Fig. 1

Pulmonary inflammation induced by Al₂O₃ NPs exposure. a sRAW was significantly increased in Al₂O₃ NPs-exposed mice (n = 10, ^* P < 0.05, compared with controls; ^*** P < 0.001, compared with control on the same day). b Inflammatory mediators were significantly increased in Al₂O₃ NPs-exposed BALF of mice (n = 4, ^* P < 0.05, ^** P < 0.01). c The total cell number, monocytic cells number and neutrophils number in BALF of Al₂O₃ NPs-exposed mice were significantly increased compared with FRA control (n = 4, ^* P < 0.05, ^*** P < 0.001). d Representative images of normal airway and airway surrounded by inflammatory cells (showed by arrow). e Representative images of distant alveoli (FRA control) f Representative images of macrophages, lymphocytes and neutrophil infiltration in alveolar area (Al₂O₃ NPs exposure) (shown by arrow). The images in the right bottom of each panel are magnified of the cell in original images highlighted with black arrows