Due to the increasing use and production of CeO 2 nanoparticles (NPs), the likelihood of exposure especially via the air rapidly grows. However, the uptake of CeO 2 NPs via the lung and the resulting distribution into various cell types of remote organs are not well understood because classical analytical methods provide limited spatial information. In this study, laser ablation− inductively coupled plasma−mass spectrometry (LA-ICP-MS) was combined with immunohistochemical (IHC) staining with lanthanide-labeled antibodies to investigate the distribution of intratracheally instilled CeO 2 NPs from the rat lung to lymph nodes, spleen, and liver after 3 h, 3 days, and 21 days. We selected regions of interest after fast imaging using LA-ICP-MS in lowresolution mode and conducted high-resolution LA-ICP-MS in combination with IHC for cellular localization. The lanthanide labeling, which was largely congruent with conventional fluorescent labeling, allowed us to calculate the association rates of Ce to specific cell types. Major portions of Ce were found to be associated with phagocytic cells in the lung, lymph nodes, spleen, and liver. In the lung, almost 94% of the Ce was co-localized with CD68-positive alveolar macrophages after 21 days. Ce was also detected in the lymph nodes outside macrophages 3 h post instillation but shifted to macrophage-associated locations. In the liver, Ce accumulations associated with Kupffer cells (CD163-positive) were found. Ce-containing populations of metallophilic and marginal zone macrophages (both CD169-positive) as well as red pulp macrophages (CD68-positive) were identified as major targets in the spleen. Overall, high-resolution LA-ICP-MS analysis in combination with IHC staining with lanthanide-labeled antibodies is a suitable tool to quantify and localize Ce associated with specific cell types and to estimate their particle burden under in vivo conditions.
In the field of nanotoxicology, the detection and size characterization of nanoparticles (NPs) in biological tissues become increasingly important. To gain information on both particle size and particle distribution in histological sections, laser ablation and single particle inductively coupled plasma–mass spectrometry (LA–spICP–MS) was used in combination with a liquid calibration of dissolved metal standards via a pneumatic nebulizer. In the first step, the particle size distribution of Ag NPs embedded in matrix-matched gelatine standards introduced via LA was compared with that of Ag NPs in a suspension and nebulizer-based ICP–MS. The data show that the particles remained intact by the ablation process as confirmed by transmission electron microscopy. Moreover, the optimized method was applied to CeO2 NPs that are highly relevant for (eco-)toxicological research but, unlike Ag NPs, are multi-shaped and have a broad particle size distribution. Upon analyzing the particle size distribution of CeO2 NPs in cryosections of rat spleen, CeO2 NPs were found to remain unchanged in size over 3 h, 3 d, and 3 weeks post-intratracheal instillation, with the fraction of smaller particles reaching the spleen first. Overall, LA–spICP–MS combined with a calibration based on dissolved metal standards is a powerful tool to simultaneously localize and size NPs in histological sections in the absence of particle standards.
The pursuit of higher energy density in lithium-ion batteries has driven the increase of the nickel content in lithium nickel cobalt manganese oxide cathode active materials (CAMs), ultimately approaching LiNiO2 (LNO). The downside of the high specific capacity of LNO is more severe degradation of the CAM during battery operation. A common approach to increase structural stability is the introduction of dopants. Various dopants are discussed and compared with each other when integrated into the CAM and tested against undoped materials in the literature, but little attention is given to the role of the process route of their introduction. In this work, we demonstrate with a series of nominally equally Zr-doped LNO samples that effects on various physico- and electrochemical properties are due not to the dopant itself, as one would assume in comparison to an undoped sample, but to the process route and the resulting particle morphology. Dopant, concentration and process routes (co-precipitation, impregnation and co-calcination) were chosen based on their significance for industrial application.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.