Fig. 4. In vitro effects of the pSiNRs without or with SPIONs, and without or with NFL-peptides (BIOT or FAM) on mitochondrial activity of rat glioblastoma cells (F98). Cells were treated with the formulations (25, 50, 100 or 200 μg mL⁻¹) or with the positive control colchicine (col, 1 μg mL⁻¹), for 72 hours, and mitochondrial activity was evaluated by MTS assay. Experiments were performed at least in triplicate. Data are represented as mean ± SEM. Statistical analysis was performed with Student's t-test (**p < 0.005 and ***p < 0.001).