Serbia-China Bilateral project 2015-2017

Design and fabrication of Nd-Fe-B based permanent magnets for magnetic drug targeting. Participants: VINCENT (Dr. Bratislav Antic) and China (Prof. Dr. Yue Ming)

Magnetic nanoparticles (MNPs) are intensively investigated to be used in diagnostics and therapies. Three main areas for their application in medicine are: magnetic hyperthermia, drug delivery and magnetic resonance imagining. In order to be used in medicine they have to be in form of stable colloids, uniform in size, biocompatible and they have to be concentrated at target tissue in the body. To meet these requirements MNPs are coated with different organic/inorganic materials, such as polyethylene glycol (PEG), sylane, polylactic-co-glycolic acid (PLGA), polyvinyl alcohol (PVA), dextran, etc. The coating influences size and interaction with the body fluids and cells. From magnetic point of view, MNPs are usually superparamagnetic with high saturation magnetization.

The main requirements of any therapy are minimization of medicament doze and localization of the medicament in specific area of the body. One of the advantages of the magnetic nanoparticles is that that they can be stirred and kept in specific place using external magnetic field. This could lead to manifold increase in dose concentration at specific sites (tumor tissue). As a consequence, the needed dose of medicament is optimized and the spreading of the medicament all over the patient’s body is minimized. The force that acts on magnetic nanoparticles inside the magnetic field is proportional to the gradient of that field. In the case of permanent magnets, high gradient fields are produced either by making magnets of specific shape or by combining several smaller magnets.

During this project, several different shapes or combinations of magnets will be designed and produced. Magnets will be produced using NdFeB, which is known for its huge remnant magnetization and magnetic hardness. In vivo experiments will be conducted to test the efficiency of the magnets – the influence of the magnets on biodistribution of injected magnetic nanoparticles will be monitored. The biodistribution will be determined combining radiotracer technique and AC susceptibility measurements.