title: Assessing the axonal translocation of CeO2 and SiO2 nanoparticles in the sciatic nerve fibers of the frog: an ex vivo electrophysiological study.
abstract: The axonal translocation of two commonly used nanoparticles in medicine, namely CeO2 and SiO2, is investigated. The study was conducted on frog sciatic nerve fibers in an ex vivo preparation. Nanoparticles were applied at the proximal end of the excised nerve. A nerve stimulation protocol was followed for over 35 hours. Nerve vitality curve comparison between control and exposed nerves showed that CeO2 has no neurotoxic effect at the concentrations tested. After exposure, specimens were fixed and then screen scanned every 1 mm along their length for nanoparticle presence by means of Fourier transform infrared microscopy. We demonstrated that both nanoparticles translocate within the nerve by formation of narrow bands in the Fourier transform infrared spectrum. For the CeO2, we also demonstrated that the translocation depends on both axonal integrity and electrical activity. The speed of translocation for the two species was estimated in the range of 0.45-0.58 mm/h, close to slow axonal transportation rate. Transmission electron microscopy provided direct evidence for the presence of SiO2 in the treated nerves.
authors.affiliation: Aerosol and Particle Technology Laboratory (APTL), CERTH/CPERI, Thessaloniki, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Kastrinaki
authors.affiliation: Laboratory of Animal Physiology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Samsouris
authors.affiliation: Laboratory of Physiology, Department of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Efstratios K
authors.initials: EK
authors.lastname: Kosmidis
authors.affiliation: Aerosol and Particle Technology Laboratory (APTL), CERTH/CPERI, Thessaloniki, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Papaioannou
authors.affiliation: Aerosol and Particle Technology Laboratory (APTL), CERTH/CPERI, Thessaloniki, Greece ; Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Konstandopoulos
authors.affiliation: Laboratory of Animal Physiology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Theophilidis
mesh_terms: D000818:Animals; D001001:Anura / Q000502:physiology*; D001369:Axons / Q000378:metabolism*; D002563:Cerium / Q000378:metabolism*; D004594:Electrophysiology / Q000379:methods*; D005260:Female; D008297:Male; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009412:Nerve Fibers / Q000378:metabolism* / Q000648:ultrastructure; D012584:Sciatic Nerve / Q000378:metabolism*; D012822:Silicon Dioxide / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002563:Cerium; C030583:ceric oxide; D012822:Silicon Dioxide
keywords: CeO2; FTIR; SiO2; ex vivo electrophysiology; frog sciatic nerve; nanoparticles; translocation