Engineering Biomimetic Corneal Constructs

工程仿生角膜结构

• 批准号: 7936910
• 负责人: Jeffrey W Ruberti
• 金额: $ 38.03万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2012-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7936910
• 关键词: Artificial skin; Ascorbic Acid; Basic Science; Biochemical; Biochemistry; Biocompatible Materials; Biology; Biomechanics; Biomedical Engineering; Biomimetics; Bioreactors; Caliber; Cell Communication; Cells; Chemicals; Chemistry; Cicatrix; Clinical; Collagen; Collagen Fibril; Collagen Type V; Complex; Connective Tissue; Cornea; Cues; Deposition; Development; Disease; Endothelium; Engineering; Environment; Epithelium; Event; Fibroblasts; Freezing; Future; Gel; Generations; Genetic; Glycosaminoglycans; Goals; Human; Hybrids; Image; In Vitro; Intelligence; Investigation; Keratoplasty; Kinetics; Laser In Situ Keratomileusis; Life; Liquid substance; Mechanical Stimulation; Mechanics; Mesenchymal; Mesenchymal Stem Cells; Methods; Microscope; Microscopy; Morbidity - disease rate; Morphology; Operative Surgical Procedures; Optics; Outcome; Patients; Periodicity; Physical condensation; Population; Principal Investigator; Printing; Procedures; Production; Property; Proteoglycan; Refractory; Regenerative Medicine; Research; Resolution; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Transduction; Solutions; Stem Cell Research; Stem cells; Stromal Cells; Structure; System; Testing; Time; Tissue Donors; Tissue Engineering; Tissues; Umbilical Cord Blood; United States; alternative treatment; base; cell motility; fibrillogenesis; implantation; improved; in vivo; insight; light transmission; liquid crystal; meetings; mimetics; model development; monomer; programs; proteoglycan core protein; public health relevance; response; scaffold; stem; success; triple helix

DESCRIPTION (provided by applicant): Every year in the United States, over 33,000 corneal transplants are performed. The success rate for this procedure is fairly high (90% after two years) and although current access to donor tissue is adequate, the quality of tissue varies significantly which influences surgical outcomes. In addition, the proliferation of LASIK procedures, which disqualifies a cornea for transplantation, threatens to reduce the availability of donor corneas in the near future. In recent years, laudable attempts have been made to produce corneal equivalents by tissue engineering. These constructs have proven the concept that three layers of cells, resembling the epithelium, keratocytes and endothelium may be cultured into a collagen matrix. However, such constructs have only met with limited success because the stromal matrix, which provides the cornea with its unique (and critically important) mechanical and optical properties, has not been reproduced. Randomly oriented collagen gels, which represent the typical starting point for tissue engineered corneas, are not likely to be strong enough or clear enough for clinical use. In addition, expecting a significant in vivo remodeling response to integrate a partially functioning artificial cornea is not acceptable. The artificial construct should be functional at the time of implantation. For these reasons, we propose a stromal-centric approach toward the generation of an artificial cornea. We start by investigating precisely how fibroblastic cells produce organized tissue in vitro by tracking human fibroblasts live as they produce matrix on a long-term live imaging culture system. Then by combining bioengineering, biology, biomechanics and biochemistry an attempt will be made to produce biomimetic stromal lamellae (the building blocks for an artificial cornea). The method entails using the intelligence already "encoded" into the collagen triple helix which produces organized arrays of fibrils simply by concentrating the monomers to induce liquid crystalline structure formation and fibrillogenesis. The resulting organized arrays of fibrils will be used as starting point for comprehensive investigation into the role of matrix molecules on collagen fibril morphology and spacing. Once our arrays are well-characterized, human corneal fibroblasts and human cord blood derived stem cells will be seeded into them and exposed to mechanical stimulation. We expect to induce differentiation in both populations of cells. Completion of this application will provide insight both to the basic science of understanding corneal stromal development and to achieving our ultimate goal, which is the ex vivo generation of a functional, biomimetic artificial cornea from natural components. PUBLIC HEALTH RELEVANCE: Completion of this application will provide insight both to the basic science of understanding corneal stromal development and to achieving our ultimate goal, which is the ex vivo generation of a functional, biomimetic artificial cornea from natural components. Given recent advances in biomaterials engineering and stem cell research (which are combined in this application) we expect to ultimately enhance the ability of clinicians to offer patients with significant morbidity viable alternative treatment options based on engineered tissue.

描述（由申请人提供）：美国每年进行超过 33,000 例角膜移植手术。该手术的成功率相当高（两年后为 90%），尽管目前获得供体组织的机会充足，但组织的质量差异很大，这会影响手术结果。此外，LASIK 手术的普及导致角膜移植资格丧失，在不久的将来可能会减少供体角膜的可用性。近年来，通过组织工程生产角膜等效物进行了值得称赞的尝试。这些构建体证明了这样的概念：类似上皮、角膜细胞和内皮的三层细胞可以培养成胶原基质。然而，这种构造只取得了有限的成功，因为为角膜提供独特（且至关重要）机械和光学特性的基质基质尚未被复制。随机取向的胶原凝胶代表了组织工程角膜的典型起点，但其强度或清晰度不足以满足临床使用。此外，期望显着的体内重塑反应来整合部分功能的人造角膜是不可接受的。人工构建体在植入时应该具有功能。由于这些原因，我们提出了一种以基质为中心的方法来生成人工角膜。我们首先通过跟踪人类成纤维细胞在长期活体成像培养系统上产生基质的情况，精确研究成纤维细胞如何在体外产生有组织的组织。然后，通过结合生物工程、生物学、生物力学和生物化学，将尝试生产仿生基质薄片（人造角膜的构件）。该方法需要使用已经“编码”到胶原蛋白三螺旋中的智能，只需浓缩单体以诱导液晶结构形成和原纤维生成，即可产生有组织的原纤维阵列。由此产生的有组织的原纤维阵列将用作全面研究基质分子对胶原原纤维形态和间距的作用的起点。一旦我们的阵列得到充分表征，人类角膜成纤维细胞和人类脐带血干细胞将被播种到其中并受到机械刺激。我们期望诱导两个细胞群的分化。该应用的完成将为理解角膜基质发育的基础科学和实现我们的最终目标提供深入的见解，即从天然成分中体外生成功能性仿生人工角膜。公共健康相关性：完成本申请将为理解角膜基质发育的基础科学和实现我们的最终目标（即利用天然成分离体生成功能性仿生人工角膜）提供见解。鉴于生物材料工程和干细胞研究（在本应用中结合）的最新进展，我们期望最终增强临床医生为患有严重疾病的患者提供基于工程组织的可行替代治疗选择的能力。