Biomaterials are likely to have an increasingly important role in the treatment of nervous system disorders. Recently developed biomaterials can enable and augment the targeted delivery of drugs or therapeutic proteins to the brain, allow cell or tissue transplants to be effectively delivered to the brain and help to rebuild damaged circuits. Similarly, biomaterials are being used to promote regeneration and to repair damaged neuronal pathways in combination with stem cell therapies. Many of these approaches are gaining momentum because nanotechnology allows greater control over material-cell interactions that induce specific developmental processes and cellular responses including differentiation, migration and outgrowth.