Fig. 3

CD-NPs produced a more pronounced acute inflammatory response in vitro and in vivo. A The morphology of CD adsorbed cells was observed under a microscope after treating with 300 µg/mL CD-MPs and CD-NPs for 24 h. Red arrows point to vacuoles produced by cells stimulated by CD particles. B and C Cytokines were quantified in cell supernatants by ELISA assay after treatment with 300 µg/mL CD-MPs and CD-NPs for 72 h in vitro. Data were expressed as the mean ± SD, n = 3. *P < 0.05, **P < 0.01 and ***P < 0.001. n.s no significance. D Cytokines were quantified in mouse bronchoalveolar lavage fluid by ELISA assay after treatment with 32 μg mixed CD/day for 2 weeks in vivo. Data were expressed as the mean ± SD, n = 3. *P < 0.05, **P < 0.01 and ***P < 0.001. E The acute inflammatory hyperplasia in lung tissue was detected by HE and Masson staining after treatment with 32 μg mixed CD/day for 2 weeks in vivo. CD-MPs coal dust micron particles, CD-NPs coal dust nanoparticles, CD coal dust