Co-Culture & Cyclic Tension to Direct Differentiation at Bone-Ligament Interface

共培养

基本信息

批准号：
7530207
负责人：
Johnna S Temenoff
金额：
$ 22万
依托单位：
GEORGIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-01 至 2010-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7530207
关键词：
Address Adhesions Adhesives Allografting Anterior Cruciate Ligament Architecture Arts Athletic Injuries Autologous Autologous Transplantation Biochemical Biological Biological Models Bioreactors Bone Transplantation Cell Differentiation process Cell Proliferation Cells Characteristics Coculture Techniques Complex Condition Controlled Study Distant Elements Encapsulated Engineering Environment Enzymes Exhibits Extracellular Matrix Fibroblasts Fibrocartilages Future Gene Expression Generations Goals Heterogeneity Histocompatibility Testing Hydrogels Implant In Vitro Individual Injury Joints Ligaments Ligand Binding Ligands Marrow Matrix Metalloproteinases Mechanics Mesenchymal Stem Cells Modeling Morbidity - disease rate Object Attachment Orthopedics Oryctolagus cuniculus Osteoblasts Other Body Part Outcome Study Patients Peptides Phenotype Procedures Production Property Public Health Role Rupture Signal Transduction Site Stromal Cells Structure System Testing Time Tissue Engineering Tissues Urination Work bone chemical property day design extracellular glycyl-arginyl-glycyl-aspartic acid improved in vivo innovation insight interfacial novel pathogen physical property receptor reconstruction response success tool

项目摘要

DESCRIPTION (provided by applicant): Tissue engineering approaches have been explored as a means to create grafts for ligament reconstruction procedures without potential donor-site morbidity. Our long-term goal is the creation of a tissue-engineered bone-ligament-bone graft that fully reproduces the tissue architecture found at the insertions in vivo. We believe that both extracellular matrix (ECM) alignment and controlled ECM heterogeneity are crucial elements to the long-term success of such an autologous implant. However, use of patient-derived marrow stromal cells (MSCs) to produce grafts with these characteristics is hampered by a lack of clear understanding of what occurs near the ligament-bone interface to direct alignment and differentiation of these cells. Therefore, as a first step toward our long-term goal, the objective of this application is to use a unique system combining a novel layered, enzyme-sensitive hydrogel carrier and precise control of macroscopic loading parameters to determine how two important characteristics of the extracellular environment, physicochemical properties of the surroundings and co-culture with osteoblasts, influence alignment and phenotypic expression by MSCs. The central hypothesis of this proposal is that, under cyclic tension, expression of the fibroblastic phenotype by MSCs can be modulated in a predictable manner by altering 1) physicochemical characteristics of the microenvironment and 2) the presence of nearby osteoblasts. Our overall objective will be accomplished by testing our central hypothesis in the following two specific aims: 1) Determine the effect of biochemical properties (adhesive ligand concentration) and physical properties (enzymatic degradation of the polymeric network) of the hydrogel microenvironment on cellular alignment and the extent of fibroblast phenotypic expression by encapsulated rabbit MSCs exposed to cyclic tensile loading over 21 days. 2) Determine the effect of the presence of osteoblasts on the timing and extent of fibroblastic/fibrochondrocytic differentiation by encapsulated rabbit MSCs under cyclic tensile loading over 21 days. The proposed work is innovative because the combination of a novel, well-defined three- dimensional cellular environment, including the laminated structures allowing for the co-culture of MSCs and osteoblasts, and the precise control of macroscopic mechanical loading provide a unique platform for controlled study of the influences on MSC differentiation near the bone-ligament interface. Completion of these studies is expected to distinguish the effects of the physicochemical properties of the microenvironment and the interplay with neighboring cells on the fibroblastic differentiation of MSCs. Such key information will direct the design of future strategies for production of patient-specific tissue-engineered grafts to replace damaged ligaments and restore full joint function. PUBLIC HEALTH RELEVANCE: This proposal examines the effects of 1) chemical properties of the microenvironment and 2) interplay with neighboring cells on fibroblastic differentiation of marrow stromal cells in order to create a tissue-engineered bone-ligament-bone graft that reproduces the tissue architecture found at ligament-bone insertions in vivo.

描述（由申请人提供）：组织工程方法已被探索作为一种为韧带重建手术创建移植物的方法，而不会产生潜在的供体部位发病率。我们的长期目标是创建一种组织工程骨-韧带-骨移植物，完全再现体内插入处发现的组织结构。我们相信，细胞外基质 (ECM) 排列和受控的 ECM 异质性是此类自体植入物长期成功的关键因素。然而，由于缺乏对韧带-骨界面附近发生的情况以指导这些细胞的排列和分化的清楚了解，使用患者来源的骨髓基质细胞（MSC）来生产具有这些特征的移植物受到阻碍。因此，作为实现我们长期目标的第一步，本申请的目标是使用一种独特的系统，结合新型层状酶敏感水凝胶载体和宏观加载参数的精确控制，以确定细胞外的两个重要特征如何环境、周围环境的理化特性以及与成骨细胞的共培养都会影响 MSC 的排列和表型表达。该提议的中心假设是，在循环张力下，MSC 成纤维细胞表型的表达可以通过改变 1) 微环境的物理化学特征和 2) 附近成骨细胞的存在以可预测的方式进行调节。我们的总体目标将通过测试以下两个具体目标的中心假设来实现：1）确定水凝胶微环境的生化特性（粘附配体浓度）和物理特性（聚合物网络的酶促降解）对细胞排列的影响和暴露于循环拉伸载荷超过 21 天的封装兔 MSC 的成纤维细胞表型表达程度。 2) 确定成骨细胞的存在对封装的兔 MSC 在 21 天的循环拉伸载荷下成纤维细胞/纤维软骨细胞分化的时间和程度的影响。所提出的工作具有创新性，因为新颖的、明确的三维细胞环境（包括允许间充质干细胞和成骨细胞共培养的层压结构）和宏观机械载荷的精确控制的结合提供了一个独特的平台来控制研究对骨-韧带界面附近MSC分化的影响。这些研究的完成预计将区分微环境的理化特性以及与邻近细胞的相互作用对间充质干细胞成纤维细胞分化的影响。这些关键信息将指导未来生产患者特异性组织工程移植物的策略设计，以取代受损的韧带并恢复完整的关节功能。公共健康相关性：该提案研究了 1) 微环境的化学特性和 2) 与邻近细胞的相互作用对骨髓基质细胞成纤维细胞分化的影响，以创建可复制组织结构的组织工程骨-韧带-骨移植物发现于体内韧带骨插入处。