Toxicity and Protective Effects of Cerium Oxide Nanoparticles (Nanoceria) Depending on Their Preparation Method, Particle Size, Cell Type, and Exposure Route

Abstract

Nanoceria (cerium oxide nanoparticles) toxicity is currently a concern because of its use in motor vehicles in order to reduce carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons in exhaust gases. In addition, many questions arise with respect to its biomedical applications exploiting its potential to protect cells against irradiation and oxidative stress. Indeed, toxicology studies on nanoceria report results that seem contradictory, demonstrating toxic effects in some studies, protective effects in others, and sometimes little or no effect at all. The variability in the experimental setups and particle characterization makes these studies difficult to compare and the toxicity of newly developed nanoceria materials challenging to predict. This microreview aims to compare the toxicity of nanoceria in terms of preparation method, particle size, concentration, host organism, and exposure method.

Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice

“…While studies reported that CeO 2 NPs have antioxidant properties and protect against oxidative stress induced by cigarette smoke and X-ray radiation, as well as, in animal models, ischemia/reperfusion, stroke, and neurodegeneration, other studies have, however, reported that these nanoparticles cause oxidative stress both in vivo following pulmonary exposure and in vitro in human monocytes [44]. The reason behind these discrepancies could be related to the preparation methods of CeO 2 NPs, the pH of the biological milieu in which the nanoparticles are tested, the particle size, the cell types, and the route of exposure [44]. Our data show that, as a consequence of the route of exposure to CeO 2 NPs, that is, through the lung, all the markers of oxidative stress assessed were affected in the lung tissue.…”

Hot Topics and Challenges of Regenerative Nanoceria in Application of Antioxidant Therapy

“…Tarnuzzer's group found that nanoceria exhibited radioprotection of normal human breast epithelial cells, but not to MCF-7 cancer cells for the first time [24]. In addition, the size, shape, agglomeration state, surface charge, and surface modification of nanoceria together determine its bioresponse to cancer cells [41][42][43][44]. Dextran-coated nanoceria prepared by Alili et al [45] has been used to prevent myofibroblast formation and tumor invasion in tumor-stroma interaction.…”

Cerium oxide nanoparticles: green synthesis and biological applications

“…[1][2][3][4][5] In general, cerium can exist in two oxidation states: Ce 3+ and Ce 4+ . Therefore, cerium dioxide can have two different oxide forms, CeO 2 (Ce 4+ ) or Ce 2 O 3 (Ce 3+ ), in bulk material.…”

“…1,36 Recently, biosynthesis of NPs using yeast and fungi has also been noted. Munusamy et al had explained rapid and extracellular synthesis of cerium oxide NPs using fungus Curvularia lunata culture media.…”