| 1. |
- Aref, Mohaddeseh, et al.
(författare)
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Potentiometric pH Nanosensor for Intracellular Measurements: Real-Time and Continuous Assessment of Local Gradients
- 2021
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 93:47, s. 15744-15751
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Tidskriftsartikel (refereegranskat)abstract
- We present a pH nanosensor conceived for single intracellular measurements. The sensing architecture consisted of a two-electrode system evaluated in the potentiometric mode. We used solid-contact carbon nanopipette electrodes tailored to produce both the indicator (pH nanosensor) and reference electrodes. The indicator electrode was a membrane-based ion-selective electrode containing a receptor for hydrogen ions that provided a favorable selectivity for intracellular measurements. The analytical features of the pH nanosensor revealed a Nernstian response (slope of -59.5 mV/pH unit) with appropriate repeatability and reproducibility (variation coefficients of <2% for the calibration parameters), a fast response time (<5 s), adequate medium-term drift (0.7 mV h(-)(1)), and a linear range of response including physiological and abnormal cell pH levels (6.0-8.5). In addition, the position and configuration of the reference electrode were investigated in cell-based experiments to provide unbiased pH measurements, in which both the indicator and reference electrodes were located inside the same cell, each of them inside two neighboring cells, or the indicator electrode inside the cell and the reference electrode outside of (but nearby) the studied cell. Finally, the pH nanosensor was applied to two cases: (i) the tracing of the pH gradient from extra-to intracellular media over insertion into a single PC12 cell and (ii) the monitoring of variations in intracellular pH in response to exogenous administration of pharmaceuticals. It is anticipated that the developed pH nanosensor, which is a label-free analytical tool, has high potential to aid in the investigation of pathological states that manifest in cell pH misregulation, with no restriction in the type of targeted cells.
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| 2. |
- Philipsen, Mai H., 1988, et al.
(författare)
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Mass Spectrometry Imaging Shows Modafinil, A Student Study Drug, Changes the Lipid Composition of the Fly Brain
- 2021
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Ingår i: Angewandte Chemie-International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 60:32, s. 17378-17382
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Tidskriftsartikel (refereegranskat)abstract
- Modafinil, a widely used psychoactive drug, has been shown to exert a positive impact on cognition and is used to treat sleep disorders and hyperactivity. Using time-of-flight secondary ion mass spectrometric imaging, we studied the changes of brain lipids of Drosophila melanogaster induced by modafinil to gain insight into the functional mechanism of modafinil in the brain. We found that upon modafinil treatment, the abundance of phosphatidylcholine and sphingomyelin species in the central brain of Drosophila is significantly decreased, whereas the levels of phosphatidylethanolamine and phosphatidylinositol in the brains show significant enhancement compared to the control flies. The alteration of brain lipids caused by modafinil is consistent with previous studies about cognition-related drugs and offers a plausible mechanism regarding the action of modafinil in the brain as well as a potential target for the treatment of certain disorders.
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| 3. |
- Ranjbari, Elias, et al.
(författare)
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Combined electrochemistry and mass spectrometry imaging to interrogate the mechanism of action of modafinil, a cognition-enhancing drug, at the cellular and sub-cellular level
- 2021
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Ingår i: QRB Discovery. - : Cambridge University Press (CUP). - 2633-2892. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- (A) Microscope view during the intracellular vesicle impact electrochemical cytometry experiment (scale bar = 20 μm). (B) Normalised frequency histogram for the number of molecules stored in vesicles in control (blue) and modafinil-Treated cells (red). The distribution fits are shown for control cells with a dashed line and modafinil-Treated cells with a solid line. (C) Average of the number of molecules stored per vesicle in PC12 cells treated without (control) or with 10 μM modafinil. Number of analysed cells: control cells (15 cells) and modafinil-Treated cells (18 cells). The results were compared by a two-Tailed Mann-Whitney rank-sum test,*p < 0.05, p < 0.01 and***p < 0.001. ©
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