title: Magnetofection: a reproducible method for gene delivery to melanoma cells.
abstract: Magnetofection is a nanoparticle-mediated approach for transfection of cells, tissues, and tumors. Specific interest is in using superparamagnetic iron oxide nanoparticles (SPIONs) as delivery system of therapeutic genes. Magnetofection has already been described in some proof-of-principle studies; however, fine tuning of the synthesis of SPIONs is necessary for its broader application. Physicochemical properties of SPIONs, synthesized by the co-precipitation in an alkaline aqueous medium, were tested after varying different parameters of the synthesis procedure. The storage time of iron(II) sulfate salt, the type of purified water, and the synthesis temperature did not affect physicochemical properties of SPIONs. Also, varying the parameters of the synthesis procedure did not influence magnetofection efficacy. However, for the pronounced gene expression encoded by plasmid DNA it was crucial to functionalize poly(acrylic) acid-stabilized SPIONs (SPIONs-PAA) with polyethyleneimine (PEI) without the adjustment of its elementary alkaline pH water solution to the physiological pH. In conclusion, the co-precipitation of iron(II) and iron(III) sulfate salts with subsequent PAA stabilization, PEI functionalization, and plasmid DNA binding is a robust method resulting in a reproducible and efficient magnetofection. To achieve high gene expression is important, however, the pH of PEI water solution for SPIONs-PAA functionalization, which should be in the alkaline range.
authors.affiliation: Kolektor Group, Nanotesla Institute Ljubljana, Stegne 29, 1521 Ljubljana, Slovenia.
authors.forename: Lara
authors.initials: L
authors.lastname: Prosen
authors.forename: Sara
authors.initials: S
authors.lastname: Prijic
authors.forename: Branka
authors.initials: B
authors.lastname: Music
authors.forename: Jaka
authors.initials: J
authors.lastname: Lavrencak
authors.forename: Maja
authors.initials: M
authors.lastname: Cemazar
authors.forename: Gregor
authors.initials: G
authors.lastname: Sersa
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D004247:DNA / Q000378:metabolism; D003911:Dextrans / Q000138:chemical synthesis; D018014:Gene Transfer Techniques; D008280:Magnetics / Q000379:methods*; D058185:Magnetite Nanoparticles; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D010957:Plasmids / Q000378:metabolism; D011094:Polyethyleneimine / Q000737:chemistry; D015203:Reproducibility of Results; D012996:Solutions; D014867:Water
chemical_list: D000180:Acrylic Resins; D003911:Dextrans; D058185:Magnetite Nanoparticles; D012996:Solutions; D014867:Water; C006903:carbopol 940; D011094:Polyethyleneimine; D004247:DNA; C065507:ferumoxides