Mitsumori M, Hiraoka M, Shibata T, Okuno Y, Masunaga S, Koishi M, Okajima K, Nagata Y, Nishimura Y, Abe M
Department of Radiology, Faculty of Medicine, Kyoto University, Japan.
Int J Hyperthermia. 1994 Nov-Dec;10(6):785-93. doi: 10.3109/02656739409012371.
Dextran-magnetite complex (DM) is a colloidal sol of subdomain magnetite particles (i.e. a 'magnetic fluid'). The specific absorption rate of DM in an AC magnetic field is much higher than those of multidomain ferrite particles due to its different mechanism of heat generation. We designed two DM-containing embolic materials (a DM/Lipiodol emulsion and a DM/degradable starch microsphere suspension) to heat target tissues with the use of an external AC magnetic field. In vitro experiments showed that the heat-generating capacity of DM was not reduced in these mixtures. When these materials were injected into the renal arteries of Japanese white rabbits, they both achieved embolization of the artery and selective heating of the embolized kidney by exposure to a 100 kHz AC magnetic field of approximately 15,000 A/m. Histological examination showed a homogeneous distribution of DM in the embolized kidney. These results suggest the possibility of using DM-containing embolic materials for inductive hyperthermia.
葡聚糖-磁铁矿复合物（DM）是亚畴磁铁矿颗粒的胶体溶液（即一种“磁流体”）。由于其不同的产热机制，DM在交流磁场中的比吸收率远高于多畴铁氧体颗粒。我们设计了两种含DM的栓塞材料（一种DM/碘油乳剂和一种DM/可降解淀粉微球混悬液），以利用外部交流磁场加热靶组织。体外实验表明，在这些混合物中DM的产热能力并未降低。当将这些材料注入日本白兔的肾动脉时，通过暴露于约15,000 A/m的100 kHz交流磁场中，它们都实现了动脉栓塞以及栓塞肾脏的选择性加热。组织学检查显示DM在栓塞肾脏中分布均匀。这些结果表明使用含DM的栓塞材料进行感应热疗的可能性。
