CHONDROGENESIS IN A CELL-POLYMER-BIOREACTOR SYSTEM

Chondrogenesis was studied under controlled in vitro conditions using a cell-polymer-bioreactor system. Bovine calf articular chondrocytes w ere seeded onto biodegradable polymer scaffolds and cultured in rotati ng bioreactor vessels. Concomitant increases in the amounts of glycosa minoglycan (GAG) and type II collagen resulted in cell-Polymer constru cts with continuous cartilaginous matrix over their entire cross secti ons (6.7 mm diameter x 5 mm thick) after 40 days of cultivation. As co mpared to natural calf cartilage, constructs had comparable cellularit ies, 68% as much GAG and 33% as much type II collagen per gram wet wei ght, The progression of chondrogenesis in chondrocyte-polymer construc ts was similar to that suggested previously for precursor cells in vit ro and developing limbs in vivo. In particular, the polymer scaffold p rovided a three-dimensional structure that could be seeded with chondr ocytes at high cell densities in order to establish cell-to-cell contr acts and initiate cartilage tissue development, whereas the bioreactor vessel provided a permissive microenvironment for chondrogenesis. Thi s work demonstrates the promise of using tissue engineered constructs for in vitro studies of cell interactions and differentiation. (C) 199 8 Academic Press.