Fig. 8. The zinc ions absorption of the small intestines. (a) The amount of zinc ions absorption on small intestines after co-incubation with different systems for 2 h; (b) the amount of zinc ions after co-incubation with different systems with small intestines for 2 h (black column: the amount of zinc ions in the solutions without the small intestines; gray column: the amount of zinc ions in the solutions within the small intestines). Data are presented as the mean ± S.D. *P < 0.05 compared with the group of ZnO NPs plus CPP. **P < 0.01 compared with the group of ZnO NPs plus CPP. ^#p < 0.05 compared with the group of ZnO NPs plus VC. ^##p < 0.01 compared with the group of ZnO NPs plus VC.