Nanostructured iron oxide - silica particles have been prepared using SBA- 15 mesoporous silica particles as a template. Iron oxide nanoparticles were impregnated inside the mesopores of the silica particles via a wet impregnation method. The resultant material exhibited superparamagnetic properties with an unsaturated magnetic moment due to the formation of iron ( III) oxide nanoparticles inside the mesopores. The surface of these iron oxide - silica particles has also been coated with polyethyleneimine ( PEI) to enable attachment of DNA. The PEI- coated particles showed a high DNA binding capacity and have great potential for development as a new vehicle for gene delivery.