Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST) , Seoul, South Korea.
Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST) , Seoul, South Korea.
Biomicrofluidics. 2015 Apr 15;9(2):024115. doi: 10.1063/1.4917508. eCollection 2015 Mar.
We present an engineered three-dimensional (3D) in vitro brain microvasculature system embedded within the bulk of a collagen matrix. To create a hydrogel template for the functional brain microvascular structure, we fabricated an array of microchannels made of collagen I using microneedles and a 3D printed frame. By culturing mouse brain endothelial cells (bEnd.3) on the luminal surface of cylindrical collagen microchannels, we reconstructed an array of brain microvasculature in vitro with circular cross-sections. We characterized the barrier function of our brain microvasculature by measuring transendothelial permeability of 40 kDa fluorescein isothiocyanate-dextran (Stoke's radius of ∼4.5 nm), based on an analytical model. The transendothelial permeability decreased significantly over 3 weeks of culture. We also present the disruption of the barrier function with a hyperosmotic mannitol as well as a subsequent recovery over 4 days. Our brain microvasculature model in vitro, consisting of system-in-hydrogel combined with the widely emerging 3D printing technique, can serve as a useful tool not only for fundamental studies associated with blood-brain barrier in physiological and pathological settings but also for pharmaceutical applications.
我们提出了一种工程化的三维（3D）体外脑微血管系统，该系统嵌入在胶原基质的主体中。为了创建功能性脑微血管结构的水凝胶模板，我们使用微针和 3D 打印框架制造了由 I 型胶原制成的微通道阵列。通过在圆柱形胶原微通道的腔表面上培养小鼠脑内皮细胞（bEnd.3），我们在体外重建了具有圆形横截面的脑微血管阵列。我们通过基于分析模型测量 40kDa 荧光素异硫氰酸酯-葡聚糖（Stokes 半径约为 4.5nm）的跨内皮通透性来表征我们的脑微血管的屏障功能。在 3 周的培养过程中，跨内皮通透性显著降低。我们还展示了高渗甘露醇对屏障功能的破坏以及随后在 4 天内的恢复。我们的体外脑微血管模型由系统在凝胶中的组合以及广泛出现的 3D 打印技术组成，不仅可以作为与生理和病理环境下血脑屏障相关的基础研究的有用工具，也可以作为药物应用的有用工具。
