Synovium-based articular cartilage tissue engineering

描述(申请人提供)：骨性关节炎是西方国家老年人最常见的疾病之一。这种致残性关节紊乱通常是多因素的，因此在个别病例中原因不明。在骨关节炎的早期阶段，关节软骨层的局限性损伤是一种特征性的现象。一旦启动，这一损害进程是渐进的，没有任何预防措施可以阻止它。同样，目前还没有既定的基于生物的治疗策略来诱导这些结构性缺陷的愈合。目前正在努力采用一种更具生物学合理性的方法，利用组织工程学原理修复关节软骨损伤。我们最近开发了一种基于生长因子的策略，可以诱导小关节软骨缺损的愈合。但是，当应用于实验动物(山羊)中非常大的缺陷时，同样的策略无法在短时间内诱导它们修复。-我们推测，通过自体滑膜瓣移植将成体干细胞群体直接引入缺损区，可以克服这些困难，并诱导修复大面积和大体积的缺损区。我们假设，在一次干预(手术或关节镜)中进行的“分层滑膜成形术”可以形成修复大量关节软骨缺损的基础。在控制释放系统中，一层层的滑膜瓣将被插入含有生长因子的基质中，这将确保它们的转化。-我们将首先使用基于新鲜滑膜组织(来自年轻成年奶牛)的组织培养系统来优化转化条件。-我们还假设，身体不同滑膜关节内的成体干细胞群体包含有关其向关节特异性关节软骨分化的位置信息。在这种情况下，成人滑膜干细胞的局部招募将是一个巨大的优势，因为这些细胞将携带局部位置信息，以形成相同类型的关节特异性关节软骨。我们将使用来自三个不同牛关节的关节软骨组织和滑膜组织来验证这一假设，这三个不同的牛关节在结构和功能上都有很大的差异，即来自肩关节、膝关节和来自牛的跖骨关节。-在微调之后，将使用取自膝关节的成年山羊材料在体外交叉检查优化的方案。最终的方案将在成年山羊的中期(手术后5周)和长期(手术后6个月)进行测试。将对修复组织进行定量分析，包括mRNA表达谱和软骨基质成分翻译后的表达，以及形态计量学、超微结构和生物力学。我们相信，这一项目具有很高的创新性，这项研究的结果将对未来骨关节炎病变的治疗和美国人口健康状况的改善产生重大影响。

DESCRIPTION (provided by applicant): Osteoarthritis is one of the most common diseases suffered by elderly persons in Western countries. This disabling joint disorder is usually multifactorial in nature and thus of unknown origin in individual cases. During the early stages of osteoarthritis, localized lesioning of the articular cartilage layer is a characteristic occurrence. Once initiated, this lesioning process is progressive, and no prophylactic measures are available to arrest it. Likewise, no established biologically-based treatment strategies are available to induce the healing of these structural defects. Endeavours are now being made to adopt a more biologically rational approach to the repair of articular cartilage lesions using tissue-engineering principles. We have recently developed a growth-factor-based strategy which induces the healing of small articular cartilage defects. But when applied to very large defects in experimental animals (goats), the same strategy is unable to induce their repair within a short period of time. - We postulate that by introducing an adult stem cell population directly into the defect space by the autotransplantation of synovial membrane flaps, the difficulties can be overcome and the repair of large defect areas and volumes induced. We hypothesize that a "layered synovioplasty" performed in a single intervention (surgery or arthroscopy) can form the basis for the repair of bulk volume articular cartilage defects. Layers of synovial flaps will be interposed with a matrix containing growth factors in a controlled release system, which will assure their transformation. - We will first optimize the transformation conditions using a tissue-culture system based on the availability of fresh synovial bovine tissue (from young adult cows). - We also hypothesize that adult stem cell populations within different synovial joints of the body contain positional information respecting their differentiation potential into joint- specific articular cartilage. This being the case, the local recruitment of adult synovial stem cells would be a great advantage, in that the cells would carry local positional information to form the same type of joint-specific articular cartilage. We will test this hypothesis using articular cartilage tissue as well as synovial tissue from three different bovine joints that differ significantly both structurally and functionally, i.e., from the shoulder joint, from the knee joint and from the metatarsal joint of bovine origin. - Following fine-tuning, the optimized protocols will be cross- checked in vitro using adult goat material derived from the knee joint. The finalized protocols will be tested at mid- term (5 weeks post-operatively) and long-term (6 months post-operatively) junctures in adult goats. The repair tissue will be analyzed quantitatively with respect to mRNA expression profiles and the post-translational expression of cartilage matrix components, as well as morphometrically, ultrastructurally and biomechanically. We believe that this project is highly innovative and that the results of this research will have a significant impact on the future treatment of osteoarthritic lesions and on improvement of the health status of the US population.