Stimulation of fibrin gel monocultures with IL-1ß, IL-6 or IL-8 for 7 days. BMSC (white bars), mixed cultures (BMSC + chondrocytes 1:1, grey bars) or chondrocytes (black bars) embedded in fibrin gel were stimulated for 7 days with 5 ng/ml IL-1ß, 5 ng IL-6 or 10 ng IL-8 in chondrogenic medium-containing dexamethasone and TGF-ß-3. Specimens were analyzed for gene expression of aggrecan (ACAN), matrix metalloproteinase (MMP)2, MMP3 and MMP13 at day 7. The log fold change (log2) was calculated via a calibrator that represents the unstimulated monocultures and is represented by a line at 0. Results are mean with standard deviation (SD). N =5; *P <0.05, **P <0.01, ***P <0.001. BMSC, bone marrow-derived mesenchymal stem cells; IL-1ß, interleukin; IL-6, interleukin-6; IL, interleukin-8; TGF, transforming growth factor.