title: Intracellular Delivery of siRNA by Polycationic Superparamagnetic Nanoparticles.
abstract: The siRNA transfection efficiency of nanoparticles (NPs), composed of a superparamagnetic iron oxide core modified with polycationic polymers (poly(hexamethylene biguanide) or branched polyethyleneimine), were studied in CHO-K1 and HeLa cell lines. Both NPs demonstrated to be good siRNA transfection vehicles, but unmodified branched polyethyleneimine (25 kD) was superior on both cell lines. However, application of an external magnetic field during transfection (magnetofection) increased the efficiency of the superparamagnetic NPs. Furthermore, our results reveal that these NPs are less toxic towards CHO-K1 cell lines than the unmodified polycationic-branched polyethyleneimine (PEI). In general, the external magnetic field did not alter the cell's viability nor it disrupted the cell membranes, except for the poly(hexamethylene biguanide)-modified NP, where it was observed that in CHO-K1 cells application of the external magnetic field promoted membrane damage. This paper presents new polycationic superparamagnetic NPs as promising transfection vehicles for siRNA and demonstrates the advantages of magnetofection.
authors.affiliation: Department of Chemistry, University of Puerto Rico at Humacao, Humacao 00791, Puerto Rico.
authors.forename: Betzaida
authors.initials: B
authors.lastname: Castillo
authors.forename: Lev
authors.initials: L
authors.lastname: Bromberg
authors.forename: Xaira
authors.initials: X
authors.lastname: López
authors.forename: Valerie
authors.initials: V
authors.lastname: Badillo
authors.forename: Jose A
authors.initials: JA
authors.lastname: González Feliciano
authors.forename: Carlos I
authors.initials: CI
authors.lastname: González
authors.forename: T Alan
authors.initials: TA
authors.lastname: Hatton
authors.forename: Gabriel
authors.initials: G
authors.lastname: Barletta