A 3D Microfluidic Blood–Brain Barrier Chip for Real-Time Assessment of Micro/Nanoplastics Permeability and Neuroinflammatory Injury

The micro/nanoplastics (MNPs) have been evidenced to exert detrimental effects on the blood–brain barrier (BBB) and the central nervous system (CNS). However, there is still a lack of effective research models on the mechanism of nerve injury caused by microplastics particles. This study focuses on analyzing the particle size characteristics of MNPs precipitated from plastic water bottles under different conditions of storage and uses 3D BBB microfluidic chips to assess the permeability and dynamic neurotoxicity of MNPs. The results showed that there was a significant increase in the average diameter of MNPs in purified water stored in plastic bottles. Moreover, the cultivation of BBB cells or neuronal cells with two different particle sizes of MNPs showed a significant decrease in cell survival rates. When MNPs were infused into the peripheral unit of the biomimetic chip, they could penetrate from the endothelial cell unit to the neuronal unit and induce a dynamic injury process with neuroinflammation, accompanied by tight junction disruptions, increased ROS levels, decreased mitochondrial membrane potential, decreased lipid droplet levels, and increased inflammatory effects. The research results based on engineering 3D microfluidic chips lay the foundation for a deeper understanding of the inflammatory damage to nerve cells caused by MNPs crossing the BBB.