Development of Magnetic Field Control for Magnetically Targeted Drug Delivery System Using a Superconducting Magnet

We have been developing the device for magnetically targeted drug delivery system (MT-DDS), which can allow us to navigate and to accumulate the drug at the local diseased part inside the body by controlling to magnetic field strength and/or gradient generated by the superconducting magnets. In considering an application of this technique to the network of the blood vessel, a number of magnets should be placed within a small region. The magnetic field at the branching point is superimposed the fields from the magnets. The optimal arrangement of magnetic field for MT-DDS was calculated and experimental verification was made using several different sizes of Y-shaped glass tubes with multiple branching points as a model system of blood vessel. Ferromagnetic particles were injected into the Y-shape glass tube and were navigated by the magnetic field which was generated by the magnet optimally arranged based on the calculation. The ratio of the amount of the navigated ferromagnetic particle to the dosed amount was measured as magnetic navigation efficiency. It is found that experimental result of magnetic navigation efficiency agreed with the calculation results, which shows that magnetic navigation by the superconducting magnet can be a promising way for realization of MT-DDS.