<p>Rabbit annulus fibrosus cells were cultured in a pellet culture system, for three weeks, with chondrogenic medium or control medium (DMEM+1%FBS+1% ITS). A) Gross morphology of cell-pellet. B) GAG in the cell-pellet was measured with the dimethymethylene blue colorimetric assay using chondroitin sulfate as a standard; values are normalized to cell DNA content. C) Expression of collagen II and aggrecan genes are significantly increased in the chondrogenic culture medium compared to control medium. D) Representative images of Safranin-O staining for proteoglycan and immunostaining for type II collagen in the cell-pellet. Scale bar = 500 µm. * p<0.05; ** p<0.01.</p
