Fig. 5From: Understanding the impact of more realistic low-dose, prolonged engineered nanomaterial exposure on genotoxicity using 3D models of the human liverRelease of IL-8 (pro-)inflammatory cytokines in 3D HepG2 liver spheroids following a prolonged (120 h) exposure using a single, bolus dosing regimen or a fractionated, repeated dosing regimen with 0.5 and 5.0 µg/mL of TiO2 and ZnO ENMs. An untreated, media only sample was used as the negative control whilst 0.25 µg/mL of TNF-α protein (NBP2-35,076-50ug, Biotechne, UK) was used as the positive assay control, as indicated by the red dotted line which represents the mean positive control response. Mean data of three biological replicates, analysed in triplicate (n = 9) are presented ± SEM. Significance indicated in relation to the negative control: * = p ≤ 0.05Back to article page