Fig. 6

Histology in the lungs of mice 3 days after nickel nanoparticle exposure. Mice were instilled intratracheally with 50 µg per mouse of Nano-Ni, or with either partially passivated (Nano-Ni–P) or carbon-coated (Nano-Ni–C) nickel nanoparticles with same molar concentration of Ni as Nano-Ni. Control mice were instilled with physiological saline. Lung tissue sections collected from mice 3 days post-exposure were analyzed by H&E staining. A The normal structure of lung parenchyma in a control mouse. B Shows acute inflammation in the lungs of a mouse with Nano-Ni exposure. A large amount of polymorphonuclear (PMN) cells and macrophages infiltration in the perivascular, peribronchial, or peribronchiolar areas, and alveolar space. Acute inflammation was also observed in Nano-Ni–P-exposed lungs (C), but very mild in Nano-Ni–C-exposed lungs (D). Arrows: macrophages; arrowheads: neutrophils. Scale bar in D represents 50 µm for all panels