Similar pulmonary toxicity and gene expression changes after short-term inhalation exposure to surface-modified copper oxide nanoparticles

This study investigated the pulmonary toxicity of Copper oxide nanoparticles (CuO NPs) surface modified with polyethylenimine (PEI) or ascorbate (ASC), was investigated. Rats were exposed nose-only to a fixed exposure concentration of ASC or PEI coated CuO NPs for 5 consecutive days. On day 6 and day 27 post-exposure, pulmonary toxicity markers in bronchoalveolar lavage fluid (BALF) were analyzed and histopathological evaluation of the lungs was performed, along with microarray analyses on whole lung tissue samples. This experiment examined lung tissues from 8 weeks old male rats (Wistar RjHan:WI, Janvier, France) exposed to 6 hour equivalent doses of 3 and 8.6 mg NPs / m3 of CuO nanomaterials (black material) positively charged coating (PEI) or 6 hour equivalent doses of 3.8 and 10.9 mg NPs / m3 of CuO nanomaterials negatively charged coating (ASC) by nose only inhalation according to the OECD test Guideline 403 for Acute Inhalation Toxicity Test. Rats were exposed to five consecutive days and lung tissues were sampled on day 1 after the last exposure (referrred to as T6) and day 22 post-exposure (referred to as T27). Control animals were exposed to air only. Each treatment group consisted of 5 animals. Exposure and sample collection were conducted at the National Institute for Public Health (RIVM) at Bilthoven, The Netherlands, under permit number 201300190. Experimental procedures were in accordance with the European directive on the protection of animals for scientific purposes (Directive 2010/63/EU).