Nonstick trick in the brain

Coated particles can slip past brain’s barriers

Getting drugs into the brain has proved to be a nanoscale puzzle: Anything bigger than 64 nanometers — about the size of a small virus — gets stuck in the space between brain cells once it gets through the blood-brain barrier. Justin Hanes of Johns Hopkins University School of Medicine and colleagues got around this rule by coating particles destined for brain cells in a dense layer of a polymer called polyethylene glycol.