关键词: 软骨缺损, 复合支架, 兔龄, 胶原/丝素蛋白

Abstract: Objective　To investigate the repair effect of collagen/silk fibroin composite scaffolds on knee joint cartilage defects in rabbits of different ages. It provides a reference for the selection of age appropriate animals in knee joint cartilage defect models.Methods　Twenty-four New Zealand white rabbits were divided into three age groups, 3, 6, and 9 months, with 8 rabbits in each group. A bone cartilage defect model was established in the medial condyle of both femurs of the rabbits. Collagen/silk fibroin composite scaffolds were implanted in the defect site of right knee (scaffold group), while the left knee remained untreated as a blank control (control group). At 6 and 12 weeks post-surgery, four rabbits (containing eight joints) of each age group were euthanized and the bilateral knne joints were dissected for morphological examination. Histological evaluation was conducted according to the International Cartilage Repair Society (ICRS) histological scoring criteria, with HE staining and safranin O-fast green staining used for analysis. The repair effects were compared across groups.Results　At 6 weeks post-surgery, there was no significant difference in the ICRS scores between the 3-month scaffold group and control group. The ICRS scores of the 6-month scaffold group were significantly higher than those of control group (P<0.05), while no significant difference was observed between the 9-month scaffold group and control group. At 12 weeks post-surgery, the trends in ICRS score comparisons between scaffold groups and control groups for the 3, 6, and 9-month groups were consistent with those at 6 weeks. HE staining and safranin O-fast green staining indicated no significant difference in repair between the 3-month scaffold group and control group at both 6 and 12 weeks. The 6-month scaffold group showed significantly better repair than control group, while no significant difference was found in the repair between the 9-month scaffold group and control group.Conclusion　There are differences in the repair of cartilage damage in rabbits across different age groups when using collagen/silk fibroin composite scaffolds, suggesting a relationship between cartilage repair and age. In this study, 6 months age are deemed suitable for the rabbit knee joint cartilage defect model.

Key words: cartilage defect, scaffold, age of rabbit, collagen/silk fibroin