The use of growth factors in the proliferation of avian articular chondrocytes in a serum-free culture system

The purpose of this research was to develop a serum-free culture system for the proliferation of articular chondrocytes. Various growth factors and ho rmones were tested for their ability to stimulate avian articular chondrocy te proliferation in a defined, serum-free media. Multiple members of the fi broblast growth factor (FGF) family (FGFs: 2, 4, and 9), insulin-like growt h factor-1 (IGF-1) and transforming growth factor beta (TGF-beta) significa ntly stimulated H-3-thymidine uptake by chondrocytes grown in an adherent s erum-free, culture system. Double or triple combinations of these mitogenic growth factors further stimulated cell proliferation to levels that were e quivalent to, or surpassed those of cells grown in serum. Although prolifer ation was maximally stimulated, chondrocytes grown in the presence of FGF-2 , IGF-1, and TGF-beta, began to exhibit changes in morphology and collagen II expression declined. This culture system could be used to rapidly expand a population of articular chondrocytes prior to transferring these cells t o a non-adherent culture system, which could then stabilize the chondrocyte phenotype and maximize matrix synthesis and integrity.