Stem Cell-Driven Regeneration of the Mandibular Joint

干细胞驱动的下颌关节再生

基本信息

批准号：
7067184
负责人：
JEREMY J MAO
金额：
$ 39.3万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-07-21 至 2009-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The human temporomandibular joint is susceptible to osteoarthritis, rheumatoid arthritis, fractures, ankylosis, and dysfunctional syndromes, collectively affecting over 10 million individuals in the U.S. alone. The current clinical gold standards for surgical replacement of the mandibular condyle such as bone/cartilage grafts and artificial materials suffer from substantial deficiencies such as donor site defects, limited supply, immunorejection, and transmission of pathogens. In response to NIDCR's RFA, the overall objective of the present proposal is to regenerate the mandibular condyle of the temporomandibular joint using mesenchymal stem cells seeded in biocompatible polymers. Specific Aim 1, will optimize the densities of adult bone marrow-derived mesenchymal stem cells (MSCs). Once extracted from mouse tibiofemoral bones, MSCs will be expanded in cell culture, induced to differentiate into osteoprogenitor and chondroprogenitor cells and seeded in hydrogels shaped in prefabricated molds of human mandibular condyles. The regenerative outcome of tissue-engineered mandibular condyles including architecture, chondrogenesis and osteogenesis will be evaluated qualitatively and quantitatively by our published methods such as selective histologic labels, immunohistochemistry of bone and cartilage markers, computerized histomorphometry, and micromechanical testing with atomic force microscopy. In Specific Aim 2, multilayered osteochondral constructs will be fabricated in the shape of human mandibular condyle, and implanted in the dorsum of immunodeficient mice. Substrartified osteochondral constructs are anticipated to mimic normal condylar development. Specific Aim 3 will focus on functional enablement of tissue-engineered osteochondral constructs. In vitro hydraulic micromechanical stresses will be applied to osteochondral constructs shaped in human mandibular condyle ex vivo so that they experience simulated functional environments. In Specific Aim 4, autologous adult bone-marrow derived mesenchymal stem cells will be extracted from the rabbit tibia by needle aspiration, seeded in hydrogel scaffolds in the shape of rabbit mandibular condyle. After up to 16 weeks of surgical implantation of rabbit mandibular condyles in autologous rabbits, the harvested, tissue-engineered mandibular condyles will be implanted to replace surgically created, unilateral mandibular condyle defects in each autologous rabbit. Normal masticatory functions will be allowed for up to 16 weeks followed by biochemical, histomorphometric and biomechanical analyses of the tissue-engineered mandibular joint. The anticipated findings may have implications in the ultimate fabrication of functional, tissue-engineered human mandibular condyles using autologous human stem cells for clinical implantation.

描述（由申请人提供）：人类颞下颌关节易患骨关节炎、类风湿性关节炎、骨折、强直和功能障碍综合征，仅在美国就有超过 1000 万人受到影响。目前下颌骨髁突手术置换的临床金标准（例如骨/软骨移植物和人造材料）存在重大缺陷，例如供体部位缺陷、供应有限、免疫排斥和病原体传播。为了响应 NIDCR 的 RFA，本提案的总体目标是使用接种在生物相容性聚合物中的间充质干细胞来再生颞下颌关节的下颌骨髁。具体目标 1 将优化成人骨髓来源的间充质干细胞 (MSC) 的密度。一旦从小鼠胫股骨中提取，间充质干细胞将在细胞培养物中扩增，诱导分化为骨祖细胞和软骨祖细胞，并接种在人下颌髁预制模具中成型的水凝胶中。组织工程下颌骨髁的再生结果，包括结构、软骨生成和成骨，将通过我们发表的方法进行定性和定量评估，例如选择性组织学标记、骨和软骨标记的免疫组织化学、计算机组织形态测量和原子力显微镜微机械测试。在具体目标 2 中，多层骨软骨结构将被制造成人类下颌骨髁的形状，并植入免疫缺陷小鼠的背部。预计底层化的骨软骨结构可以模拟正常的髁突发育。具体目标 3 将重点关注组织工程骨软骨结构的功能实现。体外液压微机械应力将应用于离体人类下颌髁突形成的骨软骨结构，以便它们体验模拟的功能环境。在具体目标 4 中，将通过针吸从兔胫骨中提取自体成体骨髓来源的间充质干细胞，并将其种植在兔下颌骨髁形状的水凝胶支架中。在自体兔中进行长达 16 周的手术植入兔下颌骨髁后，收获的组织工程下颌骨髁将被植入，以取代每只自体兔中通过手术产生的单侧下颌骨髁缺陷。正常的咀嚼功能将被允许长达 16 周，然后对组织工程下颌关节进行生化、组织形态测量和生物力学分析。预期的发现可能会对使用自体人类干细胞进行临床植入的功能性组织工程人类下颌髁的最终制造产生影响。