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(申请人提供)：在美国，每年进行的角膜移植手术超过33,000例。这种手术的成功率相当高(两年后为90%)，虽然目前获得供体组织的途径充足，但组织的质量差异很大，这影响了手术结果。此外，LASIK手术的扩散使角膜失去了移植资格，在不久的将来可能会减少供体角膜的供应。近年来，通过组织工程学制造角膜替代物的尝试值得称道。这些构造证明了这样一个概念，即类似于上皮、角质细胞和内皮的三层细胞可以培养成胶原基质。然而，这种结构只取得了有限的成功，因为为角膜提供独特(和至关重要的)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化角膜的典型起点，但不太可能足够坚固或足够透明，不适合临床使用。此外，期望有显著的体内重塑反应来整合部分功能的人工角膜是不可接受的。人工构建物在植入时应具有功能性。基于这些原因，我们提出了一种以基质为中心的方法来生成人工角膜。我们从精确研究成纤维细胞如何在体外产生有组织的组织开始，通过跟踪活的人成纤维细胞在长期的活成像培养系统中产生基质。然后，通过将生物工程、生物学、生物力学和生物化学相结合，将尝试制造仿生基质板层(人造角膜的构建块)。这种方法需要使用已经编码到胶原蛋白三螺旋中的智能，它只需通过浓缩单体来诱导液晶结构形成和纤维形成，就可以产生有组织的纤维阵列。由此得到的有组织的纤维阵列将被用作全面研究基质分子对胶原纤维形态和间距的作用的起点。一旦我们的阵列具有良好的特性，人类角膜成纤维细胞和人类脐带血干细胞将被植入其中，并暴露在机械刺激下。我们希望在这两类细胞中都能诱导分化。这一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洞察力，即从天然成分体外生成具有功能的仿生人工角膜。公共卫生相关性：这项应用的完成将为了解角膜基质发育的基础科学和实现我们的最终目标提供洞察力，即从天然成分体外生成具有功能的仿生人工角膜。鉴于生物材料工程和干细胞研究的最新进展(在这一应用中结合在一起)，我们希望最终提高临床医生的能力，为有显著发病率的患者提供基于工程组织的可行替代治疗方案。