Fig. 7. In vitro cytotoxicity and TNF-α release from macrophages (RAW 264.7 cells) in response to treatment with silk nanoparticles. (A) For cytotoxicity tests, 2.5 to 100 μg mL⁻¹ of 110 nm and 215 nm silk nanoparticles (SNPs) were incubated with the cells for 48 h. (B) The TNF-α release into culture supernatants was quantified following a 24 h of exposure to 15 ng of LPS (positive control) or 10 μg mL⁻¹ and 500 μg mL⁻¹ of 110 nm and 215 nm silk nanoparticles and compared to release by untreated control cells (basal TNF-α levels). Dunnett's post hoc test was used to evaluate statistical differences between the basal and the samples. Error bars are hidden in the plot-symbol when not visible, ±SD, n = 3.