Multifunctional SPIONs for Theranostics in Cancer

Due to their magnetic properties, superparamagnetic iron oxide nanoparticles (SPIONs) offer a large variety of possibilities for medical applications. In Magnetic Particle Imaging (MPI) to date SPIONs are the only tracers or imaging agents so far. It is proposed that the optimal tracer for MPI is a single core SPION with a core diameter of around 30 nm. However, such particles seem not to be optimal for magnetically enhanced drug delivery. On the other hand, there are multicore particles equipped with a high loading capacity for drugs, which can be accumulated e.g. in a tumor by a static magnetic field and additionally be heated by an alternating magnetic field. Here we show that such particles cannot be only imaged by magnetic resonance imaging (MRI) but also do show a MPI-signal. Providing, that the sensitivity of MPI for such particles and therefore also the resolution is high enough, this could be exploited to estimate the SPION-mediated drug load in a tumor after Magnetic Drug Targeting (MDT) as a real theranostic approach.Int. J. Mag. Part. Imag. 4(1), 2018, Article ID: 1808001, DOI: 10.18416/IJMPI.2018.180800