Effect of hydrostatic pressurization on chondrocyte differentiation

It has been hypothesized that intermittent hydrostatic pressure induces chondrocyte differentiation of mesenchymal stem cells. This hypothesis was tested in a murine mesenchymal stem cell (C3H/10T 1/2 embryo fibroblasts) micromass model culture system. The culture medium was supplemented with either 10 ng/mL or 100 ng/mL recombinant human bone morphogenetic protein, rhBMP-2. Cells were subjected to 90 minutes pressurization at 0.1 Hz to a peak stress of 585 kPa each day for 7 consecutive days. Control cultures were grown in the presence of rhBMP-2 but were not mechanically stimulated. Cell proliferation and total sulfated glycosaminoglycan (sGAG) content were quantified, and type II collagen content was qualitatively assessed. Contrary to what was expected, no differences were observed in the cell proliferation, total sGAG synthesized, or amount of type II collagen produced among the experimental and control groups.