Department of Bone Tumor, Tianjin Hospital, Tianjin, China.
Graduate School, Tianjin Medical University, Tianjin, China.
Orthop Surg. 2022 Oct;14(10):2657-2668. doi: 10.1111/os.13465. Epub 2022 Aug 24.
Pre-implantation sterilization procedures for tendons are important measures to reduce the risk of disease transmission, however these procedures may compromise tendon microarchitecture and biomechanical properties to varying degrees. We explore the effects of different sterilization procedures on the micro-histology, biomechanical strength and biochemical properties of human tendon allografts in vitro study.
The tendon allografts were harvested from cadaveric donors after the donors were serologically screened by antibody or nucleic acid testing of infectious agents. All samples were divided into five groups, which were fresh-frozen group (control group), 15 kGy gamma irradiation group, 25 kGy gamma irradiation group, 70% ethanol group, and peracetic acid-ethanol group. Each group included 10 tendons for testing. Histological staining and transmission electron microscopy were applied to observe the internal structure and arrangement of tendon collagen fibers, while the machine learning classifier was trained to distinguish the darker cross-sections of collagen fibers and brighter backgrounds of the electron micrograph to detect the distribution of diameters of tendon collagen fibers. The viscoelasticity, mechanical properties and material properties of tendon allografts were examined to detect the influence of different intervention factors on the biomechanical properties of tendons.
Histological staining and transmission electron microscopy showed that the structure of fresh-frozen tendons was similar to the structures of other experimental groups, and no obvious fiber disorder or delamination was observed. In the uniaxial cyclic test, the cyclic creep of 25 kGy irradiation group (1.5%) and peracetic acid-ethanol group (1.5%) were significantly lower than that of the control group (3.6%, F = 1.52, P = 0.039) while in the load-to-failure test, the maximum elongation and maximum strain of the peracetic acid-ethanol group were significantly higher than those of the control group (F = 4.60, P = 0.010), and there was no significant difference in other biomechanical indicators. According to the experimental results of denatured collagen, it could be seen that no matter which disinfection procedure was used, the denaturation of the tendon sample would be promoted (F = 1.97, P = 0.186), and high-dose irradiation seemed to cause more damage to collagen fibers than the other two disinfection procedures (296.2 vs 171.1 vs 212.9 μg/g).
Biomechanical experiments and collagen denaturation tests showed that 15 kGy gamma irradiation and 70% ethanol can preserve the biomechanical strength and biochemical properties of tendons to the greatest extent, and these two sterilization methods are worthy of further promotion.
肌腱的植入前消毒程序是降低疾病传播风险的重要措施，但这些程序可能会在不同程度上损害肌腱的微观结构和生物力学性能。我们通过体外研究探索了不同消毒程序对同种异体肌腱的微观组织学、生物力学强度和生化特性的影响。
从经抗体或核酸检测感染性物质筛选的尸检供体中获取肌腱同种异体移植物。所有样本均分为五组：新鲜冷冻组（对照组）、15kGyγ射线照射组、25kGyγ射线照射组、70%乙醇组和过氧乙酸-乙醇组。每组包含 10 根肌腱进行测试。通过组织学染色和透射电子显微镜观察肌腱胶原纤维的内部结构和排列，同时训练机器学习分类器来区分胶原纤维较暗的横截面和电子显微镜较亮的背景，以检测肌腱胶原纤维直径的分布。检测肌腱同种异体移植物的粘弹性、力学性能和材料性能，以检测不同干预因素对肌腱生物力学性能的影响。
组织学染色和透射电子显微镜显示，新鲜冷冻肌腱的结构与其他实验组的结构相似，未观察到明显的纤维紊乱或分层。在单轴循环试验中，25kGy 照射组（1.5%）和过氧乙酸-乙醇组（1.5%）的循环蠕变明显低于对照组（3.6%，F=1.52，P=0.039），而在破坏试验中，过氧乙酸-乙醇组的最大伸长率和最大应变明显高于对照组（F=4.60，P=0.010），其他生物力学指标无显著差异。根据变性胶原的实验结果可以看出，无论使用哪种消毒程序，都会促进肌腱样本的变性（F=1.97，P=0.186），高剂量照射似乎比其他两种消毒程序对胶原纤维造成更大的损伤（296.2 vs 171.1 vs 212.9μg/g）。
生物力学实验和胶原变性试验表明，15kGyγ射线照射和 70%乙醇可以最大限度地保持肌腱的生物力学强度和生化特性，这两种消毒方法值得进一步推广。
