Stokes shift (195 nm) when reacted with Sec. With the advantages of high sensitivity (a detection limit of 10 nM), good selectivity and low cytotoxicity, Fsec-1 was able to recognize both exogenous and endogenous Sec in living cells. The probe was also successfully applied in visualizing both exogenous and endogenous Sec in living mice. Notably, endogenously generated Sec in living tumors xenografted in nude mice was selectively detected by our reaction-based NIR probe for the first time. These results indicated that our new probe could serve as an efficient tool in monitoring endogenous Sec in vivo and exploring the anticancer mechanism of selenium.

Bioluminescence Imaging of Selenocysteine in Vivo with a Highly Sensitive Probe.

Selenocysteine (Sec), a vital member of reactive selenium species, is closely implicated in diverse pathophysiological states, including cancer, cardiovascular diseases, diabetes, neurodegenerative diseases, and male infertility. Monitoring Sec in vivo is of significant interest for understanding the physiological roles of Sec and the mechanisms of human diseases associated with abnormal levels of Sec. However, no bioluminescence probe for real-time monitoring of Sec in vivo has been reported. Herein, we present a novel bioluminescent probe BF-1 as an effective tool for the determination of Sec in living cells and in vivo for the first time. BF-1 has advantages of high sensitivity (a detection limit of 8 nM), remarkable bioluminescence enhancement (580-fold), reasonable selectivity, low cytotoxicity, and high signal-to-noise ratio imaging feasibility of Sec in living cells and mice. More importantly, BF-1 affords high sensitivity for monitoring Sec stimulated by Na2SeO3 in tumor-bearing mice. These results demonstrate that our new probe could serve as a powerful tool to selectively monitor Sec in vivo, thus providing a valuable approach for exploring the physiological and pathological functions and anticancer mechanisms of selenium.