Long-Term Imaging of Cys in Cells and Tumor Mice by a Solid-State Fluorescence Probe.

Cysteine is an important biological thiol and is closely related to cancer. It remains a challenge to develop a probe that can provide long-term fluorescence detection and imaging of Cys in cells as well as in living organisms. Here, a solid-state fluorophore HTPQ is combined with an acrylate group to construct a solid-state fluorescent probe HTPQC for Cys recognition. The fluorescence of the probe is quenched when the photoinduced electron transfer (PET) process is turned on and the excited-state intramolecular proton transfer (ESIPT) process is turned off. In the presence of Cys, an obvious solid-state fluorescence signal can be observed. The double quenching mechanism makes the probe HTPQC have the advantages of high sensitivity, good selectivity, and high contrast of biological imaging. Due to low cytotoxicity, the probe HTPQC can be used to detect exogenous and endogenous Cys in living cells and is capable of imaging over long periods of time. By making full use of long wavelengths, the probe can be applied for the detection of Cys levels in tumor mice and equipped with the ability to conduct long-term imaging in vivo.

A HPQ-based far-red fluorescent probe for monitoring viscosity in mice model of acute inflammation.

Viscosity is an essential microenvironmental parameter, which is related to various diseases such as acute inflammation. So it is necessary to develop a probe to monitor viscosity changes during the inflammatory progression in vivo. Herein, a HPQ (2-(2'-hydroxyphenyl)-4(3H)-quinazolinone)-based fluorescent probe named HPQ-BI-V is prepared for detecting viscosity in biological systems. The introduction of benzindole groups extends the π conjugation of HPQ, resulting in far-red emission wavelength at 610 nm. When the viscosity raises from 3.11 cP to 567.1 cP, the fluorescence signal increases 711 times, indicating the high sensitivity of the probe. Furthermore, this probe displays excellent selectivity for viscosity in comparison with other interfering analytes. Furthermore, the probe has excellent photostability and outstanding response capability in the physiological pH range. Given these advantages, HPQ-BI-V can be applied for detecting viscosity changes in HepG2 cells and zebrafish. In particular, the probe can successfully visualize viscosity changes in acute inflammatory mice induced by LPS and the assessment of anti-inflammatory drug.

A novel precipitating-fluorochrome-based fluorescent probe for monitoring carbon monoxide during drug-induced liver injury.

Carbon monoxide (CO), as one of significant gas transmitter, is closely associated with a variety of physiological and pathological processes. Although plenty of fluorescent probes have been prepared for detecting CO, most of them suffer from water-soluble fluorophores and short emission wavelength, which tends to diffuse and is limited to apply in vivo. Herein, a novel water-soluble fluorescent probe (HPQ-MQ-CO) is prepared to detect CO by releasing a precipitating fluorochrome (HPQ-MQ-OH), which is developed by introducing the 1-ethyl-2-methylquinoline group into HPQ to obtain long emission wavelength and good diffusion resistant ability. Allyl formate, as the identification unit of CO, has good water solubility and quenches the fluorescence of HPQ-MQ-CO. When the probe reacts with CO and Pd2+, an long-emission and solid-state fluorescence signal at 650 nm can be observed, which is based on excited-state intramolecular proton transfer (ESIPT) mechanism. When the concentration of CO is raised to 100.0 µM, the fluorescence is increased 29 times, indicating the sensitivity of the probe. Moreover, this probe shows prominent selectivity for CO compared with other interfering species. Given these advantages, HPQ-MQ-CO can be used for CO detection in HepG2 cells and zebrafish by in-situ and long-term fluorescence imaging. In addition, this probe can monitor the up-regulation of CO in HepG2 cells and zebrafish during drug-induced liver injury (DILI).

[Effect of tirofiban in acute anterior myocardial infarction patients without ST segment resolution after primary percutaneous coronary intervention].

OBJECTIVE: To observe the effect of glycoprotein receptor blockade tirofiban in acute anterior myocardial infarction patients without ST segment resolution after primary percutaneous coronary intervention (PCI). METHODS: From April 2006 to April 2008, 157 acute anterior myocardial infarction patients without ST segment resolution after PCI were randomly allocated to tirofiban (intravenous bolus 10 microg/kg followed by intravenous infusion of 0.15 microgxkg(-1)xmin(-1) for 48 h, n = 80) or equal volume saline (control group, n = 77). Baseline characteristics, PCI features and clinical outcomes during hospitalization, left ventricular ejection fractions (LVEF) and major adverse cardiac events (MACE, including death, re-infarction and target vessel revascularization) at 30 and 180 days after discharge were compared between the two groups. RESULTS: The baseline clinical characteristics were comparable between the two groups. Compared to control group, the MACE rates and re-infarction rates at 30 days (6.3% vs.18.2%, P < 0.05; 1.3% vs.9.1%, P < 0.05, respectively) and 180 days (10.0% vs.23.4%, P < 0.05; 2.5% vs.10.4%, P < 0.05, respectively) were significantly reduced in tirofiban group. LVEF value was significantly higher in tirofiban group at 30 days and 180 days compared with those in control group [(51 +/- 6)% vs. (46 +/- 8)%, P < 0.05; (57 +/- 7)% vs. (50 +/- 9)%, P < 0.05]. Hemorrhagic complications were similar between the two groups. CONCLUSION: Use of tirofiban for acute anterior myocardial infarction patients without ST segment resolution after PCI is safe and can significantly improve 30 and 180 days clinical outcomes after discharge.