| Project/Area Number |
18390373
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thoracic surgery
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| Research Institution | Akita University |
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Principal Investigator |
OGAWA Jun-ichi Akita University, School of Medicine, Professor (20112774)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Hajime Akita University, School of Medicine, lecturer (20323149)
MARUYAMA Kiyotomi Akita University, School of Medicine, Assistant Professor (80361228)
MITOBE Kazutaka Akita University, Faculty of Engineering and Resource Science, lecturer (60282159)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥17,390,000 (Direct Cost: ¥15,200,000、Indirect Cost: ¥2,190,000)
Fiscal Year 2007: ¥9,490,000 (Direct Cost: ¥7,300,000、Indirect Cost: ¥2,190,000)
Fiscal Year 2006: ¥7,900,000 (Direct Cost: ¥7,900,000)
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| Keywords | hyperthermia / Cancer / ferromagnetic material / induction heating |
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| Research Abstract |
Hyperthermia has been used for many years to treat variety of malignant tumors. The Curie temperature (Tc) is a transition point at which magnetic materials lose of its magnetic properties, which causes a cessation of current and thus heat production. The Tc enables automatic temperature control throughout a tumor as a result of the self-regulating nature of the thermosensitive material. We have developed a method of magnetically induced hyperthermia using thermosensitive ferromagnetic particles (FMPs) with low Tc (43℃) enough to mediate automatic temperature control.
B16 melanoma cells were subcutaneously injected into the backs of C57BL/6 mice, after which tumors were allowed to grow to 5mm in diameter. FMPs were then injected into the tumors, and the mice were divided into three groups: group-I (no hyperthermia; control), group-II (one hyperthermia treatment) and group-III (hyperthermia twice a week for 4 weeks) . When exposed to a magnetic field, the FMPs showed a sharp rise in heat production, reaching the Tc in tissue within 7min, after which the tissue temperature stabilized at around the Tc. In groups-I and II, all mice died within 30 to 45days. In group-III, however, 6 of 10 mice remained alive 120days after beginning treatment.
Our findings suggest that repeated treatment with magnetically induced self-regulating hyperthermia, mediated by FMPs with a low Tc, is an effective means of suppressing melanoma growth. A key advantage of this hyperthermia system is that it is minimally invasive, requiring only a single injection for repeated treatments with automatic temperature control.
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