Red-emitting pyrene-benzothiazolium: unexpected selectivity to lysosomes for real-time cell imaging without alkalinizing effect.
Ontology highlight
ABSTRACT:
SUBMITTER: Abeywickrama CS
PROVIDER: S-EPMC6446231 | biostudies-literature | 2019 Mar
REPOSITORIES: biostudies-literature
Publications
Red-emitting pyrene-benzothiazolium: unexpected selectivity to lysosomes for real-time cell imaging without alkalinizing effect.
Abeywickrama Chathura S CS Wijesinghe Kaveesha J KJ Stahelin Robert V RV Pang Yi Y
Chemical communications (Cambridge, England) 20190301 24
A series of pyrene-benzothiazolium probes were synthesized. By replacing the pyridinium with a benzothiazolium unit, the selectivity of pyrene-derivatives is found to switch from nuclear to cellular lysosomes. New probes do not require proton participation and exhibit high biocompatibility and long-term imaging ability. ...[more]
Similar Datasets
Project description:Hyperpolarized substrates prepared via dissolution dynamic nuclear polarization have been proposed as magnetic resonance imaging (MRI) agents for cancer or cardiac failure diagnosis and therapy monitoring through the detection of metabolic impairments in vivo. The use of potentially toxic persistent radicals to hyperpolarize substrates was hitherto required. We demonstrate that by shining UV light for an hour on a frozen pure endogenous substance, namely the glucose metabolic product pyruvic acid, it is possible to generate a concentration of photo-induced radicals that is large enough to highly enhance the (13)C polarization of the substance via dynamic nuclear polarization. These radicals recombine upon dissolution and a solution composed of purely endogenous products is obtained for performing in vivo metabolic hyperpolarized (13)C MRI with high spatial resolution. Our method opens the way to safe and straightforward preclinical and clinical applications of hyperpolarized MRI because the filtering procedure mandatory for clinical applications and the associated pharmacological tests necessary to prevent contamination are eliminated, concurrently allowing a decrease in the delay between preparation and injection of the imaging agents for improved in vivo sensitivity.
| S-EPMC3831441 | biostudies-literature
Project description:We synthesized new pyrene derivatives with strong bis(para-methoxyphenyl)amine donors at the 2,7-positions and n-azaacene acceptors at the K-region of pyrene. The compounds possess a strong intramolecular charge transfer, leading to unusual properties such as emission in the red to NIR region (700?nm), which has not been reported before for monomeric pyrenes. Detailed photophysical studies reveal very long intrinsic lifetimes of >100?ns for the new compounds, which is typical for 2,7-substituted pyrenes but not for K-region substituted pyrenes. The incorporation of strong donors and acceptors leads to very low reduction and oxidation potentials, and spectroelectrochemical studies show that the compounds are on the borderline between localized Robin-Day class-II and delocalized Robin-Day class-III species.
| S-EPMC6973242 | biostudies-literature
Project description:New complexes of Zn(ii), Pd(ii) and Pt(ii) with Schiff bases are prepared in a one-step condensation of 4-(dibutylamino)-2-hydroxybenzaldehyde and 4,5-diaminophthalonitrile in the presence of a metal salt. The complexes possess efficient absorption in the blue-green part of the spectrum with molar absorption coefficients up to 98?000 M-1 cm-1. The Pt(ii) complex shows very strong red phosphorescence in anoxic solutions at room temperature with a quantum yield of 65% in toluene which places it among the brightest emitters available for this spectral range. The phosphorescence of the Pd(ii) complex under the same conditions is very weak (? < 1%) but is enhanced to ? > 10% upon immobilization into polymers. Optical thermometers based on self-referenced lifetime read-out are prepared upon immobilization of the dyes into gas-blocking poly(vinylidene chloride-co-acrylonitrile). At 25 °C, the materials based on Pd(ii) and Pt(ii) complexes show sensitivities of -2.1 and -0.52%?/K, respectively. Application of the sensors for imaging of temperature on surfaces (planar optode) and for monitoring of fast temperature fluctuations (fiber-optic microsensor) is demonstrated. Immobilized into a gas-permeable matrix, the Pt(ii) complex also performs as a promising oxygen-sensing material. The new systems are also attractive for imaging of oxygen or temperature with the help of multi-photon microscopy, due to a good match with the biological optical window and much better brightness under two photon excitation compared to that of the conventional Pt(ii) meso-tetra-(pentafluorophenyl)porphyrin.
