Feasibility of repairing articular cartilage defects with particulated juvenile cartilage allograft / 中国组织工程研究

ABSTRACT

BACKGROUND: Particulated juvenile cartilage allograft is simple and easy to obtain, and relevant clinical studies are underway in the USA. However, how the transplanted juvenile cartilage fragments exert biological effects through biochemical mechanisms and genetic signal transduction is still unclear. There is as yet no report on this technology in China. OBJECTIVE: To explore the feasibility of articular cartilage defects repaired with particulated juvenile cartilage allograft. METHODS: The cartilage fragments were obtained from juvenile Pitman-Moore strains (provided by the Laboratory Animal Center of the Army Medical University in China) and cultured in vitro. Brdu immunofluorescence assay was performed at 1, 3, and 7 days of culture. The particulated juvenile cartilage allograft/fibrin gel composites were subcutaneously transplanted into the SCID rats (provided by the Laboratory Animal Center of the Army Medical University). The specimens were taken for hematoxylin-eosin staining, safranin O staining and immunohistochemistry after 1 month. Cartilage defects of 8 mm in diameter were made in the knee joint of 10 adult Pitman-Moore strains (Laboratory Animal Center of the Army Medical University), and were randomized into two groups, which were then transplanted with the particulated juvenile cartilage allograft/fibrin gel composites (experimental group) or nothing (control group). The specimens were taken for hematoxylin-eosin staining, safranin O fast green staining, toluidine blue and immunohistochemistry at 3 months after transplantation. RESULTS AND CONCLUSION: Little Brdu incorporation was detected in juvenile cartilage fragments at 1 day of culture, some Brdu incorporation was defected at 3 days of culture. At 7 days of culture, a progressive increase in the Brdu signal was detected in chondrocytes within the cultured cartilage fragments, which seemed to localize along the tissue edge. At 1 month after subcutaneous transplantation, the particulated juvenile cartilage allograft still survived and were surrounded by few proliferative chondrocytes. There was no obvious tissue repair in the control group at 3 months after transplantation. In the experimental group, there was obvious tissue repair, the color of the newly formed tissues was similar to the normal cartilage tissue, which integrated well with the surrounding normal cartilage tissue, and the cells distributed evenly. These results imply that particulated juvenile cartilage allograft can achieve good results in repairing articular cartilage defects.