P50DEVELOPING A PHYSIOLOGICALLY RELEVANT BLOOD BRAIN BARRIER MODEL FOR THE STUDY OF DRUG DISPOSITION IN GLIOMA

INTRODUCTION: Many in vitro blood brain barrier (BBB) models have been designed to study the underlying mechanism involved in drug transport across the BBB, but most have not included glioma or cells of human origin. Trans-endothelial electrical resistance (TEER) is a key measure of membrane potential and resistance and can be used to quantify the tightness of the BBB. The aim of this study was to evaluate the integrity of various models of the in vitro BBB as determined by TEER measurements. METHOD: Varying combinations of co-culture models were set up using primary cells of human origin which included human macrovascular endothelial cells (HBMEC), human brain vascular pericytes (HBVP), human astrocytes (HA) and human glioma. All cells were grown as monolayers to 80 % confluency in respective media supplemented with 5 % foetal bovine serum and incubated at 37°C, 5 % CO2 prior to establishing the co-culture. Culture dishes and inserts were coated with extracellular matrix (poly-L-lysine or fibronectin). The TEER was measured across the insert for 15 days. RESULTS: A steady increase in TEER was exhibited by all the models up to day 10. The highest TEER value of 250 Ω was recorded for the tri-culture comprising of HBMEC on the insert, HBVP cells in contact and HA cells out of contact of the well. The lowest TEER value of 100 Ω was recorded for the monolayer culture of HBMEC and the co-culture model (HBMEC and HBVP cells). CONCLUSION: The TEER values suggested that the tri culture model showed the highest membrane potential. This model would further be tested by various permeability assays to assess its functionality as an in vitro BBB model.