ABSTRACT
Objective To examine matrix proteoglycan metabolic markers and probe into the turnover of matrix proteoglycan and enzyme-mediated role of matrix metalloproteinases (MMPs) and aggrecanases in reparative tissues with tissue engineering cartilage. Methods Tissue-engineered cartilage was constructed by cancellous bone matrix gelatin (BMG) with allogeneic chondrocytes in vitro for 2 weeks, then implanted to repair osteochondral defects of rabbit knee joint. Samples were obtained 6 months later to explore the expressions of 3-B-3(-) epitope, MMPs, MMP-generated epitope BC-4 and aggrecanases-generated epitope BC-13. Results In repaired tissues, the expression of 3-B-3(-) epitope increased, but that of MMPs and MMP-generated epitope BC-4 reduced. There was no expression of aggrecanases-generated epitope BC-13. Conclusion Expressions of 3-B-3(-), MMPs, BC-4 and BC-13 can help probe into the matrix proteoglycan turnover in reparative cartilage tissues. Anabolism exceeds catabolism in the repaired tissues. MMPs play an important role in the conservative baseline turnover of proteoglycan and remodeling of the graft tissues.