The blood-brain barrier (BBB) protects the human brain from external aggression. Despite its great importance, very few in vitro models of the BBB reproducing its complex organization are available yet. Here we fabricated such a three-dimensional (3D) self-organized in vitro model of BBB microvasculature by means of a combination of collagen microfibers (CMF) and fibrin gel. The interconnected fibers supported human brain microvascular endothelial cell migration and the formation of a capillary-like network with a lumen diameter close to in vivo values. Fibrin, a protein involved in blood vessel repair, favored the further 3D conformation of the brain microvascular endothelial cells, astrocytes and pericytes, ensured gel cohesion and avoided shrinkage. The maturation of the BBB microvasculature network was stimulated by both the CMF and the fibrin in the hydrogel. The expression of essential tight-junction proteins, carriers and transporters was validated in regards to bidimensional simple coculture. The volume of gel drops was easily tunable to fit in 96-well plates. The cytotoxicity of D-Mannitol and its impacts on the microvascular network were evaluated, as an example of the pertinence of this 3D BBB capillary model for screening applications.

血脑屏障 (BBB) 保护人脑免受外部侵害。尽管它非常重要，但很少有 BBB 的体外模型再现其复杂的组织。在这里，我们通过胶原微纤维 (CMF) 和纤维蛋白凝胶的组合制作了 BBB 微血管的这种三维 (3D) 自组织体外模型。相互连接的纤维支持人脑微血管内皮细胞迁移和管腔直径接近体内的毛细血管样网络的形成值。纤维蛋白是一种参与血管修复的蛋白质，有利于脑微血管内皮细胞、星形胶质细胞和周细胞的进一步三维构象，确保凝胶内聚力并避免收缩。BBB 微血管网络的成熟受到 CMF 和水凝胶中纤维蛋白的刺激。基本紧密连接蛋白、载体和转运蛋白的表达在二维简单共培养方面得到验证。凝胶滴的体积很容易调节以适合 96 孔板。评估了 D-甘露醇的细胞毒性及其对微血管网络的影响，作为此 3D BBB 毛细管模型用于筛选应用的相关性示例。