FEM based simulation of magnetic drug targeting in a multibranched vessel model

Background and objective: Magnetic drug targeting (MDT) is a promising technology to improve cancer therapy. MDT describes the accumulation of drug loaded superparamagnetic iron oxide nanoparticles (SPIONs) at a desired location, e. g. a tumor, by application of a magnetic field. Here, we evaluate the effectivity of MDT for an endoscopic placement of two different configurations of magnet arrays, i. e. six magnets with same poles facing each other and a Halbach array. Compared to conventional magnet setups outside the body, this endoscopic placement gives the possibility to achieve higher magnetic field gradients inside the tumor. Methods: For such a MDT concept, we present FEM based simulations of MDT tracing single SPIONs in a 3D geometry of eight multibranched vessels with sizes in the range of capillaries. In these simulations, the effect of the magnetic field gradient as well as of magnet distance to the vessel geometry, magnetic flux density of the magnets, SPIONs hydrodynamic diameter and magnetic moment on the MDT effectivity is calculated. The blood flow is modelled as an incompressible Newtonian fluid and the SPIONs are suspended in the blood flow. Statistical significance of the targeting effectivity results is tested with the Mann-Whitney-U-Test. Results: The results show that the magnetic targeting effectivity is up to 32 % higher than the one calculated without the presence of a magnetic field. In the investigated vessel network, this effect on the targeting effectivity is dependent on the number of local magnetic field maxima that are approached with a high gradient and is noticeable up to 200 mu m distance of the magnet to the vessel geometry. Conclusions: We conclude that for an effective application of MDT, the magnet configuration needs to be placed close to the tumor and should yield a large number of magnetic field maxima that are approached with a high gradient. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The results demonstrate that magnetic targeting effectivity can be up to 32% higher when a magnetic field is present. In the investigated vessel network, the effectiveness of targeting depends on the number of magnetic field maxima with a high gradient that are approached, and is noticeable up to a distance of 200 micrometers from the magnet to the vessel geometry.