Novel Osteochondral Co-culture Strategies using Stem Cell and Biomaterials

描述（由申请人提供）：本提案旨在分化干细胞用于病变和受损组织的修复，并评估骨软骨病微环境三维生物材料模拟中的组织相互作用。骨软骨微环境涉及软骨细胞、成骨细胞和间充质干细胞（MSCs）之间多方面相互作用的复杂环境。在疾病状态下，如骨关节炎和骨质疏松症，这种信号被破坏。目前的修复策略受限于对细胞间通讯、组织相互作用以及疾病状态和分化状态对修复的影响的理解不足。这些问题与传统的二维培养相结合，传统的二维培养通常用于表征细胞，不能准确地代表天然的三维组织结构。此外，使用条件培养基和transwell培养进行的细胞相互作用的传统研究受到细胞类型之间缺乏接近性的限制，从而降低了体内可能正常发生的可溶性信号因子的浓度和细胞之间的串扰。最后，关于MSCs在修复中的主要作用是作为细胞来源还是作为其他细胞修复的刺激物，仍然存在争议。本提案旨在评估细胞分化状态、疾病状态和MSCs在修复中的双重作用的影响。本研究将利用双层聚乙二醇凝胶和一种新型共培养系统来同时支持软骨和骨组织的形成。该系统将由支持软骨组织形成的聚乙二醇层和支持骨组织形成的聚乳酸-羟基磷灰石层组成。使用这两种系统将允许广泛分析MSCs形成组织和刺激健康和病变组织修复的能力。假设间充质干细胞分化的中间阶段会增强间充质干细胞的刺激和组织的形成。这个项目有可能影响干细胞的输送策略。具体来说，它可能会影响骨软骨疾病的治疗，包括骨关节炎、骨质疏松症和其他骨和软骨疾病。随着美国人口的持续老龄化，涉及软骨和骨骼的疾病（如骨关节炎和骨质疏松症）的发病率继续增加。本研究旨在通过增加对细胞和组织相互作用的理解来增强骨软骨疾病的修复策略。

DESCRIPTION (provided by applicant): This proposal aims to differentiate stem cells for repair of diseased and damaged tissues and to evaluate tissue interactions in three-dimensional biomaterial mimics of the osteochondral disease microenvironment. The osteochondral microenvironment involves a complex milieu of multifaceted interactions between chondrocytes, osteoblasts, and mesenchymal stem cells (MSCs). In disease states, such as osteoarthritis and osteoporosis, this signaling is disrupted. Current repair strategies are limited by inadequate understanding of cell-cell communication, tissue interactions, and the impact of disease state and differentiation state on repair. These issues are compounded by traditional two-dimensional culture which is generally used to characterize cells and fails to accurately represent the native three-dimensional tissue architecture. Furthermore, traditional studies of cell interactions using conditioned media and transwell culture are limited by lack of proximity between cell types, thus reducing the concentration of soluble signaling factors and crosstalk between cells that may normally occur in vivo. Finally, controversy remains over whether the primary role of MSCs In repair is as a cell source or stimulator of other cellular repair. This proposal aims to evaluate the effects of cellular differentiation state, disease state, and the dual roles of MSCs in repair. This research will utilize bilayered poly(ethylene glycol) gels in addition to a novel co- culture system developed to simultaneously support cartilage and bone tissue formation. This system will consist of a layer of poly(ethylene glycol) to support cartilage tissue formation and a poly(lactic-co-glycolic acid) with hydroxyapatite layer to support bone tissue formation. Use of both systems will allow extensive analysis of the ability of MSCs to form tissue and stimulate repair of healthy and diseased tissues. It is hypothesized that intermediate stages of MSC differentiation will enhance MSC stimulation and formation of tissues. This project has the potential to impact delivery strategies for stem cells. Specifically, it may impact treatments of osteochondral ailments including osteoarthritis, osteoporosis, and other diseases of bone and cartilage. As the American population continues to age, the incidence of diseases involving both cartilage and bone (such as osteoarthritis and osteoporosis) continues to increase. This research seeks to enhance repair strategies in osteochondral diseases through increased understanding of cell and tissue interactions.