Wang Ying I, Abaci Hasan Erbil, Shuler Michael L
Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 381 Kimball Hall, Ithaca, New York, 14853-7202.
Biotechnol Bioeng. 2017 Jan;114(1):184-194. doi: 10.1002/bit.26045. Epub 2016 Jul 21.
Efficient delivery of therapeutics across the neuroprotective blood-brain barrier (BBB) remains a formidable challenge for central nervous system drug development. High-fidelity in vitro models of the BBB could facilitate effective early screening of drug candidates targeting the brain. In this study, we developed a microfluidic BBB model that is capable of mimicking in vivo BBB characteristics for a prolonged period and allows for reliable in vitro drug permeability studies under recirculating perfusion. We derived brain microvascular endothelial cells (BMECs) from human induced pluripotent stem cells (hiPSCs) and cocultured them with rat primary astrocytes on the two sides of a porous membrane on a pumpless microfluidic platform for up to 10 days. The microfluidic system was designed based on the blood residence time in human brain tissues, allowing for medium recirculation at physiologically relevant perfusion rates with no pumps or external tubing, meanwhile minimizing wall shear stress to test whether shear stress is required for in vivo-like barrier properties in a microfluidic BBB model. This BBB-on-a-chip model achieved significant barrier integrity as evident by continuous tight junction formation and in vivo-like values of trans-endothelial electrical resistance (TEER). The TEER levels peaked above 4000 Ω · cm on day 3 on chip and were sustained above 2000 Ω · cm up to 10 days, which are the highest sustained TEER values reported in a microfluidic model. We evaluated the capacity of our microfluidic BBB model to be used for drug permeability studies using large molecules (FITC-dextrans) and model drugs (caffeine, cimetidine, and doxorubicin). Our analyses demonstrated that the permeability coefficients measured using our model were comparable to in vivo values. Our BBB-on-a-chip model closely mimics physiological BBB barrier functions and will be a valuable tool for screening of drug candidates. The residence time-based design of a microfluidic platform will enable integration with other organ modules to simulate multi-organ interactions on drug response. Biotechnol. Bioeng. 2017;114: 184-194. © 2016 Wiley Periodicals, Inc.
在中枢神经系统药物研发中，实现治疗药物有效穿越具有神经保护作用的血脑屏障（BBB）仍是一项艰巨挑战。高保真的血脑屏障体外模型有助于对靶向大脑的候选药物进行有效的早期筛选。在本研究中，我们开发了一种微流控血脑屏障模型，该模型能够长时间模拟体内血脑屏障特征，并允许在循环灌注条件下进行可靠的体外药物渗透性研究。我们从人诱导多能干细胞（hiPSC）中获取脑微血管内皮细胞（BMEC），并将其与大鼠原代星形胶质细胞在无泵微流控平台上多孔膜的两侧共培养长达10天。微流控系统基于人脑组织中的血液停留时间进行设计，可在无泵或外部管道的情况下以生理相关灌注速率实现培养基循环，同时将壁面剪应力降至最低，以测试剪应力是否是微流控血脑屏障模型中类似体内屏障特性所必需的。通过持续紧密连接形成以及跨内皮电阻（TEER）的类似体内值，该芯片上血脑屏障模型实现了显著的屏障完整性。芯片上第3天TEER水平峰值超过4000 Ω·cm，并在长达10天的时间内维持在2000 Ω·cm以上，这是微流控模型中报道的最高持续TEER值。我们使用大分子（异硫氰酸荧光素标记的葡聚糖）和模型药物（咖啡因、西咪替丁和阿霉素）评估了我们的微流控血脑屏障模型用于药物渗透性研究的能力。我们的分析表明，使用我们的模型测得的渗透系数与体内值相当。我们的芯片上血脑屏障模型紧密模拟了生理血脑屏障的屏障功能，将成为筛选候选药物的宝贵工具。基于停留时间的微流控平台设计将能够与其他器官模块集成，以模拟多器官对药物反应的相互作用。《生物技术与生物工程》2017年；114：184 - 194。© 2016威利期刊公司
