Yttrium iron garnet for hyperthermia applications: Synthesis, characterization and in-vitro analysis

Exclusive magnetocaloric properties of orthoferrites offer advantages for their application in the magnetic hyperthermia as well as imaging applications. In the present study, the effect of yttrium concentration on the magnetic characteristics of the iron oxide based nanomaterials was analyzed to assess their potential for the hyperthermia applications. The Sol-gel method was used to synthesize the Yttrium Iron Garnet (YIG) based nanoparticles, using different molar ratios of Fe and Y precursors, followed by the calcination at 900, 1000 and 1100 °C. XRD analysis determined the formation of the pure phase of yttrium iron garnet Y₃Fe₅O₁₂ (YIG) at 0.5 molar ratio of yttrium at all the calcination temperatures and pure phase of yttrium iron perovskite YFeO₃ (YIP) for 1 molar ratio of yttrium at 1000 and 1100 °C. The mean particle size was observed in the range of 100 to 400 nm. The magnetic characterization studies showed the highest saturation magnetization for the sample containing 0.5 molar ratio of the yttrium calcinated at 1000 °C. The magnetization values were linearly related to the contents of YIG phases in the synthesized samples. Induction heating of YIG resulted in the hyperthermia temperature (42 to 44 °C) in 13 min with the SAR values 114.65 W/g at 1 mg/ml. The prepared samples showed no in-vitro toxic effects on the MG63 cells (>90% cell viability). In addition, in-vitro treatment at hyperthermia temperature for 15 min reduced cell viability of cancer cells (A549) to 55%, while no toxic effect was observed on MG 63 cells. The present study postulates Yttrium Iron Garnet as an effective therapeutic agent for hyperthermia cancer treatment.

Keywords: Cancer; Cell viability; Magnetic hyperthermia; Orthoferrites; SAR; Sol-gel.