Development of a BBB model to study transendothelial cell migration

描述(申请人提供)：在体外复制脑血管节段的生理特征是一个关键问题。对脑血管系统进行适当的建模可以极大地帮助理解疾病的机制并改善疾病的药理学，在这种疾病中，白细胞在脑血管系统中迁移的作用得到了证明。多亏了之前的支持(第一阶段)，我们能够制作和测试一种新的动态体外模型的血脑屏障(DIV-BBB)，允许白细胞外渗。我们最初的努力旨在以可重复的方式穿透中空纤维；结果最近发表了。我们发现，人工穿孔的中空纤维允许白细胞通过血脑屏障，以响应促炎刺激和血流动力学变化。我们还可以通过改变系统的流变学参数(例如，改变剪应力)来产生毛细血管-微静脉段。此外，我们最近开发了一种系统，将中空纤维的孔尺寸增加到生理上相应的5？m，并对纤维末端进行控制牵引，扫描电子显微镜显示拉伸后的纤维内有扩大的孔。为了进一步发展这一新的BBB模型所提供的商业机会，我们提出了以下第二阶段的具体目标：优化脑血管系统允许白细胞外渗的动态体外毛细血管-小静脉模型的性能。确定由具有不同跨壁通透性的纤维组成的对照和病变毛细血管-小静脉段中白细胞外渗的模式(来自目标1)。将使用这些DIV-BBB模型的结果与其他最先进的体外BBB模型进行比较。我们最初将为多发性硬化症和癫痫的研究和药物开发量身定制DIV毛细血管-小静脉系统的使用。我们已经组建了一个跨脑血管的白细胞迁移领域的研究人员和专家组成的多学科团队。商业化计划中详细说明了更多与临床相关的场所。鉴于我们的初步结果和本申请中详细描述的确认性进展报告，以及在此期间新药的开发仍然是神经系统疾病治疗中的一个主要问题，我们认为，旨在改进药物开发的良好成就记录和合理的实验设计相结合是这一第二阶段提案的基本方面。

DESCRIPTION (provided by applicant): Reproducing in vitro the physiological characteristics of brain vascular segments represents a critical issue. Adequate modeling of the cerebrovasculature could significantly help understand the mechanisms and improve the pharmacology of disease where a role for leukocytes migrating across the cerebrovasculature is demonstrated. Thanks to the previous support (Phase I) we were able to prototype and test drive a new dynamic in vitro model of the BBB (DIV- BBB) permissive for leukocyte extravasation. Our initial effort aimed at piercing hollow fibers in a reproducible manner; the results were recently published. We found that manually perforated hollow fibers allow leukocytes passage across the BBB in response to pro-inflammatory stimuli and hemodynamic changes. We were also able to produce a capillary-venule segment by varying the rheological parameters (e.g., changing the shear stress) of the system. In addition we recently developed a system to mechanically "stretch" the hollow fibers increasing the pore size up to the physiologically relevant size of ~5 ¿m. Controlled traction was applied to the end of the fibers and scanning electron microscopy showed enlarged pores within the stretched fiber. To further the commercial opportunity afforded by this new BBB model, we propose the following Phase II Specific Aims: To optimize the performance of a dynamic in vitro capillary-venules model of the brain cerebrovasculature permissive for leukocyte extravasation. To determine the pattern of leukocytes extravasation in control and diseased capillary-venules segments composed of fibers with different transmural permeability properties (from Aim 1). To compare the results obtained using these DIV- BBB models to other state-of-art in vitro BBB models. We will initially tailor the use of the DIV capillary-venules system to multiple sclerosis and epilepsy research and drug development. We have assembled a multi-disciplinary team of investigators and experts in the field of leukocyte migration across the cerebrovasculature. Additional clinically relevant venues are detailed in the Commercialization Plan. Given our preliminary results and the confirmatory progress report described in detail in this application, and given the fact that i the meantime development of new drugs has remained a major issue in the treatment of neurological diseases, we believe that the combination of a strong record of accomplishment and sound experimental design aimed at improving drug development are fundamental aspects of this Phase 2 proposal.