Development of Magnetic Drug Delivery System Using Superconducting Bulk Magnet

Side-effects and the reduced effect of drugs due to their diffusion, such as those involved with anticancer agents, are serious issues in medication. To solve these problems, it is necessary to control the drugs quantitatively, spatially and temporally within the human body. The magnetic drug delivery system (MDDS) is one technology that can make this possible. In this system, ferromagnetic drugs that are injected into a blood vessel are directed to the diseased part via an external magnetic force. This is achieved using a superconducting bulk magnet and ferromagnetic needle. The ultimate goal of our study is to further develop the MDDS, and fundamental experiments to reinforce the effectiveness of the MDDS were conducted. To estimate the magnetic force required to accumulate ferromagnetic particles in the blood vessel, particle distribution in limited biomedical tissues was calculated. To check the validity of the calculations, an experiment relating to the accumulation of ferromagnetic particles in a model tissue consisting of glass beads packed in a glass tube was conducted. Based on these results, local accumulation using a permanent magnet system with a HTS bulk magnet was performed in a rat liver.