Fig. 2.

a Viability (MTS assay) of H441 following aSNP treatment for 4 h in serum-free medium with different-sized Sicastar Red (30, 70, 300 nm). b Lactate dehydrogenase release (LDH) of H441 following aSNP treatment for 4 h with different-sized Sicastar Red (30, 70, 300 nm). Data are depicted as mean ± SD of 3 independent experiments with n = 3 samples for each treatment. For statistical analysis, two-way ANOVA with Bonferroni′s post-test was applied. *P < 0.05, **P < 0.01 and ***P < 0.001 compared to the untreated control (uc). 30 nm-sized aSNPs caused a reduced viability and an increased LDH release in H441 compared to the larger-sized aSNPs of 70 and 300 nm