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.

PET/MRI: a frontier in era of complementary hybrid imaging.

With primitive approaches, the diagnosis and therapy were operated at the cellular, molecular, or even at the genetic level. As the diagnostic techniques are more concentrated towards molecular level, multi modal imaging becomes specifically essential. Multi-modal imaging has extensive applications in clinical as well as in pre-clinical studies. Positron Emission Tomography (PET) has flourished in the field of nuclear medicine, which has motivated it to fuse with Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for PET/CT and PET/MRI respectively. However, the challenges in PET/CT are due to the inability of simultaneous acquisition and reduced soft tissue contrast, which has led to the development of PET/MRI. Also, MRI offers the better soft tissue contrast over CT. Hence, fusion of PET and MRI results in combining structural information with functional image from PET. Yet, it has many technical challenges due to the interference between the modalities. Also, it must be resolved with various approaches for addressing the shortcomings of each system and improvise on the image quantification system. This review elaborates on the various challenges in the present PET/MRI system and the future directions of the hybrid modality. Also, the different data acquisition and analysis techniques of PET/MRI system are discussed with enhanced details on the software tools.