Figure 6
C. difficile infection-induced colitis was attenuated in mice treated with Fe3-δO4 nanoparticles. Purified CCUG 19126 spores were incubated for 20 minutes with Fe3-δO4 nanoparticles, and then the mice were injected with them. Three days later, the mice were killed. (A) The mean bodyweight-loss of the Fe3-δO4 nanoparticle-treated mice was significantly lower than that of the spores-alone control mice. (B) The mean weight-loss of the cecums of the Fe3-δO4 nanoparticle-treated mice was also significantly lower than that of spores-alone control mice. (C) The inflammation of the isolated colon from 11FNL/FVB/NJ transgenic mice with NF-κB-signal-activated bioluminescence was detected. The left image shows a spores-alone control colon and the right image a Fe3-δO4-nanoparticle-treated colon. C. difficile infection-induced inflammation was significantly lower in the Fe3-δO4 nanoparticle-treated colon (right panel). (D) A histopathological examination of the isolated colon tissue shows prominent infiltration of neutrophils (black arrows in left 400× panel) in the control group, but attenuated inflammation in the Fe3-δO4 nanoparticle-treated group (right 400× panel). Neutrophils were morphometrically counted in 10 randomly selected fields in the tissue sections. The number of neutrophils in the control group was 16 ± 5 per 170 m × 130 µm field; the number in the Fe3-δO4 nanoparticles-treated group was 2 ± 1 per 170 m × 130 µm field. (E) A reverse transcription-quantitative polymerase chain reaction (RT-QPCR) shows that the total RNA extracted from the Fe3-δO4-nanoparticle-treated spores expressed significantly lower levels of proinflammatory genes than did the spores in the control group. (*P < 0.05, **P < 0.01; Student’s t test) (n = 6).
