Figure 4

ROS production in SH-SY5Y and RAW 246.7 cells. The cells were incubated with MNP-PEI and MNP-PEI-PEG at 1.56 (white bar), 3.125 (light grey bar), 6.25 (grey bar), 12.5 (dark grey bar) and 25 μg mL^-1 (black bar) over a period of 72 h. A1 SH-SY5Y cells incubated with MNP-PEI, A2 RAW 246.7 cells incubated with MNP-PEI, B1 SH-SY5Y cells incubated with MNP-PEI-PEG, B2 RAW 246.7 cells incubated with MNP-PEI-PEG. Data were expressed as a percentage of control cells. (n = 3 ± SE). Asterisk denotes significant increase in the percentage of DCF fluorescence compared with control cells (p, 0.05).