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（由申请人提供）：胶原蛋白是体内的原理载荷分子和最丰富的蛋白质。胶原蛋白退化性疾病包括骨关节炎（影响10％或60岁以上的美国人），骨质疏松症（影响2800万美国人），动脉动脉瘤和间歇性椎间盘疾病。每年在美国进行50,000次角膜移植和200,000次初级ACL重建，表明需要适当的机械植物材料。与胶原蛋白相关的遗传疾病同样具有毁灭性；例子包括骨化不完美（在美国影响27,000人），许多软骨浮肿（4,000个出生）和各种综合症（即ehlers-danlos，Alport和Bethlem肌病）。这些疾病的经济影响是巨大的。仅骨关节炎就使美国经济造成了超过600亿美元的损失。尽管如此，对在体内控制胶原蛋白组件的机制知之甚少，该机制限制了组织工程师在实验室中繁殖胶原载荷组织的能力。取而代之的是，组织工程利用细胞种子，可降解的合成或自组装的胶原支架，需要吸收并重塑起作用。脚手架的吸收和重塑与体内疤痕重塑或伤口愈合非常相似，即使在理想的条件下也可能需要数年才能完成。因此，没有功能性负荷组织工程的当量符合临床成功。一种构建机械强，胶原基质的方法，应提高产生功能结缔组织等效物的机会。胶原型矩阵必须高度有序且高度集中才能具有足够的强度。因此，有必要以类似于胚胎发育的方式在纳米级上组织胶原蛋白，在这种方式中，成纤维细胞对胶原蛋白的原纤维生成进行精致的控制。尽管对于此过程的详细力学知之甚少，但有两个相互竞争的假设表明胶原蛋白是：a）通过单个细胞通过细胞表面纤维胶质体合成，组装和组织胶原蛋白，或者b）以单体形式分泌，然后通过胆固醇效应组装成有组织的基质。在拟议的工作中，我们将在新型的角膜基质ECM发育的体外模型中使用延时的活动态差异干扰成像观察到有组织的基质组装。然后，我们将通过模仿目前正在我们的实验室开发的两个无细胞的系统之一中的一种开发机制来生产有组织的胶原矩阵。如果成功，则提出的研究将回答有关开发的关键基础科学问题，然后将这些结果转化为能够产生承重胶原组织等效物的过程。