A Study of Thermo-chemo-embolization Using Dextran Magnetite Incorporated Liposomes

电容加热主要通过射频热疗来进行，通过射频热疗，仅可能进行广泛和非选择性加热。另一方面，可以通过使用适当的高热剂或材料的感应方法来实现选择性加热。在前期的研究中，我们发展了以葡聚糖磁铁矿（DM）和温敏磁性脂质体（TM）为磁性材料的治疗方法，并报道了其特点和治疗效果。由于其温度敏感性的性质，TM对于响应于局部高热的药物（例如，抗癌剂等）释放是潜在有用的。但是，TM的粒径很小，不足以作为栓塞剂。为了解决这些问题，DM白蛋白微球（DM-AMs）被重新开发。在这项研究中，我们研究了在体外和在体内的电磁场中的DM-AM的加热性能。本研究中使用的DM-AM直径为4至6 μ m，铁含量为39.6%。的尺寸α 关于我们 可以容易地改变端浓度。将不同浓度的DM-AM悬浮液（如铁）暴露于由频率为500 kHz、输出功率为7 kW的感应加热单元产生的电磁场中。在10 mg Fe/mI和20 mg Fe/mI的浓度下，感应加热的温升分别约为6 ℃/ 7 min和6 ℃/13 min。用DM-Ams经动脉栓塞大鼠肝尾叶，并暴露于诱导场。在TM中使用10 mg Fe/mI的DM-Ams进行25 mm感应加热，温度升高至43 ℃。由于DM-Ams间接加热，直肠温度略有升高，但肿瘤与直肠之间的温差明显且显著。在组织学检查中，在肝尾叶窦和种植瘤内取DM-AM。周边部瘤细胞排列不规则，中央部瘤细胞呈坏死和纤维样改变。DM-Ams具有释放药物的特性，提示DM-Ams可用于高热化疗栓塞治疗。只有一个肿瘤被选择性地加温，并建议通过栓塞来进行选择性热疗。这些结果在第14和第15届日本热疗学会大会上报告。少

A capacitive heating has been mainly performed by radio-frequency hyperthermia, by which broad and nonselective heating is only possible. On the other hand, it is possible to accomplish a selective heating by an inductive method using an adequate hyperthermic agent or materials. ln a previous study, we have developed the method that used dextran magnetite (DM) and thermosensitive magneto-liposome (TMs) as magnetic materials, and reported the characteristics and the result of treatment. Due to its nature of temperature sensitivity, TMs are potentially useful for drug (example ; anticancer agents etc) release in response to local hyperthermia. But the particle size of TMs was small and inadequate as an embolus. To solve these problems, DM albumin micro sphere (DM-AMs) was developed afresh. In this study, we investigated in vitro and in vivo heating properties of DM- AMs in an electromagnetic field. DM-AMs used in this study is 4 to 6 mum of in diameter, 39.6 % in iron content. The size a … More nd concentration can be changed easily. DM-AMs suspeusions at its various concentrations (as iron) were exposed to an electromagneric field by an inductive heating unit at a 500 kHz frequency with an output of 7 kW.The temperature of the solution was monitored by using a fluoroptic thermometer. There were temperature rises of approximately 6 ﾟC / 7 min and 6 ﾟC 1 3 min by inductive heating at the concentrations of 10 mg Fe/mI and 20 mg Fe/mI respectively. The caudal lobe of liver of rat was embolized via arterial with DM-Ams, and exposed to an induction field. There was a temperature rise up to 43ﾟC for 25 mm-inductive heating using DM-Ams of 10 mg Fe/mI in TMs.was performed of rat was warmed to 43 degrees with induction hyperthermia. The rectum temperature was slightly elevated due to indirect heating with DM-Ams, but the temperature difference between the tumor and rectum was obvious and significant. ln histological examination, DM-AMs was taken in sinus of the caudal lobe of liver and inside of implanted tumor. Tumor cells showed rough arrangement in peripheral part, and necrosis and fibrous change were recognized in the central part. DM-Ams had a nature to release incorporated drugs, then it is suggested that DM-AMs are usefull for hyperthrmo-chemo-embolization treatment. Only a tumor was warmed selectively, and possibility to can do selective hyperthermia was suggested by doing embolism. These results were reported in the 14th and 15th congress of Japanese hyperthermia society. Less