High-Gradient Magnetic Field for Magnetic Nanoparticles Drug Delivery System

Magnetic nanoparticles (MNPs), which can be transported through the vascular system and concentrated at the specific position of the body under an external magnetic field, are attracting increasing attention in tumor treatment. The MNPs should work under a high-gradient magnetic field for generating the enough magnetic forces to overcome the hydrodynamic drag force acting on the nanoparticles from the blood flow. Previous study on magnet-guided drug delivery has focused mainly on the synthesis and surface engineering of MNPs. In this study, the REBa ₂ Cu ₃ OX [RE = rare earth] (REBCO) magnet, which is composed of three sets of coils, was designed for providing the gradient magnetic field in three perpendicular directions. The magnet system is geometrically compact to allow the mice to lie down. The three gradient magnetic fields and uniform magnetic fields near the magnetic field center can be generated in X- , Y- , and Z -directions, respectively. This paper describes the design and electromagnetic analysis of the superconducting magnet. In addition, the advantages and limitations of our design and future development will be presented.