2017 年 52 巻 2 号 p. 98-104
For the medical application of superconducting magnets, we investigated a new magnetic drug delivery system that utilizes a rotating magnetic field. To improve the efficiency of drug treatment, a technique that can accumulate the drug in a targeted area is needed. Recently, utilizing a magnetic field by combining ferromagnetic particles and the drugs (ferromagnetic drugs) and applying the magnetic field has been investigated (i.e., Magnetic Drug Delivery System: MDDS). In conventional MDDS, however, the drug can be accumulated only near the body surface because the magnetic field is applied from outside of the body. This indicates that it is difficult to accumulate the drug to a deep target inside the body. We aim to resolve this problem by means of MDDS utilizing a Rotating Magnetic Field (RMF) with superconducting magnets. With this technique it is possible to accumulate a drug selectively in a targeted area, preventing drug accumulation outside of the target by rotating the magnetic field around the central axis of the targeted area. As a fundamental study, we used multiple electromagnets in order to rotate a magnetic field inside the body by controlling the electric current. As a result, we established a fundamental technique to accumulate ferromagnetic particles (a model ferromagnetic drug) at the central axis of the RMF. The feasibility of the technique to accumulate ferromagnetic drugs selectively deep inside the body using the strong magnetic field of superconducting magnets was proven.