Figure 1

Cell culture models. (A) Bone marrow-derived stem cells (BMSCs), mixed cultures (BMSCs and chondrocytes in a ratio of 1:1), and chondrocytes were embedded in fibrin gels and applied onto the surface of osteoarthritis articular cartilage explants (co- and tri-cultures). As controls, cells were embedded in fibrin gels and cultured without cartilage (monocultures). All experimental setups were kept for up to 28 days in chondrogenic medium. Samples were harvested at days 7 and 28. Chondrocytes, BMSCs, and cartilage explants were not used autologous, and each “N” represents different donors. (B) Representative overview of alcian blue stained fibrin gels of BMSCs, mixed cultures (BMSCs + chondrocytes 1:1), and chondrocytes after 28 days of mono-, co-, or tri-culture with osteoarthritis cartilage. F, monocultures (without cartilage explants); FC, co- and tri-cultures with cartilage explants.