Engineering biomimetic corneal constructs

工程仿生角膜结构

• 批准号: 6870794
• 负责人: Jeffrey W Ruberti
• 金额: $ 46.18万
• 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 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6870794
• 关键词: ascorbate; bioengineering /biomedical engineering; biomechanics; biomimetics; clinical research; collagen; corneal stroma; extracellular matrix; fibroblasts; human tissue; immunocytochemistry; mass tissue /cell culture; tissue engineering

DESCRIPTION (provided by applicant): Every year in the United States, over 45,000 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. By combining engineering, biology, biomechanics and biochemistry, two different routes, both designed to produce biomimetic stromal lamellae (the building blocks for an artificial cornea) will be attempted. The first method employs microfluidics to influence the self-assembly of thin, aligned lamellar sheets comprising collagen and proteoglycans. This approach is acellular and is designed to produce a biomimetic stromal scaffold de novo. The second approach utilizes mechanical cues such as contact guidance (provided by the de novo lamellae) and strain to "direct" the synthesis of matrix by ascorbic acid stimulated human corneal fibroblasts. An extensive characterization of the synthetic response to the imposed stimuli will be conducted to gain a fundamental understanding of synthesis, remodeling and homoeostasis of highly structured matrix. Completion of both parts of this proposal will provide insight critical to achieving our ultimate goal, which is the ex vivo generation of a functional, biomimetic artificial cornea from natural components.

描述（由申请人提供）：每年在美国，进行超过45,000个角膜移植。该过程的成功率相当高（两年后90％），尽管目前获得供体组织的访问足够，但组织质量差异很大，这会影响手术结果。此外，LASIK程序的扩散是取消角膜进行移植的资格，威胁要在不久的将来降低捐赠者角膜的可用性。近年来，已经为通过组织工程制作角膜当量而值得称赞的尝试。这些结构证明了这样一个概念，即三层细胞，类似于上皮，角膜细胞和内皮，可以培养为胶原基质。但是，这种构建体仅取得了有限的成功，因为尚未再现了角膜的基质基质（基质基质）独特（非常重要）的机械和光学特性。 随机定向的胶原蛋白凝胶代表了组织工程角膜的典型起点，不太可能足够强或足够清晰供临床使用。另外，期望体内重要 重塑响应以整合部分功能的人造角膜是不可接受的。人造 构造在植入时应起作用。 由于这些原因，我们提出了一种以基于基础的人造角膜来产生的基于基础的方法。 通过结合工程，生物学，生物力学和生物化学，两种不同的途径都将尝试产生仿生基质片（人造角膜的基础）。第一种方法采用微流体来影响包含胶原蛋白和蛋白聚糖的薄层状层片的自组装。这种方法是细胞的，旨在产生仿生的基质支架。第二种方法利用机械提示，例如联系指导（由 从头层状）和应变以“直接”抗坏血酸刺激人角膜成纤维细胞合成基质。 将对对施加的刺激的合成反应进行广泛的表征，以获得对高度结构化基质的合成，重塑和同性恋的基本理解。 该提案的两个部分的完成将为实现我们的最终目标提供至关重要的见解，这是从天然成分的实用，仿生的人造角膜的实体产生。