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，影响多达15%的成年人，主要表现为关节软骨成分的退行性变，通常伴有软骨下骨病变。了解骨性关节炎的发病机制对于合理开发骨性关节炎药物（DMOADs）具有重要意义。虽然大多数OA的研究都集中在关节关节的软骨或骨成分的研究上，但骨软骨复合体代表了一个更生理学上相关的目标，因为该疾病最终是骨软骨完整性和功能的紊乱。在这个应用中，我们建议构建一个体外三维微系统来模拟关节骨软骨复合体的结构和生物学。成骨和软骨组织组件将使用从骨髓和脂肪中提取的成人间充质干细胞（MSCs），并将其植入具有明确内部结构的光立体固化生物材料支架中。3d打印的灌注准备容器平台，其尺寸适合96孔培养板格式，用于容纳和维护具有以下特征的骨软骨微系统：(1)解剖软骨/骨双相结构，具有功能界面；(2)来自单一成体间充质干细胞来源的所有组织成分，以消除可能的年龄/组织类型不相容；(3)单独的隔室为“滑膜”和“骨”成分构成单独的微环境；(4)细胞种子包膜代表“滑膜”和“内皮”；(5)可通过引入生物活性剂或候选效应细胞、组织/培养基取样和成分分析来控制和调节的可接近的单个隔室；(6)与施加机械载荷和摄动的兼容性；(7)成像能力，允许非侵入性功能监测。骨软骨微系统的稳健性和生理相关性将在以下基础上进行测试：(1)独立的“滑膜”和“骨”隔室的结构完整性和潜在连通性；(2)维持独特的软骨和骨表型，并形成组织学上独特的骨软骨连接点或潮汐标记；(3)组织对机械载荷的适用性和响应性；(4)成像和分析能力。机械损伤、炎症细胞因子暴露和骨质量受损对软骨成分退行性改变的影响将在骨软骨微系统中进行研究，作为其最终应用的第一步，作为一种改进的高通量体外模型，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.