A Biomimetic Human Multi-Cellular In Vitro Model of the Blood-Brain Barrier

Area of Science:

• Biomedical Engineering
• Neuroscience
• Cell Biology

Background:

• Current in vitro models inadequately replicate the human blood-brain barrier (BBB) physiology.
• A reliable BBB model is crucial for studying central nervous system (CNS) diseases and drug permeability.

Purpose of the Study:

• To develop a 3D co-culture model using primary human cells to better mimic the human BBB.
• To assess the barrier function and physiological relevance of the developed model.

Main Methods:

• Co-culture of primary human astrocytes (A) and endothelial cells (HAECs) within a gelatin methacrylate (GelMA) hydrogel scaffold.
• Assessment of tight junction marker expression (CLDN5, CDH1).
• Measurement of trans-endothelial electrical resistance (TEER) and Evans blue albumin (EBA) permeability.

Main Results:

• The 3D HAEC+A co-culture showed a 12-fold increase in CLDN5 and CDH1 expression compared to 2D models.
• The 3D HAEC+A model achieved the highest TEER (45 Ω·cm²), significantly higher than 2D or 3D HAEC-only cultures.
• This 3D model exhibited significantly lower EBA permeability, indicating enhanced barrier function.

Conclusions:

• The developed 3D co-culture model effectively replicates key physiological features of the human BBB in vitro.
• This model provides a robust platform for investigating BBB permeability to drugs, cells, and pathogens.
• The model holds promise for advancing research in CNS diseases and therapeutic development.