JP2011032238A - Heating element for magnetic thermotherapy and manufacturing method of the same - Google Patents

Heating element for magnetic thermotherapy and manufacturing method of the same Download PDF

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JP2011032238A
JP2011032238A JP2009181597A JP2009181597A JP2011032238A JP 2011032238 A JP2011032238 A JP 2011032238A JP 2009181597 A JP2009181597 A JP 2009181597A JP 2009181597 A JP2009181597 A JP 2009181597A JP 2011032238 A JP2011032238 A JP 2011032238A
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ferrite
heating element
magnetic
ferrite fine
aqueous solution
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Masanori Abe
正紀 阿部
Takashi Nakagawa
貴 中川
Masaru Tada
大 多田
Shuhei Yamamoto
修平 山本
Hiroshi Handa
宏 半田
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Tokyo Institute of Technology NUC
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a new heating element for magnetic thermotherapy. <P>SOLUTION: When a ferrite fine-grain dispersed liquid is prepared by dispersing ferrite fine-grains of grain diameters of 10 to 25 nm in sodium alginate solution and the ferrite fine-grain dispersed liquid is dripped to calcium chloride solution using an ink-jet nozzle, alginic acid gel grains containing a plurality of ferrite fine-grains are formed and are used as the heating element for the magnetic thermotherapy. The heating element for the magnetic thermotherapy includes high biocompatibility, biodegradability, additionally, and high heating efficiency. The grain diameters are freely controlled, and the heating element is manufactured inexpensively, simply and easily. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、磁気温熱療法用発熱体およびその製造方法に関する。   The present invention relates to a heating element for magnetic thermotherapy and a method for producing the same.

近年、癌の治療法として温熱療法が注目されている。癌の温熱療法(抗癌ハイパーサーミア)とは、癌細胞が健常細胞に比べて熱に弱く、また、加温に対して癌組織が健常組織より早く昇温することに着目した治療法であり、癌患部を加温することによって癌細胞のみを死滅させることを目的とするものである。抗癌ハイパーサーミアの最も大きな特徴は、癌の種類に関係なくその効果が期待できる上に、目立った副作用がなく、患者のQOL(Quality of Life)を高く維持できる点にある。   In recent years, hyperthermia has attracted attention as a cancer treatment method. Cancer hyperthermia (anti-cancer hyperthermia) is a treatment method that focuses on the fact that cancer cells are less susceptible to heat than healthy cells, and that cancer tissues heat up faster than healthy tissues against heating, The object is to kill only cancer cells by heating the cancerous part. The most important feature of anti-cancer hyperthermia is that it can be expected to have an effect regardless of the type of cancer, has no noticeable side effects, and can maintain a high QOL (Quality of Life) of the patient.

現在、採用されている抗癌ハイパーサーミアの多くは誘電型加温法によるものであり、癌細胞が存在する身体の部位を電極で挟み、ラジオ波と同程度の周波数の交流電流を流すことによって、ジュール損失と誘電損失で患部を加温するものである。しかしながら、この原理は、電界の印加によって組織内の水分子を加熱するものであり、癌組織だけでなく正常組織まで加温してしまうため、実際には、患者の負担を考慮して、42℃までの加温が限界となっており、癌細胞をハイパーサーミアのみで完全に退縮させることは困難であった。   Many of the currently used anti-cancer hyperthermia are based on dielectric heating, and the body part where cancer cells are present is sandwiched between electrodes, and an alternating current with a frequency similar to that of radio waves is applied. The affected area is heated by Joule loss and dielectric loss. However, this principle heats water molecules in the tissue by applying an electric field, and heats not only the cancer tissue but also the normal tissue. Heating up to 0 ° C. was the limit, and it was difficult to completely regress cancer cells with hyperthermia alone.

この点に鑑み、近年、磁性微粒子を癌組織に導入し、これに交流磁界を印加することによって、癌組織のみを選択的に加温することを特徴とした磁気温熱療法用(磁気ハイパーサーミア)の採用が検討されている。この磁気ハイパーサーミアは、交流磁界の印加によって、癌組織に集積した磁性微粒子を発熱させるものであり、組織中の水分子を直接加熱するものではないため、健常組織を限界温度まで加温することなく、癌細胞だけを選択的に42.5℃以上の高温にまで加温して死滅させることが可能となる。   In view of this point, in recent years, magnetic hyperthermia (magnetic hyperthermia) is characterized in that only a cancer tissue is selectively heated by introducing magnetic fine particles into the cancer tissue and applying an alternating magnetic field thereto. Adoption is being considered. This magnetic hyperthermia heats magnetic fine particles accumulated in cancer tissue by applying an alternating magnetic field and does not directly heat water molecules in the tissue, so that the healthy tissue is not heated to the limit temperature. Only cancer cells can be selectively killed by heating to a high temperature of 42.5 ° C. or higher.

これを受けて、近年、磁気ハイパーサーミア用発熱体について広く研究開発がなされている。例えば、国際公開第2006/080243号(特許文献1)は、磁性粒子をリポソームで被覆してなる温熱療法用治療剤を開示する。   In response, in recent years, research and development have been extensively conducted on heating elements for magnetic hyperthermia. For example, International Publication No. 2006/080243 (Patent Document 1) discloses a therapeutic agent for thermotherapy obtained by coating magnetic particles with liposomes.

国際公開第2006/080243号International Publication No. 2006/080243

磁気温熱療法用発熱体には、当然にして高い生体適合性が要求される。また、ハイパーサーミア治療は一般に数日間にわたり複数回実施されるので、この間、磁気温熱療法用発熱体を患部に滞留させることが望ましく、一方で、治療終了後には、完全に体外へ排出されることが要請される。さらに、身体への負担軽減の観点から、その投入量をできるだけ少なくする必要があり、そのために、磁気温熱療法用発熱体には、より高い発熱効率が要求される。   Naturally, high biocompatibility is required for the heating element for magnetic thermotherapy. In addition, since hyperthermia treatment is generally carried out several times over several days, it is desirable to retain the heating element for magnetic thermotherapy in the affected area during this period, while it may be completely discharged from the body after the treatment is completed. Requested. Furthermore, from the viewpoint of reducing the burden on the body, it is necessary to reduce the input amount as much as possible. For this reason, the heating element for magnetic thermotherapy requires higher heat generation efficiency.

本発明は、上記課題に鑑みてなされたものであり、本発明は、高い生体適合性と生体内分解性に加え、高い発熱効率を備え、その粒径を自在に制御でき、且つ、低廉な製造コストで簡便に製造することができる新規な磁気温熱療法用発熱体を提供することを目的とする。   The present invention has been made in view of the above problems, and the present invention has high heat generation efficiency in addition to high biocompatibility and biodegradability, and its particle size can be freely controlled, and is inexpensive. It is an object of the present invention to provide a novel heating element for magnetic thermotherapy that can be easily manufactured at a manufacturing cost.

