N-hexanoyl chitosan-stabilized magnetic nanoparticles: enhancement of adenoviral-mediated gene expression both in vitro and in vivo.

We developed hexanoyl chloride-modified chitosan (Nac-6) stabilized iron oxide nanoparticles (Nac-6-IOPs) as magnetic nanoparticles for viral gene (Ad/LacZ) delivery via magnetofection. This vector, Nac-6-IOPs/Ad/LacZ, binds to K562 cells in the presence of external magnetic fields and results in enhanced expression of the transgene in those cells that do not exhibit the coxsackie-adenovirus receptor (CAR). Our results demonstrate that Nac-6-IOPs/Ad/LacZ is able to transduce K562 cells specifically with reduced infection of CAR- cells. The dramatic enhancement in intracellular trafficking of the adenovirus without genetically modified vesicles can lead to enhanced nuclear transfer, especially in CAR- cells. In vivo magnetofection results also clearly demonstrated that the present Nac-6-IOPs could be applied in other cell lines. Whether cells or organs, in the presence of magnetic fields Nac-6-IOPs/Ad/LacZ has high transduction efficiency. The newly formulated Nac-6-IOPs, introduced by magnetofection, provide a high-throughput gene screening both in vitro and in vivo.