Invited PaperMagnetic fluid hyperthermia (MFH): Cancer treatment with AC magnetic field induced excitation of biocompatible superparamagnetic nanoparticles
Section snippets
Basic principles of hyperthermia
Heating of certain organs or tissues to temperatures between 41°C and 46°C preferentially for cancer therapy is called `Hyperthermia'. Higher temperatures up to 56°C, which yield widespread necrosis, coagulation or carbonization (depending on temperature) is called `thermo-ablation'. Both mechanisms act completely different concerning biological response and application technique. The `classical’ hyperthermia induces almost reversible damage to cells and tissues, but as an adjunct it enhances
Clinical hyperthermia
State-of-the-art radiofrequency (RF-) hyperthermia systems, e.g. annular phased array systems (APAS) for regional hyperthermia of deep seated tumors, are still limited by the known heterogeneity of tissue electrical conductivities or high perfused tissues, which makes selective heating of those regions with such E-field dominant systems very difficult. Further application techniques are whole body hyperthermia (WBH, with water-filtered infra-red irradiation), local hyperthermia (e.g. with
Much more than simple particle heating: the biological concept of magnetic fluid hyperthermia (MFH)
In the early 1960s, a few US groups were the first, who tried to perform hyperthermia with magnetizable microparticles, which were heated by an externally applied AC magnetic field. The use of H-field dominant systems together with power absorbing material instead of power steering of E-field dominant systems is therefore an old idea. However, before the early nineties, the status of this research was diffuse and clinical application was unthinkable. Poor defined animal systems [18] or ex vivo
Recent results
In order to proceed from the encouraging results with the mammary carcinoma of the mouse, more animal experiments are required to fix the current state of MFH as an almost site-specific modality, which allows regional heating in different locations of the body. As a precondition, the technology of AC magnetic field application is currently under development [24]. If an almost regional AC magnetic field application could be realized, migration of any ferrofluid to distant locations could be
Perspectives
It is still a fascinating concept, that tumor cells could be loaded with thousands of particles, which would become activated – comparable to genes – only by a specific signal, yielding the death of all particle containing cells as soon as an AC magnetic field is applied. Our cellular observations so far indicate that a tumor, which has taken up these particles, will not be able to get rid of them. Daughter cells from a particle containing parent cells should therefore contain up to 50% of the
Acknowledgements
The authors wish to thank Mrs. Lajoux and Prof. Schnoy of the Department of Electron Microscopy and Prof. Maier-Hauff of the Department of Neurosurgery, both of the University Clinic Charité, for valuable co-operation and helpful discussions. This project is supported by the Deutsche Forschungsgemeinschaft (DFG), Sonderforschungsbereich 273 (TP A8), Bonn, Germany.
References (26)
- et al.
Cancer Letters
(1995) Int. J. Radiat. Oncol. Biol. Phys.
(1997)- et al.
Int. J. Radiat. Oncol. Biol. Phys.
(1994) - et al.
Int. J. Radiat. Oncol. Biol. Phys.
(1996) - et al.
Int. J. Oncol. Biol. Phys.
(1998) - et al.
Med. Hypothesis
(1979) J. Magn. Magn. Mater
(1991)- et al.
- et al.
Int. J. Hyperthermia
(1997) - P. Burgman, A. Nussenzweig, G.C. Li, in: M.H. Seegenschmiedt, P. Fessenden, C.C. Vernon (Eds.), Thermoradiotherapy and...