Advance in blood-brain barrier in vitro models: Integrating bioprinting with microfluidic chips for compound evaluation

The blood-brain barrier (BBB) is a vital defense interface of the central nervous system that selectively regulates molecular transport into the brain and maintains brain homeostasis. Disruption of BBB integrity contributes to various neurological diseases and represents a key target for therapeutic compounds. However, traditional in vitro models are hard to recreate BBB’s complex structure and dynamic functions. Recent advances in microfluidics and three-dimensional bioprinting have enabled the construction of high-fidelity BBB in vitro models that imitate the brain’s vascular microenvironment. By integrating principles from materials science, microfabrication, and cell biology, these “BBB‑on‑a‑chip” platforms support physiologically relevant shear stress, cell–cell interactions, and barrier properties, making them powerful tools for compound screening and mechanistic research. This review summarizes the advance in BBB in vitro model and the application of bioprinting and microfluidic technology for compound evaluation.