borderline significantp = 0.068
Compared to vehicle control, exposure to the positive control nanoparticles Printex 90 and Printex XE2B induced substantial changes in the total number of BAL cells and neutrophils 1 and 3 days after instillation, while at Day 28 only Printex XE2B still induced a significant increase in the total number of BAL cells and borderline significant increase in the number of neutrophils ( p = 0.068).