Pulmonary pathobiology induced by zinc oxide nanoparticles in mice: A 24-hour and 28-day follow-up study

Abstract Inhaled zinc oxide nanoparticles (ZnONPs) have high deposition rates in the alveolar region of the lungs; however, the adverse health effects of ZnONPs on the respiratory system are unclear. Herein, pathobiological responses of the respiratory system of mice that received intratracheal administration of ZnONPs were investigated by a combination of molecular and imaging (SPECT and CT) approaches. Also, normal BEAS-2B and adenocarcinoma A549 cells were used to confirm the results in mice. First, female BALB/c mice were administrated a series of doses of 20-nm ZnONPs and were compared to the phosphate-buffered saline control for 24-h and 28-day follow-up observations. Field emission-scanning electron microscopy and an energy-dispersive X-ray microanalysis were first used to characterize ZnONPs. After 24 h, instilled ZnONPs had caused significant increases in lactic dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), caspase-3, and the p63 tumor marker in lung tissues ( p p p in vivo and in vitro . This work provides unique findings on the p63 response and the pathobiology in response to ZnONPs, which could be important to the study of pulmonary toxicity and repair.