Targeting Hyperthermia by RF Inductive Heating for Selective Heating of Cancer

1. 研究了射频容性热疗中颗粒加热介质的特性。采用8mhz射频加热装置对四种铁磁性铁氧体颗粒(Cu(II)Fe(III)2O3、Mg(II)Fe(III)2O3、Mn(II)Fe(III)2O3和Ni（II)Fe(III)2O3）以及磁铁矿颗粒和其他非铁磁性金属氧化物颗粒（a-Fe2O3、a-氧化铝、Ag(II)O和ZnO）进行了测试。结果表明，在射频电容中，铁磁性粒子可以产生特定的热，而非铁磁性粒子则不能。此外，颗粒的分散性是产生热量的重要参数。制备生物相容性加热介质磁铁矿针，其中磁铁矿颗粒被塑造成针状，我们将其作为细胞内热疗的加热介质。我们研究了高温对雌性F344大鼠股骨区域实体皮下胶质瘤的影响。暴露在磁场中的许多老鼠的肿瘤组织完全消失，针头只是通过注射器注射。磁铁矿针将是一种新型的、潜在有效的热疗介质，可用于治疗其他恶性实体瘤，且无严重的副作用。磁颗粒在射频加热中的特异性加热及效应研究将磁性阳离子脂质体（mcl）注射于大鼠股骨肿瘤中，并在“轻度加热”条件下对大鼠进行8mhz射频电容加热。注射mcl的肿瘤加热到43℃以上，未注射mcl的肿瘤只加热到41℃。3 .加热后观察肿瘤坏死区。加热介质的安全性：所有研究均未观察到加热介质的毒性作用。

1. Improvement of RF specific heating deviceCharacteristics of particulate heating mediators in radiofrequency (RF) capacitive hyperthermia were investigated. Four ferromagnetic ferrite particles (Cu(II)Fe(III)2O3, Mg(II)Fe(III)2O3, Mn(II)Fe(III)2O3, and Ni(II)Fe(III)2O3) in addition to magnetite particles and other non-ferromagnetic metal oxide particles (a-Fe2O3, a-Alumina, Ag(II)O, and ZnO) were tested using 8 MHz RF heating device. As a result, ferromagnetic particles could generate heat specifically in RF capacitive, but non-ferromagnetic particles could not. In addition, dispersiblity of particles was an important parameter for heat generation.2. Preparation of biocompatible heating mediatorMagnetite needle, in which magnetite particles are molded into needle-shape, was developed and we applied it as a heating mediator for intracellular hyperthermia. We investigated the hyperthermic effect on solid subcutaneous gliomas in the femoral region of female F344 rats. The tumor tissue completely disappeared in many rats exposed to a magnetic field, and the needles were simply administered through a syringe. The magnetite needle will be a novel and potentially effective mediator of hyperthermia that can be used to treat other malignant solid tumors without severe side effects.3. Specific heating and effect of magnetic particles in RF heatingMagnetite cationic liposomes (MCLs) were injected in a rat tumor on femur and an 8 MHz-RF capacitive heating was applied to the rat under the conditions of 'mild heating'. The MCLs-injected tumor was heated over 43℃ whereas it was only heated until 41℃ in the case of the rats injected no MCLs. The necrotic area of tumor was observed in the heated rat.4. Safety of heating mediatorNo toxico effect of heating mediator was observed in all invetigations.