RESUMO
We investigated the feasibility of repairing cartilage defect with cultured mesenchymal stem cell from bone marrow. Mesenchyaml stem cells were aspirated from bone marrow of mature rabbits, and cultured in monolayer. Osteochondral defect was artificially made on the patellar groove of distal femur of the same rabbit, and fascia overlying quadriceps was harvested and sutured around the defect, then cultured mesenchymal cells were injected to the defects. Sixteen mature New Zealand white rabbits were used as experimental group and 13 rabbits were used as control. The rabbits were killed at after 14 weeks. Healing of defect was investigated histologically with H-E and toluidine blue staining, biochemically with immunohistochemical staining for Type II collagen, and also at molecular level through RT-PCR for mRNA of type II collagen. Semiquantitative histological scores were significantly higher in experimental group than thoese in control(P<0.05). Immunohistochemical staining showed high signal thor type II collagen on newly formed cartilage in the defect. RT-PCR detected mRNA for type II collagen from mature chondrocytes. Our data suggest that repair of cartilage defect can be enhanced with transplantation of cultured mesenchymal stem cell.