Show High Efficacy and Specificity at

rain tumors affect over 600000 pa-tients in the United States, with glio-blastoma (GBM) being the most common form of primary brain tumor in adults1 and considered the most lethal and aggressive form of brain cancer. Nearly 25000 new cases of brain cancer are diag-nosed in the United States each year, ac-counting for nearly 15000 deaths.24 Patients who suffer from GBM have a median survival of 14.6months despite surgery, radiation, and chemotherapy combined.2,57 This devastat-ing prognosis for a GBM patient has not significantly changed for the past decades, which underlines the important necessity of developing new alternative therapies. One potential strategy for improving GBM patient outcomes is the incorporation of therapeutic genes in patients with brain tumors. Gene therapy can induce the expression of genes that induce apoptosis if expressed by tumor cells, are neuroprotective if expressed by the noncancerous tissue, or modulate immune responses to the tumor.813 However, most common gene therapy approaches involve the use of viral vectors, which are character-ized by several safety concerns that limit their translational potential.14 Viral vectors often show insufficient gene delivery effi-cacy in vivo and are immunogenic, prevent-ing effective initial infection as well as repeated administration.15 For example, a study using adenovirus-mediated suicide gene delivery in a primate model for glioma found that the dosage of viral particles was limited by toxicity and the development of * Address correspondence t