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

摘要： 目的　探讨胶原/丝素蛋白复合支架对不同年龄兔膝关节软骨缺损的修复效果,为兔膝关节软骨缺损模型构 建中适龄兔的选择提供理论依据。方法　普通级健康新西兰兔24只,按月龄分为3、6、9月龄组,每组8只。新西 兰兔双侧股骨滑车切迹处制备骨软骨缺损模型,右侧关节缺损处植入胶原/丝素蛋白复合支架(支架组),左侧缺损 处未予处理作为空白对照(对照组)。术后6周、12周各组分别安乐死实验兔4只,解剖取材双膝关节,进行形态学 观察。根据国际软骨修复协会(ICRS)组织学评分标准进行组织修复评分,采用HE染色和番红O-固绿染色进行组 织学评估,比较各组修复效果的差异。结果　术后6周,3月龄支架组与对照组的ICRS 评分无显著差异;6月龄支 架组ICRS评分显著高于对照组(P<0.05);9月龄支架组ICRS评分与对照组无显著差异。术后12 周,3、6、9月龄 支架组与对照组ICRS评分比较的趋势与术后6周一致。HE 染色与番红O-固绿染色表明,术后6周和12周,3月 龄支架组与对照组的修复无明显差异;6月龄支架组明显优于对照组;9月龄支架组与对照组的修复无明显差异。 结论　胶原/丝素蛋白复合支架对不同年龄组兔软骨损伤修复作用存在差异,提示软骨损伤后的修复与年龄间存 在相关性,6月龄是兔膝关节软骨缺损模型构建的理想兔龄。

关键词: 软骨缺损, 复合支架, 兔龄, 胶原/丝素蛋白