Figure 2.

Release of MMP3 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=4; macrophages, n=3). MMP3 contents are displayed relative to the untreated control. Data are presented as box plots. ^*P≤0.05 and ^**P<0.01 vs. particle exposure. °P≤0.05 vs. 0.01 mg/ml (Mann-Whitney U test). MMP, matrix metalloproteinase; PMMA, polymethylmethacrylate; ZrO₂, zirconiumoxide; TiO₂, titanium dioxide.