Tissue Engineered Total Disc Replacement in a Large Animal Model

腰部疼痛是最常见的原因，最常见的原因是腰椎间盘退变 退伍军人的慢性疼痛。目前治疗腰椎间盘退变的临床治疗方法，包括脊柱融合术，是有限的。 因为它们不能恢复健康的盘结构或功能。为了克服这一限制，我们团队开发了 一种完整的组织工程化终板修饰圆盘状角铺层结构(EDAPS) 纤维环、髓核和终板区。到目前为止，我们已经完成了长期评估 在小动物模型中对eDAPS进行短期评价，在大动物、山羊颈椎间盘中进行短期评价 替换模型。当前提案的首要目标是生成体外和体内数据，以 推动这项技术的首次人体试验。我们将通过以下具体措施来实现这一翻译目标 目的：特定目标1：评估组织工程化椎间盘置换术的长期功能 在我们的大型动物模型中受到生理负荷。为了实现这一目标，我们将首先确定 组织工程化盘在体内的最佳长期性能所需的固定化。到时候我们会的 开发和测试可吸收临时固定系统，以便与工程化盘结合使用 植入物，这将消除第二次手术的需要，并增加我们的临床可译性 技术具体目标2：确定组织工程椎间盘置换恢复健康的能力 当植入退行性环境时，运动节段的结构和功能。在这个目标上，我们将诱导 用我们建立的软骨素酶ABC注射法建立山羊颈椎间盘退变模型。 在变性进展了12周后，将进行第二次手术，将eDAPS与 Aim开发的可吸收固定系统1.动物将在eDAPS后1年被安乐死 植入。在此期间，植入状态将通过系列X光片和活体核磁共振进行跟踪。一种习俗 将实施肌电和运动跟踪系统，以评估颈椎肌肉的激活和范围 运动作为疼痛和功能的客观衡量标准。在1年的研究终点，eDAPS植入物将 与未经治疗的退行性对照相比，通过分析 使用多尺度和多模式方法的整个运动片段(椎间盘/植入物、小关节、神经结构)。 目的3：利用人体细胞构建解剖型组织工程光盘。在目标3中，我们将评估其使用情况 用于种植eDAPS构建物的不同人间充质细胞来源。人骨髓 除了来自人类诱导多能性的AF样和NP样细胞外，还将利用衍生的干细胞 干细胞，并与天然的椎间盘组织细胞进行比较。产生具有结构功能的结构的细胞来源 将利用与原始人类椎间盘最接近的属性来生成适合人类腰椎和腰椎的eDAP 颈椎。总体而言，拟议的工作将显著推动eDAPS植入物的平移 脊柱疗法的临床应用和最新进展。

Low back pain, which is most commonly caused by intervertebral disc degeneration, is the most common source of chronic pain in veterans. Current clinical treatments for disc degeneration, including spinal fusion, are limited in that they do not restore healthy disc structure or function. To overcome this limitation, our group has developed a whole, tissue engineered endplate-modified disc-like angle ply structure (eDAPS) composed of engineered annulus fibrosus, nucleus pulposus and endplate regions. To date, we have completed the long-term evaluation of the eDAPS in a small animal model, in addition to short-term evaluation in a large animal, goat cervical disc replacement model. The overarching goal of the current proposal is to generate in vitro and in vivo data to motivate the first in man trials of this technology. We will achieve this translational goal via the following specific aims: Specific Aim 1: Evaluate the long-term function of a tissue-engineered intervertebral disc replacement that is subjected to physiologic loading in our large animal model. In this Aim, we will first establish the duration of immobilization necessary for optimal long-term performance of the tissue engineered disc in vivo. We will then develop and test a resorbable provisional fixation system to be utilized in conjunction with the engineered disc implant, which will eliminate the need for a second surgery and increase the clinical translatability of our technology. Specific Aim 2: Determine the ability of a tissue-engineered disc replacement to restore healthy motion segment structure and function when implanted in a degenerative environment. In this Aim, we will induce degeneration of the goat cervical intervertebral disc using our established model of chondroitinase ABC injection. After degeneration has progressed for 12 weeks, a second surgery will be performed to implant the eDAPS with the resorbable fixation system developed in Aim 1. Animals will be euthanized after 1 year of eDAPS implantation. During this time, implant status will be tracked with serial radiographs and in vivo MRI. A custom EMG and kinematic tracking system will be implemented to assess cervical spine muscle activation and range of motion as objective measures of pain and function. At the 1 year study endpoint, eDAPS implants will be compared to untreated, degenerative controls by analyzing the structural and function properties across the whole motion segment (disc/implant, facet joints, neural structures) using a multiscale and multimodal approach. Aim 3: Fabricate anatomical tissue-engineered discs from human cell sources. In Aim 3, we will evaluate the use of different human mesenchymal cell sources for the seeding of the eDAPS constructs. Human bone marrow derived stem cells will be utilized, in addition to AF-like and NP-like cells derived from human induced pluripotent stem cells and compared to native disc tissue cells. The cell source yielding constructs with structure-function properties nearest to the native human disc will be utilized to generate eDAPS sized for the human lumbar and cervical spine. Overall, the proposed work will significantly drive the translation of the eDAPS implant towards clinical use and advance the state of the art in spine therapeutics.