本発明者らは、高い生体適合性と生体内分解性に加え、高い発熱効率を備え、その粒径を自在に制御でき、且つ、低廉な製造コストで簡便に製造することができる新規な磁気温熱療法用発熱体につき鋭意検討した結果、フェライト微粒子をアルギン酸ゲル粒子に包含させてなる発熱体の構成に想到し、本発明に至ったのである。   In addition to high biocompatibility and biodegradability, the present inventors have a novel magnetism that has high heat generation efficiency, can freely control its particle size, and can be easily manufactured at a low manufacturing cost. As a result of diligent investigations on a heating element for thermotherapy, the inventors have conceived a configuration of a heating element in which ferrite fine particles are included in alginate gel particles, and have reached the present invention.

すなわち、本発明によれば、複数のフェライト微粒子を包含するアルギン酸ゲル粒子として構成される磁気温熱療法用発熱体が提供される。本発明においては、前記フェライト微粒子の粒径を10〜25nmとすることが好ましい。また、本発明によれば、アルギン酸塩水溶液にフェライト微粒子を分散させてフェライト微粒子分散液を調製する工程と、前記フェライト微粒子分散液の微細液滴を多価金属塩水溶液に対して導入し、該微細液滴をゲル化する工程とを含む、磁気温熱療法用発熱体の製造方法が提供される。本発明においては、分散させる前記フェライト微粒子をクエン酸被覆しておくことが好ましい。また、本発明においては、前記フェライト微粒子の粒径を10〜25nmとすることが好ましい。さらに、本発明においては、インクジェットノズルによって前記微細液滴の大きさを制御して導入することができ、あるいは、前記フェライト微粒子分散液を噴霧することによって、前記微細液滴を前記多価金属塩水溶液に対して導入することができる。また、本発明においては、前記アルギン酸塩水溶液としてアルギン酸ナトリウム水溶液を、前記多価金属塩水溶液として塩化カルシウム水溶液を用いることができる。   That is, according to the present invention, a heating element for magnetic thermotherapy configured as alginate gel particles including a plurality of ferrite fine particles is provided. In the present invention, the ferrite fine particles preferably have a particle size of 10 to 25 nm. According to the present invention, a step of preparing a ferrite fine particle dispersion by dispersing ferrite fine particles in an alginate aqueous solution, introducing fine droplets of the ferrite fine particle dispersion into the polyvalent metal salt aqueous solution, There is provided a method for producing a heating element for magnetic hyperthermia comprising a step of gelling fine droplets. In the present invention, the ferrite fine particles to be dispersed are preferably coated with citric acid. In the present invention, the ferrite fine particles preferably have a particle size of 10 to 25 nm. Furthermore, in the present invention, the size of the fine droplets can be controlled by an inkjet nozzle, or the fine droplets can be introduced by spraying the ferrite fine particle dispersion. It can introduce | transduce with respect to aqueous solution. In the present invention, a sodium alginate aqueous solution can be used as the alginate aqueous solution, and a calcium chloride aqueous solution can be used as the polyvalent metal salt aqueous solution.

上述したように、本発明によれば、高い生体適合性と生体内分解性に加え、高い発熱効率を備え、その用途に応じて粒径を自在に制御でき、且つ、低廉な製造コストで簡便に製造することができる新規な磁気温熱療法用発熱体が提供される。   As described above, according to the present invention, in addition to high biocompatibility and biodegradability, it has high heat generation efficiency, the particle size can be freely controlled according to its use, and it can be easily manufactured at low cost. A novel heating element for magnetic hyperthermia that can be manufactured is provided.

本発明の磁気温熱療法用発熱体の製造方法を概念的に示す図。The figure which shows notionally the manufacturing method of the heat generating body for magnetic thermotherapy of this invention. 本実施例の発熱評価用実験装置を示す図。The figure which shows the experimental apparatus for the heat_generation | fever evaluation of a present Example. 本実施例で作製したフェライトナノ粒子のXRD測定の結果を示す図。The figure which shows the result of the XRD measurement of the ferrite nanoparticle produced in the present Example. 本実施例で作製したフェライトナノ粒子を含むサンプル(水・寒天)の室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図。The figure which showed the relationship between the temperature rising from room temperature (degreeC) of the sample (water * agar) containing the ferrite nanoparticle produced in the present Example, and magnetic field application time (min). フェライトナノ粒子の結晶子径d(nm)と磁界印加時間(min)毎の室温からの上昇温度(℃)の関係を示した図。The figure which showed the relationship between the crystallite diameter d (nm) of a ferrite nanoparticle, and the temperature rise (degreeC) from room temperature for every magnetic field application time (min). 磁気温熱療法用発熱体のレーザ顕微鏡像を示す図。The figure which shows the laser microscope image of the heat generating body for magnetic thermotherapy. 本実施例で作製した磁気温熱療法用発熱体を含む寒天サンプルの室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図。The figure which showed the relationship between the temperature rising from room temperature (degreeC) and the magnetic field application time (min) of the agar sample containing the heating element for magnetic thermotherapy produced in the present Example. 本実施例で作製した磁気温熱療法用発熱体と非被覆のフェライトナノ粒子について室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図。The figure which showed the relationship between the temperature rising from room temperature (degreeC), and magnetic field application time (min) about the heating element for magnetic thermotherapy produced in the present Example, and the uncoated ferrite nanoparticle.

以下、本発明を図面に示した実施の形態をもって説明するが、本発明は、図面に示した実施の形態に限定されるものではない。   Hereinafter, the present invention will be described with reference to embodiments shown in the drawings, but the present invention is not limited to the embodiments shown in the drawings.

アルギン酸は、褐藻類より抽出されるきわめて親水性の高い天然高分子であり、我が国では食品添加物として指定されるなど、人体に無害な物質として知られている。アルギン酸は、分子中のカルボン酸基が水酸化アルカリ金属や炭酸アルカリ金属などと塩を形成する条件下では高粘性の水溶液となり、分子中のカルボン酸基が多価金属イオンとキレート構造を形成することによってゲル化する性質を有する。一方、フェライトは、水溶液中でも安定で毒性がなく、酸化物の中で最も高い磁化量を有する磁性体である。そこで、本発明においては、発熱媒体としてフェライト微粒子を採用し、これをアルギン酸ゲル内に包含させることによって磁気温熱療法用発熱体を形成する。   Alginic acid is a highly hydrophilic natural polymer extracted from brown algae, and is known as a harmless substance to the human body, such as being designated as a food additive in Japan. Alginic acid is a highly viscous aqueous solution under conditions where the carboxylic acid group in the molecule forms a salt with an alkali metal hydroxide or alkali metal carbonate, and the carboxylic acid group in the molecule forms a chelate structure with the polyvalent metal ion. It has the property of gelling. On the other hand, ferrite is a magnetic substance that is stable and non-toxic even in an aqueous solution and has the highest amount of magnetization among oxides. Therefore, in the present invention, a ferrite fine particle is employed as a heat generating medium, and this is included in an alginate gel to form a heating element for magnetic thermotherapy.

