Complex MNPs-to- VPratio(fg Fe/VP) x (mV) Dh(nm) t0.5 (s) υ0.5 (μm/s) M(10-15 Am2) N=M/meff RAd-PEI-Mag2 1.5 +11.4 ± 1.1 601 154 26 3.9 4.8E+04 RAd-PEI-Mag2 2.5 +10.2 ± 0.5 521 168 24 3.1 3.8E+04 RAd-Atto550-PEI-Mag2 4 +12.1 ± 0.2 937 22 184 43.2 5.2E+05

Table 1: Characteristics of the magnetic adenoviral vectors assembled at different MNP-to-VP ratios. After applying a magnetic flux density and field gradient of 0.16 T and 33.5 T/m, respectively, the following parameters were measured: electrokinetic or ξ-potential, intensity weighted mean hydrodynamic diameter Dh, time for agnetic separation of 50% of the complexes t0.5, median values of the magnetophoretic mobility υ0.5, magnetic moment M of the complex and number of magnetic nanoparticles N per complex/complex assembly. Meff=effective magnetic moment of the core of the nanoparticles accounting for the average diameter of the magnetite core of 9 nm and saturation magnetization of 62 emu/g iron.