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

- GNRs were induced pulmonary toxicity by various BAL fluid parameters in rats.
- Generation of oxidative stress is one of the mechanisms of toxicity of GNRs.
- GNRs exposure also displayed rat lung histopathological changes.
- The study suggest that the dose-size-dependent pulmonary toxicity of GNRs.

The present investigation was aimed to evaluate the pulmonary toxicity of 10 and 25 nm 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 1 day, 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. 10 nm GNRs increased all BAL fluid parameters significantly following 1 day, 1 week and 1 month post exposure periods whereas 25 nm GNRs have shown similar effects but less extent. These investigations proposed that the dose and size dependent pulmonary toxicity of GNRs.