図1は、本発明の磁気温熱療法用発熱体の製造方法を概念的に示す図である。本発明の磁気温熱療法用発熱体は、アルギン酸塩水溶液にフェライト微粒子を分散させてフェライト微粒子分散液10を調製し、フェライト微粒子分散液10の微細液滴を多価金属塩水溶液12に導入することによって作製する。なお、フェライト微粒子は、共沈法、部分酸化法、錯体沈澱法などの方法によって適宜作製することができる。微細液滴が多価金属塩水溶液12に導入されると、アルギン酸分子中のカルボン酸基が多価金属塩水溶液12中の多価金属イオンとキレート構造を形成することにより、微細液滴は、その大きさを維持したままゲル化し、アルギン酸ゲル粒子14を形成する。その結果、紙面右下に拡大して示すように、アルギン酸ゲル粒子14内に複数のフェライト微粒子16を包含した磁気温熱療法用発熱体20が形成される。なお、本発明においては、人体への影響を考慮し、アルギン酸塩水溶液としてアルギン酸ナトリウム水溶液を、多価金属塩水溶液として塩化カルシウム水溶液を用いることが好ましい。   FIG. 1 is a diagram conceptually illustrating a method for producing a heating element for magnetic thermotherapy according to the present invention. The heating element for magnetic thermotherapy of the present invention comprises preparing ferrite fine particle dispersion 10 by dispersing ferrite fine particles in an alginate aqueous solution, and introducing fine droplets of ferrite fine particle dispersion 10 into polyvalent metal salt aqueous solution 12. To make. The ferrite fine particles can be appropriately produced by a method such as a coprecipitation method, a partial oxidation method, or a complex precipitation method. When the fine droplet is introduced into the polyvalent metal salt aqueous solution 12, the carboxylic acid group in the alginic acid molecule forms a chelate structure with the polyvalent metal ion in the polyvalent metal salt aqueous solution 12, The gel is formed while maintaining the size to form alginate gel particles 14. As a result, as shown in an enlarged view on the lower right side of the drawing, a heating element 20 for magnetic thermotherapy including a plurality of fine ferrite particles 16 in the alginate gel particles 14 is formed. In the present invention, it is preferable to use a sodium alginate aqueous solution as the alginate aqueous solution and a calcium chloride aqueous solution as the polyvalent metal salt aqueous solution in consideration of the influence on the human body.

本発明においては、既存のインクジェットノズルを用いてフェライト微粒子分散液の微細液滴を多価金属塩水溶液12に滴下して導入することができる。例えば、ピエゾ式ノズルによれば、数十μmオーダーの液量を均一に吐出することができ、この吐出量を制御することによって、所望の粒径のアルギン酸ゲル粒子(すなわち、磁気温熱療法用発熱体)を作製することができる。   In the present invention, fine droplets of the ferrite fine particle dispersion can be dropped into the polyvalent metal salt aqueous solution 12 using an existing inkjet nozzle. For example, according to a piezo-type nozzle, a liquid amount of the order of several tens of μm can be discharged uniformly, and by controlling the discharge amount, alginate gel particles having a desired particle size (ie, heat generation for magnetic thermotherapy) Body).

また、別法としては、スプレー装置を利用してフェライト微粒子分散液を噴霧することによって、フェライト微粒子分散液の微細液滴を多価金属塩水溶液に導入することもできる。なお、当該方法においては、得られたアルギン酸ゲル粒子を適切なふるいにかけて所望の粒径範囲のアルギン酸ゲル粒子を分取することもできる。   Alternatively, fine droplets of the ferrite fine particle dispersion can be introduced into the polyvalent metal salt aqueous solution by spraying the ferrite fine particle dispersion using a spray device. In addition, in the said method, the obtained alginic acid gel particle can be sieved appropriately and the alginate gel particle of a desired particle size range can also be fractionated.

上述したように、本発明においては、企図する使用態様に応じて、導入するフェライト微粒子分散液の微細液滴の大きさ(液量)を制御するだけで、所望の粒径の磁気温熱療法用発熱体を自在に作製することができる。例えば、毛細血管の管径(3〜10 μm)より十数倍大きいサイズ(50〜1000μm)の粒径の磁気温熱療法用発熱体を作製し、これを目的とする癌患部近傍に直接注射して導入する方法が考えられる。この場合、導入された磁気温熱療法用発熱体は、毛細血管から血流と共にすぐに流出せず、数日間にわたって患部に滞留することが期待できる。   As described above, in the present invention, according to the intended use mode, the size of the fine droplets of the ferrite fine particle dispersion to be introduced (the amount of liquid) can be controlled only for magnetic thermotherapy with a desired particle size. A heating element can be produced freely. For example, a heating element for magnetic hyperthermia with a particle size (50 to 1000 μm) that is ten times larger than the capillary diameter (3 to 10 μm) is prepared and directly injected into the vicinity of the affected cancer site Can be considered. In this case, the introduced heating element for magnetic hyperthermia does not immediately flow out along with the blood flow from the capillaries and can be expected to stay in the affected area for several days.

以上、説明したように、本発明の磁気温熱療法用発熱体は、人体に無害なフェライトとアルギン酸塩から構成され、またその製造過程において有機溶媒を使用しないので、人体に悪影響を及ぼすことがない。また、治療終了後は、アルギン酸ゲルは代謝分解され、フェライト微粒子とともに体外へ排出される。さらに、本発明の磁気温熱療法用発熱体は、安価な材料で簡便に作製することができるため、製造コストの面でも有利である。   As described above, the heating element for magnetic thermotherapy according to the present invention is composed of ferrite and alginate that are harmless to the human body, and does not use an organic solvent in the manufacturing process, and thus does not adversely affect the human body. . In addition, after the treatment is completed, the alginate gel is metabolically decomposed and discharged out of the body together with the ferrite fine particles. Furthermore, since the heating element for magnetic thermotherapy of the present invention can be easily produced with an inexpensive material, it is advantageous in terms of manufacturing cost.

次に、本発明の磁気温熱療法用発熱体に包含されるフェライト微粒子について説明する。磁気ハイパーサーミアにおける磁性微粒子の発熱特性は、磁性微粒子の粒子径に大きく依存し、一般に、フェライトでは、粒径が数十nm以上の場合はヒステリシス損失が発熱を支配する一方、粒径がこれを下回る場合には、ヒステリシス損失はほとんど無くなり、ブラウン緩和損失とネール緩和損失が支配的となる。この点に鑑み、本発明においては、高い発熱効率を実現すべく、粒径10〜25nmのフェライト微粒子を包含させることが好ましい。   Next, the ferrite fine particles included in the heating element for magnetic thermotherapy of the present invention will be described. The heat generation characteristics of magnetic fine particles in magnetic hyperthermia greatly depend on the particle size of magnetic fine particles. Generally, in ferrite, when the particle size is several tens of nanometers or more, hysteresis loss dominates heat generation, but the particle size is lower than this. In some cases, hysteresis loss is almost eliminated, and Brownian relaxation loss and Neel relaxation loss dominate. In view of this point, in the present invention, it is preferable to include ferrite fine particles having a particle diameter of 10 to 25 nm in order to achieve high heat generation efficiency.

