Tissue-Engineered Constructs for Treatment of Intervertebral Disc Degeneration

描述 本项目的目的是开发一种组织工程化结构，包括工程化的髓核和纤维环，用于治疗纤维环(AF)和退行性变的椎间盘(IVD)。具体目标1包括在透明质酸(HA)水凝胶结构中建立兔和人NP和MSC细胞的体外组织工程化NP构建，以及评估细胞活力、基因调控、ECM产生和生物力学特性作为凝胶生物物理特性、细胞种植密度和盘状环境中扩展培养的函数。具体目标2需要从兔和人的房颤和MSC种子纳米纤维支架在体外建立和评估细胞渗透和功能成熟的工程化房颤结构。特效AIMS 3将结合AIMS 1和AIMS 2中开发的组织工程化NP和AF，形成复合盘状结构，然后将该结构应用于全椎间盘切除的活体兔椎间盘模型。疗效将通过磁共振T2成像和随后的运动节段机械、生化和组织学特性的体外分析来评估。研究设计：这项研究将利用体外组织培养的特定目标1-2；特定目标3将利用兔动物模型和磁共振成像(MRI)。方法：特殊目标1和2是基于实验室的研究，将利用体外组织培养。具体目标3将在活体内进行，兔模型用于椎间盘切除和组织工程化椎间盘植入，随后将对脊柱进行体外磁共振成像和组织分析。具体目标1-3的主要研究结果指标是组织培养的生化分析和组织工程构建的生物力学分析。此外，特定目标3将利用这些相同的结果，以及实施植入的组织工程结构的量化磁共振T2图，并与对照(未治疗的椎间盘切除)和邻近的正常椎间盘进行比较。调查结果：目前不适用。临床关系：该项目的目标是开发治疗退行性腰椎间盘疾病的组织工程化结构，并验证放射学方法，以非侵入性评估退行性腰椎间盘疾病的潜在治疗方法。影响/意义：预计拟议的研究将提供对退行性腰椎间盘疾病的更多了解，以及潜在的新的治疗方法，以逆转退行性变化并降低复发的风险。此外，它还将为申请人在费城退伍军人医学中心和宾夕法尼亚大学发展脊柱外科研究密集型临床实践提供关键支持。

DESCRIPTION The objective of this project is to develop a tissue-engineered construct including an engineered nucleus pulposus and annulus fibrosus to treat defects of the annulus fibrosus (AF) and degenerative changes of the intervertebral disc (IVD). Three Specific Aims are pursued: " Specific Aim 1 will consist of establishing in vitro tissue engineered NP fabrication from rabbit and human NP and MSC cells in hyaluronic acid (HA)-based hydrogel constructs, and evaluation of cell viability, gene regulation, ECM production, and biomechanical properties as a function of gel biophysical properties, cell seeding density, and extended culture in a disc-like environment. " Specific Aim 2 will entail establishing and evaluating cellular infiltration and functional maturation engineered AF-like structures starting from rabbit and human AF and MSC seeded nanofibrous scaffolds in vitro. " Specific Aim 3 will combine the tissue-engineered NP and AF developed in Aims 1 and 2 to form a composite disc-like construct, and to then apply this construct to an in vivo rabbit disc model of total discectomy. Efficacy will be assesse via MRI T2 mapping and subsequent ex vivo analysis of motion segment mechanical, biochemical, and histologic properties. Research Design: This study will utilize in vitro tissue culture for Specific Aims 1-2; Specific Aim 3 will utilize a rabbit animal model and magnetic resonance imaging (MRI). Methodology: Specific Aims 1 and 2 are laboratory-based studies that will utilize in vitro tissue culture. Specific Aim 3 will be performed in vivo with a rabbit mdel for discectomy and tissue-engineered disc implantation with subsequent ex vivo MRI of the spine and tissue analysis. The primary study outcome measures for Specific Aims 1-3 are biochemical analysis of tissue culture and biomechanical analysis of tissue-engineered constructs. Additionally, Specific Aim 3 will utilize these same outcomes, as well as implement quantitative MRI T2 maps of the implanted tissue-engineered constructs with comparisons made to control (non-treated discectomy) and adjacent normal discs. Findings: n/a at this time. Clinical Relationships: The goal of this project is to develop tissue-engineered constructs to trea degenerative disc disease as well as to validate radiologic methods to noninvasively assess potential therapeutic treatments of degenerative disc disease. Impact/Significance: It is anticipated that the proposed study will offer an increased understanding of degenerative disc disease and potential novel therapeutic treatment to both reverse degenerative changes as well as decrease risk of recurrent disc herniation. Further, it will provide critical support for the applicant as he develops a research-intensive clinical practice in spine surgery at the Philadelphia VA Medical Center and the University of Pennsylvania.