Europium doping of superparamagnetic iron oxide nanoparticles enables their detection by fluorescence microscopy and for quantitative analytics.

Title Europium doping of superparamagnetic iron oxide nanoparticles enables their detection by fluorescence microscopy and for quantitative analytics.
Authors Y. Kobayashi; R. Hauptmann; H. Kratz; M. Ebert; S. Wagner; M. Taupitz
Journal Technol Health Care
DOI 10.3233/THC-161285
Abstract

BACKGROUND: Pharmacokinetic studies and histological detection of superparamagnetic iron oxide nanoparticles (SPIO) in biomedical research are limited due to a high iron background especially in pathological tissues.

OBJECTIVE: The suitability of doping the iron oxide cores of SPIO with europium (Eu) was tested for improved histologic detection and for quantitative analysis without changing their properties as probes for magnetic resonance imaging (MRI). A special variant of SPIO, so called very small superparamagnetic iron oxide nanoparticles (VSOP), was used for this approach.

METHODS: VSOP, stabilized by a citrate coating, were synthesized with and without addition of Eu (Eu-VSOP and VSOP, respectively). MR signal enhancing effects of Eu-VSOP and VSOP were studied in vitro. Cellular uptake of Eu-VSOP and VSOP was examined in RAW264.7 cells. For Eu-VSOP, fluorescence microscopy and spectrophotometry were used. Eu fluorescence was enhanced by means of an antenna system. For VSOP, Prussian blue staining and photometry using the phenanthroline method were applied. Results for both VSOP variants were compared.

RESULTS: Eu-VSOP and VSOP did not differ with respect to MR signal enhancing effects nor to uptake characteristics in the RAW264.7 cell experiments. Fluorescence microscopy detects Eu-VSOP with higher sensitivity compared to light microscopy using Prussian blue staining. In microscopy as well as in the analytical quantification using fluorescence, detection of Eu-VSOP is not contaminated by Fe background.

CONCLUSIONS: Doping the VSOP with Eu allows for their improved detection by fluorescence microscopy and quantitative analysis without changing their cellular uptake characteristics or their MR signal enhancing effects and thus would allow for a multimodal approach for studying their pharmacokinetics and biodistribution in experimental research.

Citation Y. Kobayashi; R. Hauptmann; H. Kratz; M. Ebert; S. Wagner; M. Taupitz.Europium doping of superparamagnetic iron oxide nanoparticles enables their detection by fluorescence microscopy and for quantitative analytics.. Technol Health Care. 2016. doi:10.3233/THC-161285

Related Elements

Europium

See more Europium products. Europium (atomic symbol: Eu, atomic number: 63) is a Block F, Group 3, Period 6 element with an atomic radius of 151.964. Europium Bohr ModelThe number of electrons in each of Europium's shells is 2, 8, 18, 25, 8, 2 and its electron configuration is [Xe]4f7 6s2. The europium atom has an atomic radius of 180 pm and a Van der Waals radius of 233 pm. Europium was discovered by Eugène-Anatole Demarçay in 1896, however, he did not isolate it until 1901. Europium was named after the continent of Europe.Elemental Europium Picture Europium is a member of the lanthanide or rare earth series of metals. In its elemental form, it has a silvery-white appearance but it is rarely found without oxide discoloration. Europium is found in many minerals including bastnasite, monazite, xenotime and loparite. It is not found in nature as a free element.

Iron

See more Iron products. Iron (atomic symbol: Fe, atomic number: 26) is a Block D, Group 8, Period 4 element with an atomic weight of 55.845. The number of electrons in each of Iron's shells is 2, 8, 14, 2 and its electron configuration is [Ar] 3d6 4s2. Iron Bohr ModelThe iron atom has a radius of 126 pm and a Van der Waals radius of 194 pm. Iron was discovered by humans before 5000 BC. In its elemental form, iron has a lustrous grayish metallic appearance. Iron is the fourth most common element in the Earth's crust and the most common element by mass forming the earth as a whole. Iron is rarely found as a free element, since it tends to oxidize easily; it is usually found in minerals such as magnetite, hematite, goethite, limonite, or siderite.Elemental Iron Though pure iron is typically soft, the addition of carbon creates the alloy known as steel, which is significantly stronger.

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