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，通过射频热疗，只能进行广泛的非选择性加热。另一方面，可以使用适当的热剂或材料通过感应方法实现选择性加热。在之前的研究中，我们开发了以葡聚糖磁铁矿（DM）和热敏磁脂质体（TMs）为磁性材料的方法，并报道了其特性和处理结果。由于其对温度敏感的性质，TMs对药物（例如抗癌药物等）在局部高温下的释放有潜在的用处。但TMs颗粒较小，不足以作为栓子。为了解决这些问题，人们重新开发了白蛋白微球（DM- ams）。在本研究中，我们研究了DM- AMs在电磁场中的体外和体内加热性能。本研究使用的DM-AMs直径为4 ~ 6 μ m，铁含量为39.6%。尺寸和浓度可以很容易地改变。将不同浓度的DM-AMs悬浮液（如铁）通过感应加热装置暴露在频率为500 kHz、输出功率为7 kw的电磁场中，并用荧光光学温度计监测溶液的温度。在Fe/mI浓度为10 mg和20 mg时，感应加热的温度分别升高约6 C / 7 min和6 C / 13 min。用DM-Ams经动脉栓塞大鼠肝尾叶，并在诱导场下暴露。在TMs中使用10 mg Fe/mI的DM-Ams进行25 mm的感应加热，温度升高到43ºC。将大鼠加热至43度，进行诱导热疗。DM-Ams间接加热使直肠温度略有升高，但肿瘤与直肠温差明显且显著。组织学检查在肝尾叶窦及植入瘤内取DM-AMs。肿瘤细胞外周排列粗糙，中央可见坏死和纤维样改变。DM-Ams具有释放掺入药物的特性，因此建议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热，并且通过栓塞可以进行选择性热疗的可能性。这些结果在日本热疗学会第十四届和第十五届大会上报道。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