Figure 6.

Release of IL-8 by human (A) osteoblasts and (B) macrophages. Cells were cultivated under standard culture conditions and later treated with the respective particles for 48 h. Subsequently, cell culture supernatants were collected and analyzed using multiplex enzyme-linked immunosorbent assays (osteoblasts, n≥3; macrophages, n=3). IL-8 contents are displayed relative to the untreated control. ^*P≤0.05 and ^**P<0.01 vs. particle exposure. °P≤0.05 and °°P<0.01 vs. 0.01 mg/ml (Mann-Whitney U test). IL-8, interleukin 8; PMMA, polymethylmethacrylate; ZrO₂, zirconiumoxide; TiO₂, titanium dioxide.