Optimization of engineered endplates to improve in vivo integration of atissue engineered intervertebral disc

优化工程终板以改善组织工程椎间盘的体内整合

• 批准号: 10020800
• 负责人: SARAH E GULLBRAND
• 金额: --
• 依托单位: PHILADELPHIA VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10020800
• 关键词: Address; Adult; Aging; Alkaline Phosphatase; Animal Model; Animals; Area; Back Pain; Biological; Biological Assay; Biological Process; Biomechanics; Blood Vessels; Caring; Cartilage; Clinical; Clinical Treatment; Convection; Deposition; Development; Diffusion; Economic Burden; Engineering; Fibrocartilages; General Population; Genes; Geometry; Goals; Growth Factor; Histologic; Histology; Homeostasis; Human; Hyaline Cartilage; Hydrogels; Hydroxyapatites; Image; Implant; In Vitro; Injections; Injury; Intervertebral disc structure; Label; Lesion; Location; Low Back Pain; Magnetic Resonance Imaging; Mechanics; Mesenchymal Stem Cells; Microcapsules drug delivery system; Microfils; Microspheres; Minerals; Modification; Molds; Monitor; Motion; Nutrient; Operative Surgical Procedures; Oryctolagus cuniculus; Osteogenesis; Outcome; Pathology; Patients; Performance; Physiological; Play; Polymers; Procedures; Process; Reaction; Rehabilitation therapy; Research; Role; Sodium Chloride; Speed; Spinal; Structure; Surface; System; Technology; Testing; Thinness; Tissue Engineering; Tissues; Torsion; Translations; Tube; United States; Vascular Endothelial Growth Factors; Vascularization; Vertebral Bone; Vertebral column; Veterans; Weight-Bearing state; Work; active duty; analog; bone; caprolactone; cell growth; chronic pain; contrast enhanced; cortical bone; design; disability; disc regeneration; fluorexon; implantation; improved; in vivo; insight; interfacial; intervertebral disk degeneration; military veteran; mineralization; neovascularization; nucleus pulposus; nutrition; osteogenic; release factor; restoration; scaffold; small molecule; social; spine bone structure; treatment strategy; vertebra body

Low back pain, most commonly caused by degeneration of the intervertebral disc, places a significant social and economic burden on the general public, active duty military and veterans alike. Current clinical treatments for disc degeneration are limited in that they do not restore disc structure or function. To address this, our group has developed a whole, tissue engineered intervertebral disc composite (eDAPS) composed of engineered annulus fibrosus, nucleus pulposus and endplate regions. The endplate component, composed of an acellular porous polymer foam, is a critical aspect of the design that forms the interface between the engineered disc and native vertebral bone, but has yet to be optimized to promote the accelerated development of a vascularized, boney interface. The purpose of this study is to generate design modifications to the endplate region of the eDAPS that will accelerate integration following in vivo implantation. We will achieve this translational goal through two Aims: Aim 1: Modify the composition and geometry of the endplate region of the eDAPS to enhance osteogenesis and neovascularization. In this Aim, poly(ε-caprolactone) (PCL) endplates will be fabricated via a salt-leaching procedure with various design modifications to promote osteogenesis and neovascularization. PDMS molds will first be used to create macroscopic channel geometries within the endplates. Endplates will be further modified via hydroxyapatite deposition, and the incorporation of microspheres containing vascular endothelial growth factor (VEGF). The potential for mesenchymal stem cell osteogenesis on the hydroxyapatite modified scaffolds will be established in vitro, via the alkaline phosphatase assay, qPCR analysis of osteogenic genes, and histology. The bioactivity of the VEGF released from the microsphere containing scaffolds will also be assessed in vitro using the tube formation assay. Aim 2: Determine the effect of optimized endplate design on the in vivo integration and nutrition of a whole tissue engineered disc construct. In this Aim, optimized endplates will be utilized in eDAPS to be implanted in vivo in the rabbit lumbar spine for 10 or 20 weeks. New bone and vascular formation in the endplates following in vivo implantation will be assessed via calcein and alizarin labelling and microFil enhanced µCT, respectively. Small molecule trans-endplate diffusion into the engineered disc implants will be assessed via post-contrast enhanced MRI. Integration strength of the eDAPS with the native vertebral bodies will be assessed via tension, compression and torsional mechanical testing at physiologic loads. Animal functional rehabilitation following eDAPS implantation will be assessed via activity monitoring using the Motionwatch-8R, and ground reaction force mapping during ambulation using a Tekscan system. The proposed work will advance the state-of-the art in the field of intervertebral disc tissue-engineering, and provide insights that will speed translation of the eDAPS technology towards clinical use.

腰痛，最常见的原因是椎间盘退变， 给广大公众、现役军人带来沉重的社会和经济负担 军人和退伍军人都一样。目前针对椎间盘退变的临床治疗方法有限 因为它们不能恢复椎间盘结构或功能。为了解决这个问题，我们小组 开发了一种完整的组织工程椎间盘复合材料（eDAPS） 工程化的纤维环、髓核和终板区域。端板 由无孔多孔聚合物泡沫组成的组件是 形成工程椎间盘和天然椎骨之间界面的设计， 但还有待优化以促进血管化的加速发展， 骨头接口。本研究的目的是对 eDAPS 的终板区域将加速体内整合 植入。我们将通过两个目标来实现这一转化目标： 目标 1：修改 eDAPS 终板区域的组成和几何形状以增强 成骨和新血管形成。为此，聚(ε-己内酯) (PCL) 端板 将通过盐浸程序制造，并进行各种设计修改 促进成骨和新血管形成。 PDMS 模具将首先用于制造 终板内的宏观通道几何形状。端板将进一步修改 通过羟基磷灰石沉积，以及掺入含有血管的微球 内皮生长因子（VEGF）。间充质干细胞成骨的潜力 羟基磷灰石修饰的支架将在体外通过碱性建立 磷酸酶测定、成骨基因的 qPCR 分析和组织学。生物活性 从含有支架的微球中释放的 VEGF 也将在 体外使用管形成试验。目标 2：确定优化终板的效果 整个组织工程椎间盘的体内整合和营养设计 构造。在此目标中，将在 eDAPS 中使用优化的终板，以植入 兔腰椎体内10或20周。新骨和血管形成 体内植入后的终板将通过钙黄绿素和茜素进行评估 分别是标记和 microFil 增强 µCT。小分子跨终板 将通过对比后增强来评估扩散到工程椎间盘植入物中的情况 核磁共振成像。将评估 eDAPS 与天然椎体的整合强度 通过生理负荷下的拉伸、压缩和扭转机械测试。动物 eDAPS 植入后的功能康复将通过活动进行评估 使用 Motionwatch-8R 进行监测，并绘制地面反作用力图 使用 Tekscan 系统进行移动。拟议的工作将推进最先进的技术 在椎间盘组织工程领域，并提供将加速 将 eDAPS 技术转化为临床应用。