Observations on the Use of Ferromagnetic Implants for Inducing Hyperthermia

Stauffer, Paul R.; Cetas, Thomas C.; Fletcher, A.; DeYoung, Donald W.; Dewhirst, Mark W.; Oleson, James R.; Roemer, R. B.

doi:10.1109/tbme.1984.325373

Cited by 149 publications

(55 citation statements)

References 20 publications

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“…The use of medically-safe magnetic fields to selectively heat Curie thermoregulated ferromagnetic materials in vivo to temperatures of , has been demonstrated in a number of hyperthermia studies [13][14][15][16][17][18] suggesting the feasibility of the same approach to actuate SMP devices in vivo. The impact of particle size and material processing on the magnetic loss mechanisms and heating characteristics of magnetic particles is quite complicated but is fairly well understood thanks to previous research [19,20].…”

Section: Introductionmentioning

confidence: 99%

Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices

Buckley

McKinley

Wilson

et al. 2006

IEEE Trans. Biomed. Eng.

321

205

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Presently there is interest in making medical devices such as expandable stents and intravascular microactuators from shape memory polymer (SMP). One of the key challenges in realizing SMP medical devices is the implementation of a safe and effective method of thermally actuating various device geometries in vivo. A novel scheme of actuation by Curiethermoregulated inductive heating is presented. Prototype medical devices made from SMP loaded with Nickel Zinc ferrite ferromagnetic particles were actuated in air by applying an alternating magnetic field to induce heating. Dynamic mechanical thermal analysis was performed on both the particle-loaded and neat SMP materials to assess the impact of the ferrite particles on the mechanical properties of the samples. Calorimetry was used to quantify the rate of heat generation as a function of particle size and volumetric loading of ferrite particles in the SMP. These tests demonstrated the feasibility of SMP actuation by inductive heating. Rapid and uniform heating was achieved in complex device geometries and particle loading up to 10% volume content did not interfere with the shape recovery of the SMP.

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Section: Introductionmentioning

confidence: 99%

Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices

Buckley

McKinley

Wilson

et al. 2006

IEEE Trans. Biomed. Eng.

321

205

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“…1) Various methods have been employed, such as whole body hyperthermia, 2) radiofrequency hyperthermia, 3) and inductive hyperthermia using microwave antenna 4) or implantable needles. 5) However, it is always difficult to achieve uniform heating of the tumor region to the desired temperature without damaging normal tissue. Therefore, some researchers have proposed intracellular hyperthermia and developed submicron magnetic particles for this purpose.…”

mentioning

confidence: 99%

Antitumor Immunity Induction by Intracellular Hyperthermia Using Magnetite Cationic Liposomes

Yanase

Shinkai

Honda

et al. 1998

Japanese Journal of Cancer Research

153

107

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Induction of antitumor immunity to T-9 rat glioma by intracellular hyperthermia using functional magnetic particles was investigated. Magnetite cationic liposomes (MCLs), which have a positive surface charge, were used as heating mediators for intracellular hyperthermia. Solid T-9 glioma tissues were formed subcutaneously on both femurs of female F344 rats, and MCLs were injected via a needle only into the left solid tumors (treatment side). The rats were then divided into two groups, which received no irradiation, or irradiation for 30 min given three times at 24-h intervals with an alternating magnetic field (118 kHz, 384 Oe). On the treatment side, the tumor tissue disappeared completely in many rats exposed to the magnetic field. The tumor tissue on the opposite side also disappeared completely, even though MCLs were not injected into the right solid tumors. To examine whether a long-lasting and tumor-specific immunity could be generated, the rats that had been cured by the hyperthermia treatment were rechallenged with T-9 cells 3 months later. After a period of transient growth, all tumors disappeared. Furthermore, immunocytochemical assay revealed that the immune response induced by the hyperthermia treatment was mediated by both CD8 Various methods have been employed, such as whole body hyperthermia, 2) radiofrequency hyperthermia, 3) and inductive hyperthermia using microwave antenna 4) or implantable needles. 5) However, it is always difficult to achieve uniform heating of the tumor region to the desired temperature without damaging normal tissue. Therefore, some researchers have proposed intracellular hyperthermia and developed submicron magnetic particles for this purpose.6-8) These magnetic particles are easily incorporated into cells and generate heat under an alternating magnetic field through hysteresis loss. 9) We have also developed 'magnetite cationic liposomes' (MCLs) for intracellular hyperthermia.10, 11) MCLs were developed to improve adsorption and accumulation into the tumor cells and show ten-fold higher affinity for tumor cells than neutrally charged magnetoliposomes, 10) owing to electrostatic interaction with the negatively charged cell membrane. 12,13) The hyperthermic effect of the MCLs was examined in vivo.14) MCLs were injected into solid tumors formed subcutaneously in F344 rats and the rats were irradiated three times for 30 min with an alternating magnetic field. Histological observations were carried out just after the irradiation and showed that some tumor cells survived, especially in the peripheral area. However, complete tumor regression was observed one month after the irradiation. We were interested in the possibility that antitumor immunity had been induced by the hyperthermic treatment using MCLs.In the present paper, it is demonstrated that our hyperthermia system can induce an antitumor immune response and the acquired immunity is long-lasting. MATERIALS AND METHODS MaterialsDilauroylphosphatidylcholine and dioleoylphosphatidylethanolamine were purchased from Sigma Ch...

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“…However, the procedure is very painful for the patient because many needles must be implanted to achieve homogeneous heating of tumor tissue. 7,8) If fine particles can be used as heating mediators instead of needles, this difficulty may be overcome. For this reason, we developed submicronsized magnetite particles for heating tumor cells.…”

mentioning

confidence: 99%

Intracellular Hyperthermia for Cancer Using Magnetite Cationic Liposomes: An in vivo Study

Yanase

Shinkai

Honda

et al. 1998

Japanese Journal of Cancer Research

206

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The effect of hyperthermia on solid glioma tissue formed subcutaneously in the left femoral region of female F344 rats was investigated. Magnetite cationic liposomes (MCLs), which have a positive surface charge, were used as heating mediators for intracellular hyperthermia. MCLs were injected into the solid tumors, which were then subjected to irradiation by an alternating magnetic field (118 kHz, 384 Oe). The rats were divided into four groups, which received no irradiation (control: group I), or irradiation for 30 min given once (group II), twice (group III) or three times (group IV), and the hyperthermic effect on tumor growth was evaluated. Complete tumor regression was observed in 87.5% of the rats in group IV. In the other groups, tumors completely regressed in 20 and 60% of the rats in groups II and III, respectively. Histological observations showed that in group I tumors, MCLs were localized only around the point where they were injected, while in group II tumors they were a little more dispersed. In the cases of group III and IV tumors, however, the distribution of the MCLs was found to be widespread, and necrotic cells were observed throughout almost the entire tumor tissue. The high percentage of complete regression of group IV is considered to be due to this wide distribution of the MCLs. Furthermore, the treated rats showed no severe side-effects. These results suggest that our magnetic particles are potentially effective tools for the treatment of solid tumors.

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Observations on the Use of Ferromagnetic Implants for Inducing Hyperthermia

Cited by 149 publications

References 20 publications

Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices

Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices

Antitumor Immunity Induction by Intracellular Hyperthermia Using Magnetite Cationic Liposomes

Intracellular Hyperthermia for Cancer Using Magnetite Cationic Liposomes: An in vivo Study

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