Istituto Italiano di Tecnologia, Smart Bio-Interfaces, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy.
Scuola Superiore Sant'Anna, The BioRobotics Institute, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy.
Lab Chip. 2024 Nov 5;24(22):5085-5100. doi: 10.1039/d4lc00633j.
A significant challenge in the treatment of central nervous system (CNS) disorders is represented by the presence of the blood-brain barrier (BBB), a highly selective membrane that regulates molecular transport and restricts the passage of pathogens and therapeutic compounds. Traditional models are constrained by high costs, lengthy experimental timelines, ethical concerns, and interspecies variations. models, particularly microfluidic BBB-on-a-chip devices, have been developed to address these limitations. These advanced models aim to more accurately replicate human BBB conditions by incorporating human cells and physiological flow dynamics. In this framework, here we developed an innovative microfluidic system that integrates thin-film electrodes for non-invasive, real-time monitoring of BBB integrity using electrochemical impedance spectroscopy (EIS). EIS measurements showed frequency-dependent impedance changes, indicating BBB integrity and distinguishing well-formed from non-mature barriers. The data from EIS monitoring was confirmed by permeability assays performed with a fluorescence tracer. The model incorporates human endothelial cells in a vessel-like arrangement to mimic the vascular component and three-dimensional cell distribution of human astrocytes and microglia to simulate the parenchymal compartment. By modeling the BBB-on-a-chip with an equivalent circuit, a more accurate trans-endothelial electrical resistance (TEER) value was extracted. The device demonstrated successful BBB formation and maturation, confirmed through live/dead assays, immunofluorescence and permeability assays. Computational fluid dynamics (CFD) simulations confirmed that the device mimics shear stress conditions. Drug crossing assessment was performed with two chemotherapy drugs: doxorubicin, with a known poor BBB penetration, and temozolomide, conversely a specific drug for CNS disorders and able to cross the BBB, to validate the model predictive capability for drug crossing behavior. The proposed sensorized microfluidic device represents a significant advancement in BBB modeling, offering a versatile platform for CNS drug development, disease modeling, and personalized medicine.
中枢神经系统（CNS）疾病治疗的一个重大挑战是血脑屏障（BBB）的存在，它是一种高度选择性的膜，可调节分子运输并限制病原体和治疗化合物的通过。传统模型受到高成本、漫长的实验时间表、伦理问题和种间差异的限制。 模型，特别是微流控 BBB 芯片设备，已被开发出来以解决这些限制。这些先进的模型旨在通过整合人类细胞和生理流动动力学来更准确地复制人类 BBB 条件。在这个框架中，我们开发了一种创新的微流控系统，该系统集成了薄膜电极，可使用电化学阻抗谱（EIS）进行非侵入性、实时监测 BBB 完整性。EIS 测量显示出频率相关的阻抗变化，表明 BBB 完整性，并很好地区分了成熟和非成熟的屏障。EIS 监测数据通过荧光示踪剂进行的渗透性测定得到证实。该模型将人类内皮细胞整合在类似于血管的排列中，以模拟血管成分和人类星形胶质细胞和小胶质细胞的三维细胞分布，从而模拟实质部分。通过对 BBB-on-a-chip 进行等效电路建模，可以提取更准确的跨内皮电阻（TEER）值。该设备通过死活测定、免疫荧光和渗透性测定成功地模拟了 BBB 的形成和成熟。计算流体动力学（CFD）模拟证实，该设备模拟了切应力条件。用两种化疗药物进行药物穿越评估：阿霉素，已知穿透 BBB 的能力差，而替莫唑胺则相反，是一种专门用于 CNS 疾病的药物，能够穿透 BBB，以验证该模型对药物穿越行为的预测能力。该传感器微流控设备是 BBB 建模的重大进展，为 CNS 药物开发、疾病建模和个性化医疗提供了一个多功能平台。
