Dextran coated magnetite high susceptibility nanoparticles for hyperthermia applications

In this study, the magnetic fluid with various concentrations of well-dispersed dextran coated Fe₃O₄ nanoparticles were synthesized for hyperthermia application. The dextran-coated colloidal suspension, in the form of clusters of several Fe₃O₄ nanoparticles, maintains superparamagnetic behavior of Fe₃O₄ with the saturation magnetization of 59 emu/g at room temperature. The coated nanoparticles dispersed in aqueous medium agglomerate to form a monodisperse system and its average polydispersity index is 0.096. The inter-particle interaction caused the large susceptibility (1239 emu/gT) in dextran coated Fe₃O₄ nanoparticles. Effect of magnetic dipole interaction between the clusters on magnetic properties and heat capacity was examined by comparing specific loss power (SLP) of magnetic fluids at different Fe₃O₄ concentration. The intrinsic loss power (ILP) parameter increases with decreasing concentration of the dextran coated Fe₃O₄ and reaches the value of 15.6 nHm²/kg, which is 35% better than the best commercial equivalents. This result clearly shows that magnetic interaction between coated particles strongly influences induction heating efficiency of magnetic fluid. The in vitro toxicity experiments of magnetic fluids with Madin Darby Canine Kidney cells prove that our obtained magnetic fluids are promising for the hyperthermia cancer treatment application.