Assessment of pulmonary toxicity of gold nanorods following intra-tracheal instillation in rats.

The present investigation was aimed to evaluate the pulmonary toxicity of 10 and 25nm gold nanorods (GNRs) following intra-tracheal instillation in rats using bronchoalveolar lavage (BAL) fluid and lung histopathological analysis. The GNRs displayed that the dose-dependent toxicity via elevated lactate dehydrogenase leakage, alkaline phosphatase, lipid peroxidation and total microprotein levels in BAL fluids after 1day, 1 week and 1 month post exposure periods. All the parameters were returned to normal values after 3 months post exposure period may be due to recovery. The rat lung histopathology displayed that accumulation of macrophages, inflammatory response and tissue thickening for both sizes of GNRs. 10nm GNRs increased all BAL fluid parameters significantly following 1day, 1 week and 1 month post exposure periods whereas 25nm GNRs have shown similar effects but less extent. These investigations proposed that the dose and size dependent pulmonary toxicity of GNRs.