Human Brain Endothelial Cell Seeded on Inner Surface of Alginate Hollow Microfibers

Barrier functionality of the blood-brain barrier (BBB) is provided by the tight junctions formed by a monolayer of the human brain endothelial cells (HBECs) internally around the blood capillaries. To mimic such barrier functionality in vitro, replicating the hollow tubular structure of the BBB along with the HBECs monolayer on its inner surface is crucial. Here, we developed an invasive microfluidic technique to obtain the HBECs monolayer on the inner surface of alginate-based hollow microfibers. The HBECs were seeded on the inner surface of these microfibers using a custom-built microfluidic device. The seeded HBECs were monitored for 9 days after manufacturing and cultured to form a monolayer on the inner surface of the alginate hollow microfibers in the maintenance media. A higher cell seeding density of 217 cells/mm length of the hollow microfiber was obtained using our microfluidic technique. Moreover, high accuracy of around 96 % was obtained in seeding cells on the inner surface of alginate hollow microfibers. The microfluidic method illustrated in this study could be extrapolated to obtain a monolayer of different cell types on the inner surface of alginate hollow microfibers with cell-compatible ECM matrix proteins. Furthermore, it will enable us to mimic a range of microvascular systems in vitro by closely replicating the structural attributes of the native structure.