A conventional Petri dish with flat electrodes is not enough. For a more realistic study, cells need to flourish within three-dimensional surroundings. This allows for an accurate study of brain cell operations or testing on the individual effect(s) of medication on cells.
Bart Schurink, a researcher at the University of Twente‘s MESA+ Institute for Nanotechnology, has developed a sieve with 900 openings, each taking the shape of an inverted pyramid. A micro-reactor on top of these pyramids takes care of the cell growth.
For brain cells to be cultured, a brain-on-a-chip demands more than a series of electrodes in 2D. Mimicking the brain in a realistic way allows for a more fluid flow as even when kept in predefined spaces the cells need some freedom for themselves. Thus, Schurink developed a microsieve structure with hundreds of openings on a 2 by 2 mm surface. Each pyramid has an electrode measuring electrical signals or stimuli to the network. At the same time, liquids flow through tiny holes. These are needed to capture cells and send nutrients or medication to a cell.
Once neurons are inside the pyramids, they will start to form a network. The network between the holes is not just 2D either. By placing a microreactor on top of the sieve, a neuron network can also develop in a vertical direction. The growth and electrical activity are later monitored, with each individual cell identified by the pyramid it is in.
Coming up with this system demanded a lot of production collaboration between the NanoLab of the UT and the creative solutions of the designers as guaranteeing that every hole was the same size was quite the challenge.
The new µSEA (microsieve electrode array), developed by Schurink, was tested with living cells using the brains of laboratory rats. The positioning of the cells and neuronal network growth were all tested. The end result of his research is a totally new platform which performs an analysis of the brain, the groundwork for the study of diseases and effects of different medications on the brain.