Rostock University Medical Center, Department of Orthopedics, Biomechanics and Implant Technology Laboratory, Rostock, Germany.
Rostock University Medical Center, Core Facility Multimodal Small Animal Imaging, 18057 Rostock, Germany.
Biomed Res Int. 2018 Aug 8;2018:6432742. doi: 10.1155/2018/6432742. eCollection 2018.
In the present study, a newly introduced bovine cross-linked collagen scaffold (test material) was investigated in vivo in an Achilles tendon defect model and compared to a commercially available porcine collagen scaffold (control material). In total, 28 male Sprague Dawley rats (about 400 g) were examined. The defined Achilles tendon defect of 5 mm of the right hind limb was replaced by one of the scaffold materials. After euthanasia, the hind limbs were transected for testing. Biomechanical evaluation was carried out via tensile testing (n = 8 each group, observation time: 28 days). Nonoperated tendons from the bilateral side were used as a control (native tendon, n = 4). For the histological evaluation, 12 animals were sacrificed at 14 and 28 days postoperatively (n = 3 each group and time point). Stained slices (Hematoxylin & Eosin) were evaluated qualitatively in terms of presence of cells and cell migration into scaffolds as well as structure and degradation of the scaffold. All transected hind limbs were additionally analyzed using MRI before testing to verify if the tendon repair using a collagen scaffold was still intact after the observation period. The maximum failure loads of both scaffold materials (test material: 54.5 ± 16.4 N, control: 63.1 ± 19.5 N) were in the range of native tendon (76.6 ± 11.6 N, p ≥ 0.07). The stiffness of native tendons was twofold higher (p ≤ 0.01) and the tear strength was approximately fivefold higher (p ≤ 0.01) compared to the repaired tendons with both scaffolds. Histological findings indicated that neither the test nor the control material induced inflammation, but the test material underwent a slower remodeling process. An overall repair failure rate of 48% was observed via MRI. The experimental data of the newly developed test material showed similar outcomes compared to the commercially available control material. The high repair failure rate indicated that MRI is recommended as an auxiliary measurement tool to validate experimental data.
在本研究中，我们将一种新的牛交联胶原支架（试验材料）在体内跟腱缺损模型中进行了研究，并与市售的猪胶原支架（对照材料）进行了比较。总共检查了 28 只雄性 Sprague Dawley 大鼠（约 400g）。右侧后肢的 5mm 定义跟腱缺损由支架材料之一替代。安乐死后，后肢被截断进行测试。生物力学评估通过拉伸试验进行（每组 n = 8，观察时间：28 天）。双侧未手术的肌腱用作对照（天然肌腱，n = 4）。为了进行组织学评估，12 只动物在术后 14 天和 28 天（每组 n = 3，每组时间点）时被处死。染色切片（苏木精和伊红）在定性方面评估了细胞的存在及其向支架中的迁移，以及支架的结构和降解情况。在测试前，所有截断的后肢还使用 MRI 进行了分析，以验证在观察期后使用胶原支架修复的肌腱是否仍然完整。两种支架材料（试验材料：54.5 ± 16.4 N，对照：63.1 ± 19.5 N）的最大失效负荷均在天然肌腱（76.6 ± 11.6 N，p ≥ 0.07）范围内。天然肌腱的刚度高两倍（p ≤ 0.01），撕裂强度高约五倍（p ≤ 0.01），而两种支架修复后的肌腱均如此。组织学发现，试验材料和对照材料均未引起炎症，但试验材料的重塑过程较慢。通过 MRI 观察到整体修复失败率为 48%。新开发的试验材料的实验数据与市售对照材料的结果相似。高修复失败率表明 MRI 是验证实验数据的推荐辅助测量工具。
