Large core & small shell particles facilitate physiological viscosity differentiation via MPS

Magnetic nanoparticles (MNP) are researched for in-vivo applications and represent a key tool in both therapy via magnetic fluid hyperthermia (MFH) and diagnostics using magnetic particle spectroscopy (MPS) and imaging (MPI). In-vivo, MNP are exposed to various physiological environments, binding to blood and cells and are thereby subjected to constantly changing conditions. In this simulative work, the performance of MNP in MPS was investigated with regard to core size, hydrodynamic size and distribution width and under different physiological viscosities of water, blood and inside cells. Our preliminary results from stochastic Neel-Brownian coupled relaxation dynamics simulations suggest that for MPS, differentiation of MNP binding states across water, blood, and intracellular environments appears feasible for MNP of large cores above 20 nm with small hydrodynamic sizes below 50 nm.