Cartilage Regeneration from Bone Marrow Cells Using RWV Bioreactor and Its Automation System for Clinical Application

Articular cartilage covers the end of bones in joints and determines the load-bearing characteristics and mobility of joints. It has a thin, smooth, low friction surface with a remarkable resiliency to compressive forces. In general, chondrocytes occupy lacunae in the matrix, and produce cartilaginous ECM (extracellular matrix), which consists of type II collagen (13%), proteoglycans (7%), and water (80%). Cartilage defects result from aging, joint injury, and developmental disorders, causing joint pain and loss of mobility. Articular cartilage is metabolically active, however, the chondrocytes have a slow turnover rate. Thus, articular cartilage might suffer progressive damage and degeneration with a limited spontaneous repair capability. Total joint arthroplasty is the final choice of treatment, however, it is not suitable for young patients because of the limited life span of the artificial joint. Marrow-stimulating techniques such as microfracturing, multiple drilling, mosaicplasty and autologous chondrocyte implantation are clinically available for young patients, but have some limitations (Ikada, 2006). Marrowstimulating techniques result in a fibrocartilage with less mechanical strength than hyaline cartilage and only limited repair capacity. The major problems with mosaicplasty are a limited availability of autologous tissue and donor site morbidity, the destruction of healthy non-weight-bearing tissue to repair diseased tissue. Autologous chondrocyte transplantation with a periosteal graft has shown encouraging results, however, predictability and reliability are still questionable. Ochi et al. (2002) showed a clinical advantage of transplanting autologous chondrocytes cultured in collagen gel for the treatment of full-thickness defects of cartilage in 28 knees over a minimum period of 25 months. Arthroscopic assessment indicated that 26 knees (93%) had a good or excellent outcome. Wakitani et al. (2002) applied cell transplantation to repair human articular cartilage defects in osteoarthritis knee joints. The study group comprised 24 patients with knee OA. Adherent cells expanded from bone marrow aspirates were embedded in collagen gel and transplanted into the articular cartilage defects of 12