Introduction
Articular cartilage is an avascular, aneural, and alymphatic tissue that has limited capacity to regenerate. Numerous techniques have been employed to repair or regenerate; however, the success rate varies. In fact, most of them result in the formation of fibrocartilage, not hyaline cartilage. The future of treating cartilage defects lies in providing biologic solutions through cartilage regeneration. Mesenchymal stem cells (MSCs) represent a promising therapy for cartilage regeneration. These cells secrete factors that enhance cartilage repair. In this study, the effects of intra-articular injection of human umbilical cord MSC (hUC-MSC) secretome on cartilage damage was studied in a sheep model and we combine microfracture and secretome injection to evaluate the capability of secretome in cartilage regeneration after microfracture.
Methods
Standardized rectangular full-thickness chondral defects were created in the lateral femoral condyle of 15 adult sheeps. Three treatment groups were tested: 4 microfracture perforations using 1.0mm diameter awls (group 1), intra-articular injection of hUC-MSC secretome (group 2), and combination of microfracture and intra-articular injection of hUC-MSC secretome (group 3). Osteochondral repair was assessed at 6 months using established macroscopic and histological analyses.
Results
Macroscopically, application of combined therapy shows significant improvement of cartilage repair compared to microfracture alone (p=0.004). Microscopically, the application of combined therapy shows significant improvement of cartilage repair compared to secretome injection alone (p=0.031)
Conclusion
Microfracture combined with injection of hUCB-MSCs secretome could be an effective alternative for repairing articular cartilage defects in vivo.