Fig. 6

Histopathology at 60 days after exposure to a high dose of purified and subsequently functionalized MWCNTs. a Representative photomicrographs taken at 40x magnification of Gomori’s trichrome-stained lung sections. Red arrows indicate granulomatous lesions in lung tissue. Dotted lines with arrows linking panels indicate derivation of the purified or functionalized MWCNTs with the parent pristine NC7000 MWCNT sample. b Results of quantitative morphometry showing numbers of granulomatous lesions (left graph) and size (area) of granulomatous lesions (right graph). N = 4 mice per group/treatment. Statistically significant difference to the vehicle control: *P < 0.05, ***P < 0.001, or to the chemically purified CP7000 sample: ## P < 0.01 compared to CP7000