Long-term storage and preservation of tissue engineered articular cartilage.

With limited availability of osteochondral allografts, tissue engineered cartilage grafts may provide an alternative treatment for large cartilage defects. An effective storage protocol will be critical for translating this technology to clinical use. The purpose of this study was to evaluate the efficacy of the Missouri Osteochondral Allograft Preservation System (MOPS) for room temperature storage of mature tissue engineered grafts, focusing on tissue property maintenance during the current allograft storage window (28 days). Additional research compares MOPS to continued culture, investigates temperature influence, and examines longer-term storage. Articular cartilage constructs were cultured to maturity using adult canine chondrocytes, then preserved with MOPS at room temperature, in refrigeration, or kept in culture for an additional 56 days. MOPS storage maintained desired chondrocyte viability for 28 days of room temperature storage, retaining 75% of the maturity point Young's modulus without significant decline in biochemical content. Properties dropped past this time point. Refrigeration maintained properties similar to room temperature at 28 days, but proved better at 56 days. For engineered grafts, MOPS maintained the majority of tissue properties for the 28-day window without clearly extending that period as it had for native grafts. These results are the first evaluating engineered cartilage storage.