Pulmonary toxicity, distribution, and clearance of intratracheally instilled silicon nanowires in rats.
Roberts-JR; Mercer-RR; Chapman-RS; Cohen-GM; Bangsaruntip-S; Schwegler-Berry-D; Scabilloni-JF; Castranova-V; Antonini-JM; Leonard-SS
J Nanomater 2012 May; 2012:398302
Silicon nanowires (SiNWs) are being manufactured for use as sensors and transistors for circuit applications. The goal was to assess pulmonary toxicity and fate of Si NW using an in vivo experimental model. Male Sprague-Dawley rats were intratracheally instilled with 10, 25, 50, 100, or 250 microg of Si NW (~20-30 nm diameter; ~2-15 microm length). Lung damage and the pulmonary distribution and clearance of Si NW were assessed at 1, 3, 7, 28, and 91 days after-treatment. Si NW treatment resulted in dose-dependent increases in lung injury and inflammation that resolved over time. At day 91 after treatment with the highest doses, lung collagen was increased. Approximately 70% of deposited Si NW was cleared by 28 days with most of the Si NW localized exclusively in macrophages. In conclusion, Si NW induced transient lung toxicity which may be associated with an early rapid particle clearance; however, persistence of Si NW over time related to dose or wire length may lead to increased collagen deposition in the lung.
Biological-effects; Cell-biology; Cellular-reactions; Chemical-properties; Chemical-reactions; Exposure-assessment; Exposure-levels; Exposure-methods; Laboratory-animals; Laboratory-testing; Lung-cells; Particulates; Pulmonary-system; Risk-analysis; Toxic-effects; Toxic-effects; In-vivo-study; Dose-response; Silicon-compounds; Immune-reaction; Pulmonary-clearance
Jenny R. Roberts, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
Journal of Nanomaterials