Chemical stabilization of cartilage matrix.

Severe destruction of articular cartilage in osteoarthritis manifests clinically when repair processes cannot keep up with the catabolic processes. Loss of proteoglycans, which give the tissue its ability to undergo reversible deformation, precedes and probably contributes significantly to breakdown of the matrix in the most superficial layers of articular cartilage. In this study, we have examined the ability of dithiobis[succinimidyl propionate], a bifunctional reagent with a 1.2-nm span that cross-links proteins at lysine amino acid, and poly-L-lysine of high molecular weight (average MW 360,000) to reduce passive loss of proteoglycans and collagen from thin slices (40 and 200 microns) of bovine nasal and human patellar cartilage incubated for 7 days in buffer at 4 degrees C. We present evidence that treatment of thin slices of cartilage with either of these agents is effective in reducing the loss of proteoglycans and collagen from the cartilage matrix and we define conditions (length of treatment and concentrations required) under which the stabilization of the cartilage matrix is optimized. Chemical stabilization of cartilage matrix may become an important modality of treatment in osteoarthritis by protecting the environment around chondrocytes during the repair process.