Cytotoxicity of a) MWCNT
and b) MWCNT
plotted against the intensity of the unique radical formed by MWCNT
in medium + 0.6 mg/ml BSA in cell-free (80, 160, 320, 640 and 1000 μg/ml, representing 10, 20, 40, 80 and 125 μg/cm2) and cellular settings (80, 160, 320 and 640 μg/ml, representing 10, 20, 40 and 80 μg/cm2). The dose 10 μg/cm2 (80 μg/ml) was not tested in cell-free settings, and 1000 μg/ml (125 μg/cm2) was not tested in the cells. Columns represent the peak surface, i.e. area under curve (AUC), obtained by double integration of the unique peak (±SD). Lines represent cytotoxicity results (0-200 μg/cm2, representing 0-760 μg/ml). The average number of living cells is expressed as percentage of the number of living cells in control cultures. Symbols represent means. P < 0.001 (cell-free) and P < 0.0001 (cellular) for dose-dependent formation of the unique radical by both MWCNTLNL1 and MWCNTLNL2.