Nanoparticulate Vanadium Oxide Potentiated Vanadium Toxicity in Human Lung Cells

Abstract

Metal oxides may hold, as nanosized particles, a toxic potential to human health and the environment that is not present in the bulk material. Due to the high surface-to-volume ratio, small amounts can lead to strong oxidative damage within biological systems, impairing cellularfunctions as a consequence of their high surface reactivity. We report here on a new nanosized V203 material that has a needle-like structure with diameters of less than 30 nm and variable lengths. The potentiated toxicity of nanoscale vanadium oxide (V203) compared to bulk material is demonstrated here in human endo- and epithelial lung cells, and might be due to the higher catalytic surface of the particles. Reduction in cell viability is almost ten times stronger and starts with lowest concentrations of "nanoscaled" material (10 microg/mL). Vanadium oxide leads to an induction of heme oxygenase 1 (HO-1) in a dose dependent manner in ECV304 cells whereas a reduction in protein levels can be observed for the epithelial cells (A549). Lipid peroxidation can be observed also for "nanoscaled" vanadium oxide to a much stronger extent in macrophages (RAW cells) than for bulk material. The observed effects can not only be explained by oxidation from V2O3 to V2O5 as there are significant differences between the novel nano vanadium and all used bulk materials (V203 and V205). It appears rather to be a nanoeffect of a high surface reactivity, here coupled with a yet unknown toxicity potentiating effect of a technically important catalyst.

Biodistribution of PEG-modified gold nanoparticles following intratracheal instillation and intravenous injection

“…In fact, the interaction of NPs with lung structures [24,25] as well as the translocation from the lungs into the circulation [26] is highly dependent on the particle size. Effects of PEGylation regarding the translocation across the air-blood-barrier have not been investigated, yet.…”

Nanotoxikologie – eine interdisziplinäre Herausforderung

“…Dafür spricht, dass für das Auftreten von Entzündungsmarkern in der Lunge eine lineare Korrelation zur spezifischen Gesamtoberfläche von TiO 2 -Partikeln unterschiedlicher Größe, nach Verabreichung an Ratten und Mäusen, aufgezeigt werden konnte. [113] Eine vergleichbare Beziehung zwischen Größe und Wirkung konnte in vitro an Lungenzellen für unterschiedlich große Vanadiumoxidpartikel, [114] in vivo für Nickel [115] als auch für verschieden große Kohlenstoffpartikel aus Verbrennungsprozessen [116] bestätigt werden. Aus diesen Resultaten kann abgeleitet werden, dass die Größe bzw.…”

“…[116] Weitere Studien haben dies im Inhalationsversuch für verschieden große Nickelpartikel [115] und andere Materialien beschrieben. [141] Zusätzlich konnte für Polystyrolpartikel, [142] Kohlenstoffpartikel, CNTs [143,144] SiO 2 -Partikel [51] und Vanadiumoxide [114] ein solcher größenabhängiger Effekt in Zellkulturen oder auch im Tierversuch nachgewiesen werden. Darüber hinaus ist die Reaktivität der Partikel ein wichtiger Faktor, der auch direkt von der spezifischen Oberfläche abhängt.…”

Os nanomateriais e a questão ambiental

“…Quanto ao tamanho destas, o principal problema é que raramente uma partícula será encontrada no ambiente em sua forma primária e isolada, mas sim formando aglomerados que podem variar enormemente de tamanho (> 100 nm) pela mudança das condições ambientais como força iônica e pH. 15,71,72 Estes aglomerados são promovidos por forças relativamente fracas, tais como interações hidrofóbicas, mudando radicalmente o modo como são dispersos no ar e em fase aquosa, sendo este estado de dispersão uma das características mais difíceis de quantificar até então. 73 Assim, uma tendência é o desenvolvimento e o aprimoramento de técnicas que permitam quantificar o tamanho dos agregados depois de dosados nos ensaios em fase aquosa e gasosa.…”