Polymer-iron oxide nano-complex, uses thereof and preparation method thereof

A method of reducing expression of a gene, the method comprising:

• incubating a polymer-iron oxide composite nanostructure comprising a DNA encoding the gene in an incubator comprising a DNA expression kit for the DNA at 30° C. for 8 hours, while applying a magnetic field to the polymer-iron oxide composite nanostructure by a neodymium magnet placed at a bottom of the incubator;
• and
• confirming the reduction in gene expression when the polymer-iron oxide nanostructure is incubated in the presence of the magnetic field,
• wherein the polymer-iron oxide composite nanostructure comprises;
• a polymer-iron oxide composite nanoparticle;
• a silica coating layer coated on a surface of the polymer-iron oxide composite nanoparticle;
• and
• the DNA encoding the gene and attached to the silica coating layer.