Fig. 4

The cytotoxicity (a) of neutral-FLG, amine-FLG, carboxyl-FLG and CB upon differentiated THP-1 macrophages was determined by Trypan blue exclusion following a 24-h exposure. Supernatant was harvested and the (pro)-inflammatory response was quantified by analysing the release of IL-8 (b). THP-1 cells which had undergone differentiation following a PMA treatment at 50 nM for 24 h were then exposed to ENMs for a further 24 h. IL-8 levels in the d.THP-1 cells were quantified including an additional exposure with LPS (100 ng/ml) serving as a positive control. Results were considered significant (*) when p < 0.05. N = 3