| S-EPMC6333324 | biostudies-literature
Project description:Most fluorescent indicators for Mg2+ suffer from poor selectivity against other divalent cations, especially Ca2+, thus do not provide reliable information on cellular Mg2+ concentrations in processes in which such metals are involved. We report a new set of highly selective fluorescent indicators based on alkoxystyryl-functionalized BODIPY fluorophores decorated with a 4-oxo-4H-quinolizine-3-carboxylic acid metal binding moiety. The new sensors, MagQ1 and MagQ2, display absorption and emission maxima above 600 nm, with a 29-fold fluorescence enhancement and good quantum yields (? > 0.3) upon coordination of Mg2+ in aqueous buffer. Fluorescence response to Mg2+ is not affected by the presence of competing divalent cations typically present in the cellular milieu, and displays minimal pH dependence in the physiologically relevant range. The choice of alkoxy groups decorating the styryl BODIPY core does not influence the basic photophysical and metal binding properties of the compounds, but has a marked effect on their intracellular retention and thus in their applicability for detection of cellular Mg2+ by fluorescence imaging. In particular, we demonstrate the utility of a triethyleneglycol (TEG) functionalization tactic that endows MagQ2 with superior cellular retention in live cells by reducing active extrusion through organic anion transporters, which are thought to cause fast leakage of typical anionic dyes. With enhanced retention and excellent photophysical properties, MagQ2 can be applied in the detection of cellular Mg2+ influx without interference of high concentrations of Ca2+ akin to those involved in signaling.
| S-EPMC6366848 | biostudies-literature
Project description:Phagocytosis by glial cells is essential to regulate brain function during health and disease. Therapies for Alzheimer's disease (AD) have primarily focused on targeting antibodies to amyloid β (Aβ) or inhibitng enzymes that make it, and while removal of Aβ by phagocytosis is protective early in AD it remains poorly understood. Impaired phagocytic function of glial cells during later stages of AD likely contributes to worsened disease outcome, but the underlying mechanisms of how this occurs remain unknown. We have developed a human Aβ1-42 analogue (AβpH) that exhibits green fluorescence upon internalization into the acidic organelles of cells but is non-fluorescent at physiological pH. This allowed us to image, for the first time, glial uptake of AβpH in real time in live animals. We find that microglia phagocytose more AβpH than astrocytes in culture, in brain slices and in vivo. AβpH can be used to investigate the phagocytic mechanisms responsible for removing Aβ from the extracellular space, and thus could become a useful tool to study Aβ clearance at different stages of AD.
| S-EPMC8372545 | biostudies-literature
Project description:Thermally activated delayed fluorescence (TADF) materials have provided new strategies for time-resolved luminescence imaging (TRLI); however, the development of hydrophilic TADF luminophores for specific imaging in cells remains a substantial challenge. In this study, a mitochondria-induced aggregation strategy for TRLI is proposed with the design and utilization of the hydrophilic TADF luminophore ((10-(1,3-dioxo-2-phenyl-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)-9,9-dimethyl-9,10-dihydroacridin-2-yl)methyl)triphenylphosphonium bromide (NID-TPP). Using a nonconjugated linker to introduce a triphenylphosphonium (TPP+) group into the 6-(9,9-dimethylacridin-10(9H)-yl)-2-phenyl-1H-benzo[de]isoquinoline-1,3(2H)-dione (NID) TADF luminophore preserves the TADF emission of NID-TPP. NID-TPP shows clear aggregation-induced delayed fluorescence enhancement behavior, which provides a practical strategy for long-lived delayed fluorescence emission in an oxygen-containing environment. Finally, the designed mitochondrion-targeting TPP+ group in NID-TPP induces the adequate accumulation of NID-TPP and results in the first reported TADF-based time-resolved luminescence imaging and two-photon imaging of mitochondria in living cells.
