Effect of concentration on hydrodynamic size of magnetite-based ferrofluid as a potential MRI contrast agent

In this work, ferrofluids containing dextran coated magnetite nanoparticles have been synthesized via co-precipitation method. FT-IR results verified presence of dextran molecules on the particles surface. TEM results showed that mean particle size is 7.23 nm, while mean hydrodynamic size determined via PCS technique varies between 39.8 and 125.8 nm depending on the ferrofluid concentration. The maximum hydrodynamic size was obtained in mid concentrations. To the best of our knowledge, effect of concentration on mean hydrodynamic size has not been systematically studied before. VSM results confirmed the superparamagnetic behavior of the synthesized nanoparticles with saturation magnetization of 57.82 emu/g. The stable ferrofluids were intravenously injected into mice and used as MRI contrast agent. Results showed that these ferrofluids can be considered as potential MRI contrast agents especially for imaging lymphatic system.