本発明の磁気温熱療法用発熱体は、フェライト微粒子をアルギン酸ゲル中に保持する構成を採用しているが、アルギン酸ゲル粒子の内部はある程度の流動性を備えていることが予想され、フェライト微粒子のブラウン緩和の寄与による発熱を期待することができる。しかしながら、ゲル内でフェライト微粒子が凝集していたのでは、ブラウン緩和に基づく発熱効果が期待できない。この点に鑑み、本発明においては、フェライト微粒子をクエン酸で表面修飾した後にアルギン酸塩水溶液に分散させることが好ましい。このようにすれば、フェライト微粒子を高分散状態に維持したまま、アルギン酸ゲル内に内包することができ、ブラウン緩和の寄与を期待することができる。   The heating element for magnetic thermotherapy of the present invention employs a configuration in which the ferrite fine particles are held in the alginate gel, but the inside of the alginate gel particles is expected to have a certain degree of fluidity, Heat generation due to Brownian relaxation can be expected. However, if the ferrite fine particles are aggregated in the gel, a heat generation effect based on Brownian relaxation cannot be expected. In view of this point, in the present invention, it is preferable to disperse ferrite fine particles in an aqueous alginate solution after surface modification with citric acid. In this way, the ferrite fine particles can be encapsulated in the alginic acid gel while maintaining a highly dispersed state, and the contribution of Brownian relaxation can be expected.

一方、アルギン酸ゲル粒子内のゲル化の度合いよっては、フェライト微粒子のブラウン運動(力学的遥道)が制限されることもあり得る。このような場合、発熱においては、ブラウン緩和よりもネール緩和の寄与が支配的になることが予想される。この点につき、本発明者らは、フェライト微粒子の粒径(結晶子径)と発熱効率の相関について検証を重ねた。その結果、フェライト微粒子について、ネール緩和(結晶中における磁気モーメントの回転)に基づく発熱の効率が最大となる最適粒径範囲を見出した。すなわち、本発明の磁気温熱療法用発熱体においては、包含させるフェライト微粒子の粒径を、10〜18nmとすることが好ましく、11〜15nmとすることがより好ましい。本発明においては、包含させるフェライト微粒子について上記粒径を採用することによって、仮に、アルギン酸ゲル粒子の内部でゲルが高粘度化し、フェライト微粒子のブラウン運動が制限されるような状態であっても、フェライト微粒子のネール緩和に基づいて高い発熱効率を実現することができる。   On the other hand, depending on the degree of gelation in the alginate gel particles, the Brownian motion (mechanical travel) of the ferrite fine particles may be limited. In such a case, it is expected that the contribution of Nail relaxation becomes more dominant in heat generation than Brownian relaxation. In this regard, the present inventors have repeatedly verified the correlation between the particle diameter (crystallite diameter) of the ferrite fine particles and the heat generation efficiency. As a result, the optimum particle size range in which the heat generation efficiency based on Neel relaxation (rotation of the magnetic moment in the crystal) is maximized was found for the ferrite fine particles. That is, in the heating element for magnetic thermotherapy of the present invention, the particle diameter of the ferrite fine particles to be included is preferably 10 to 18 nm, and more preferably 11 to 15 nm. In the present invention, by adopting the above particle size for the ferrite fine particles to be included, even if the gel is highly viscous inside the alginic acid gel particles, and the Brownian motion of the ferrite fine particles is limited, High heat generation efficiency can be realized based on the relaxation of the nails of the ferrite fine particles.

以下、本発明の磁気温熱療法用発熱体について、実施例を用いてより具体的に説明を行なうが、本発明は、後述する実施例に限定されるものではない。   Hereinafter, the heating element for magnetic thermotherapy of the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples described later.

(1)フェライトナノ粒子の作製
作製条件を変えることによって、異なる結晶子径dを有するフェライトナノ粒子を作製し、それぞれの発熱特性を検証した。以下、その具体的な手順を示す。
(1) Production of ferrite nanoparticles Ferrite nanoparticles having different crystallite diameters d were produced by changing the production conditions, and the respective heat generation characteristics were verified. The specific procedure is shown below.

(共沈法)
ビーカに取った純水(80 ml)にFeCl2・4H2O(0.3976 g) および FeCl3・6H2O(1.0812g)を加え、攪拌して完全に溶かしておき、この溶液に対し、純水32 mlにNaOH(5M)を8 ml添加してなる溶液を加えて30分攪拌した。その後、磁洗により回収したフェライトナノ粒子に純水を加えて25mlとした(フェライト濃度:18.4 mg/ml)。これを以下、フェライトナノ粒子(No.1)として参照する。
(Coprecipitation method)
Add FeCl 2 · 4H 2 O (0.3976 g) and FeCl 3 · 6H 2 O (1.0812 g) to pure water (80 ml) in a beaker and stir completely to dissolve. A solution obtained by adding 8 ml of NaOH (5M) to 32 ml of water was added and stirred for 30 minutes. Thereafter, pure water was added to the ferrite nanoparticles collected by magnetic washing to make 25 ml (ferrite concentration: 18.4 mg / ml). Hereinafter, this is referred to as ferrite nanoparticles (No. 1).

(部分酸化法)
ビーカに取った純水(21 ml)に対し、28 %アンモニア水溶液(15 ml)を加えてA液とし、ビーカに取った純水(36 ml)に、FeCl2・4H2O(0.3578g) および FeCl3・6H2O(0.4865 g)を加え、攪拌して完全に溶かしてB液とした。A液およびB液を5ml/minの速度でビーカに取った純水(72 ml)に攪拌(500 rpm)しながら滴下し、さらに30分攪拌した。その後、磁洗により回収したフェライトナノ粒子に純水を加えて15mlとした(フェライト濃度:18.4 mg/ml)。これを以下、フェライトナノ粒子(No.2)として参照する。
(Partial oxidation method)
Add 28% aqueous ammonia solution (15 ml) to pure water (21 ml) taken in a beaker to make solution A, add pure water (36 ml) taken in a beaker to FeCl 2 / 4H 2 O (0.3578 g) And FeCl 3 .6H 2 O (0.4865 g) were added, and the mixture was stirred and completely dissolved to obtain a solution B. Liquid A and liquid B were added dropwise to pure water (72 ml) taken in a beaker at a rate of 5 ml / min while stirring (500 rpm), and further stirred for 30 minutes. Thereafter, pure water was added to the ferrite nanoparticles collected by magnetic washing to make 15 ml (ferrite concentration: 18.4 mg / ml). Hereinafter, this is referred to as ferrite nanoparticles (No. 2).

