Small addition of Zn 2+ in Ca 2+ @DNA results in elevated gene transfection by aminated PGMA-modified silicon nanowire arrays.

Gene therapy, a promising and effective treatment, has ignited new hope in overcoming difficult-to-cure diseases. The key question in gene therapy is how to efficiently and safely deliver exogenous nucleic acids into the nuclei of target cells. To achieve stable, efficient and safe gene transfer and to ensure efficiency of gene transfer into cell nuclei, a zinc ion-assisted gene delivery nanosystem was proposed in the present study by loading a low concentration of Zn ²⁺ in Ca ²⁺ @DNA nanoparticles on ethanolamine-functionalized poly(glycidyl methacrylate) (PGEA)-modified SiNWAs (Zn ²⁺ /Ca ²⁺ @DNA + SN-PGEA). The results showed that with the help of Zn ions, this composite nanosystem could promote more DNA in the cell nuclei and thus dramatically increased the transfection efficiency by as much as 7-fold. The nanosystem with 0.2 mM Zn ²⁺ , 100 mM Ca ²⁺ and PGEA modification on SiNWAs displayed the highest transfection efficiency and good biocompatibility. This new composite nanosystem will have great potential in gene transfection for biomedical research.