ACI and MACI procedures for cartilage repair utilise mesenchymal stem cells rather than chondrocytes.

摘要

Mature articular cartilage shows only a limited capacity for repair due to the lack of inherent repair mechanisms. For younger patients with focal articular cartilage defects, there is increasing interest in the potential of cell-based strategies to provide a biological replacement of damaged cartilage [1 ]. Autologous chondrocyte implantation (ACI) has been used for the repair of focal cartilage defects combined with a membrane sutured to the edge of the cartilage defect [2], or alternatively, the cells are embedded in a collagen matrix (MACI) [3]. These procedures involve harvest of normal cartilage from the patient, digestion of tissue and release of cells assumed to be autologous chondrocytes that are then expanded in culture ex vivo. When a sufficient number of cells have been obtained, these cells are inserted back in the cartilage defect. Mesenchymal stem cells (MSCs) are a self-renewing cell population derived from the mesoderm that exhibits an ability to undergo multilineage differentiation into many cell lines including chondrocytes under appropriate culture conditions [4]. MSCs have been isolated from many different adult tissues including bone marrow, and more recently, albeit in small numbers, cartilage [5].