磁热疗用Fe_3O_4在交变磁场中的热效应

The Heat Effect of Magnetite for Hyperthermia under Alternating Magnetic Field

以肿瘤磁热疗为背景,采用共沉淀法合成了Fe3O4纳米粒子,在63kHz,7kA/m的中频交变磁场中研究其热效应.实验结果表明,Fe3O4磁粒子在交变磁场中有明显的热效应,尼尔驰豫是产热的主要原因,其产热比功率(SAR)与磁场强度的平方成正比,而与Fe3O4粒子的浓度以及分散介质的粘度无关.

The nanosized magnetite particles were synthesized by co-precipitation and their heat effect was studied under a 63 kHz, 7 kA/m magnetic field. The results show that the magnetite particles with 10 nm diameter can produce an obvious heat effect, and Néel relaxation is the main factor that generates the heat effect under an alternating magnetic field. Specific absorption rate (SAR) of magnetite particles is in direct proportion to the square law of amplitude of alternating magnetic field. Neither the concentration of magnetite nor the viscosity of carried liquids affects the SAR of materials. The result of heating experiment in vivo suggests that magnetite particles can generate enough heat to fulfill effective hyperthermia.