Preparation and characterization of polyethylenimine‐coated Fe₃O₄‐MCM‐48 nanocomposite particles as a novel agent for magnet‐assisted transfection

A new type of magnetic nanoparticle was synthesized using mesoporous silica MCM-48 as a template. Magnetite (Fe(3)O(4)) nanocrystals were incorporated onto the MCM-48 silica structure by thermal decomposition of iron(III) acetylacetonate. The particle size of these Fe(3)O(4)-MCM-48 composite particles is around 300 nm with an iron oxide content of ca. 20% w/w. Measurements from SQUID magnetometry suggest that these nanoparticles possess superparamagnetic properties similar to those of Fe(3)O(4) nanoparticles. By coating positively charged polyethylenimine on to the surface, DNA can be bound onto the Fe(3)O(4)-MCM-48 nanoparticles. Transfection studies showed that these PEI-Fe(3)O(4)-MCM-48 particles were highly effective as a transfection reagent, and a 400% increase of transfection efficiency compared with the commercial products was recorded.