Figure 8.
Time course of C57BL/6 male lung histopathology response following 300 μg aspiration exposure to pristine (CloisNa) or organomodified (Clois30B) montmorillonite nano-clay. CloisNa exposure (a) caused pulmonary edema on day 1 and robust neutrophil and macrophage inflammatory response that peaked at day 7 characterized by macrophage and type II pneuomocyte hyperplasia and focal lymphocyte infiltrate out to day 28. Conversely, Clois30B exposure resulted in mild neutrophilic inflammation associated with particle-laden macrophages. 400× magnification. Both CloisNa (b; left panel; day 28) and Clois30B (right panel; day 7) exposures caused granulomas comprised of macrophages and nanoclay particulate. 400× magnification. Blue and red arrows indicate free or macrophage engulfed particles, respectively.