Fig. 3

Response of MLg fibroblasts to the second set of MWCNTs. Panel A WST-1 assay in MLg cells after 24 h of exposure to increasing applied doses of MWCNTs (mean ± SD; n = 4 experimental replicates). Panel B Turbidity kinetics of the different MWCNT samples suspended in serum-free MEM at 50 μg/l (n = 2–6 experimental replicates). Symbols with the same letter are not statistically different (mixed effect model followed by Tukey’s test). C Femtosecond pulsed laser signal of deposited MWCNTs after 24 h in the absence (w/o) of cells (a.u., arbitrary unit; mean ± SD; n = 3 experimental replicates). D Femtosecond pulsed laser signal of deposited MWCNTs after 24 h in the presence of MLg fibroblasts (a.u., arbitrary unit; mean ± SD; n = 3 experimental replicates). Columns with the same letter are not statistically different (one-way ANOVA followed by Tukey’s multiple comparison test)