Development and assessment of a natural bio scafold for vascular reconstruction

描述（由申请人提供）：许多因素导致未能成功生产小直径血管移植物。很明显，工作移植物必须包括细胞成分，因为惰性材料不能与周围组织适当地相互作用。身体通过引发一系列复杂的生物反应对植入材料作出反应，这些生物反应大致分为血栓形成、免疫原性和增生反应。事实上，即使是含有细胞成分的移植物，这些负面的生物反应也会导致移植失败。我们的假设是，组织工程血管移植物的细胞成分无法做出适当的反应，从而导致移植物失败。因此，它是必不可少的，以确定和测量内皮细胞和平滑肌细胞（SMC）的功能，需要改善移植物的性能的具体方面。 在过去的几年里，我们的实验室已经开发了几种创新的方法来开发小直径的组织工程血管。我们使用去细胞的人脐静脉（HUV）作为可重塑的支架。该支架与组织机械隔离，产生具有均匀机械性质的长管状支架。我们已经开发了一种水凝胶“收缩包装”技术，用于快速种植高密度的人SMC到血管的外腔表面上。这些初步研究表明HUV支架具有极好的重塑能力。我们这个项目的目标是将HUV完全开发为小直径血管，然后表征和定义导致细胞表型的条件，最大限度地减少对血栓形成和炎症信号的不适当反应，包括SMC增生。 我们的具体目标是1）全面评估人脐静脉（HUV）支架作为有利于平滑肌细胞早期再生事件的环境。2)鉴定促进人内皮细胞在HUV支架管腔上附着、生长和功能（体内样）的条件。3)检验流体力学环境的细节在导致内皮细胞采用最小化血栓形成和炎症反应的表型方面至关重要的假设。4)检验将平滑肌细胞暴露于缺氧条件不会严重损害完全氧合的内皮细胞功能的假设。 公共卫生相关性：我们的目标是开发用于心脏和外周血管重建的功能性血管。采用一种独特的方法，使用来自人类脐静脉的生物支架，该生物支架由脐带加工而成，以产生机械均匀、生物相容的材料。本文提出的研究旨在确定促进血管壁再生以赋予生物功能的条件。此外，我们将研究调节不良细胞功能的参数，如伤口愈合的负面影响。我们相信，这种使用人脐静脉的独特方法与本文所述的技术相结合，可以开发出一种可行的替代方案来缓解这种临床需求。

DESCRIPTION (provided by applicant): Numerous factors have contributed to the failure to produce a successful small diameter vascular graft. It is clear that a working graft must include a cellular component since inert materials are unable to interact appropriately with the surrounding tissue. The body responds to implanted materials by initiating a complex series of biological reactions, broadly grouped as thrombotic, immunogenic and hyperplastic responses. In fact, even with grafts that include a cellular component, these negative biological responses occur leading to graft failure. It is our hypothesis that it is the inability of the cellular component of a tissue engineered vascular graft to respond appropriately that leads to graft failure. Therefore it is essential to define and measure specific aspects of endothelial and smooth muscle cell (SMC) function that are required to improve graft performance. Over the last several years, our laboratory has developed several innovative approaches for the development of a small diameter tissue engineered blood vessel. We use a decellurized human umbilical vein (HUV) as a remodelable scaffold. This scaffold is mechanically isolated from the tissue resulting in a long, tubular scaffold with uniform mechanical properties. We have developed a hydrogel 'shrink-wrapping' technique for rapidly seeding high densities of human SMC onto the ablumenal surface of the vessel. These preliminary investigations have shown the HUV scaffold to have an excellent capacity to remodel. Our goal with this project is to fully develop the HUV as a small diameter blood vessel, then characterize and define conditions leading to a cell phenotype that minimizes inappropriate responses to thrombogenic and inflammatory signals, including SMC hyperplasia. Our specific aims are 1) Comprehensively assess the human umbilical vein (HUV) scaffold as an environment favorable for early regenerative events of smooth muscle cells. 2) Identify conditions promoting attachment, growth, and function (in vivo-like) of human endothelial cells on the lumen of the HUV scaffold. 3) Test the hypothesis that details of the fluid mechanical environment are critical in causing endothelial cells to adopt a phenotype that minimizes thrombosis and an inflammatory response. 4) Test the hypothesis that exposing the smooth muscle cells to hypoxic conditions does not severely impair the function of the fully oxygenated endothelial cells. PUBLIC HEALTH RELEVANCE: Our aim to develop functional blood vessels for cardiac and peripheral vascular reconstruction. A unique approach is taken using a bioscaffold derived from the human umbilical veins that have been machined from umbilical cords to yield a mechanically uniform, biologically compatible material. The investigations proposed herein aim to defined conditions that promote regeneration of the vascular wall to confer biological functionality. Further, we will investigate parameters that modulate undesirable cell function, such as negative aspects of wound healing. We believe, this unique approach using the human umbilical vein in concert with technologies described herein, a viable alternative can be developed to alleviate this clinical demand.