Cell-Free Assembly of Organized Collagen Arrays

有组织的胶原阵列的无细胞组装

• 批准号: 7359669
• 负责人: Jeffrey W Ruberti
• 金额: $ 19.23万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7359669
• 关键词: Achievement; Address; Affect; American; Aneurysm; Architecture; Basic Science; Biocompatible Materials; Birth; Cell surface; Cell-Free System; Cells; Cicatrix; Clinical; Collagen; Collagen Fibril; Complex; Condition; Connective Tissue; Cornea; Corneal Stroma; Degenerative Disorder; Degenerative polyarthritis; Development; Disease; Economics; Embryonic Development; Engineering; Exercise; Extracellular Matrix; Fibrillar Collagen; Fibroblasts; Hereditary Disease; Image; In Vitro; Individual; Investigation; Keratoplasty; Kinetics; Laboratories; Life; Ligaments; Mechanics; Methods; Myopathy; Osteogenesis Imperfecta; Osteoporosis; Principal Investigator; Process; Production; Property; Proteins; Research; Silk; Syndrome; System; Tendon structure; Testing; Time; Tissue Engineering; Tissues; Translating; Transplanted tissue; Uncertainty; Ursidae Family; Weight-Bearing state; Work; Wound Healing; analog; base; cost; fibrillogenesis; implantation; improved; in vitro Model; in vivo; method development; mimetics; model development; monomer; nanoscale; novel; programs; reconstruction; repaired; scaffold; success; time use

DESCRIPTION (provided by applicant): Collagen is the principle load-bearing molecule and most abundant protein in the body. Collagen degenerative diseases include osteoarthritis (affecting 10% of Americans 60 years or older), osteoporosis (affecting 28 million Americans), arterial aneurysms and intervetebral disc disease. There are 50,000 corneal transplants and 200,000 primary ACL reconstructions performed in the US each year demonstrating the need for suitable, mechanically strong graft material. Collagen-related genetic disorders are equally devastating; examples include osteogenesis imperfecta (affecting 27,000 people in the US), many chondrodysplasias (1 in 4,000 births), and various syndromes (i.e. Ehlers-Danlos, Alport and Bethlem myopathy). The economic impact of these diseases is enormous; osteoarthritis alone costs the US economy more than $60 billion annually. In spite of this, little is known about the mechanisms that govern collagen assembly in vivo which has limited the ability of tissue engineers to reproduce collagenous load-bearing tissue in the laboratory. Instead, tissue engineering utilizes cell-seeded, degradable synthetic or self-assembled, collagenous scaffolds which require resorption and remodeling to be functional. Resorption and remodeling of scaffolds closely resembles in vivo scar remodeling or wound healing which can take years to complete, even under ideal conditions. Consequently, no functional load-bearing tissue-engineered equivalents have met with clinical success. A method to construct mechanically strong, collagenous matrix should improve the chances of producing functional connective tissue equivalents. Collagen matrices must be highly ordered and highly concentrated to possess adequate strength. It is thus necessary to organize collagen at the nanoscale in a manner similar to embryonic development where fibroblast cells exercise exquisite control over the fibrillogenesis of collagen. Though little is known about the detailed mechanics of this process there are two competing hypotheses which suggest that collagen is either: a) synthesized, assembled and organized by individual cells via cell-surface fibropositors or b) secreted in monomer form and then assembled into an organized matrix via cholesteric effects. In the proposed work, we will observe organized matrix assembly using time-lapse live dynamic differential interference contrast imaging of individual cells in a novel in vitro model of corneal stromal ECM development. We will then produce organized collagenous matrices de novo by mimicking the development mechanism in one of two in vitro cell-free systems currently under development in our laboratory. If successful, the proposed investigation will answer a critical basic science question regarding development and then translate those results into a process capable of producing load-bearing collagenous tissue equivalents.

描述（申请人提供）：胶原蛋白是人体最主要的承重分子，也是最丰富的蛋白质。胶原退行性疾病包括骨关节炎（影响10%的60岁或以上的美国人）、骨质疏松症（影响2800万美国人）、动脉动脉瘤和椎间盘疾病。在美国，每年有50,000例角膜移植和200,000例初级ACL重建，这表明需要合适的、机械强度高的移植材料。胶原蛋白相关的遗传疾病同样具有毁灭性；例子包括成骨不全症（影响美国27,000人），许多软骨发育不良症（每4,000个新生儿中有1个）和各种综合征（即Ehlers-Danlos， Alport和Bethlem肌病）。这些疾病的经济影响是巨大的；仅骨关节炎每年就给美国经济造成超过600亿美元的损失。尽管如此，人们对体内胶原蛋白组装的机制知之甚少，这限制了组织工程师在实验室中复制胶原承载组织的能力。相反，组织工程利用细胞种子、可降解合成或自组装的胶原支架，这些支架需要吸收和重塑才能发挥功能。支架的吸收和重塑与体内的疤痕重塑或伤口愈合非常相似，即使在理想的条件下，也需要数年才能完成。因此，没有功能承重的组织工程等效物获得临床成功。一种构建机械强度强的胶原基质的方法应该能提高产生功能性结缔组织替代物的机会。胶原蛋白基质必须高度有序和高度浓缩才能具有足够的强度。因此，有必要在纳米尺度上组织胶原蛋白，其方式类似于胚胎发育，成纤维细胞对胶原蛋白的成纤维形成进行精细的控制。尽管对这一过程的详细机制知之甚少，但有两种相互竞争的假设认为胶原蛋白要么是：a)通过细胞表面纤维支架由单个细胞合成、组装和组织，要么是b)以单体形式分泌，然后通过胆固醇调节作用组装成有组织的基质。在拟议的工作中，我们将在角膜基质ECM发育的新型体外模型中使用单个细胞的延时动态微分干涉对比成像来观察有组织的基质组装。然后，我们将通过模拟我们实验室目前正在开发的两种体外无细胞系统中的一种的发育机制，从头生成有组织的胶原基质。如果成功，这项研究将回答一个关键的基础科学问题，然后将这些结果转化为能够产生承载胶原组织当量的过程。