APPLICATION OF IN VITRO MODELS: INCORPORATING BLOOD BRAIN BARRIER MODELS WITH GLIOMA, AND THE USE OF MICROflUIDICS

Abstract

AIMS The blood brain barrier (BBB) presents one of the main obstacles for the development of novel glioblastoma treatments. The various transporters and enzymes within the BBB reduce the disposition of novel therapies into the brain. There is a need for an in vitro BBB-glioma model with proven efficacy of predicting CNS delivery at earlier stages in the drug discovery pipeline. METHOD A BBB-glioma lab-on-a-chip model could enable rapid identification of novel therapies that can cross the BBB at earlier stages of the drug development process, before going to clinical trials. The application of microfluidic technology allows for the detection of soluble tissue-derived factors and the assessment of the levels of soluble markers released from malignant tissue. Adding ‘flow’ to the model, is more reflective of the dynamic flow present at the BBB. RESULTS Validation studies of the current BBB model and converting this model over to a lab-on-a-chip model have shown the presence of an endothelial cell barrier and the tight junction proteins Zo-1 and Claudin-1, through western blotting, immunocytochemistry, and permeability experiments using varying molecular weights of FitC-dextran. These validation studies have been completed using brain endothelial monolayers on polycarbonate transwell inserts, with the immortalised cell line HCMEC/d3, and the short-term culture cells HBMEC. Also, validation studies using a co-culture of endothelial cells, astrocytes and pericytes have begun, using the same techniques to show a barrier has formed, on both the current BBB model and the lab-on-a-chip model. CONCLUSION The aim of this study is to combine the use of an all-human BBB-glioma model with lab-on-a-chip technology to produce a high throughput model to test novel therapies at an earlier stage. The lab-on-a-chip model will be validated for the purpose of measuring permeability and drug response and to investigate the expression of novel targets verses expression in conventional models.