Fig. 3
From: Cobalt nanoparticles induce lung injury, DNA damage and mutations in mice
Increased Ki-67 and PCNA expression in mouse lungs after Nano-Co exposure. Mice were instilled intratracheally with 50 μg per mouse of Nano-Co or Nano-TiO2. Control mice were instilled with physiological saline. Lung sections collected from mice 7 days (a–i) and 4 months (j–l) after exposure were analyzed by immunohistochemistry staining. Scale bar: 50 μm