Repair of Osteochondral Defects Using Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells in a Rabbit Model

Figure 3

Total gross appearance and histological results of representative samples. (a) 3 months’ group, (b) 6 months’ group, and (c) 12 months’ group. The histological analysis included hematoxylin and eosin (H&E) and toluidine blue staining. Animals were randomly assigned to four groups: (A) untreated group, (B) extracellular matrix (ECM) scaffold alone group, (C) ECM scaffold loaded with human umbilical cord Wharton’s jelly mesenchymal stem cells (hWJMSCs) group, and (D) ECM scaffold loaded with hWJMSC-Cs group (hWJMSC-Cs-ECM). Only empty defects but no repaired tissues were detected in the untreated and scaffold alone groups 3 months after implantation. The defects were partially repaired with hyaline cartilage in the hWJMSCs-ECM group, whereas most defects were filled with fibrous tissue in the hWJMSC-Cs-ECM group. Partially repaired fibrosis tissue was found in the untreated and scaffold alone groups 6 months after implantation. Partial fibrocartilage or hyaline cartilage was found in the hWJMSCs-ECM and hWJMSC-Cs-ECM groups, and hyaline cartilage was more abundant in the hWJMSCs-ECM group than in the hWJMSC-Cs-ECM group. Hyaline cartilage had completely bonded to adjacent cartilage, with restored and fully resurfaced subchondral bone in the hWJMSCs-ECM group 12 months after implantation. The concave open boxes became smaller than before and were repaired with hyaline cartilage in the hWJMSC-Cs-ECM group. However, all defects in the untreated and scaffold groups were repaired with fibrosis tissue. Bar: 200 μm.

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