A biomechanical testing method to assess tissue adhesives for annulus closure
A biomechanical testing method to assess tissue adhesives for annulus closure
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DOI：
10.1016/j.jmbbm.2022.105150
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发表时间：
2022-03-08
影响因子：
3.9
通讯作者：
Newell, Nicolas
中科院分区：
文献类型：
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作者：
Caldeira, Joana;Celiz, Adam;Newell, Nicolas
椎间盘（IVD）退变与腰痛（LBP）有关，腰痛影响了全球80%以上的人口，在残疾方面排名第一。退变随着年龄的增长而进展，通常伴有纤维环（AF）撕裂和髓核（NP）疝出。现有疗法无法恢复IVD功能，并可能使AF缺陷恶化，增加近30%患者的再疝风险。目前的AF闭合选择是无效的，存在生物学或机械限制。生物粘合剂在这一领域有潜在的用途，但评估性能的方法有限。在此，我们提出了一种生物力学测试方法来评估生物粘合剂密封AF撕裂的能力，评估了两种密封AF撕裂的候选生物粘合剂：坚韧水凝胶粘合剂和氰基丙烯酸酯胶。使用剥离试验（n=4）定量牛椎间盘和坚韧水凝胶粘合剂之间的界面处的粘合能。然后，开发了一种测量IVD爆破压力的实验方法。该方法用于量化完整（n=7）、损伤（用21 G针头穿刺AF; n=7）和密封IVD（在将坚韧的水凝胶粘合剂贴片用作密封剂后; n=5，或在AF撕裂处涂上氰基丙烯酸酯胶后; n=6）的爆破压力。在剥离试验期间，坚韧粘合剂产生239 +/- 49 J/m（2）的强粘合能。在爆破压力测试中，观察到完整椎间盘的最大压力为13.2 +/- 3.8 MPa，在受损IVD中降低了61.4%至5.1 +/- 1.5 MPa（p < 0.01））。将氰基丙烯酸酯基胶应用于受损的IVD没有恢复具有统计学显著性的爆破压力，然而，将坚韧粘合剂应用于受损的IVD，将爆破压力恢复到12.3 +/- 4.5 MPa，这与完整的爆破压力没有显著差异。已经建立了一种简单的生物力学方法来评估基于破裂压力的生物粘合剂密封AF撕裂的性能。使用该方法，发现坚韧的水凝胶粘合剂能够密封AF损伤，使得IVD爆破压力与在完整样本中测量的爆破压力相似。该方法可用于提供生物粘合剂在高量级载荷下的生物力学评估，并可补充目前用于评估AF闭合器械的现有循环试验方法，改善其临床使用前的评估。
Intervertebral disc (IVD) degeneration has been linked to Low Back Pain (LBP) which affects over 80% of the population ranking first in terms of disability worldwide. Degeneration progresses with age and is often accompanied by annulus fibrosus (AF) tearing and nucleus pulposus (NP) herniation. Existing therapies fail to restore IVD function and may worsen AF defects, increasing the risk of reherniation in nearly 30% of patients. Current AF closure options are ineffective, presenting biological or mechanical limitations. Bioadhesives have potential use in this area, however methods to assess performance are limited. Herein, we propose a biomechanical testing method to assess bioadhesives' capacity to seal AF tears.Two candidate bioadhesives to seal AF tears were evaluated; a tough hydrogel adhesive, and a cyanoacrylatebased glue. The adhesion energy at the interface between bovine discs and the tough hydrogel adhesive was quantified using a peel test (n=4). An experimental method to measure the burst pressure of IVDs was then developed. This method was used to quantify the burst pressure of intact (n=7), injured (AF punctured with a 21G needle; n=7), and sealed IVDs (after applying either the tough hydrogel adhesive patch as a sealant; n=5, or the cyanoacrylate-based glue over the AF tear; n=6).The tough adhesive yielded a strong adhesion energy of 239 +/- 49 J/m(2) during the peel tests. A maximum pressure of 13.2 +/- 3.8 MPa was observed for intact discs in the burst pressure tests, which reduced by 61.4% to 5.1 +/- 1.5 MPa in the injured IVDs (p < 0.01)). Application of a cyanoacrylate-based glue to injured IVDs did not recover the burst pressure with statistical significance, however, application of the tough adhesive to injured IVDs, restored burst pressure to 12.3 +/- 4.5 MPa, which was not significantly different to the intact burst pressures.In this study, a simple biomechanical method to assess the performance of bioadhesives to seal AF tears based upon burst pressure has been established. Using this method it was found that a tough hydrogel adhesive was able to seal an AF injury, such that the IVD burst pressures were similar to those measured in intact specimens. This method can be used to provide a biomechanical assessment of bioadhesives under high magnitude loading and can complement existing cyclic testing methods that are currently used to assess AF closure devices, improving their assessment before clinical use.