Blood brain barrier: A tissue engineered microfluidic chip

With the increasing concern of neurological diseases, the improvised therapy for neurodegenerative disorders such as Alzheimer's disease is crucial. Yet, the efficacious delivery of drug across blood-brain barrier (BBB) remains a formidable challenge. BBB acts as a gate keeper to prevent the ingress of harmful foreign agents into the brain. It has built a great interest in designing BBB models to boost the field of neurotherapeutics. Recently, microfluidic systems are gaining ground in cell culture and bio-system analysis. It creates a new era of micro engineered laboratory onto a chip by combining the benefits of both in vitro and in vivo models. The high-fidelity microfluidic BBB-on-a-Chip possess the engineered physiological microenvironment for real time monitoring of barrier properties with human derived stem cells. These emerging models have intrinsic merits of regulating micro-scale fluid delivery and versatile fabrication. Moreover, the progress of 3D printing technology and versatility of stem cells assist in fabricating these robust and reproducible models. This review revolves around the various approaches of modelling microfluidic BBBs and emphasises on the limitations of existing models and technology. It contributes to the interdisciplinary engineering aspects of BBB research and its magnificent impact on drug development.