(錯体沈澱法)
オートクレーブ用50 ml容器に取った純水(15 ml)にFeCl2・4H2O(0.3976 g) および FeCl3・6H2O(1.0812g)を加え、攪拌して完全に溶かしてA液とし、ビーカに取った純水(15 ml)にオレイン酸ナトリウム(C17H33COONa)を0.05327 g加え、攪拌して完全に溶かしてB液とした。A液にB液(15ml)を加え、5秒ほど攪拌した後、さらに、28%アンモニア水溶液(NH3・H2O)を4.5 mlを加えてC液とした。
(Complex precipitation method)
Add pure FeCl 2・ 4H 2 O (0.3976 g) and FeCl 3・ 6H 2 O (1.0812 g) to pure water (15 ml) in a 50 ml container for autoclave, stir to dissolve completely to make liquid A, 0.05327 g of sodium oleate (C17H33COONa) was added to pure water (15 ml) taken in a beaker, and the mixture was stirred to dissolve completely to obtain solution B. Liquid B was added to liquid A and stirred for about 5 seconds. Further, 4.5 ml of 28% aqueous ammonia (NH 3 .H 2 O) was added to prepare liquid C.

C液を室温で30分攪拌した後、磁洗をして溶媒を排除したものに対し、NaOH(5M)を少々加え、再度磁洗をして溶媒を排除し、さらに、純水、アセトン洗浄を行なった。最後に磁洗により回収したフェライトナノ粒子に純水を加えて25mlとした(フェライト濃度:18.4 mg/ml)。これを以下、フェライトナノ粒子(No.3)として参照する。   After stirring the liquid C for 30 minutes at room temperature, the solvent was removed by magnetic washing, a little NaOH (5M) was added, and the solvent was removed by magnetic washing again, followed by washing with pure water and acetone. Was done. Finally, pure water was added to the ferrite nanoparticles collected by magnetic washing to make 25 ml (ferrite concentration: 18.4 mg / ml). Hereinafter, this is referred to as ferrite nanoparticles (No. 3).

さらに上述したC液を5つの容器に用意し、各容器に蓋をして、ステンレスオートクレーブで密封した。各C液について異なる温度T °C (T = 100,125, 150, 200, 230) の炉に3時間保持した。それぞれについて自然冷却した後、磁洗をして溶媒を排除したものに対し、NaOH(5M)を少々加え、再度磁洗をして溶媒を排除し、さらに、純水、アセトン洗浄を行なった。最後に磁洗により回収したフェライトナノ粒子に純水を加えて25mlとした(フェライト濃度:18.4 mg/ml)。以下、保持温度100℃で作製したものをフェライトナノ粒子(No.4)、保持温度125℃で作製したものをフェライトナノ粒子(No.5)、保持温度150℃で作製したものをフェライトナノ粒子(No.6)、保持温度200℃で作製したものをフェライトナノ粒子(No.7)、保持温度230℃で作製したものをフェライトナノ粒子(No.8)、として参照する。   Furthermore, the above-mentioned C liquid was prepared in five containers, each container was covered and sealed with a stainless steel autoclave. Each liquid C was held in a furnace at a different temperature T ° C (T = 100, 125, 150, 200, 230) for 3 hours. Each was naturally cooled, then magnetically washed to remove the solvent, a little NaOH (5M) was added, the magnetic washing was carried out again to remove the solvent, and pure water and acetone were further washed. Finally, pure water was added to the ferrite nanoparticles collected by magnetic washing to make 25 ml (ferrite concentration: 18.4 mg / ml). Hereinafter, ferrite nanoparticles (No. 4) produced at a holding temperature of 100 ° C., ferrite nanoparticles (No. 5) produced at a holding temperature of 125 ° C., ferrite nanoparticles produced at a holding temperature of 150 ° C. (No. 6), those prepared at a holding temperature of 200 ° C. are referred to as ferrite nanoparticles (No. 7), and those prepared at a holding temperature of 230 ° C. are referred to as ferrite nanoparticles (No. 8).

(2)フェライトナノ粒子の発熱特性評価
上述した手順で作製したフェライトナノ粒子(No.1〜No.8)について、XRDおよびDLSによる測定を行なうと共に、以下の手順で2種類の発熱特性評価用サンプルを作製し、それぞれの発熱特性を評価した。
(2) Evaluation of heat generation characteristics of ferrite nanoparticles For ferrite nanoparticles (No. 1 to No. 8) prepared by the above procedure, XRD and DLS are used for measurement, and the following procedures are used to evaluate two types of heat generation characteristics. Samples were prepared and their heat generation characteristics were evaluated.

(発熱特性評価実験)
まず、作製したフェライトナノ粒子(No.1〜No.8)の水分散液に超音波処理を90分施した後、当該水分散液をプラスチック容器に1.5mlを取り、これに純水1.5 mlを加えて、発熱特性評価用サンプルA(フェライトナノ粒子を水に分散した試料)とした(フェライト濃度:9.2 mg/ml)。
(Heat generation characteristic evaluation experiment)
First, ultrasonic treatment was performed for 90 minutes on the aqueous dispersion of the prepared ferrite nanoparticles (No. 1 to No. 8), then 1.5 ml of the aqueous dispersion was taken into a plastic container, and 1.5 ml of pure water was added to this. To make a sample A for heat generation characteristics evaluation (a sample in which ferrite nanoparticles were dispersed in water) (ferrite concentration: 9.2 mg / ml).

一方、作製したフェライトナノ粒子(No.1〜No.8)の水分散液をプラスチック容器に1.5 mlを取り、これに対して、ビーカーに取った純水(20 ml)に粉寒天0.200gを加え湯煎して完全に溶かしたもの(以下、寒天溶液という)を1.5 ml加えて固め、発熱特性評価用サンプルB(フェライトナノ粒子を寒天中に分散して固定した試料)とした(フェライト濃度:9.2mg/ml)。   Meanwhile, 1.5 ml of the aqueous dispersion of the prepared ferrite nanoparticles (No. 1 to No. 8) is taken in a plastic container, and 0.200 g of powdered agar is added to pure water (20 ml) taken in a beaker. Add 1.5 ml of a solution that has been completely melted in a hot water bath (hereinafter referred to as an agar solution) and harden to obtain a sample B for exothermic property evaluation (a sample in which ferrite nanoparticles are dispersed and fixed in agar) (ferrite concentration: 9.2mg / ml).

