Fig. 4

Determination of LDH activity a and the release of IL-18 b-c, as well as microscopic images d after treatment of human osteoblasts (n ≥ 4) with TNF or CoCr particles and subsequent activation with CoCr particles. Morphological changes were identified by staining the cytoskeleton with Phalloidin and counterstaining the nuclei with DAPI. The picture in the lower right corner shows a darkfield image of the osteoblasts exposed to the different stimuli. The bright, white specks indicate the location of the particles. The microscopic pictures were taken with the CytoViva® Enhanced Darkfield Hyperspectral Microscope System with a 60 × objective d. Statistical significance was determined by two-way ANOVA followed by Bonferroni as a post hoc test a-d. For comparisons between 4 h ± 45 min and 72 h ± 45 min, the Shapiro–Wilk test was first used to test for normal distribution and then the Mann–Whitney test was used to determine statistical significance c-d: ***p < 0.001, *p < 0.05; ^####p < 0.0001 ^##p < 0.01 (Significance to untreated control of the corresponding time point); °p < 0.05 (Significance between 4 and 72 h or 4 h + 45 min and 72 h + 45 min between c and d); Bar: 50 µm