Toward tissue engineering of facet cartilage

项目摘要 该提案旨在设计一种同种异体关节突关节(小关节)关节表面重建术(Azar)系统 通过在三个具体目标上遵循合理的实验方法：Azar系统将由软骨组成 组件(软骨部分)与骨样支架组件(骨部分)牢固结合； 置换物将就地固定在小关节的受区骨床内。在目标1中，人类的三个层面 来自两性的微型小关节将被完全角色化，以定义Azar系统的设计标准。 AZAR系统将在目标2中分三个阶段设计和制造。第一，细胞松弛素-D和 透明质酸酶将应用于传代的小型猪软骨细胞，以设计植入物的软骨部分 具有模拟天然组织值的压缩性能。在同一阶段，使用赖氨酰氧化酶的方法 类似蛋白-2(LOXL2)和拉伸刺激(CoTenS)将被确定以改善 软骨--相当于天然组织水平。在目标2，阶段II中，骨部分(即，骨)的孔大小 部分)将进行微调，以实现最佳的软骨整合。在《目标3》中， 将开发微创外科方法在小型猪体内植入全小关节置换术， 类似于目前在人类患者身上使用的方法。最后，阿扎尔系统将被植入 在未来的研究中，在移动到两足动物模型之前，雄性和雌性小型猪都要检查它的效果。 这项提议的成功完成将第一次使整个关节表面在 使用组织工程构建的腹股沟关节。它还将揭示迄今尚未探索的结构- 研究较少的小关节的功能关系。最后，但同样重要的是，它将有助于新的治疗方法 治疗与关节有关的疾病。

Project Summary This proposal seeks to engineer an allogeneic zygapophyseal (facet joint) articular resurfacing (AZAR) system by following a rational experimental approach in three specific aims: the AZAR system will consist of a cartilage component (chondro-portion) robustly integrated with a bone-like scaffold component (osteo-portion); the replacement will be secured in situ in the recipient bone bed of the facet joint. In Aim 1, three levels of human and minipig facet joints from both sexes will be fully characterized to define design criteria for the AZAR system. The AZAR system will be designed and fabricated through three phases in Aim 2. First, cytochalasin-D and hyaluronidase will be applied to minipig passaged chondrocytes to engineer the chondro-portion of the implant with compressive properties mimetic to native tissue values. In the same phase, methods for using lysyl oxidase like protein-2 (LOXL2) and tensile stimulation (CoTenS) will be identified to improve the tensile properties of the chondro-portion to native tissue levels. In Aim 2, Phase II, the pore size of the osteo-portion (i.e., the bone portion) directly beneath the engineered cartilage will be fine-tuned for optimum cartilage integration. In Aim 3, minimally invasive surgical methods will be developed for implanting a total facet replacement in the minipig, analogous to the ones currently employed in human patients. Finally, the AZAR system will be implanted into both male and female minipigs to examine its efficacy prior to moving to bipedal models in future studies. Successful completion of this proposal will allow, for the first time, resurfacing of an entire articular surface in a diarthrodial joint using a tissue engineered construct. It will also shed light on as-of-yet unexplored structure- function relationships in the poorly studied facet joint. Last, but not least, it will contribute toward new therapies for facet-related ailments.