図2は、本実施例で使用した発熱評価用実験装置30を示す。図2に示すように、発熱特性評価用サンプル32が入ったプラスチック容器34を発砲スチロール35で覆ったものをコイル36(長さ150mm:/直径:70mm)内に静置して磁界を印加すると共に、光ファイバー温度計38によってサンプルの温度を測定した。なお、光ファイバー温度計38のプローブはサンプルの中心に位置決めして差し込み、印加する交流磁界の周波数は120
kHz、磁界強度は112 Oeで固定した。
FIG. 2 shows a heat generation evaluation experimental apparatus 30 used in this example. As shown in FIG. 2, a plastic container 34 containing a heat generation characteristic evaluation sample 32 covered with a foamed polystyrene 35 is left in a coil 36 (length 150 mm: / diameter: 70 mm) and a magnetic field is applied. At the same time, the temperature of the sample was measured by an optical fiber thermometer 38. The probe of the optical fiber thermometer 38 is positioned and inserted in the center of the sample, and the frequency of the alternating magnetic field applied is 120.
kHz and magnetic field strength were fixed at 112 Oe.

(発熱特性評価)
作製したサンプルの発熱特性の評価を行なうにあたり、まず、フェライトナノ粒子の粒径を特定した。なお、粒径が20nm以下のフェライト微粒子は単結晶であることが推定されることから、各サンプルについてのXRD測定の結果から結晶子径を算出し、これをもって各フェライトナノ粒子の粒径と見なした。図3(a)および図3(b)は、それぞれ、フェライトナノ粒子(No.1〜No.2)およびフェライトナノ粒子(No.3〜No.8)のXRD測定の結果を示す。図3(a)、(b)に示したXRD測定の結果に基づいて、Debye-Scherrerの式よりフェライトナノ粒子(No.1〜No.8)の結晶子径dを算出した。算出したフェライトナノ粒子(No.1〜No.8)の結晶子径dを下記表1に示す。
(Evaluation of heat generation characteristics)
In evaluating the heat generation characteristics of the prepared sample, first, the particle diameter of the ferrite nanoparticles was specified. Since it is estimated that ferrite fine particles having a particle size of 20 nm or less are single crystals, the crystallite size is calculated from the results of XRD measurement for each sample, and this is regarded as the particle size of each ferrite nanoparticle. I did it. 3 (a) and 3 (b) show the results of XRD measurement of ferrite nanoparticles (No. 1 to No. 2) and ferrite nanoparticles (No. 3 to No. 8), respectively. Based on the XRD measurement results shown in FIGS. 3A and 3B, the crystallite diameter d of the ferrite nanoparticles (No. 1 to No. 8) was calculated from the Debye-Scherrer equation. The calculated crystallite diameters d of the ferrite nanoparticles (No. 1 to No. 8) are shown in Table 1 below.

図4(a)〜(h)は、それぞれ、フェライトナノ粒子(No.1〜No.8)を含む発熱特性評価用サンプルの室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図である。なお、図4(a)〜(h)中、実線(Water)は発熱特性評価用サンプルAについての結果を示し、破線(Agar)は発熱特性評価用サンプルBについての結果を示す。   4 (a) to (h) show the relationship between the temperature rise from room temperature (° C.) and the magnetic field application time (min), respectively, of the sample for evaluating heat generation characteristics including ferrite nanoparticles (No. 1 to No. 8). FIG. In FIGS. 4A to 4H, the solid line (Water) indicates the results for the sample A for heat generation characteristics evaluation, and the broken line (Agar) indicates the results for the sample B for heat generation characteristics evaluation.

図4(a)〜(h)に示されるように、フェライトナノ粒子(No.1〜No.8)による温度上昇は、いずれも水に分散させたサンプルの方が寒天で固めたサンプルよりも大きかった。これは、フェライトナノ粒子が寒天で固定されるサンプルにおいては、ブラウン緩和が発熱に寄与していないためだと考えられる。   As shown in FIGS. 4 (a) to (h), the temperature increase due to the ferrite nanoparticles (No. 1 to No. 8) is higher in the sample dispersed in water than in the sample hardened with agar. It was big. This is probably because Brownian relaxation does not contribute to heat generation in the sample in which ferrite nanoparticles are fixed with agar.

また、図5は、フェライトナノ粒子(No.1〜No.8)の結晶子径d(nm)と磁界印加時間(min)毎の室温からの上昇温度(℃)との関係を示した図であり、図5(a)は、発熱特性評価用サンプルAについての結果を示し、図5(b)は、発熱特性評価用サンプルBについての結果を示す。図5(a)と図5(b)を対比するとわかるように、結晶子径dが11nm 〜 15 nm の範囲にあるフェライトナノ粒子は、水に分散した状態(発熱特性評価用サンプルA)および寒天中に固定された状態(発熱特性評価用サンプルB)のいずれにおいても大きな温度上昇を示し、フェライトナノ粒子(No.5:結晶子径d=13.5nm)を含んだサンプルにおいて最も大きい温度変化が見られた。   FIG. 5 shows the relationship between the crystallite diameter d (nm) of the ferrite nanoparticles (No. 1 to No. 8) and the temperature rise (° C.) from room temperature for each magnetic field application time (min). FIG. 5A shows the result of the heat generation characteristic evaluation sample A, and FIG. 5B shows the result of the heat generation characteristic evaluation sample B. As can be seen by comparing FIG. 5 (a) and FIG. 5 (b), the ferrite nanoparticles having a crystallite diameter d in the range of 11 nm to 15 nm are dispersed in water (sample A for heat generation characteristic evaluation) and A large temperature increase was observed in any of the samples fixed in the agar (exothermic property evaluation sample B), and the largest temperature change was observed in the sample containing ferrite nanoparticles (No. 5: crystallite diameter d = 13.5 nm). It was observed.

(3)磁気温熱療法用発熱体の作製
上述した発熱特性評価実験の結果を受け、最も大きい温度変化が見られたフェライトナノ粒子(No.5:結晶子径d=13.5 nm)を使用して本実施例の磁気温熱療法用発熱体を以下の手順で作製した。
(3) Production of heating element for magnetic thermotherapy Using ferrite nanoparticles (No. 5: crystallite diameter d = 13.5 nm) that showed the largest temperature change in response to the results of the exothermic characteristics evaluation experiment described above. A heating element for magnetic thermotherapy of this example was produced by the following procedure.

