Chondrocytes seeded onto poly (L/DL-lactide) 80%/20% porous scaffolds: a biochemical evaluation

Repair of articular cartilage remains a clinical and scientific challenge. The use of implantable chondrocyte-seeded constructs offers a promising treatment option. The present study is focused on the culture of chondrocytes onto 3-D poly (L-/DL-lactide) 80%/20% porous scaffolds. Scaffolds were seeded with bovine articular chondrocytes and cultured for up to 42 days. After an initial decrease, although not significant, the DNA content of the constructs remained constant over the culture time. A progressive increase in glycosaminoglycans and collagen was observed in the constructs during the culture period. However, a significant release of matrix molecules into the culture medium also was noticeable. On the transcriptional level, aggrecan mRNA expression was highest on day 14 and gradually decreased thereafter. Procollagen I mRNA expression constantly increased whereas procollagen II mRNA expression decreased after day 14, indicating that cells were dedifferentiating. Histologic analysis of the constructs demonstrated the deposition of a proteoglycan-rich extracellular matrix by day 42 of culture. The present data demonstrate that poly (L-/DL-lactide) 80%/20% porous scaffolds support the development of a cartilage-like extracellular matrix. The limitations of the system are the diffusion of large amounts of matrix molecules into the culture medium and the dedifferentiation of the chondrocytes with prolonged time in culture.