STANDARDIZATION OF NUTRIENT MEDIA FOR ISOLATED HUMAN ARTICULAR CHONDROCYTES IN GELIFIED AGAROSE SUSPENSION-CULTURE

Human articular cartilage cells were cultured in 1.5% agarose in Dulbe cco's modified Eagle's medium (DMEM) with 10% fetal calf serum or in s erum-free DMEM with 0.15% bovine serum albumin. S-35-aggrecan synthesi s in serum-free DMEM was between 20% and 30% of the value observed in DMEM supplemented with 10% fetal calf serum. The extent to which diffe rent growth or differentiation factors were able to restore S-35 incor poration in aggrecan in serum-free DMEM was determined: human serum tr ansferrin had no effect on aggrecan synthesis levels; bovine pancreas insulin, insulin-like growth factor (IGF)-1 and IGF-8 restored S-35-ag grecan synthesis to 35-50% of the control levels. The effects were dos e-dependent, to level off at 100 ng/ml for the three factors. No cumul ative or synergistic activities were observed when these factors were combined. Transforming growth factor (TGF)beta, at concentrations rang ing from 10-50 ng/ml stimulated aggrecan synthesis to approximately 50 % of the control values in the chondrocytes obtained from two out of f our donors, while the cells of the other two maintained within the ran ge of the control levels. In the presence of insulin (100 ng/ml) 10 ng /ml of TGF-beta stimulated aggrecan synthesis to more than 90% of the control level in the chondrocytes of all donors.