Human Embryonic Stem Cell-derived Mesenchymal Stem Cells and BMP7 Promote Cartilage Repair

ESCs are pluripotential, but their application for cartilage regenration has not been explored. Our study was designed to explore a strategy of using human embryonic stem cell-derived mesenchymal stem cells(hESC-MSCs) with BMP7 in collagen scaffold to improve the therapeutic efficacy of cartilage defect repair. Full-thickness cartilage defects (diameter=2mm, thickness=2 mm) were made in the patellar grooves of male SD rat and randomly divided into four groups: No treatment group, collagen scaffold group, hESC-MSCs in collagen scaffold group or hESC-MSCs with BMP7 in collagen scaffold group, respectively (n=11 in each group). The rats were sacrificed at 4 and 8 weeks after operation. The repaired tissues were processed for histology and for mechanical test. The histological results showed that the group treated with hESC-MSCs had more amounts of hyaline cartilage, higher ICRS histological scores and Voting's modulus of the repaired cartilage tissue. Moreover, hESC-MSCs with BMP7 group had the highest histological scores and Voting's modulus of the repaired cartilage tissue. The amounts of hyaline cartilage were significantly higher than those in hESC-MSCs group. Our results demonstrated that hESC-MSCs can improve the regeneration of cartilage tissue. It acts synergistically with BMP7 in stimulating the formation of hyaline cartilage tissues. These findings suggested that the combination of hESC-MSCs with BMP7 in collagen matrix may be used to improve the quality of cartilage repair.