Mesenchymal Stromal/Stem Cell- or Chondrocyte-Seeded Microcarriers as Building Blocks for Cartilage Tissue Engineering

In this study we have tested the use of mesenchymal stromal/stem cell (MSC)- or chondrocyte (hch)-laden microcarriers as building blocks for engineered cartilage tissue. MSCs and hchs expanded on microcarriers were used in chondrogenic coculture and compared with monoculture of MSCs or hchs. The use of cell-laden microcarriers as building blocks for cartilage tissue engineering led to a compact tissue formation with significant volume increase compared to the biomaterial-free approach. After 28 days of differentiation culture, formation of cartilaginous matrix in cocultures and chondrocyte monoculture approaches was observed. Coculture resulted in beneficial glycosaminoglycan deposition compared with monoculture of MSCs or chondrocytes attached to microcarriers. Further, the microcarrier-adhered coculture displayed increased levels of the differentiation marker ACAN and reduced levels of the dedifferentiation marker COL1A1. To our knowledge, this is the first article that successfully combines an innovative combination of cell expansion on microcarriers and the direct use of MSC- or hch-cell-laden microcarriers as building blocks in cartilage tissue engineering.