Figure 1: H&E lung histology. Representative images of hematoxylin and eosin stained lung histology sections. Naïve Sprague Dawley Rat (A), 1 day following citrate vehicle instillation (B), 7 days following instillation of citrate vehicle (C), 1 day following instillation of 20 nm AgNP (D), 7 days following instillation of 20 nm AgNP (E). No gross pathology was noted in the naïve cohort or within the citrate vehicle or 20 nm AgNP at 1 day. The citrate vehicle had some erythrocytes within the lung tissue while the 20 nm AgNP showed modset increased alveolar wall thickening at 7 days post instillation. Back bar identifies 50 μm scaling.