Magnetofection: A Reproducible Method for Gene Delivery to Melanoma Cells
Figure 2
Physicochemical properties of SPIONs, SPIONs-PAA, and the ability of SPIONs-PAA-PEI complexes to bind pDNA. (a) Specific surface area (SSABET) and calculated diameter () of SPIONs from all synthesis batches. Data are presented as AM ± SEM from three independent replicates. (b) The TEM micrograph of the representative SPIONs’ sample (S1). SPIONs were crystalline, spherical, approx. 10 nm in diameter, and slightly agglomerated. (c) X-ray diffraction patterns of SPIONs from all synthesis batches. All diffractograms exhibit characteristic peaks for iron oxide maghemite and/or magnetite. (d) The hydrodynamic diameter distribution profiles of SPIONs and SPIONs-PAA. Distribution profiles of all the synthesis batches showed related shift in the hydrodynamic diameters after coating SPIONs with PAA. (e) The hydrodynamic diameter () and calculated polydispersity index (PdI) of SPIONs and SPIONs-PAA. There were no significant differences in dDLS and PdI of SPIONs and SPIONs-PAA prepared under variable synthesis conditions. (f) Zeta potential (mV) of magnetic fluids containing SPIONs and SPIONs-PAA. After coating SPIONs with PAA zeta potentials increased to the more negative values, indicating the more negatively charged surface of SPIONs-PAA than that of SPIONs. (g) The ability of SPIONs-PAA-PEI complexes to bind pDNA. The samples were loaded onto agarose gel in the following order: DNA size marker (M), pDNA without digestion enzyme restriction (pDNA), PEI-pDNA complexes (PEI-pDNA), and SPIONs-PAA-PEI-pDNA complexes (S1–S6) prepared from all SPIONs’ synthesis batches separately. Longer arrows indicate retardation of pDNA bound to either PEI or SPIONs-PAA-PEI from all the synthesis batches. The pDNA alone migrated through the gel towards the anode.
