Figure 2.

Iron oxide NPs induce intracellular iron increase. Histogram of the means of the F₃₀/F₀ values calculated as the fluorescence values at time 30 min normalized for the fluorescence values at time 0. Fe₃O₄ NPs (blue column) caused a statistically significant quenching of Calcein compared to the controls, i.e., Calcein injected oocytes exposed to external control solution at pH 7.6 (white column). Conversely, Fe NPs (green column), aggregated Fe₃O₄ NPs (blue barred column) and BSA modified Fe₃O₄ NPs (cyan column) did not induce quenching; rDMT1 transfected oocytes exposed to iron chloride were used as positive controls (dark blue column). Bars represent ± SEM; from 10 to 40 oocytes for each column deriving from 2 to 8 batches were used. Statistical analysis was performed with One-way ANOVA and orthogonal comparisons with Holm-Bonferroni post hoc test (***p < 0.005).