Research on the blood brain barrier has proved complex. The complexity of the blood brain barrier has made it difficult for most drugs to make their way into the brain to treat brain tumors. Now scientists at the University of Portmouth have penetated that complexity by creating a model that mimics the blood brain barrier, which could pave the way for better, more efficient and reliable tests of drugs to treat brain diseases. The 3-D, all-human model of the blood brain barrier uses human cells to better simulate the blood brain barrier for the study of diseases and treatments. Currently it is common for medics to gain access to the brain by use of a pump that bypasses the blood brain barrier to deliver drugs into the brain using a catheter. Until now, researchers have had to rely on animal models. Research now is expected to widen to better understand how cancers metastasize from breast and lung to the brain as well as evaluating nano-particle drug delivery and making opportunities to create temporary openings in the barrier to allow drugs to pass through into the brain.