Figure 3.

Cytotoxicity of LPS and SiO₂ particles, determined by lactate dehydrogenase (LDH) assay. J774A.1 macrophages were prestimulated with 1-µg/mL LPS for 24 h and post-treated with a single particle type or used for sequential or simultaneous co-exposure. As a control, supernatants from non-LPS-stimulated cells were analyzed. Data was normalized to the negative control (dotted line) and expressed as a fold increase in LDH release over the negative controls. TritonX (0.2%) served as a positive control for membrane rupture. One-way ANOVA (GraphPad Prism) was used for the statistical significance analysis (* p < 0.05).