Effect of growth factors on matrix synthesis by human nasal chondrocytes cultured in monolayer and in agar

Reconstructive surgery of multiple areas of the body may require replacement bone or cartilage transplants to repair defects or lesions of skeletal tissue. Advances in cell and tissue culture techniques now permit synthesis of autologous human cartilage in vitro. Several growth factors regulate the metabolism and activation of cartilage cells. To enhance culture conditions and effectiveness for in vitro cartilage engineering, the aim of our investigations was to characterize the influence of transforming growth factor (TGF)-beta and basic fibroblast growth factor (bFGF) on human nasal septal chondrocytes. The isolated cells were cultured as monolayers on plastic and in soft agar. The biological effects of the growth factors were assessed by determining synthesis of total protein and proteoglycan. TGF-beta caused a dose-dependent stimulation of total protein as well as glycosaminoglycan synthesis by all chondrocytes cultured. This stimulatory effect of TGF-beta was greater for chondrocytes cultured in soft agar than for chondrocytes cultured on plastic. No stimulatory effects of matrix synthesis was observed for bFGF in either culture condition. Our results show that TGF-beta can be employed to enhance in vitro production of cartilage grafts for reconstructive surgery.