Fig. 2From: Sub-ohm vaping increases the levels of carbonyls, is cytotoxic, and alters gene expression in human bronchial epithelial cells exposed at the air–liquid interfaceThe presence of cilia at the surface of the cells confirms that H292 cells were grown at the air–liquid interface (ALI). a Characterization of the ALI cell culture model. H&E staining reveals the multiple cell layers on the apical surface following 1 day of exposure to either air or butter-flavored e-cig aerosol. b Scanning electron microscopy images of representative H292 cells exposed to either air or butter-flavored e-cig aerosols for 1 day at the ALI, with a higher magnification of the cilia present at the surface of the cells. Images showed are representative for each exposure group. For air-exposed cells: a total of 38 SEM images were taken; for butter-flavored e-cig aerosol-exposed cells: a total of 53 SEM images were takenBack to article page