Fig. 4
Iron and cobalt concentration. a Spectrophotometry based determination of intracellular iron concentration in Balb/3T3 cells. The intracellular Fe2+ ion and total iron (Fe2+ + Fe3+) concentration of Balb/3T3 cells with different treatments. All the data were expressed as mean ± SD of three independent experiments performed in triplicates. *p < 0.01 vs. control. b ICP-MS measurement of intracellular &extracellular cobalt concentration in Balb/3T3 cells. Compared with the control group, the concentration of cobalt inside and outside the cells in the CoNPs-treated group was significantly increased, and ALA had a significant antagonistic effect on this. Note: In this figure, the intracellular and extracellular cobalt concentrations are not comparable due to the different processing methods of the cell. All the data were expressed as mean ± SD of three independent experiments performed in triplicates. *p < 0.01 vs. control