TY - JOUR A1 - Cruz-Alonso, M. A1 - Fernandez, B. A1 - Alvarez, L. A1 - Gonzalez-Iglesias, H. A1 - Traub, Heike A1 - Jakubowski, Norbert A1 - Pereiro, R. T1 - Bioimaging of metallothioneins in ocular tissue sections by laser ablation-ICP-MS using bioconjugated gold nanoclusters as specific tags N2 - An immunohistochemical method is described to visualize the distribution of metallothioneins 1/2 (MT 1/2) and metallothionein 3 (MT 3) in human ocular tissue. It is making use of (a) antibodies conjugated to gold nanoclusters (AuNCs) acting as labels, and (b) laser ablation (LA) coupled to inductively coupled plasma – mass spectrometry (ICP-MS). Water-soluble fluorescent AuNCs (with an average size of 2.7 nm) were synthesized and then conjugated to antibody by carbodiimide coupling. The surface of the modified AuNCs was then blocked with hydroxylamine to avoid nonspecific interactions with biological tissue. Immunoassays for MT 1/2 and MT 3 in ocular tissue sections (5 μm thick) from two post mortem human donors were performed. Imaging studies were then performed by fluorescence using confocal microscopy, and LA-ICP-MS was performed in the retina to measure the signal for gold. Signal amplification by the >500 gold atoms in each nanocluster allowed the antigens (MT 1/2 and MT 3) to be imaged by LA-ICP-MS using a laser spot size as small as 4 μm. The image patterns found in retina are in good agreement with those obtained by conventional fluorescence immunohistochemistry which was used as an established reference method. KW - Nanocluster KW - Immunohistochemistry KW - Laser ablation KW - ICP-MS KW - Fluorescence KW - Bioimaging PY - 2018 U6 - https://doi.org/10.1007/s00604-017-2597-1 SN - 1436-5073 SN - 0026-3672 VL - 185 IS - 1 SP - 64 EP - 72 PB - Springer CY - Vienna AN - OPUS4-44637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garcia-Fernandez, J. A1 - Turiel, D. A1 - Bettmer, J. A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Rivas Garcia, L. A1 - Llopis, J. A1 - Sanchez-Gonzalez, C. A1 - Montes-Bayon, M. T1 - In vitro and in situ experiments to evaluate the biodistribution and cellular toxicity of ultrasmall iron oxide nanoparticles potentially used as oral iron supplements N2 - Well-absorbed iron-based nanoparticulated materials are a promise for the oral management of iron deficient anemia. In this work, a battery of in vitro and in situ experiments are combined for the evaluation of the uptake, distribution and toxicity of new synthesized ultrasmall (4 nm core) Fe2O3 nanoparticles coated with tartaric/adipic acid with potential to be used as oral Fe supplements. First, the in vitro simulated gastric acid solubility studies by TEM and HPLC-ICP-MS reveal a partial reduction of the core size of about 40% after 90 min at pH3. Such scenario confirms the arrival of the nanoparticulate material in the small intestine. In the next step, the in vivo absorption through the small intestine by intestinal perfusion experiments is conducted using the sought nanoparticles in Wistar rats. The quantification of Fe in the NPs Suspension before and after perfusion shows Fe absorption levels above 79%, never reported for other Fe treatments. Such high absorption levels do not seem to compromise cell viability, evaluated in enterocytes-like models (Caco-2 and HT-29) using cytotoxicity, ROS production, genotoxicity and lipid peroxidation tests. Moreover, regional differences in terms of Fe concentration are obtained among different parts of the small intestine as duodenum>jejunum>ileum. Complementary transmission electron microscopy (TEM) images show the presence of the intact particles around the intestinal microvilli without significant tissue damage. These studies show the high potential of these NP preparations for their use as oral management of anemia. KW - Iron nanoparticles KW - Anemia KW - ICP-MS KW - In vitro KW - In situ PY - 2020 U6 - https://doi.org/10.1080/17435390.2019.1710613 VL - 14 IS - 3 SP - 388 EP - 403 PB - Taylor & Francis Online CY - London AN - OPUS4-50314 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -