Brain homeostasis relies on the selective permeability property of the blood brain barrier (BBB). The BBB is formed by a continuous endothelium that regulates exchange between the blood stream and the brain. This physiological barrier also creates a challenge for the treatment of neurological diseases as it prevents most blood circulating drugs from entering into the brain. In vitro cell models aim to reproduce BBB functionality and predict the passage of active compounds through the barrier. In such systems, brain microvascular endothelial cells (BMECs) are cultured in contact with various biomaterial substrates. However, BMEC interactions with these biomaterials and their impact on BBB functions are poorly described in the literature. Here we review the most common materials used to culture BMECs and discuss their potential impact on BBB integrity in vitro. We investigate the biophysical properties of these biomaterials including stiffness, porosity and material degradability. We highlight a range of synthetic and natural materials and present three categories of cell culture dimensions: cell monolayers covering non-degradable materials (2D), cell monolayers covering degradable materials (2.5D) and vascularized systems developing into degradable materials (3D).

中文翻译：

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体外血脑屏障建模材料。

大脑稳态依赖于血脑屏障（BBB）的选择性通透性。BBB 由连续的内皮细胞形成，调节血流和大脑之间的交换。这种生理屏障也给神经系统疾病的治疗带来了挑战，因为它阻止了大多数血液循环药物进入大脑。体外细胞模型旨在重现 BBB 功能并预测活性化合物通过屏障的通道。在此类系统中，脑微血管内皮细胞（BMEC）与各种生物材料基质接触进行培养。然而，文献中很少描述 BMEC 与这些生物材料的相互作用及其对 BBB 功能的影响。在这里，我们回顾了用于培养 BMEC 的最常用材料，并讨论了它们对体外 BBB 完整性的潜在影响。我们研究这些生物材料的生物物理特性，包括硬度、孔隙率和材料可降解性。我们重点介绍了一系列合成和天然材料，并提出了三类细胞培养维度：覆盖不可降解材料的细胞单层（2D）、覆盖可降解材料的细胞单层（2.5D）和发育成可降解材料的血管化系统（3D）。