Comparison of chondrogensis in static and perfused bioreactor culture

As a result of the low yield of cartilage from primary patient harvests and a high demand for autologous cartilage for reconstructive surgery and stru ctural repair, primary explant cartilage must be augmented by tissue engine ering techniques. In this study, chondrocytes seeded on PLLA/PGA scaffolds in static culture and a direct perfusion bioreactor were biochemically and histologically analyzed to determine the effects of fluid flow and media pH on matrix assembly. A gradual media pH change was maintained in the biorea ctor within 7.4-6.96 over 2 weeks compared to a more rapid decrease from 7. 4 to 6.58 in static culture over 3 days. Seeded scaffolds subjected to 1 mu m/s flow demonstrated a 118% increase (p < 0.05) in DNA content, a 184% in crease (p < 0.05) in GAG content, and a 155% (p < 0.05) increase in hydroxy proline content compared to static culture. Distinct differences were noted in tissue morphology, including more intense staining for proteoglycans by safranin-O and alignment of cells in the direction of media flow. Culture of chondrocyte seeded matrices thus offers the possibility of rapid in vitr o expansion of donor cartilage for the repair of structural defects, trache al injury, and vascularized tissue damage.