Magnetic Drug Targeting is a promising alternative for cancer treatment that offers the possibility to increase the efficiency of the therapy, while side-effects for patients get reduced. Thereby, the cancer-drug is bounded to magnetic nanoparticles. These particles are injected into a vessel and guided into the tumorous tissue by an external magnetic field outside the body. However, the efficiency of the therapy strongly depends on the performance of this navigation process, which is influenced by several multiphysical parameters including the properties of the nanoparticles, the volume flux, and especially the external applied magnetic field. To investigate these effects, the propagation of particle packets in a vessel with a 45° intersection is modeled in COMSOL Multiphysics®. The particles were distributed according to the density of a parabolic velocity profile. To systematically analyze the influence of the external magnetic field, the magnetic field of a cylindrical rare earth magnet with different ratios of diameter to length and axial plus radial magnetization was evaluated. The magnets were placed shortly before the intersection and for every magnet, the transmission probability for the two paths (direct and deflection) was evaluated. Furthermore, the probability for a particle gets trapped by the magnet and stop at the wall of the vessel, was investigated. The results for the particle steering show that both, the diameter to length ratio and the magnetization, strongly influence the steering of the particles. Overall, the magnets with an axial magnetization have a higher impact on the propagation path than the radial magnetized ones. However, when a single permanent magnet is used, the results depict that it is a narrow ridge between deflecting a particle or trap it at the vessel wall.
Investigation of Particle Steering for Different Cylindrical Permanent Magnets in Magnetic Drug Targeting
Published: 14 November 2020 by MDPI in 7th International Electronic Conference on Sensors and Applications session Applications
Keywords: magnetic drug targeting; particle steering; permant magnet