Induction Heating Efficiency of Water-Dispersible Mn0.5Fe2.5O4@YVO4:Eu3+ Magnetic-Luminescent Nanocomposites in an Acceptable ac Magnetic Field: Hemocompatibility and Cytotoxicity Studies.

Abstract

Not many reports are available on magnetic-luminescent nanocomposites for cancer hyperthermia applications. Further, such nanocomposites on Mn2+-doped iron oxide may be available rather rarely. Studies on the induction heating properties within the threshold magnetic field and frequency factors are still rare. In most cases, magnetic nanoparticles are studied for hyperthermia and lanthanide-doped luminescent nanoparticles for certain biomedical applications. Here, we report on water-dispersible superparamagnetic manganese-doped iron oxide (Mn0.5Fe2.5O4) nanoparticles and a polyethylene glycol6000-coated magnetic-luminescent nanocomposite. The nanocomposite is composed of magnetic Mn0.5Fe2.5O4 (average size 10-20 nm) nanoparticles and red-emitting YVO4:Eu3+ (average size 40-50 nm) nanoparticles. These magnetic nanoparticles and nanocomposites are studied for their induction heating abilities at different acceptable Hf values ( H, strength of alternating magnetic field and f, the operating frequency). The operational Hf values lie in the ranges of 2.15 × 106 to 4.58 × 106 kA m-1 s-1 that are well below the threshold limit of 5 × 106 kA m-1 s-1. A specific absorption rate as high as 132 and 63 W/g, respectively, for Mn0.5Fe2.5O4 and Mn0.5Fe2.5O4@YVO4:Eu3+, can be achieved. The rate of heating and the temperature achieved with time can be tuned with concentrations as well as magnetic constituents in the nanocomposites. Hemocompatibility analysis revealed high blood compatibility with <5% hemolysis. The cytotoxicity analysis in the MCF-7 cell line showed that the cell viability is 74-85% for 0.2-0.5 mg of the magnetic-luminescent nanocomposites. Beyond this concentration, the percentage of cell death is very high. The red-emitting magnetic-luminescent nanocomposites will be useful for in vitro optical imaging and tracking of magnetic nanoparticles. The magnetization analysis showed that the samples have high enough saturation magnetization and low residual magnetization, which is quite suitable for clinical applications. The water dispersibility, hemocompatibility, and cytotoxicity assay in conjunction with their efficient induction heating abilities have shown that these magnetic-luminescent nanocomposites will have potential applications in magnetic fluid hyperthermia and optical imaging.