ビーカに取ったフェライトナノ粒子(No.5:結晶子径d=13.5 nm)に純水を加えて14 mlとし、これに2.0 wt%アルギン酸ナトリウム水溶液を5 ml加え、攪拌して均一にした上で、HCl水溶液を適量加えてpHを7.02±0.02の範囲に調製した。最後に純水を加えて全量を20mlとした(フェライト濃度:46 mg/ml)。上述した手順でフェライトナノ粒子を分散させたアルギン酸ナトリウム水溶液(以下、フェライトナノ粒子分散液として参照する)に対してホーン型超音波装置を用いて10分間超音波処理を行なった後、これをインクジェット用母液容器に移してインクジェット装置(ピエゾ式ノズル:φ= 60 μm)にセットした。   Add pure water to ferrite nanoparticles (No. 5: crystallite diameter d = 13.5 nm) in a beaker to make 14 ml, add 5 ml of 2.0 wt% sodium alginate aqueous solution, and stir to homogenize. Then, an appropriate amount of aqueous HCl solution was added to adjust the pH to a range of 7.02 ± 0.02. Finally, pure water was added to make a total volume of 20 ml (ferrite concentration: 46 mg / ml). The sodium alginate aqueous solution (hereinafter referred to as ferrite nanoparticle dispersion) in which ferrite nanoparticles are dispersed by the above-described procedure is subjected to ultrasonic treatment for 10 minutes using a horn type ultrasonic device, and then this is ink-jetted. The product was transferred to a mother liquor container and set in an ink jet apparatus (piezo type nozzle: φ = 60 μm).

その後、予めビーカーに取っておいた、10 wt%塩化カルシウム水溶液(25 ml)に対してインクジェット装置からフェライトナノ粒子分散液を吐出した(500000個)。最後に純水で磁気洗浄を5回行なって、本実施例の磁気温熱療法用発熱体を得た。図6は、磁気温熱療法用発熱体のレーザ顕微鏡像を示す。図6に示されるように、得られた磁気温熱療法用発熱体の形状はほぼ球状であり、その粒径は50〜60nm であった。   Thereafter, the ferrite nanoparticle dispersion was discharged from the ink jet apparatus to the 10 wt% calcium chloride aqueous solution (25 ml) previously stored in the beaker (500,000 pieces). Finally, magnetic washing with pure water was performed 5 times to obtain a heating element for magnetic thermotherapy of this example. FIG. 6 shows a laser microscope image of a heating element for magnetic thermotherapy. As shown in FIG. 6, the shape of the obtained heating element for magnetic thermotherapy was almost spherical, and its particle size was 50-60 nm.

(4)磁気温熱療法用発熱体の発熱効果の検証
プラスチック容器に寒天溶液(1.5 ml)を加えて固めた後、その上に上述した手順で作製した磁気温熱療法用発熱体(500000個)を移し、さらにその上から寒天溶液(1.5ml)を加えて固め、発熱効果検証用サンプルとした。これを図2に示したのと同様の態様でコイル内に静置して磁界を印加すると共に、光ファイバー温度計によってサンプルの温度を測定した。なお、印加する交流磁界の周波数は120kHz、磁界強度は112 Oeで固定した。
(4) Verification of heat generation effect of heating element for magnetic thermotherapy After agar solution (1.5 ml) was added to a plastic container and hardened, the heating element for magnetic thermotherapy (500,000 pieces) prepared according to the procedure described above was added to it. Further, an agar solution (1.5 ml) was added and hardened from above, and a sample for verifying the exothermic effect was obtained. This was left in the coil in the same manner as shown in FIG. 2 to apply a magnetic field, and the temperature of the sample was measured with an optical fiber thermometer. The frequency of the AC magnetic field to be applied was fixed at 120 kHz and the magnetic field strength was 112 Oe.

図7は、発熱効果検証用サンプルの室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図である。図7に示されるように、本実施例の磁気温熱療法用発熱体が導入された寒天において、磁界を20分間印加した結果、11.6 °Cの温度上昇が確認された。   FIG. 7 is a diagram showing the relationship between the temperature rise from room temperature (° C.) and the magnetic field application time (min) of the heat generation effect verification sample. As shown in FIG. 7, a temperature increase of 11.6 ° C. was confirmed as a result of applying a magnetic field for 20 minutes in the agar in which the heating element for magnetic thermotherapy of this example was introduced.

(5)アルギン酸ゲル被覆がフェライトナノ粒子の発熱に与える影響の検証
アルギン酸ゲルで被覆したフェライトナノ粒子と非被覆のフェライトナノ粒子単体の発熱特性を以下の手順で比較した。まず、部分酸化法によってフェライトナノ粒子を作製した。作製したフェライトナノ粒子のTEM画像を解析した結果、その平均粒径は約19nmであった。作製したフェライトナノ粒子に対し、クエン酸三ナトリウムとクエン酸を添加して撹拌し、粒子表面をクエン酸によって被覆した。クエン酸被覆の前後でフェライトナノ粒子の水懸濁液について、粒径の重量換算分布の測定を行なったところ、クエン酸被覆前には4000nm前後にあった粒径分布が、クエン酸被覆後には30nm前後に粒径分布が観察され、フェライトナノ粒子の分散性が向上していることが確認できた。
(5) Verification of effect of alginate gel coating on heat generation of ferrite nanoparticles The heat generation characteristics of ferrite nanoparticles coated with alginate gel and uncoated ferrite nanoparticles alone were compared by the following procedure. First, ferrite nanoparticles were prepared by a partial oxidation method. As a result of analyzing the TEM image of the produced ferrite nanoparticles, the average particle size was about 19 nm. To the prepared ferrite nanoparticles, trisodium citrate and citric acid were added and stirred to coat the particle surface with citric acid. For the aqueous suspension of ferrite nanoparticles before and after the citric acid coating, the weight conversion distribution of the particle size was measured, and the particle size distribution that was around 4000 nm before the citric acid coating was A particle size distribution was observed around 30 nm, and it was confirmed that the dispersibility of the ferrite nanoparticles was improved.

上述したフェライトナノ粒子(クエン酸被覆)の水懸濁液に2.0 wt%アルギン酸ナトリウム水溶液を加えて攪拌した後、噴霧器にセットした。容器に入った10 wt%塩化カルシウム水溶液(30 cm×35cm×2 cm)に対し、液面上50 cmの高さからフェライトナノ粒子−アルギン酸ナトリウム分散液を噴霧した後(Nガス:15L/min,0.2Mpa)、容器内に形成されたアルギン酸ゲル粒子を45μmと212μmのふるいにかけて分級した。分級したアルギン酸ゲル粒子の顕微鏡画像を解析した結果、その平均粒径は約80μmであった。 A 2.0 wt% aqueous sodium alginate solution was added to the aqueous suspension of ferrite nanoparticles (citrate-coated) described above and stirred, and then set in a sprayer. To 10 wt% calcium chloride solution in a container (30 cm × 35cm × 2 cm ), ferrite nanoparticles from the liquid level on the 50 cm - after spraying sodium alginate dispersion (N 2 gas: 15L / min, 0.2 Mpa), and the alginate gel particles formed in the container were classified through 45 μm and 212 μm sieves. As a result of analyzing the microscopic image of the classified alginate gel particles, the average particle size was about 80 μm.

