Fig. 2

Cytotoxicity of NP1 to NP6 as a function of their surface charge density in THP1 cells. Cells were incubated with 200 µg/mL of the NPs for 24 h and their viability was assessed with the MTT assay. Results are expressed as percentage of viability loss when compared to control (unexposed cells). They are means ± SEM of n = 3–6 experiments. Statistical differences when compared to controls (CTL) were determined by one-way ANOVA followed by the Dunnett’s test. **p < 0.01 ; ***p < 0.001. ζ-potential of NPs are indicated above the bars