METHODS: In our study, forty-four 9-week-old male C57/BL6 mice underwent transection and reattachment of the Achilles tendon insertion to investigate tendon-to-bone healing. At 2 and 4 weeks postoperatively, mice were killed for histological, Micro-CT, biomechanical, and real-time polymerase chain reaction tests.
RESULTS: Histological staining revealed that the original tissue structure was disrupted and replaced by a fibrovascular scar. Although glycosaminoglycan deposition was present in the cartilage area, the native structure had been destroyed. Biomechanical tests showed that the failure force constituted approximately 44.2% and 77.5% of that in intact tissues, and the ultimate tensile strength increased from 2 to 4 weeks postoperatively. Micro-CT imaging demonstrated a gradual healing process in the bone tunnel from 2 to 4 weeks postoperatively. The expression levels of ACAN, SOX9, Collagen I, and MMPs were detected, with all genes being overexpressed compared to the control group and maintaining high levels at 2 and 4 weeks postoperatively.
CONCLUSIONS: Our results demonstrate that the healing process in our model is aligned with the natural healing process, suggesting the potential for creating a new, efficient, and reproducible mouse animal model to investigate the cellular and molecular mechanisms of tendon-to-bone healing.
方法:在我们的研究中,44只9周龄的雄性C57/BL6小鼠进行了横切和跟腱插入的重新连接,以研究肌腱到骨的愈合。术后2周和4周,小鼠因组织学而被杀死,Micro-CT,生物力学,和实时聚合酶链反应测试。
结果:组织学染色显示原始组织结构被破坏并被纤维血管瘢痕所取代。尽管软骨区域存在糖胺聚糖沉积,原生结构已被摧毁。生物力学测试表明,破坏力约占完整组织的44.2%和77.5%,极限抗拉强度从术后2周增加到4周。Micro-CT成像显示,术后2至4周,骨隧道逐渐愈合。ACAN的表达水平,SOX9,胶原蛋白I,并检测到MMPs,与对照组相比,所有基因都过表达,并在术后2和4周保持高水平。
结论:我们的结果表明,我们模型中的愈合过程与自然愈合过程一致,暗示了创造新的潜力,高效,和可重复的小鼠动物模型,以研究腱-骨愈合的细胞和分子机制。