Ternary composite nanomaterials based on deferoxamine-coated superparamagnetic iron oxide nanoparticles (8–10 nm), circular plasmid DNA (∼4 kb) with fluorescent/luminescent reporter group, and branched polyethylenimine (25 kDa, PDI = 2.5) were prepared and compared in terms of their efficiencies in transfecting brain tumor cells at low concentration.