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

电容式加热主要是通过射频热疗来实现的，只有通过射频热疗才能实现广泛的、非选择性的加热。另一方面，可以使用适当的加热剂或材料通过感应方法来实现选择性加热。在以前的研究中，我们发展了以葡聚糖磁铁矿(DM)和热敏磁脂质体(TMS)为磁性材料的方法，并报道了这种方法的特点和处理结果。由于其温度敏感性的性质，TMS可能用于药物(如抗癌药物等)的释放，以响应局部热疗。但TMS颗粒较小，不足以作为栓子。为了解决这些问题，人们重新开发了DM白蛋白微球。在本研究中，我们研究了DM-AM在电磁场中的体内外加热特性。本研究所使用的DM-AM直径为4~6微米，含铁量为39.6%。…的大小更多的钕浓度可以很容易地改变。将不同浓度的DM-AMS悬浮液(如铁)置于电磁场中，频率为500 kHz，输出功率为7 kW，用荧光温度计监测溶液温度。在10mgFe/mI和20mgFe/mI的感应加热下，温升分别约为6ﾟC/7min和6ﾟC 1 3min。用DM-Ams经动脉栓塞大鼠肝尾叶，暴露于诱导场中。用10 mg铁/毫升的DM-AMS对TMS进行25 mm的感应加热，温升达43ﾟC，用感应加热法加热至43度。DM-Ams间接加热可使直肠温度略有升高，但肿瘤与直肠的温差明显且显著。在组织学检查中，在肝尾叶窦和移植瘤内取DM-AMS。瘤细胞周边排列粗糙，中心可见坏死、纤维性改变。DM-AM具有释放药物的特性，提示DM-AM可用于化疗栓塞术。仅对肿瘤进行选择性加温，并通过栓塞术提出了选择性加温的可能性。这些结果发表在第14届和第15届日本热疗学会大会上。较少

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