3-D Osteochondral Micro-tissue to Model Pathogenesis of Osteoarthritis

描述（由申请人提供）：骨关节炎（OA）是最常见的关节炎形式，影响高达15%的成年人群，主要特征为关节的关节软骨成分退化，通常伴有软骨下骨病变。了解OA的发病机制对于合理开发改善OA疾病的药物（DMOAD）具有重要意义。虽然大多数关于OA的研究都集中在关节的软骨或骨成分的研究上，但骨软骨复合物代表了一个更生理相关的目标，因为该疾病最终是骨软骨完整性和功能的障碍。在本申请中，我们建议构建一个体外三维微系统，模拟关节骨软骨复合物的结构和生物学。将使用源自骨髓和脂肪的成人间充质干细胞（MSC）生产成骨和成软骨组织成分，所述MSC接种在具有定义的内部结构的光立体光刻制造的生物材料支架内。设计尺寸适合96孔培养板格式的3D打印的灌注就绪容器平台以容纳和维持具有以下特征的骨软骨微系统：（1）具有功能界面的解剖学软骨/骨双相结构;（2）来源于单一成人间充质干细胞来源的所有组织组分以消除可能的年龄/组织类型不相容性;（3）构成“滑膜”和“骨”组分的单独微环境的单独隔室;（4）代表“滑膜”和“内皮”的细胞接种包膜;（5）可通过引入生物活性剂或候选效应细胞以及组织/培养基取样和组成测定来控制和调节的可接近的单独隔室;（6）与机械负荷和扰动的应用的兼容性;以及（7）允许非侵入性功能监测的成像能力。骨软骨微系统的稳健性和生理相关性将根据以下方面进行测试：（1）分离的“滑膜”和“骨”隔室的结构完整性和潜在连接性;（2）不同软骨和骨表型的维持以及组织学上不同的骨软骨连接或潮标的形成;（3）对机械负荷的适用性和组织反应性;以及（4）成像和分析能力。机械损伤的后果，暴露于炎性细胞因子，和受损的骨质量对软骨成分的退行性变化将在骨软骨微系统中进行检查，作为其最终应用的第一步，作为一个改进的和高通量的体外模型，用于预测候选DMOAD的疗效，安全性，生物利用度和毒理学结果。

DESCRIPTION (provided by applicant): Osteoarthritis (OA), the most prevalent form of arthritis, affects up to 15% of the adult population and is principally characterized by degeneration of the articular cartilage component of the joint, often with accompanying subchondral bone lesions. Understanding the mechanisms underlying the pathogenesis of OA is important for the rational development of disease modifying OA drugs (DMOADs). While most studies on OA have focused on the investigation of either the cartilage or the bone components of the articular joint, the osteochondral complex represents a more physiologically relevant target as the disease ultimately is a disorder of osteochondral integrity and function. In this application, we propose to construct an in vitro 3-dimensional microsystem that models the structure and biology of the osteochondral complex of the articular joint. Osteogenic and chondrogenic tissue components will be produced using adult human mesenchymal stem cells (MSCs) derived from bone marrow and adipose seeded within biomaterial scaffolds photostereolithographically fabricated with defined internal architecture. A 3D-printed, perfusion-ready container platform with dimensions to fit into a 96-well culture plate format is designed to house and maintain the osteochondral microsystem that has the following features: (1) an anatomic cartilage/bone biphasic structure with a functional interface; (2) all tissue components derived from a single adult mesenchymal stem cell source to eliminate possible age/tissue type incompatibility; (3) individual compartments to constitute separate microenvironment for the "synovial" and "osseous" components; (4) cell-seeded envelopes to represent "synovium" and "endothelium"; (5) accessible individual compartments that may be controlled and regulated via the introduction of bioactive agents or candidate effector cells, and tissue/medium sampling and compositional assays; (6) compatibility with the application of mechanical load and perturbation; and (7) imaging capability to allow for non-invasive functional monitoring. The robustness and physiological relevance of the osteochondral microsystem will be tested on the basis of: (1) structural integrity and potential connectivity of the separate "synovial" and "osseous" compartments; (2) maintenance of distinct cartilage and bone phenotypes and the development of a histologically distinct osteochondral junction or tidemark; (3) applicability and tissue responsiveness to mechanical loading; and (4) imaging and analytical capabilities. The consequences of mechanical injury, exposure to inflammatory cytokines, and compromised bone quality on degenerative changes in the cartilage component will be examined in the osteochondral microsystem as a first step towards its eventual application as an improved and high-throughput in vitro model for prediction of efficacy, safety, bioavailability, and toxicology outcomes for candidate DMOADs.