KAIST "Precise Measurement of Brain 'Organoids' Possible... Expected to Replace Animal Testing"

A monitoring system that enables the measurement of subtle electrophysiological signals sent by brain organoids has been developed. Organoids are three-dimensional cell aggregates created based on human-derived stem cells. Recently, they have attracted attention as experimental models to replace animal testing models and two-dimensional cell culture models.

However, organoids such as those of the brain and heart generate very small electrical signals, making it extremely difficult to measure the electrophysiological signals generated by organoids. The developed monitoring system is meaningful in that it can serve as a basis to overcome these limitations.

(Back row from left) Professor Hyunju Lee, Dr. Miyoung Son, Dr. Miok Lee (Front row from left) PhD candidate Gieop Kim, PhD candidate Youngsun Lee. Provided by KAIST

On the 14th, KAIST announced that Professor Hyun-Joo Lee’s research team from the Department of Electrical Engineering and Computer Science, in collaboration with Senior Researcher Mi-Young Son’s team from the National Agenda Research Division at the Korea Research Institute of Bioscience and Biotechnology, and Dr. Mi-Ok Lee’s team from the Stem Cell Fusion Research Center, developed a ‘highly stretchable protruding microelectrode array platform’ for non-invasive electrophysiological signal measurement of organoids.

Until now, organoid-related research has mainly focused on genetic analysis, and functional studies of organoids have been relatively insufficient. From the same perspective, the development of technology capable of preserving the three-dimensional form and condition of organoids while monitoring their function in real time has been urgently needed for effective drug evaluation and precise biological research.

In particular, measuring electrophysiological signals of brain and heart organoids, where electrical signals are generated, has been considered very difficult because the size of organoids varies widely from several hundred micrometers (μm) to several millimeters (mm) depending on the organoid production method, and their shapes are irregular. Measuring by attaching electrodes closely to the external surface without damaging the organoids was regarded as extremely challenging.

Accordingly, the joint research team developed a highly stretchable protruding microelectrode array that can stretch by itself and adhere closely to the surface according to the size and shape of the organoid. They also succeeded in real-time measurement and evaluation of changes in electrophysiological signals generated by organoids using this technology.

The joint research team developed a microelectromechanical systems (MEMS) process to fabricate a highly stretchable microelectrode array based on a serpentine structure and produced protruding microelectrodes through an electroplating process.

The protruding microelectrodes enable stronger adhesion of electrodes to the organoids, allowing stable measurement of electrophysiological signals without causing damage to the organoids, the joint research team explained.

Professor Hyun-Joo Lee of KAIST said, “The highly stretchable protruding microelectrode array developed by the joint research team can be applied to organoids of various sizes and has the advantage of real-time measurement and evaluation of the organoid’s condition. We expect this technology to be immediately applicable for replacing experimental animals in new drug development or for quality evaluation of organoids used as regenerative therapeutics.”

Meanwhile, this research was conducted with support from the Ministry of Trade, Industry and Energy’s 3D Bio-Tissue Chip-Based New Drug Development Platform Technology Development Project, the Ministry of Science and ICT’s Domestic Research Equipment Technology Competitiveness Enhancement Project, and the Bio and Medical Technology Development Project.

Dr. Ki-Up Kim, a doctoral candidate at KAIST’s Department of Electrical Engineering and Computer Science, and Dr. Young-Sun Lee, a doctoral candidate at the Korea Research Institute of Bioscience and Biotechnology, participated as first authors. The research results were published online on December 15 last year in the international academic journal Advanced Materials.

This content was produced with the assistance of AI translation services.