Disclosed are methods and compositions for selectively targeting sites of traumatic brain injury (TBI). A brain injury-specific 4-amino acid peptide (sequence CAQK), identified by in vivo phage display screening in mice with acute brain injury, shows selective binding to mouse and human brain injury lesions, and when systemically injected, specifically homes to sites of injury in penetrating and non-penetrating (controlled cortical impact) brain injury models. Also disclosed are methods and compositions for delivering therapeutic compounds to such sites. CAQK-coated nanoparticles containing silencing oligonucleotides provide an alternative to local delivery of therapeutics, which is invasive and can add complications to the injury.