Fig. 1

Cell viability of primary chondrocytes treated with CSE. Serum-starved primary chondrocytes were treated for 72 h with varying concentrations of CSE (up to 40 μg/ml). Cell-viability was evaluated using a MTT-based proliferation assay. The experiment was repeated twice with cells from different donors, and each experimental condition was set up in quadruplicate. Mean values and standard deviations are given with respect to untreated cells (100% viability). *indicates significant differences with respect to untreated controls (P < 0.05)