Behavior of Magnetic Nanoparticles in the Phantom of the Biological Medium

The possibility of using magnetic nanoparticles of iron oxide (magnetite) Fe3O4(II, III) as a filler in the matrix of microcrystalline cellulose in the form of massive tablets, as well as in the liquid medium of polymethylsiloxane (phantom biological medium) in the form of suspension has been considered. The magnetic nanoparticles were approximately spherical in shape with an average size of 10–12 nm, some of them formed large agglomerates. We found that in the magnetization field in the range ± 200 μT, all samples had hysteresis-free behavior characteristic of superparamagnetic nanoparticles, and in the range ± 80 mT, hysteresis is observed on all samples. The samples were subjected to vibration exposure of 2000 prm for 1 min. In the modes “before vibration” and “after vibration” the values of the residual magnetic field and specific magnetic moment in massive samples differ insignificantly, while in suspensions these values change significantly by 1.5–12 times. In suspensions, the relaxation time of the residual magnetic field is 4.5–7.5 times shorter in the “after vibration” mode, which is mainly determined by the Brownian relaxation mechanism. In this work we emphasize the prospectivity of the studied magnetic nanoparticles in suspensions in theranostics of osteoarthritis diseases.