| 1. |
- Snipstad, Sofie, et al.
(författare)
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Labeling nanoparticles : Dye leakage and altered cellular uptake
- 2017
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Ingår i: Cytometry Part A. - : John Wiley & Sons. - 1552-4922 .- 1552-4930. ; 91:8, s. 760-766
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Tidskriftsartikel (refereegranskat)abstract
- In vitro and in vivo behavior of nanoparticles (NPs) is often studied by tracing the NPs with fluorescent dyes. This requires stable incorporation of dyes within the NPs, as dye leakage may give a wrong interpretation of NP biodistribution, cellular uptake, and intracellular distribution. Furthermore, NP labeling with trace amounts of dye should not alter NP properties such as interactions with cells or tissues. To allow for versatile NP studies with a variety of fluorescence-based assays, labeling of NPs with different dyes is desirable. Hence, when new dyes are introduced, simple and fast screening methods to assess labeling stability and NP-cell interactions are needed. For this purpose, we have used a previously described generic flow cytometry assay; incubation of cells with NPs at 4 and 37C. Cell-NP interaction is confirmed by cellular fluorescence after 37C incubation, and NP-dye retention is confirmed when no cellular fluorescence is detected at 4C. Three different NP-platforms labeled with six different dyes were screened, and a great variability in dye retention was observed. Surprisingly, incorporation of trace amounts of certain dyes was found to reduce or even inhibit NP uptake. This work highlights the importance of thoroughly evaluating every dye-NP combination before pursuing NP-based applications. © 2016 International Society for Advancement of Cytometry.
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| 2. |
- Sulheim, Einar, et al.
(författare)
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Contrast Enhanced Magnetic Resonance Imaging of Amyloid-beta Plaques in a Murine Alzheimers Disease Model
- 2023
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Ingår i: Journal of Alzheimer's Disease. - : IOS PRESS. - 1387-2877 .- 1875-8908. ; 93:2, s. 411-419
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of amyloid-beta(A beta) aggregates is a critical step to improve the treatment of Alzheimers disease (AD) because neuronal damage by the A beta aggregates occurs before clinical symptoms are apparent. We have previously shown that luminescent conjugated oligothiophenes (LCOs), which are highly specific towards protein aggregates of A beta, can be used to fluorescently label amyloid plaque in living rodents. Objective: We hypothesize that the LCO can be used to target gadolinium to the amyloid plaque and hence make the plaque detectable by T-1-weighted magnetic resonance imaging (MRI). Methods: A novel LCO-gadolinium construct was synthesized to selectively bind to A beta plaques and give contrast in conventional T-1-weighted MR images after intravenous injection in Tg-APPSwe mice. Results: We found that mice with high plaque-burden could be identified using the LCO-Gd constructs by conventional MRI. Conclusion: Our study shows that MR imaging of amyloid plaques is challenging but feasible, and hence contrast-mediated MR imaging could be a valuable tool for early AD detection.
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