Lab-on-a-chip device integrating a human stem cell-based blood-brain barrier model with neural organoids for translational research

For advanced biomedical research, complex, well-described human blood-brain barrier (BBB) models are crucial for studying central nervous system pathologies and brain targeting of nanotherapeutics. Our aim was to establish and characterize a complex lab-on-a-chip (LOC) system integrating a BBB model with neural organoids (NO). We optimized the conditions for BBB-NO models under static and dynamic circumstances. The combination of a human stem cell-derived BBB co-culture model with human midbrain organoids in a microfluidic LOC allowed the observation of BBB and neural tissue changes and the separate analysis of the barrier and brain units. The LOC design enabled phase contrast and fluorescent microscopy on the whole brain endothelial culture surface, barrier integrity and permeability measurements across the BBB model, and molecule passage into NOs. BBB-specific endothelial morphology, gene and protein expression, and good barrier integrity were demonstrated, corroborating the strength of the LOC engineering and cellular design. The transport of targeted nanoparticles across the BBB model followed by their entry to neural organoids validated the barrier integrity and transporter functionality of the dynamic integrated complex model. As a proof-of-concept experiment to confirm the translational value of the BBB-NO model integrated in the LOC device, we examined a clinically used hyperosmolar iodinated contrast agent, iopamidol, with confirmed neurological side effects. We corroborated that iopamidol induces transient BBB dysfunction and neural effects in the complex system, not only validating the complex dynamic BBB-NO model but also pointing to the necessity to study BBB changes together with NO functions.