上述した手順で作製したアルギン酸ゲル粒子を水に分散させたものをサンプルXとし、先に作製した非被覆のフェライトナノ粒子を水に分散させたものをサンプルYとした。なお、両サンプルは、その鉄濃度がいずれも10.5mgFe/mlとなるように調製した。調製した両サンプルについて、図2に示したのと同様の装置を使って交流磁界を印加した。なお、印加する交流磁界の周波数は900kHz、磁界強度は45 Oeで固定した。   Sample X was prepared by dispersing alginic acid gel particles prepared in the above-described procedure in water, and sample Y was prepared by dispersing previously prepared uncoated ferrite nanoparticles in water. Both samples were prepared so that the iron concentration was 10.5 mgFe / ml. An alternating magnetic field was applied to both of the prepared samples using the same apparatus as shown in FIG. The frequency of the AC magnetic field to be applied was fixed at 900 kHz, and the magnetic field strength was fixed at 45 Oe.

図8は、上記両サンプルの室温からの上昇温度(℃)と磁界印加時間(min)の関係を示した図である。図8に示されるように、アルギン酸ゲルで被覆したフェライトナノ粒子のサンプルXは、非被覆のフェライトナノ粒子のサンプルYとほぼ同様の温度上昇カーブを描いており、フェライトナノ粒子の発熱特性は、アルギン酸ゲルの被覆によって大きく損なわれないことが示された。特に、実際の適用において目標とされる上昇温度7℃に至るまでに関しては、アルギン酸ゲルで被覆したフェライトナノ粒子は、非被覆のフェライトナノ粒子と全く遜色のない発熱特性を示し、わずか1分で目標温度に達成した。   FIG. 8 is a graph showing the relationship between the temperature rise from room temperature (° C.) and the magnetic field application time (min) for both samples. As shown in FIG. 8, sample X of ferrite nanoparticles coated with alginate gel has a temperature rise curve similar to that of sample Y of uncoated ferrite nanoparticles, and the exothermic characteristics of ferrite nanoparticles are It was shown that the coating with alginate gel was not significantly impaired. In particular, up to 7 ° C., which is the target temperature in practical applications, the ferrite nanoparticles coated with alginate gel show exothermic properties that are completely comparable to uncoated ferrite nanoparticles, in just 1 minute. The target temperature has been reached.

上述した実施例より、本発明の磁気温熱療法用発熱体が温熱療法に適用するのに十分な発熱効果を発揮することが示された。また、本発明の磁気温熱療法用発熱体は、高い発熱効率を有することが示された。よって、本発明の磁気温熱療法用発熱体によれば、最低限の投入量で高い加温効果が期待でき、患者の負担を軽減することが可能になる。   From the Example mentioned above, it was shown that the heat generating body for magnetic thermotherapy of this invention exhibits sufficient exothermic effect to apply to thermotherapy. Moreover, it was shown that the heating element for magnetic thermotherapy of the present invention has high heat generation efficiency. Therefore, according to the heating element for magnetic thermotherapy of the present invention, a high heating effect can be expected with a minimum input amount, and the burden on the patient can be reduced.

以上、説明したように、本発明によれば、高い生体適合性と生体内分解性に加えて高い発熱効率を備え、その用途に応じて粒径を自在に制御でき、且つ、低廉な製造コストで簡便に製造することができる新規な磁気温熱療法用発熱体が提供される。本発明の磁気温熱療法用発熱体を臨床に適用することによって、患者のQOLを損なうことのない、新しい癌の治療方法が確立されることを期待する。   As described above, according to the present invention, in addition to high biocompatibility and biodegradability, it has high heat generation efficiency, the particle size can be freely controlled according to its use, and the manufacturing cost is low. Thus, a novel heating element for magnetic thermotherapy that can be easily manufactured is provided. It is expected that a new cancer treatment method that does not impair the patient's QOL will be established by applying the heating element for magnetic thermotherapy of the present invention to the clinic.

10…フェライト微粒子分散液、12…多価金属塩水溶液、14…アルギン酸ゲル粒子、16…フェライト微粒子、20…磁気温熱療法用発熱体、30…発熱評価用実験装置、32…発熱特性評価用サンプル、34…プラスチック容器、35…発砲スチロール、36…コイル、38…光ファイバー温度計 DESCRIPTION OF SYMBOLS 10 ... Ferrite fine particle dispersion, 12 ... Polyvalent metal salt aqueous solution, 14 ... Alginate gel particle, 16 ... Ferrite fine particle, 20 ... Heat generating body for magnetic thermotherapy, 30 ... Experimental apparatus for exothermic evaluation, 32 ... Sample for exothermic property evaluation 34 ... Plastic container, 35 ... Styrofoam, 36 ... Coil, 38 ... Optical fiber thermometer

Claims (8)

フェライト微粒子を包含するアルギン酸ゲル粒子として構成される磁気温熱療法用発熱体。   A heating element for magnetic thermotherapy configured as alginate gel particles including ferrite fine particles. 前記フェライト微粒子の粒径が10〜25nmである、請求項1に記載の磁気温熱療法用発熱体。   The heating element for magnetic thermotherapy according to claim 1, wherein the ferrite fine particles have a particle size of 10 to 25 nm. アルギン酸塩水溶液にフェライト微粒子を分散させてフェライト微粒子分散液を調製する工程と、
前記フェライト微粒子分散液の微細液滴を多価金属塩水溶液に対して導入し、該微細液滴をゲル化する工程とを含む、
磁気温熱療法用発熱体の製造方法。
A step of preparing a ferrite fine particle dispersion by dispersing ferrite fine particles in an alginate aqueous solution;
Introducing the fine droplets of the ferrite fine particle dispersion into the polyvalent metal salt aqueous solution, and gelling the fine droplets.
A method for producing a heating element for magnetic thermotherapy.
分散させる前記フェライト微粒子はクエン酸被覆されたものである、請求項3に記載の製造方法。   The manufacturing method according to claim 3, wherein the ferrite fine particles to be dispersed are coated with citric acid. 前記フェライト微粒子の粒径が10〜25nmである、請求項3または4に記載の製造方法。   The manufacturing method of Claim 3 or 4 whose particle diameter of the said ferrite fine particle is 10-25 nm. インクジェットノズルによって前記微細液滴の大きさを制御して導入する、請求項3〜5のいずれか1項に記載の製造方法。   The manufacturing method according to claim 3, wherein the size of the fine droplets is controlled by an inkjet nozzle. 前記フェライト微粒子分散液を噴霧することによって、前記微細液滴を前記多価金属塩水溶液に対して導入する、請求項3〜5のいずれか1項に記載の製造方法。   The manufacturing method according to claim 3, wherein the fine droplets are introduced into the aqueous polyvalent metal salt solution by spraying the ferrite fine particle dispersion. 前記アルギン酸塩水溶液は、アルギン酸ナトリウム水溶液であり、前記多価金属塩水溶液は、塩化カルシウム水溶液である、請求項3〜7のいずれか1項に記載の製造方法。   The manufacturing method according to claim 3, wherein the alginate aqueous solution is a sodium alginate aqueous solution, and the polyvalent metal salt aqueous solution is a calcium chloride aqueous solution.
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