Exothermic effect of dextran-coated Fe3O4 magnetic fluid and its compatibility with blood

The magnetic fluid (MF) for hyperthermia should be superparamagnetic, non-toxic and biocompatible. The compatibility between blood and dextran-stabilized Fe3O4 MF was first investigated; then the influences of the MF concentration and the magnetic field intensity on the heating ability was studied; at last the effects of temperature, shear rate and applied magnetic field on the viscosity of blood and MF/blood mixtures was measured. The results revealed that the viscosity and coagulation time of blood are almost unaffected by small addition of dextran-stabilized Fe3O4 MF, showing good compatibility with blood. The Fe3O4 MF under alternating magnetic field can generate enough energy to heat tumor tissue for hyperthermia therapy.

Compared to blood, the viscosity of MF/blood mixture is much easier to be affected by a magnetic field. The dextran chains and protein chains in the MF/blood mixture are intertwisted together. Some MNPs in the MF/blood mixture have been bonded to the dextran chains through the chelation among iron ion and hydroxyl groups on the dextran chains. MNPs can be magnetized in magnetic field, which leading to the accelerated sedimentation of erythrocytes. Therefore, the viscosity of MF/blood mixture increase.Figure optionsDownload as PowerPoint slideHighlights
► The viscosity and coagulation time of blood are nearly not affected by the addition of small amounts of dextran-stabilized MF.
► An applied magnetic field can accelerate the sedimentation of erythrocytes and increase the viscosity of blood and MF/blood mixture.
► The MF can generate enough heat in an alternating magnetic field and the heating temperature can be controlled by adjusting the dosage of MF and the intensity of magnetic field.
► The heating effect of MF was proved by simulation theoretically.