Limited inflammatory response in rats after acute exposure to a silicon carbide nanoaerosol

Abstract

Inhalation represents the major route of human exposure to manufactured nanomaterials (NMs). Assessments are needed about the potential risks of NMs from inhalation on different tissues and organs, especially the respiratory tract. The aim of this limited study is to determine the potential acute pulmonary toxicity in rats exposed to a dry nanoaerosol of silicon carbide (SiC) nanoparticles (NPs) in a whole-body exposure (WBE) model. The SiC nanoaerosol is composed of a bimodal size distribution of 92.8 and 480 nm. The exposure concentration was 4.91 mg/L, close to the highest recommended concentration of 5 mg/L by the Organisation for Economic Co-operation and Development. Rats were exposed for 6 h to a stable and reproducible SiC nanoaerosol under real-time measurement conditions. A control group was exposed to the filtered air used to create the nanoaerosol. Animals were sacrificed immediately, 24 or 72 h after exposure. The bronchoalveolar lavage fluid from rat lungs was recovered. Macrophages filled with SiC NPs were observed in the rat lungs. The greatest load of SiC and macrophages filled with SiC were observed on the rat lungs sacrificed 24 h after acute exposure. A limited acute inflammatory response was found up to 24 h after exposure characterized by a lactate dehydrogenase and total protein increase or presence of inflammatory cells in pulmonary lavage. For this study a WBE model has been developed, it allows the simultaneous exposure of six rats to a nanoaerosol and six rats to clean-filtered air. The nanoaerosol was generated using a rotating brush system (RBG-1000) and analyzed with an electrical low pressure impactor in real time.J. Laloy and O. Lozano have contributed equally in the study reported here.Electronic supplementary material The online version of this article (

Comparison of Oral, Intranasal and Aerosol Administration of Amiodarone in Rats as a Model of Pulmonary Phospholipidosis

“…study also included a cull on day 7 post-final dose and both aerosol studies included cull groups on days 7 and 28 post-final dose. All control groups (saline or air treated) showed outcomes in line with values reported in literature [19,29,30], i.e., total cell counts were normal, and no inflammatory cells were present in the BAL cellular fraction (Figure 1). Regardless of the administration route, total BAL cell numbers did not increase in any of the amiodarone-treated groups tested (Figure 1).…”