3D Shell MEA to Record Electrical Activity of Brain Organoids

As organoids have become one of the premier models for experimentation due to their ability to mimic in vivo organs through their existence as a three dimensional (3D) multicellular in vitro model created from tissue culture, researchers have studied various different organs using organoids mimicking those organs. In this study, brain organoids were studied for their 3D microenvironment retaining cytoarchitecture seen in the brain utilizing Multielectrode Arrays (MEAs). MEAs allow for both the recording and the stimulation of electrical activity from electrogenic–involving the production of changes in electric potential–cells. Conventional MEAs are two dimensional (2D) in nature. They were designed originally for 2D monolayer cell cultures, which means they do not fully grasp the potential of electrical recording of organoids, which are 3D in nature. In this study, we developed miniature chip-integrated MEA caps that have the capability to maximize electrode contact with brain organoids, therefore allowing for more effective electrical recording. The optically transparent shells were created from self-folding polymer leaflets with conductive polymer-coated metal electrodes sandwiched in between the polymer bilayer. The MEAs tunable nature allows for versatile recording of brain organoids from 400 μm to 600 μm for up to four weeks, which was validated through glutamate stimulation. Our work suggests that 3D shell MEAs provide significantly effective results related to signal-to-noise and 3D spatiotemporal recordings for brain organoids