At Vanderbilt University researchers have developed a mimic of the blood-brain barrier in the form of a microfluidic device. To show a proof-of-concept of this “organ-on-chip” technology, the team studied how inflammation affects the blood-brain barrier continuously for an extended period of time, while previous approaches have only provided discrete snapshots of the process.
The device is called NeuroVascular Unit (NVU) on a chip and it consists of a tiny space separated by a porous membrane. On top of the membrane is the “brain” side and the bottom is the “blood” side. Each of the sides has input and output tubes driven by micropumps that can sample the insides and deliver nutrients, drugs, pathogens, and anything else involved in an experiment.
To actually create a true blood-brain barrier, human endothelial cells are introduced on the “blood” side after flipping the device. Then fluid is pumped through the chamber with the cells. Interestingly, the cells begin aligning parallel with the direction of flow, creating an even layer of organized cells that resemble the structure of the blood-brain barrier. After two days of this, the cells are aligned and attached to the membrane separating the chambers. The device is flipped and astrocytes, pericytes, and excitatory neurons, which are also present in the barrier, are then added to the “brain” side of the device. The newly added cells slowly move through the membrane separating the chambers, interacting and sticking to the endothelial cells on the other side, resulting in perhaps the closest laboratory copy of the blood-brain barrier.
Here’s a Vanderbilt video discussing the new device: