Synthesis rate of sGAG in chondrocytic pellet cultures under (A) hypoxic and (B) normoxic culture conditions. Human chondrocytes were cultured as pellet cultures and stimulated with TGF-β1 and/or IGF-1. After 24, 48, 72 h as well as 14 and 35 days, supernatants of each stimulating experiment were digested overnight with papain (65°C) and afterwards analysed by Blyscan. The sGAG content was calculated using a defined standard curve and related to the total protein content (µg/mg). Data in the diagrams are presented as box plots with median, interquartile ranges and minimum/maximum values (n=3). Additionally, dots within boxes indicate the mean values. No statistical significance was detected (Wilcoxon Test). sGAG, sulphated glycosaminoglycan; TGF-β1 transforming growth factor-β1; IGF-1, insulin-like growth factor-1.