["Brain disorders remain the world's leading cause of disability, and account for more hospitalizations and prolonged care than almost all other diseases combined. The majority of drugs, proteins and peptides do not readily permeate into brain due to the presence of the blood-brain barrier (BBB), thus impeding treatment of these conditions.", 'Attention has turned to developing novel and effective delivery systems to provide good bioavailability in the brain.', 'Intranasal administration is a non-invasive method of drug delivery that may bypass the BBB, allowing therapeutic substances direct access to the brain. However, intranasal administration produces quite low drug concentrations in the brain due limited nasal mucosal permeability and the harsh nasal cavity environment. Pre-clinical studies using encapsulation of drugs in nanoparticulate systems improved the nose to brain targeting and bioavailability in brain. However, the toxic effects of nanoparticles on brain function are unknown.'] Do nanoneurotherapeutics approach intended for direct nose to brain delivery?