Stem Cells Morph Into Blood-Brain Barrier

Its great they can recreate the blood brain barrier but I would think that technology has already passed them by in the form of nanoparticles.
http://cen.acs.org/articles/90/i27/Stem-Cells-Morph-Blood-Brain.html

For the first time, researchers have coaxed human stem cells to transform into crucial components of the blood-brain barrier (BBB), a defensive wall that protects the brain from blood-borne invaders such as bacteria (Nat. Biotechnol., DOI: 10.1038/nbt.2247). Mats of the tightly packed cells mimic the BBB in humans, the research team says, so they could be used in the future to screen neurological drug candidates.

Starting with stem cells, scientists have previously grown endothelial cells, which typically line the inside of blood vessels. But researchers have never before generated endothelial cells that behave like those in the BBB, says Eric V. Shusta, one of the team leaders and a chemical engineer at the University of Wisconsin, Madison. Like the cells in a human’s BBB, these new petri-dish-derived cells pack together extremely tightly and are studded with specific energy-burning proteins that pump molecules in and out of cells.

To produce the new cells, Shusta says the team first grew stem cells in a culture medium that doesn’t specifically generate any one cell type. That way, he explains, both nerve cells and endothelial cells develop side by side.