Nanotechnology-based approaches to direct stem-cell-based neural regeneration: multifunctional nanoparticles deliver bioactive molecules that promote cell differentiation, patterned surfaces with immobilized extracellular matrix (ECM) proteins and/or nanomaterials direct neuronal growth and polarization and 3-D nanoscaffolds support gene delivery, axonal alignment, and cell differentiation. Adapted with permission from ref. 149. Copyright (2016) American Chemical Society.