Disclosed herein is an adeno-associated virus (AAV) particle comprising a surface-bound peptide that enhances transduction of cells across the blood-brain barrier (BBB). Also disclosed herein is a modified AAV capsid protein comprising an insertion of a polypeptide that enhances transduction of cells across the BBB, and an AAV particle comprising the modified AAV capsid protein. Specific peptides are provided. Pharmaceutical formulations and method of administering/delivering a nucleic acid to a cell of the brain and/or central nervous system are also disclosed.