The
clinical implantation of gene therapy is hindered by the limitations
of current gene delivery vectors, namely, safety issues regarding
viral vectors and low transfection efficacy regarding nonviral vectors.
Thus, the design of safe and efficient gene carriers is a key point
for the success of such therapies. In addition, when employing genetically
modified cells for further applications, the selection of successfully
modified cells becomes crucial. To address these issues, we have developed
multicomponent nanoparticles composed of poly(ß-amino ester)
(pBAE) polymers, plasmid DNA, and superparamagnetic iron oxide nanoparticles
(SPIONs). Whereas pBAEs were initially employed as safe and biocompatible
carriers with improved transfection efficiency, as compared to commercial
vectors, SPIONs were used because of their magnetic character that
enables cell selection. Surprisingly, the results presented here revealed
an unexpected enhancer effect of SPIONs on the transfection efficiency
of pBAE/pDNA polyplexes in both permissive and reluctant to transfection
cell lines. This unanticipated outcome, together with the allowance
to perform a selective magnetic sorting of genetically modified cells
without interfering in cell transfection, opens the door to SPION-containing
nanoparticles as promising tools for cell therapy approaches.