Fig. 2

Characterization and toxicological evaluation of ferrocene-derived magnetic nanoparticles (FMP). Extracted FMPs were characterized and exposed to hatchling chickens via aerosol inhalation, resulting pulmonary toxicities were evaluated in 0- and 1-month-old animals. Data were expressed as mean ± SD; * indicates significant difference from the blank control group (p < 0.05); ** indicates significant difference from the blank control group (p < 0.01). (A) Mass fraction of FMP in ferrocene-doped diesel exhaust particle samples (N = 3 per group). (B) Representative SEM images showing FMP enriched from 820 mg/L ferrocene-doped diesel exhaust particles. (C) Representative TEM images of lung tissues post-exposure, with red arrows indicating FMP attachment or entry into epithelium cells. (D) Representative pictures of lung tissue sections from animals exposed to FMP stained with H&E, Masson’s trichrome, and Sirius Red post-exposure (doses: 0.3 mg/kg, 0.6 mg/kg, 1.2 mg/kg; scale bars represent 100 μm). H&E staining indicated thickening of alveolar wall and loss of lung architecture in exposed samples, blue staining in Masson’s trichrome and red staining in Sirius Red staining represent collagen deposition. (E) Quantifications of lung tissue Ashcroft scores and fibrotic lesion ratios (N = 5 per group)