Co-Culture of Mesenchymal Stem Cells with Mature Chondrocytes: Producing Cartilage Construct for Application in Cartilage Regeneration

Background: cell-based treatment approach using differentiated mesenchymal stem cells (mscs) and mature chondrocytes has been considered as an advanced treatment for cartilage repair.we investigated the differentiated level of these two celltypes that is crucial for their repair capacity for cartilage defectat a co-culture micro mass system.methods: passaged-2 mscs isolated from the mouse bone marrow and the primary-cultured chondrocytes obtained from rat costal cartilage were mixed at different ratios including 1:1,1:2, and 2:1, and cultivated in the micro mass culture systems(experimental groups). both the mscs and chondrocytes alonein micro mass cultures were considered as the controls. after21 days, the cultures were sectioned and examined by toluidineblue staining. furthermore, the cells at different groups were analyzed by semiquantitative reverse transcription-polymerasechain reaction using the specific primers designed to detect the expression of both mouse and rat cartilage-specific genes.results: according to the toluidine blue staining, metachromaticstain appeared to be more intense at 1:2 ratios than the other groups. based on semiquantitative analysis, all coculture spossessed significantly more cartilage-specific geneexpression than the controls (p<0.01). while mouse aggrecanand collagen ii genes had significantly more expression at 1:2ratio, rat collagen ii gene was expressed in higher rate at coculturewith 2:1 ratio (p<0.01).conclusion: co-culture of mscs with mature chondrocytesseemed to provide an appropriate microenvironment whereby the two cell types exhibit higher differentiated phenotype than when they were cultured alone, and sufficient to be used as thecellular material for repair of cartilage defects.