Biochemical response of triple cell co-culture system following CNC exposure. (a) Tumor necrosis factor α (TNF-α) release, (b) Interleukin 8 (IL-8) release and (c) oxidative stress status of the in vitro triple cell co-culture model after exposure to c-CNCs (black) or t-CNCs (grey) to the three test concentrations (n = 3; +SEM). The respective controls are shown in white; DQ12 [0.23 ± 0.08 μg/cm2], LFA [100 μL of 0.05 mg/mL], LPS [100 μL of 1 μg/mL] and TBHP [250 μL of 100 mM]. Dashed lines (--- ) represent the level of the negative control. Data is presented as the fold increase relative to the negative control. TNF-μ and IL-8 data is expressed as a logarithmic scale (y-axis). * equals p < 0.05.