Published online 15 March 2006
E1 DNA transfer |
Enhancement of the efficiency of non-viral gene delivery by application of pulsed magnetic field
Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich Winterthurerstrasse 190, 8057 Zurich, Switzerland 1Laboratory of Powder Technology, Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne, Switzerland 2MatSearch Chemin Jean Pavillard 14, 1009 Pully, Switzerland 3Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich Winterthurerstrasse 260, 8057 Zurich, Switzerland
*To whom correspondence should be addressed. Tel: +41 44 6355474; Fax: +41 44 6356840; Email: hottiger{at}vetbio.unizh.ch
Received December 22, 2005. Revised January 25, 2006. Accepted February 21, 2006.
New approaches to increase the efficiency of non-viral gene delivery are still required. Here we report a simple approach that enhances gene delivery using permanent and pulsating magnetic fields. DNA plasmids and novel DNA fragments (PCR products) containing sequence encoding for green fluorescent protein were coupled to polyethylenimine coated superparamagnetic nanoparticles (SPIONs). The complexes were added to cells that were subsequently exposed to permanent and pulsating magnetic fields. Presence of these magnetic fields significantly increased the transfection efficiency 40 times more than in cells not exposed to the magnetic field. The transfection efficiency was highest when the nanoparticles were sedimented on the permanent magnet before the application of the pulsating field, both for small (50 nm) and large (200–250 nm) nanoparticles. The highly efficient gene transfer already within 5 min shows that this technique is a powerful tool for future in vivo studies, where rapid gene delivery is required before systemic clearance or filtration of the gene vectors occurs.