{'fraction_non_alphanumeric': 0.038569424964936885, 'fraction_numerical': 0.019635343618513323, 'mean_word_length': 5.3991031390134525, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Biodistribution and oxidative stress effects of a systemically-introduced commercial ceria engineered nanomaterial

The objective was to characterize the biodistribution of nanoscale ceria from blood and its effects on oxidative stress endpoints. A commercial 5% crystalline ceria dispersion in water (average particle size ~31±4 nm) was infused intravenously into rats (0, 50, 250 and 750 mg/kg), which were terminated 1 or 20 h later. Biodistribution in rat tissues was assessed by microscopy and ICP-AES/MS. Oxidative stress effects were assessed by protein-bound 4-hydroxy 2-trans-nonenal (HNE), protein-bound 3-nitrotyrosine (3-NT), and protein carbonyls. Evans blue (EB)-albumin and Na fluorescein (Na2F) were given intravenously as blood-brain barrier integrity markers. The initial ceria t½ in blood was ~7 min. Brain EB and Na2F increased some at 20 h. Microscopy revealed peripheral organ ceria agglomerations but little in the brain. Spleen Ce concentration was >liver >blood >brain. Reticuloendothelial tissues cleared ceria. HNE was significantly increased in the hippocampus at 20 h. Protein carbonyl and 3-NT changes were small. The nanoparticle characterizations before and after biodistribution, linked with the physiological responses, provide a foundation for evaluating the effects of engineered nanomaterial physico-chemical properties on peripheral organ distribution, brain entry and resultant toxicity.