The effect of timing of glycosaminoglycan removal on decellularization and recellularization of cartilage

The intricate architecture of the extracellular matrix (ECM) may play an important role in providing the mechanical strength necessary to cushion and lubricate the joints. Therefore, one approach to cartilage tissue engineering is to decellularize cartilage so as to preserve the complex collagen network while removing immunogenic chondrocytes and use the remaining structure as a scaffold. In this study, porcine articular cartilage plugs were subjected to freeze-thaw cycles and detergent cycles to decellularize the ECM. Three variations of this protocol were tested, with chondroitinase ABC (chABC) added at a different time point in each protocol. ChABC was added to degrade glycosaminoglycans (GAGs) that may block cell exit, infiltration, or both. Decellularized samples were seeded with synoviocytes then cultured for 72 h. Later chABC treatment generally resulted in more GAG removal without affecting the DNA or collagen content significantly. H&E staining showed some successful chondrocyte removal from lacunae across all groups, but cellular remains were still present in the ECM.