Comparison of mesenchymal stem cells from bone marrow, umbilical cord blood, and umbilical cord tissue in regeneration of a full-thickness tendon defect in vitro and in vivo

Although mesenchymal stem cells (MSCs) can be obtained from various tissues such as bone marrow (BM), umbilical cord blood (UCB) and umbilical cord tissue (UC), the comparative efficacy of each MSC in tendon regeneration is unknown. Therefore, we investigated the efficacy of MSCs isolated from three different sources on tendon regeneration after injury. We evaluated the potential of BM-, UCB- and UC-MSC to differentiate into tendon-like cells in tensioned three-dimensional construct (T-3D) using gene and histological analysis. In animal experiments, full-thickness tendon defect (FTD) was created in supraspinatus of rats, and injected with Saline and BM-, UCB- and UC-MSC. After two and four weeks, histological evaluations were performed. After inducing tenogenic differentiation, the gene expression of scleraxis, mohawk, type I collagen and tenascin-C was upregulated by 3.12-, 5.92-, 6.01- and 1.61-fold respectively and formation of tendon-like matrix was increased 4.22-fold in UC-MSC compared to BM-MSC in T-3D. In animal experiments, the total degeneration score was lower in the UC-MSC group than in BM-MSC group at both weeks. In heterotopic matrix formation, glycosaminoglycan-rich area was reduced in the UC-MSC group, whereas area was larger in the BM-MSC group than in Saline group at four weeks. In conclusion, UC-MSC is superior to other MSCs in differentiating into tendon-like lineage cells and forming a well-organized tendon-like matrix under T-3D conditions. UC-MSC enhances regeneration of FTD in terms of histological properties compared to BM- and UCB-MSC.