Fabrication of a microfluidic system with columnar structures using DRIE for blood brain barrier applications

A novel concept and the batch orientated fabrication of a microfluidic structure as environment for an in vitro model of a blood-brain-barrier (BBB) is presented. The system is based on a permeable central channel consisting of parallel pillar rows for separation of abluminal and luminal side. Abluminal and luminal compartments are realized in a planar configuration which allows easy access e.g. for microscopy. Within this paper, the fluid initiation of hydrogel precursor liquids to the pillar lined middle channel, in combination with a hydrophilic surface, is analyzed. The experiments show, that the liquid guiding performance of the circular pillars can be utilized for various fluid initiation sequences without liquid spreading to the lateral channels. Therefore, the developed layout provides a promising platform for triple cell cultivation procedures and thus for an in-vitro BBB-model.