Representative TEM images of AuNP in BAL macrophages. A, B) Scnn1b-Tg mice. C, D) Wt mice. A, C) Large AuNP agglomerates (> 100 nm in diameter) were predominantly localized in medium-sized (150 – 1000 nm) and large vesicles (> 1000 nm). B, D) Single or small AuNP agglomerates (< 100 nm) were localized in small vesicles (< 150 nm), whereby the vesicle diameters still largely exceeded particle size. Note the close localization of the AuNP to the organell’s membrane.