Figure 5.

Passages induce alteration of HAC phenotype, which is reversed by alginate culture. Human articular chondrocytes were passaged twice and subsequently maintained in culture for 7 d. At the end of the incubation, RNA was extracted and reversed transcribed. Then, aggrecan, COL2A1, COL1A1, COL1A2 and COL3A1 mRNA levels were assayed by real-time PCR (A). P3 (at three passages) HACs were also cultured 1 or 21 d in alginate beads (B–D,) and collagen mRNA levels were assayed by real-time PCR (B). ***P < 0.001; **P < 0.01; *P < 0.05 versus controls. P3, at three passages.