Preparation and Characterization of Manganese FerriteNanoparticles via Co-precipitation Method forHyperthermia: Mn ferrite nanoparticles preparation

In this work, Mn ferrite nanopowders were prepared by co-precipitation method and were characterized. Phase identification of the nanopowders was performed by X-ray diffraction method and the mean particle size of the nanopowders was calculated by Scherrer's formula, using necessary corrections. Magnetic parameters of the prepared nanopowders were measured by a vibrating sample magnetometer .Asensitive thermometer was used to measure the increase in temperature due to application of an alternating magnetic field on suspended magnetic nanopowders in water. Transmission electron microscope investigations showed that the particle size distribution was homogeneous and their size was in a good agreement with those obtained by Scherrer's formula. The results show that a single phase Mn ferrite can be obtained by co-precipitation method at 70 °C with a mean particle size of 5 nm and a 5 °C temperature increase is achievable in an AC magnetic field

Versatile theranostics agents designed by coating ferrite nanoparticles with biocompatible polymers

Three biocompatible polymers, polyethylene glycol (PEG), dextran and chitosan, have been used in this work to control the colloidal stability of magnetic nanoparticles (14 ± 5 nm in diameter) and to vary the aggregation state in order to study their effect on relaxometric and heating properties. Two different coating strategies have been deeply developed; one based on the formation of an amide bond between citric acid coated nanoparticles (NPs) and amine groups present on the polymer surface and the other based on the NP encapsulation. Relaxometric properties revealed that proton relaxation rates strongly depend on the coating layer hydrophilicity and the aggregation state of the particles due to the presence of magnetic interactions. Thus, while PEG coating reduces particle aggregation by increasing inter-particle spacing leading to reduction of both T1 and T2 relaxation, dextran and chitosan lead to an increase mainly in T2 values due to the aggregation of particles in bigger clusters where they are in close contact. Dextran and chitosan coated NPs have also shown a remarkable heating effect during the application of an alternating magnetic field. They have proved to be potential candidates as theranostic agents for cancer diagnosis and treatment. Finally, cytotoxicity of PEG conjugated NPs, which seem to be ideal for intravenous administration because of their small hydrodynamic size, was investigated resulting in high cell viability even at 0.2 mg Fe ml−1 after 24 h of incubation. This suspension can be used as drug/biomolecule carrier for in vivo applications.Isfahan University of Technology (Iran)European CommissionDepto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu