Repair of articular cartilage defect with layered chondrocyte sheets and cultured synovial cells

In this study, we investigate the effects of treatment with layered chondrocyte sheets and synovial cell transplantation. An osteochondral defect was created of 48 Japanese white rabbits. In order to determine the effects of treatment, the following 6 groups were produced: (A) synovial cells (1.8 × 106 cells), (B)layered chondrocyte sheets (1.7 × 106 cells), (C) synovial cells (3.0 × 105 cells) + layered chondrocyte sheets, (D)synovial cells (6.0 × 105 cells) + layered chondrocyte sheets, (E)synovial cells (1.2 × 106 cells) + layered chondrocyte sheets, (F) osteochondral defect. Layered chondrocyte sheets and synovial cells were transplanted, sacrificed four and 12 weeks postoperatively. An incapacitance tester (Linton) was used to find trends in the weight distribution ratio of the damaged limbs after surgery. Sections were stained with Safranin-O. Repair sites were evaluated using ICRS grading system. In groups (A) to (E), the damaged limb weight distribution ratio had improved. The repair tissue stained positively with Safranin-O. Four and 12 weeks after surgery, groups (A) to (E) exhibited significantly higher scores than group (F), and groups (D) and (E) exhibited significantly higher scores than groups (A) and (B). This suggests the efficacy of combining layered chondrocyte sheets with synovial cells.