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

Near-infrared fluorescent probe for the imaging of viscosity in fatty liver mice and valuation of drug efficacy

Fatty liver disease affects at least 25 percent of the population worldwide and is a severe metabolic syndrome. Viscosity is closely related to fatty liver disease, so it is urgent to develop an effective tool for monitoring viscosity. Herein, a NIR fluorescent probe called MBC-V is developed for imaging viscosity, consisting of dimethylaniline and malonitrile-benzopyran. MBC-V is non-fluorescent in low viscosity solutions due to intramolecular rotation. In high viscosity solution, the intramolecular rotation of MBC-V is suppressed and the fluorescence is triggered. MBC-V has long emission wavelength at 720 nm and large Stokes shift about 160 nm. Moreover, MBC-V can detect changes in cell viscosity in fatty liver cells, and can image the therapeutic effects of drug in fatty liver cells. By taking advantage of NIR emission, MBC-V can be used as an imaging tool for fatty liver disease and a way to evaluate the therapeutic effect of drug for fatty liver disease.

A red-emitting mitochondria targetable fluorescent probe for detecting viscosity in HeLa, zebrafish, and mice

Viscosity, an essential parameter of the cellular microenvironment, has the ability to indicate the condition of living cells. It is closely linked to numerous diseases like Alzheimer's disease, diabetes, and cardiovascular disorders. Therefore, it is necessary to design tools to effectively monitor viscosity changes, which could provide promising avenues for therapeutic interventions in these diseases. Herein, we report a novel mitochondria-targeting fluorescent probe GX-VS which was suitable for the detection of viscosity changes in vivo and in vitro. The probe GX-VS had many advantages such as long emission wavelength (650 nm), large Stokes shift (105 nm), significant fluorescence enhancement (59-fold), high sensitivity, good biocompatibility and so on. Biological experiments showed that the probe could target mitochondria and detect viscosity alterations in HeLa cells. Moreover, it has been successfully utilized to monitor viscosity changes induced by lipopolysaccharides (LPS) in inflammatory zebrafishes and living mice, which further underscored the capacity of GX-VS to explore fluctuations in viscosity within living organisms.

Development of a novel near-infrared molecule rotator for early diagnosis and visualization of viscosity changes in acute liver injury models

Acute liver injury leading to acute liver failure can be a life-threatening condition. Therefore, timely and accurate early diagnosis of the onset of acute liver injury in vivo is critical. Viscosity is one of the key parameters that can accurately reflect the levels of relevant active analytes at the cellular level. Herein, a novel near-infrared molecule rotator, DJM, was designed and synthesized. This probe exhibited a highly sensitive (461-fold from PBS solution to 95% glycerol solution) and selective response to viscosity with a maximum emission wavelength of 760 nm and a Stokes shift of 240 nm. Furthermore, DJM has exhibited a remarkable capacity to discern viscosity changes induced by nystatin in viable cells with sensitivity and selectivity and further applied in the zebrafish and mouse model of acute liver injury. Additionally, DJM may potentially offer direction for the timely observation and visualization of viscosity in more relevant disease models in the future.

NIR Mitochondrial Fluorescent Probe for Visualizing SO2/Polarity in Drug Induced Inflammatory Mice

SO₂ and polarity are important microenvironmental parameters in cells, which are closely related to physiological activities in organisms. The intracellular levels of SO₂ and polarity are abnormal in inflammatory models. To this end, a novel near-infrared fluorescent probe BTHP that can simultaneously detect SO₂ and polarity was studied. BTHP can sensitively detect polarity change with emission peak change from 677 to 818 nm. BTHP can also detect SO₂ with fluorescence change from red to green. After addition of SO₂, the fluorescence emission intensity ratio I₅₁₇/I₇₆₈ of the probe increased by about 33.6 times. BTHP can determine bisulfite in single crystal rock sugar with high recovery rate (99.2%-101.7%). Fluorescence imaging of cells showed that BTHP could better target mitochondria and monitor exogenous SO₂ in A549 cells. More importantly, BTHP has been successfully used for dual channel monitoring SO₂ and polarity in drug-induced inflammatory cells and mice. In particular, the probe showed increased green fluorescence with the generation of SO₂ and increased red fluorescence with the decrease of polarity in inflammatory cells and mice.

Water-Dispersible Activatable Nanoprobe for Detecting Cadmium-Ion-Induced Oxidative Stress in Edible Crops via Near-Infrared Second-Window Fluorescence Imaging

Edible crops are important in terms of food security and sustainable agriculture. Heavy-metal-ion contamination of water/soil has deleterious impacts on the growth of edible crops. Among the heavy metals, cadmium (Cd) is toxic to plants, people, and animals, as it is widely used in industry; it has become the most important metal ion in the soil/water pollution. Once the toxic Cd ion enters edible crops via the water/soil in which the crops grow, it will induce oxidative stress (overproduction of reactive oxygen species with H₂O₂ being the most abundant) in the crops, and strong oxidative stress leads to the crops' growth depression or inhibition. Hence, it is of great significance to accurately monitor the oxidative stress induced by Cd ions in edible crops, as the monitoring results could be employed for the early warning of Cd-ion pollution in water/soil. Herein, we design an activatable nanoprobe that can detect Cd-ion-induced oxidative stress in edible crops via near-infrared second-window (NIR-II) fluorescence imaging. The molecular probe IXD-B contains the diphenylamine-modified xanthene group acting as the electron-donating unit, bis(methylenemalononitrile)indan as the electron-accepting unit, and the methenephenylboronic acid group as the recognition moiety for H₂O₂ and the fluorescence quencher. The probe molecules being encapsulated by the amphiphilic DSPE-PEG2000 render the water-dispersible nanoprobe (IXD-B@DSPE-PEG2000). When the nanoprobe enters the edible crops, it can be activated by the overexpressed H₂O₂ therein and consequently emit strong NIR-II fluorescence signals for visualizing and tracking the oxidative stress in edible crops induced by Cd ions.