title: Nanoparticles and pop-off technique for electron microscopy: a known technique for a new purpose.
abstract: Because of the size of the nanoparticles, their detection and exact anatomical localization in tissue samples are very difficult. Consequently, suitable methods are needed to prove their presence, especially co-localized to histological lesions. Therefore, the aim of this study was to investigate whether nanoparticles were detectable in specimens after reprocessing samples from glass slides using the pop-off technique. Tissue slides containing agglomerates of titanium dioxide nanoparticles already visible on a light microscopic level and amorphous silicium dioxide (SiO2) particles not observable in tissue slides were reprocessed. Furthermore, cytospots of bronchoalveolar lavage acquired from rats that previously inhaled carbon nanotubes were used. After reprocessing the samples, they were investigated using transmission electron microscopy. In all the reprocessed samples, the respective nanoparticles were detectable. Even the light microscopically invisible amorphous SiO2 particles were observed as electron dense structures. Titanium and silicium were additionally confirmed in the respective nanoparticles by energy-dispersive X-ray spectroscopy (EDX). In summary, the pop-off technique represents a fast and easy way to detect nanoparticles in histological sections. This enables further characterization of these particles by additional techniques such as EDX, and their direct correlation with light microscopic lesions at exactly the same location is investigated.
authors: Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany Department of Pathology, University of Veterinary Medicine, Hannover, Germany Center for Systems Neuroscience, Hannover, Germany.
authors: Annika
authors: A
authors: Lehmbecker
authors: Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany.
authors: Susanne
authors: S
authors: Rittinghausen
authors: Department of Pathology, University of Veterinary Medicine, Hannover, Germany.
authors: Kerstin
authors: K
authors: Rohn
authors: Department of Pathology, University of Veterinary Medicine, Hannover, Germany Center for Systems Neuroscience, Hannover, Germany.
authors: Wolfgang
authors: W
authors: Baumgärtner
authors: Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany dirk.schaudien@item.fraunhofer.de.
authors: Dirk
authors: D
authors: Schaudien
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D007830:Larynx / Q000187:drug effects / Q000473:pathology; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008854:Microscopy, Electron / Q000379:methods*; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D014025:Titanium / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: electron microscopy; energy-dispersive X-ray spectroscopy; nanoparticles; nanopathology; nanotoxicology; pop-off technique.