Mahalingam Vasudevan D, Behbahani-Nejad Nilofar, Ronan Elizabeth A, Olsen Tyler J, Smietana Michael J, Wojtys Edward M, Wellik Deneen M, Arruda Ellen M, Larkin Lisa M
1Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.
2Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan.
Tissue Eng Part C Methods. 2015 Jun;21(6):548-56. doi: 10.1089/ten.TEC.2014.0542. Epub 2014 Dec 29.
Surgical intervention is often required to restore knee instability in patients with anterior cruciate ligament (ACL) injury. The most commonly used grafts for ACL reconstruction are tendon autografts or allografts. These current options, however, have shown failure rates requiring revision and continued instability in the long term. The mismatched biomechanical properties of the current tendon grafts compared with native ACL tissue are thought to contribute to these poor outcomes and potential risk of early onset osteoarthritis. As a possible solution to these issues, our laboratory has fabricated tissue-engineered ligament constructs that exhibit structural and functional properties similar to those of native ACL tissue after 6 months implantation. In addition, these tissue-engineered grafts achieve vascular and neural development that exceeds those of patellar tendon grafts. However, the utility of our tissue-engineered grafts is limited by the labor-intensive method required to produce the constructs and the need to use the constructs fresh, directly from the cell culturing system. Ideally, these constructs would be fabricated and stored until needed. Thus, in this study, we investigated the efficacy of freezing our tissue-engineered constructs as a method of preservation before use for ACL reconstruction. We hypothesized that frozen constructs would have similar histological and biomechanical outcomes compared with our fresh model. Our results showed that 6 months postimplantation as an ACL replacement graft, both our tissue-engineered fresh and frozen grafts demonstrated similar mechanical and histological outcomes, indicating that freezing is a suitable method for preserving and storing our graft before ACL reconstruction. The ability to use frozen constructs significantly increases the versatility of our graft technology expanding the clinical utility of our graft.
对于前交叉韧带（ACL）损伤患者，通常需要手术干预来恢复膝关节的稳定性。ACL重建最常用的移植物是自体肌腱移植物或异体肌腱移植物。然而，目前的这些选择已显示出长期存在需要翻修的失败率以及持续的不稳定情况。与天然ACL组织相比，当前肌腱移植物的生物力学特性不匹配被认为是导致这些不良结果以及早期发生骨关节炎潜在风险的原因。作为解决这些问题的一种可能方法，我们实验室制备了组织工程韧带构建体，其在植入6个月后表现出与天然ACL组织相似的结构和功能特性。此外，这些组织工程移植物实现的血管和神经发育超过了髌腱移植物。然而，我们的组织工程移植物的实用性受到生产构建体所需的劳动密集型方法以及需要直接从细胞培养系统中新鲜使用构建体的限制。理想情况下，这些构建体将被制造并储存直至需要时使用。因此，在本研究中，我们研究了冷冻我们的组织工程构建体作为ACL重建术前保存方法的有效性。我们假设与我们的新鲜模型相比，冷冻构建体将具有相似的组织学和生物力学结果。我们的结果表明，作为ACL替代移植物植入6个月后，我们的组织工程新鲜移植物和冷冻移植物均表现出相似的力学和组织学结果，这表明冷冻是在ACL重建术前保存和储存我们的移植物的合适方法。使用冷冻构建体的能力显著提高了我们移植物技术的通用性，扩大了我们移植物在临床上的应用。
