Chondrocyte physiopathology and drug efficacy.

After a brief exposition on the physiopathology of cartilage, and characteristic features of chondrocytes and proteoglycans (PGs) in osteoarthritis (OA), it is underlined how different molecules of GAGs and aggregated PGs added to the culture media can prevent damage and reduction of GAGs and fibril production in chondrocytes cultured with NSAIDs and corticosteroids. In animal models of OA, the local or general administration of GAGPS reduces the proteinase activity, the level of uronic acid in synovial fluid and the number of inflammatory cells in synovia. In the Pond-Nuki dog, GAGPS improves the cartilage surface. These favourable events can also occur in human OA, where it is, moreover, difficult to monitor the patients. For this purpose, patients must be selected in the first two stages of primary OA, and followed using NMR, the only device able to scan cartilage and subchondral bone, to determine their consistency and thickness, and to provide information on water content.