Coculture of human synovial mesenchymal stem cells and chondrocytes to construct cell sheet for cartilage defect repair.

Cell sheet technology is applied to human articular chondrocytes to construct a tissue-like structure as an alternative treatment for cartilage defect. However, the dedifferentiation of chondrocytes during cell expansion is one of the barriers in chondrocyte sheet construction. In this study, we aim to reduce the number of dedifferentiated chondrocytes and incubation time for cell expansion. Human synovial mesenchymal stem cells (SMSCs) will be used as a model to develop coculture cells and construct the cell sheet. SMSCs is generally isolated from synovial tissue, which is accessible during arthroscopy. It has been reported that SMSCs can be differentiated into chondrocytes within chondrogenic environment. In this study, we the effects of morphological changes on the maintenance of chondrogenic capacity by observing the expression patterns of chondrogenic (collagen type II and aggrecan) and dedifferentiation (collagen type I) markers. After preparing chondrocyte sheets, the biological and mechanical properties of these tissues will be investigated. We propose that SMSCs could be used as a supporting cell to construct chondrocyte sheets by reducing the number of dedifferentiated chondrocytes and incubation time, which had the therapeutic potential for cartilage defect repair.