Scheme 1. Schematic illustration of targeting DNA origami nanostructures for biotherapy and chemotherapy. Aptamer C2NP were anchored on the top of DNA nanostructures with different densities (RE-4Apt, RE-16Apt). On one hand, aptamer C2NP can help DOX loaded DNA origami nanostructures (DOX@RE-4Apt, DOX@RE-16Apt) get into cells effectively, enhancing the anticancer activity of DOX. On the other hand, C2NP can induce cell apoptosis, exhibiting synergic biological effect with chemotherapy on cancer therapy.