[Studies on liposomal ferromagnetic particles and a technique of high frequency inductive heating--in vivo studies of rabbits].

The tumor can be more selectively heated by applying of high frequency inductive heating after administration of ferromagnetic particles into a tumor. In order to devise a technique used for the selective hyperthermia of a tumor with high frequency inductive heating, we continued fundamental studies using liposomal ferromagnetic particles (HP-LM), which were prepared as follows: triiron tetoraoxide (Fe3O4) particles were coated with liposomal membrane contained hematoporphyrin with neoplastic affinity. In Vivo Studies of Rabbits: We used high frequency inductive heater (NIHON KOSHUHA CO. LTD. YKN-10), frequency: 400 kHz, out put: 10 kW, coil diameter: 90 mm. VX-2 tumor cells at 1.5 X 10(7) were implanted to the lower thigh of rabbit. When the implanted tumor grew up 3 cm in diameter, A-D group were heated and studied. Group A: In a dose of 200 mg/kg of HP-LM was administered into the femoral artery, Group B: In a dose of 100 mg/kg of Fe3O4 was administered into the femoral artery, Group C: Ligation of femoral artery, Group D: Nonadministrated, and then was immediately heated. Group A: In a dose of 200 mg/kg of HP-LM, with heating for 10 minutes, temperature was elevated 14. 8 degrees C at center of tumor. Group B: In a dose of 100 mg/kg of Fe3O4, with heating for 10 minutes, temperature was elevated 10.6 degrees C at center of tumor. Group C: In a ligation of femoral artery, with heating for 10 minutes, temperature was elevated 6.5 degrees C at center of tumor.(ABSTRACT TRUNCATED AT 250 WORDS)