| 1. |
- Hu, Zhang-Jun, et al.
(författare)
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A TPA-caged precursor of (imino)coumarin for "turn-on" fluorogenic detection of Cu
- 2016
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Ingår i: Analytica Chimica Acta. - : ELSEVIER SCIENCE BV. - 0003-2670 .- 1873-4324. ; 933, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- We strategize to utilize the precursors of (imino) coumarin fluorophores to deliver novel reactive Cu+ probes, where tris[(2-pyridyl)-methyl] amine (TPA) works as a reactive receptor towards Cu+. To verify this strategy, CP1, a representative probe and relevant sensing behaviors towards Cu+ are presented here. CP1 features good solubility and fast response for monitoring labile copper in aqueous solution and live cells. The sensing mechanism of CP1 is determined by HPLC titration and mass spectrometric analysis. The probe CP1 exhibits a 60-fold fluorescence enhancement and a detection limitation of 10.8 nM upon the detection of Cu+. CP1 is further applied for imaging labile copper in live cells. This work provides a starting point for future development of Cu+ probes, based on in situ formation of (imino) coumarin scaffolds, as well as their further investigations of copper signaling and biological events. (C) 2016 Elsevier B.V. All rights reserved.
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| 2. |
- Eriksson, Peter, 1989-
(författare)
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Cerium Oxide Nanoparticles and Gadolinium Integration : Synthesis, Characterization and Biomedical Applications
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A challenging task, in the area of magnetic resonance imaging is to develop contrast enhancers with built-in antioxidant properties. Oxidative stress is considered to be involved in the onset and progression of several serious conditions such as Alzheimer’s and Parkinson’s disease, and the possibility to use cerium-contained nanoparticles to modulate such inflammatory response has gained a lot of interest lately. The rare earth element gadolinium is, due to its seven unpaired f-electrons and high symmetry of the electronic state, a powerful element for contrast enhancement in magnetic resonance imaging. Chelates based on gadolinium are the most commonly used contrast agents worldwide. When introducing external contrast agents there is always a risk that it may trigger inflammatory responses, why there is an urgent need for new, tailor-made contrast agents.Small sized cerium oxide nanoparticles have electronic structures that allows coexistence of oxidation states 3+ and 4+ of cerium, which correlates to applicable redox reactions in biomedicine. Such cerium oxide nanoparticles have recently shown to exhibit antioxidant properties both in vitro and in vivo, via the mechanisms involving enzyme mimicking activity.This PhD project is a comprehensive investigation of cerium oxide nanoparticles as scaffold materials for gadolinium integration. Gadolinium is well adopted into the crystal structure of cerium oxide, enabling the combination of diagnostic and therapeutic properties into a single nanoparticle. The main focus of this thesis project is to design cerium oxide nanoparticles with gadolinium integration. A stepwise approach was employed as follows: 1) synthesis with controlled integration of gadolinium, 2) material characterization by means of composition crystal structure, size, and size distribution and 3) surface modification for stabilization. The obtained nanoparticles exhibit remarkable antioxidant capability in vitro and in vivo. They deliver strongly enhanced contrast per gadolinium in magnetic resonance imaging, compared to commercially available contrast agents.A soft shell of dextran is introduced to encapsulate the cerium oxide nanoparticles with integrated gadolinium, which protects and stabilizes the hard core and to increases their biocompatibility. The dextran-coating is clearly shown to reduce formation of a protein corona and it improves the dispersibility of the nanoparticles in cell media. Functionalization strategies are currently being studied to endow these nanoparticles with specific tags for targeting purposes. This will enable guidance of the nanoparticles to a specific tissue, for high local magnetic resonance contrast complemented with properties for on-site reduced inflammation.In conclusion, our cerium oxide nanoparticles with integrated gadolinium, exhibit combined therapeutic and diagnostic, i.e. theragnostic capabilities. This type of nanomaterial is highly promising for applications in the field of biomedical imaging.
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| 3. |
- Eriksson, Peter, et al.
