One of our goals in the field of tissue engineering is to develop the remodeled artificial cartilage for the treatment of cartilage defects. Many studies described that intermittent hydrostatic pressure stimulation is efficient in culturing for chondrocytes, because the internmittent HSP could keep the specific ability of chondrocytes to synthesize aggrecan and type2collagen. In this work we constructed the culturing system with intermittent hydrostatic pressure, which can control the gas pressure of pCO_2, pO_2 and frequency of HSP around chondrocytes. In addition we studied the effects of hydrostatic pressure on gene expression of the chondrocytes. Primary cultures of bovine chondrocytes were exposed to hydrostatic pressure applied intermittently 0.5Hz, 3.5MPa for 4 or 24 hours a day in medium containing 10% fetal bovine serum and cultured for 4 days. As the result, we found that the hydrostatic pressure reduced the expression of type1collagen-mRNA, also enhanced that of type2collagen and kept that of aggrecan-mRNA. Therefore, this newly constructed pressure system must be an efficient tool to investigate the appropriate hydrostatic pressure pattern for remodeling of artificial cartilage in the future.
