Nikolaos Maniotis will present a poster on numerical simulations of interactions between magnetic nanoparticles (MNPs) and living matter. The interactions occur under varying external magnetic fields and frequencies through two experimental setups: (1) MNPs transform magnetic energy into mechanical forces on cancer cells via magnetic field gradients from permanent magnets, decreasing cell viability; (2) MNPs transform magnetic energy into heat through magnetic hyperthermia using alternating magnetic fields, inducing apoptosis. Simulations analyze MNP heating and thermal dissipation based on shape and coating. They also model the experimental setups using COMSOL Multiphysics to calculate magnetic fields, temperature distributions, and solve coupled physics phenomena.

1. XXXII Panhellenic Conference on Solid State Physics and Materials Science
Conference Center "Carolos Papoulias", 18-21 September 2016, Ioannina, Greece
Topic preference (1-6): 3
Presentation preference (oral/poster): poster
Full name of presenting author: Nikolaos Maniotis
e-mail of presenting author: nimaniot@physics.auth.gr
Numerical simulations of interactions between magnetic nanoparticles and living
matter through magnetothermal and magnetomechanical experimental setups
N. Maniotis, A. Makridis, E. Myrovali, T. Samaras and M. Angelakeris
Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
In this work we quantify numerically the interactions between magnetic nanoparticles (MNPs) and the living
matter which take place under varying external magnetic fields and frequencies through two different
procedures: The MNPs magnetic energy density transformation (i) into mechanical forces and (ii) into heat.
For the first case magnetic field gradients are induced by permanent magnets which are placed on a 3D
polymer disk and in close proximity to seeded cells (above the magnets in Fig1a). With COMSOL 3.5a
Multiphysics we estimate the mechanical forces exerted on different lines of cancer cells by cell-internalized
MNPs. Those forces are generated by high-gradient magnetic fields (Fig.1d) and dictate MNPs movements
within the cellular environment. Mechanical stress mediated by localized nanoparticles in HT.29 (human
colorectal adenocarcinoma) and CT 26 cells leads to a significant decrease of cells viability. On the other
hand in magnetic hyperthermia (Figs 1b, 1c) the combination of alternating magnetic fields and magnetic
nanoparticles allows one to cause apoptosis via heat induction. We simulate the heating process of a single
MNP inserted in a biological tissue under an external applied magnetic field. The thermal response of MNPs
with different morphological features is analysed. The results demonstrate the impact of nanoparticle shape
and surface coating in temperature dissipation in and around the nanoparticle. Finally we model the
experimental setup of magnetic hyperthermia for in – vitro experiments. The simulations are repeated for
both experimental setups of the laboratory, one consisting of two circular coils and one of eight squared coils
surrounding the solution (Figs 1e, 1f). COMSOL can easily extend convectional models for one type of
physics into multiphysics models that solve coupled physics phenomena simultaneously and so the electrical
and the thermal problem were solved, calculating the magnetic field and the temperature of the coil and the
solution respectively.
(a)
(b) (c)
(d) (e) (f)
Figure 1: From theory to experiment and vice versa: Magnetic flux density mapping of a permanent NdFeB magnet
placed in the centre of the 3D polymer magnetomechanical disk (1a,1d), Magnetic field distribution generated by two
circular coils (1b,1e) and temperature distribution in the eight squared coils (1c,1f).