(författare)
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Cerium oxide nanoparticles with antioxidant capabilities and gadolinium integration for MRI contrast enhancement
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The chelating gadolinium-complex is routinely used as magnetic resonance imaging (MRI) -contrast enhancer. However, several safety issues have recently been reported by FDA and PRAC. There is an urgent need for the next generation of safer MRI-contrast enhancers, with improved local contrast and targeting capabilities. Cerium oxide nanoparticles (CeNPs) are designed with fractions of up to 50% gadolinium to utilize the superior MRI-contrast properties of gadolinium. CeNPs are well-tolerated in vivo and have redox properties making them suitable for biomedical applications, for example scavenging purposes on the tissue-and cellular level and during tumor treatment to reduce in vivo inflammatory processes. Our near edge X-ray absorption fine structure (NEXAFS) studies show that implementation of gadolinium changes the initial co-existence of oxidation states Ce3+ and Ce4+ of cerium, thereby affecting the scavenging properties of the nanoparticles. Based on ab initio electronic structure calculations, we describe the most prominent spectral features for the respective oxidation states. The as-prepared gadolinium-implemented CeNPs are 3-5 nm in size, have r(1)-relaxivities between 7-13 mM(-1) s(-1) and show clear antioxidative properties, all of which means they are promising theranostic agents for use in future biomedical applications.
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| 4. |
- Wang, Guannan, et al.
(författare)
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Magneto-fluorescent nanoparticles with high-intensity NIR emission, T-1-and T-2-weighted MR for multimodal specific tumor imaging
- 2015
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Ingår i: Journal of materials chemistry. B. - : Royal Society of Chemistry. - 2050-750X .- 2050-7518. ; 3:15, s. 3072-3080
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticles exhibiting bright near-infrared (NIR) fluorescence, T-1-and T-2-weighted MR were synthesized for specific tumor imaging. Clinically used Fe3O4 nanoparticles exhibit an intrinsic dark signal (T-2-weighted MRI), which sometimes misleads clinical diagnosis. Here, for the first time we integrated ultrasmall Fe3O4 nanoparticles (2-3 nm) with an NIR emitting semiconducting polymer for both T-1-and T-2-weighted MRI as well as fluorescence imaging of tumors. Bio-functionalized multi-modality fluorescent magnetic nanoparticles (FMNPs) functionalized with folic acid exhibit bright fluorescence and high relaxation (r(1) = 7.008 mM(-1) s(-1), r(2) = 26.788 mM(-1) s(-1), r(2)/r(1) = 3.8). These FMNPs have a small average dynamic size of about 20 nm with low aggregation and long circulation time. In vitro studies revealed that FMNPs can serve as an effective fluorescent probe to achieve targeting images of human A549 lung cancer cells without obvious cytotoxicity. In vivo experimental results show that the FMNPs are able to preferentially accumulate in tumor tissues for specific fluorescence imaging, T-1-and T-2-weighted MRI.
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| 5. |
- Zhang, Xuanjun, 1976-, et al.
(författare)
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Coordination polymers for energy transfer: Preparations, properties, sensing applications, and perspectives
- 2015
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Ingår i: Coordination chemistry reviews. - : Elsevier. - 0010-8545 .- 1873-3840. ; 284, s. 206-235
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Forskningsöversikt (refereegranskat)abstract
- This review highlights the recent progress of bulk and nanoscale coordination polymer (CP) materials forenergy transfer. Artificial light-harvesting materials with efficient energy transfer are practically usefulfor a variety of applications including photovoltaic, white emitting devices, and sensors. In the pastdecades CP (aka Metal-organic framework, MOF) has experienced rapid development due to a multitude of applications, including catalyst, gas storage and separations, non-linear optics, luminescence, and soon. Recent research has shown that CP is a very promising light-harvesting platform because the energytransfers can occur between different ligands, from ligand to metal centers, or from MOF skeleton to guestspecies. This review comprehensively surveyed synthetic approaches to light-harvesting CPs, and postfunctionalization. Sensing applications and achievements in energy-transfer CP nanoparticles and thinfilms were also discussed.
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