Neurotoxicity & Cerebral organoids

In recent years, cerebral organoids have emerged as pivotal three-dimensional (3D) in vitro models of human cerebral cellular organization and development. However, their utility for compound toxicity screening is hindered by issues of reproducibility and scalability. To address this challenge, we combined cerebral organoid culture with a microfluidic device, NETRI’s Duplex Well, to create a Brain Organoid-on-Chip platform. This integration enhances organoid reproducibility, predictability, and industrial transferability, crucial for applications in neurodevelopmental toxicity testing and drug screening.

Our experimental strategy involves optimizing cortical organoid culture conditions within the microfluidic device, comprising two compartments separated by a porous membrane: a 3D culture chamber and a perfusion channel. By testing different organoid introduction time points and medium renewal methods, we established a robust protocol for maintaining cortical organoids in culture on-chip for up to four months. We next used this platform to develop scoring methodologies for cortical organoid characterization; one for quality control prior including an organoid in a protocol and the other for evaluation of compound toxicity. Based on this second scoring, we were able to establish a neurotoxicity prediction algorithm that we used to evaluate neurotoxicity of two compounds in acute and chronic exposures: biphenyl-2-ylamine (20-2000 µM) and vanillin (100-10000 nM).

Our findings demonstrated that compared to cortical organoids grown in conventional support, on-chip organoids exhibited enhanced intra- and inter-batch reproducibility in terms of size, growth profile, and cytoarchitectural organization, across different cell lines. Preliminary neurotoxicological studies using this Brain Organoid-on-Chip platform, along with our scoring methods and prediction algorithm, revealed dose-response neurotoxicity for biphenyl-exposed conditions, highlighting neurotoxicological effects, while an absence of toxicity for vanillin exposures. These observations were consistent with previous in vitro studies, emphasizing the potential of this platform for predicting neurotoxicity.

This Brain Organoid-on-Chip platform not only enables culture of cerebral organoids but also sets the stage for more complex applications, such as blood-brain barrier modeling and multi-organoid-on-chip platforms. Overall, our work offers a promising tool for enhanced neurotoxicity assessment and drug discovery.