| S-EPMC6402405 | biostudies-literature
Project description:BackgroundRice is a major source of dietary intake of cadmium (Cd) for populations that consume rice as a staple food. Understanding how Cd is transported into grains through the whole plant body is necessary for reducing rice Cd concentrations to the lowest levels possible, to reduce the associated health risks. In this study, we have visualized and quantitatively analysed the real-time Cd dynamics from roots to grains in typical rice cultivars that differed in grain Cd concentrations. We used positron-emitting 107Cd tracer and an innovative imaging technique, the positron-emitting tracer imaging system (PETIS). In particular, a new method for direct and real-time visualization of the Cd uptake by the roots in the culture was first realized in this work.ResultsImaging and quantitative analyses revealed the different patterns in time-varying curves of Cd amounts in the roots of rice cultivars tested. Three low-Cd accumulating cultivars (japonica type) showed rapid saturation curves, whereas three high-Cd accumulating cultivars (indica type) were characterized by curves with a peak within 30 min after 107Cd supplementation, and a subsequent steep decrease resulting in maintenance of lower Cd concentrations in their roots. This difference in Cd dynamics may be attributable to OsHMA3 transporter protein, which was recently shown to be involved in Cd storage in root vacuoles and not functional in the high-Cd accumulating cultivars. Moreover, the PETIS analyses revealed that the high-Cd accumulating cultivars were characterized by rapid and abundant Cd transfer to the shoots from the roots, a faster transport velocity of Cd to the panicles, and Cd accumulation at high levels in their panicles, passing through the nodal portions of the stems where the highest Cd intensities were observed.ConclusionsThis is the first successful visualization and quantification of the differences in whole-body Cd transport from the roots to the grains of intact plants within rice cultivars that differ in grain Cd concentrations, by using PETIS, a real-time imaging method.
| S-EPMC3247196 | biostudies-literature
Project description:Hyperspectral imaging has tremendous potential to detect important molecular biomarkers of early cancer based on their unique spectral signatures. Several drawbacks have limited its use for in vivo screening applications: most notably the poor temporal and spatial resolution, high expense, and low optical throughput of existing hyperspectral imagers. We present the development of a new real-time hyperspectral endoscope (called the image mapping spectroscopy endoscope) based on an image mapping technique capable of addressing these challenges. The parallel high throughput nature of this technique enables the device to operate at frame rates of 5.2 frames per second while collecting a (x, y, λ) datacube of 350 × 350 × 48. We have successfully imaged tissue in vivo, resolving a vasculature pattern of the lower lip while simultaneously detecting oxy-hemoglobin.
| S-EPMC3107836 | biostudies-other
Project description:Glutathione plays many important roles in biological processes; however, the dynamic changes of glutathione concentrations in living cells remain largely unknown. Here, we report a reversible reaction-based fluorescent probe-designated as RealThiol (RT)-that can quantitatively monitor the real-time glutathione dynamics in living cells. Using RT, we observe enhanced antioxidant capability of activated neurons and dynamic glutathione changes during ferroptosis. RT is thus a versatile tool that can be used for both confocal microscopy and flow cytometry based high-throughput quantification of glutathione levels in single cells. We envision that this new glutathione probe will enable opportunities to study glutathione dynamics and transportation and expand our understanding of the physiological and pathological roles of glutathione in living cells.
| S-EPMC5511354 | biostudies-literature
Project description:Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science.
| S-EPMC3665961 | biostudies-literature