Nanowires in magnetic drug targeting

Magnetic drug targeting can be used for locoregional cancer therapy, although the limitation is minuteness of the induced force. A new and simple procedure to enhance the magnetic force is changing the shape of carrier particles. It has been mathematically proved that exerting much stronger magnetic dipoles to nanowires are more possible than to spheres with the same volume. The magnetic dipole of wires having aspect quotient (ratio of length to diameter) of 3 is higher than the spheres of the same volume. Nanowires with α = 5 have magnetic dipoles 1.95 times greater than the spheres with the same volume. At a fixed radius, the magnetic dipole increases with the volume of the drug carrier. Magnetic targeting depth is an important parameter depending on the aspect quotient α of particles. Calculations show that the depth of targeting can exceed 8.5 cm if a nanowire with 15 nm radius and length larger than 150 nm is used as the drug carrier. This depth is 1.7 times more than that reported by previous authors for spherical particles with the same-volume.