Fast transfection of mammalian cells using superparamagnetic nanoparticles under strong magnetic field.

Through the use of superparamagnetic iron oxide nanoparticles (SPIONs), fast delivery of DNA into adherent and suspended cells could be achieved by the mediation of a strong impulsed magnetic field. Mammalian cells were well transfected with enhanced green fluorescent protein gene. To mediate the cellular uptake, cells and nucleic acid complexes were mixed together and exposed once or several times to impulsed magnetic field for short durations of few milliseconds. In the transfection of adherent cells, most complexes of plasmid DNA and polyethylenimine (PEI)-coated SPIONs were internalized immediately. In comparison with no magnetic pulsing, the enhancement in transfection efficiency was about two fold on average by pulsing in magnetic field of 0.6 Tesla three times. The transfection yield increased with the strength of magnetic field and the number of pulsing. Disregarding the cytotocixity of internalized PEI, the loss of cell viability by magnetic pulsing was not evidenced.