Nose-only inhalations of high-dose alumina nanoparticles/hydrogen chloride gas mixtures induce strong pulmonary pro-inflammatory response: a pilot study

Critical Review on Toxicological Mechanisms Triggered by Inhalation of Alumina Nanoparticles on to the Lungs

“…This was also demonstrated in several human cell lines, including bronchial or alveolar epithelial cells, that cytotoxicity could be modulated depending on the crystallinities of Al 2 O 3 particles [ 34 , 39 ]. On the other hand, Bourgois et al exposed rats by nose-only inhalation to a strong concentration of γ/δ-Al 2 O 3 NPs, also showing increased inflammatory response after five days [ 14 ]. However, only one elevated concentration (20 mg/m 3 ) of these well-characterized NPs was administrated to animals for only early analysis of pro-inflammatory effects.…”

“…Pro-inflammatory mechanisms triggered by nose-only inhalation exposure of Al 2 O 3 NPs seem to involve an increase in neutrophils, lymphocytes, and macrophages afflux in BALF in association with pro-inflammatory cytokines secretion and LDH release [ 14 , 15 ]. This result was also observed after whole-body inhalation of Al 2 O 3 NPs [ 16 ].…”

“…Results obtained in this study demonstrated a strong inflammatory potential of these NPs when inhaled, and authors suggested a no-observed-adverse-effect level of 1 mg/m 3 concentration. Recently, Wistar rats were also nose-only exposed to a high concentration of Al 2 O 3 NPs (size 13 nm; γ/δ crystallinity; 20.0–22.1 mg/m 3 aerosol) following two exposure scenarios: single (4 h) or repeated exposures (4 h/day for 4 days) [ 14 ]. After repeated exposures, total proteins and LDH concentrations in BALF were significantly increased, suggesting that the alveolo-capillary barrier was damaged.…”

“…Pulmonary aluminosis is a rare form of pneumoconiosis caused by aluminum or alumina powders [ 12 , 13 ]. Consequently, the majority of animal studies have focused on pro-inflammatory mechanisms triggered by the inhalation of Al 2 O 3 NPs [ 14 , 15 ]. Results showed increases in total protein, neutrophils, lymphocytes, and lactate dehydrogenase (LDH) concentration in broncho-alveolar lavages (BALF), corroborating pro-inflammatory effects of Al 2 O 3 NPs and suggesting potential permeabilization of the alveolo-capillary barrier.…”

“…Results showed increases in total protein, neutrophils, lymphocytes, and lactate dehydrogenase (LDH) concentration in broncho-alveolar lavages (BALF), corroborating pro-inflammatory effects of Al 2 O 3 NPs and suggesting potential permeabilization of the alveolo-capillary barrier. Moreover, various pro-inflammatory cytokines were secreted in animal BALFs: TNF-α, IL-6, IL-1β, IL-8, MIP-2, and IL-33 [ 14 , 15 , 16 ]. However, to the best of our knowledge, inflammatory mechanisms are poorly studied in vitro.…”