BR102018016342A2 - PROCESS OF OBTAINING BIOACTIVE AND MAGNETOCALORIC COMPOSITES FOR THE TREATMENT OF TUMORS BY HYPERTERMIA AND PRODUCT OBTAINED - Google Patents

Abstract

process of obtaining a bioactive and magnetocaloric composite for the treatment of tumors by hyperthermia and the product obtained refers to the process of obtaining a bioactive and magnetocaloric composite for the treatment of tumors by hyperthermia (fig.1), which combines simple processing steps as fusion (e1) of the precursor glasses (1 and 2), grinding (e4), addition (e5) of magnetite (3) and sintering (e5) of the tablets (6) to obtain the magnetocaloric composite (c); which combines established biological properties of bioactive glasses with magnetite properties already consolidated for the hyperthermia technique. the bioactive and magnetocaloric composite (c) has the ability to achieve the necessary thermal response to the ht technique, raising the temperature of the medium in the range of 5 to 15 ° c when exposed to an external field, in addition to the magnetostrictive effect, which allows the generation of mechanical stimuli to the surrounding tissue after implantation. the combination of the bioactive properties of f18 glass (2) or biosilicate (1) and magnetite (3) makes the composite (c) a promising material in the treatment of cancer, especially bone cancer, using the hyperthermia technique by magnetic induction.

Description

PROCESS OF OBTAINING BIOACTIVE AND MAGNETOCALORIC COMPOSITES FOR THE TREATMENT OF TUMORS BY HYPERTERMIA AND PRODUCT OBTAINED BRIEF DESCRIPTION [001] This is the present patent application for an unprecedented “PROCESS OF OBTAINING BIOACTIVE COMPOSITES AND MAGNETOCALORIC THERAPY FOR THE TREATMENT OF HYPERTRAINING THERAPY FOR THE TREATMENT OF HYPERTRAINING THERAPY. E PRODUCT OBTAINED ”which refers to the production process of a biocomposite obtained through the encapsulation of magnetite particles by a glassy matrix, composed of bioactive glass F18 (developed at the Vitreous Materials Laboratory (LaMaV) being the subject of patent application BR 10 2013 020961 9 A2) or by biosilicate (developed at the Vitreous Materials Laboratory (LaMaV) being the subject of patent application WO2004074199A1) giving rise to a bioactive and magnetocaloric material, with a single magnetic phase, for application in hyperthermia processes (HT ) for the treatment of tumors and related diseases.

FIELD OF APPLICATION [002] The present invention belongs to the human needs section, to the medical science sector; more specifically in the field of magnetotherapy, as it describes a process for obtaining a bioactive and magnetocaloric composite to be used in the treatment of tumors by hyperthermia.

CONVENTION [003] Cancer is one of the most dominant and dramatic diseases today, therefore, it is one of the areas of greatest attention in bioengineering. Among the numerous challenges and possible treatments considered, one of the most relevant is the technique of hyperthermia with the development and use of magnetic particles, from various materials of various shapes and sizes, both for the treatment of the disease and for its diagnosis. This has stimulated the investigation of materials with mechanical, thermal and magnetic characteristics, which offer better solutions and responses during treatment, in addition to the search for less invasive methods (MOJICA, 2009 and CETIN & TOPCUL, 2012).

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2/25 [004] Cancer occurs with the development of a malignant tumor that derives from a renegade cell (ANDRAS. 2010). This cell has damaged DNA that cannot be repaired by the usual mechanisms of the system, growing out of control and leading to the development of a malignant tumor. Healthy, normal cells grow, divide and die, while cancer cells grow out of control and are not sensitive to growth inhibitors, preventing their apoptosis. In addition, they have unlimited replication potential, in addition to potentiating angiogenesis (formation of blood vessels) and dissemination (invasion) (BEHROUZKIA, 2016).

[005] Currently, the challenge is to develop a therapy that cures this potentially fatal disease without generating so many side effects. However, this is not yet a reality. There are three main therapies used in clinical practice: surgery, radiotherapy and chemotherapy (VAN DER ZEE, 2012). These therapies provide solutions that are not sufficiently selective, because they destroy not only cancer cells, but also healthy ones.

[006] For a cancer therapy to be successful, there must be a balance between toxic tolerance and the desirable destruction of cancer cells. The high toxicity of the drugs used and the imbalance between the available therapeutic options and their side effects lead to the investigation and development of alternative methods such as hyperthermia (HT) (VAN DER ZEE, 2012).

[007] Hyperthermia is ideal for the treatment of tumors, by increasing the temperature of the surrounding cells using an external heat source. With the increase in temperature in the tissue, the cancer cells die or are prevented from growing, and this method, at first, does not use chemical origin or presents severe toxicity (BAHADUR & GIRI, 2003).

[008] Disruption of normal organ functions is the main disadvantage of current cancer treatments, causing various levels of side effects.

[009] In this direction, the development of methods and materials for a less invasive treatment has been promoted, avoiding the destruction of healthy cells in large areas of the body. Among the materials used for hyperthermia, superparamagnetic and ferromagnetic nanoparticles stand out, however, currently glass and

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3/25 bioactive glass-ceramics have called attention to a potential use in HT because they are materials that, when in contact with bodily fluids, are able to form a layer of hydroxyapatite that binds chemically to the bone, in addition to stimulating the growth of a new tissue the regeneration of injuries.

[010] Hyperthermia (HT) is a type of cancer treatment, along with surgery, radiation therapy, chemotherapy, genotherapy and immunotherapy. In oncology, HT uses an external heat source to increase tissue temperature and kill cancer cells or prevent their growth (BAHADUR & GIRI, 2003). There are several types of treatment to fight cancer, your choice is based on several medical exams, taking into account several factors such as the type of cancer, the progress of the disease and the individual variability of the patient, in addition to the financial resources available (VAN DER ZEE, 2012).

[011] In HT, it is essential to establish a heat supply system, so that the tumor cells are heated or inactivated, while the surrounding (normal) region is not affected. As mentioned earlier, the current methods for achieving cell heating are: microwave, ultrasound and radiofrequency (CORNELL, 2000; LEENAKUL, et al. 2015; ARCOS, et al. 2002; ARCOS, et al. 2003). In the clinical application of hyperthermia, three methods can be distinguished: local, full-body and regional.

[012] Knowledge of the properties of the material plays a fundamental role in understanding the generation of heat and temperature distribution within the tissue through the application of magnetic induction hyperthermia (SERRANO, et al.

2008). For HT applications, the most commonly used materials are superparamagnetic and ferromagnetic particles obtained from magnetite and ferrites (CORNELL, 2000).

[013] When a magnetic material is subjected to an oscillating magnetic field, it can generate heat due to the loss of magnetic hysteresis and with its contact with the diseased tissue, this temperature variation is enough to destroy it (SERRANO, et al 2008 and KOTHIYAL, et al. 2009).

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4/25 [014] The synthesis of magnetic nanoparticles for HT using different techniques, such as micelles, co-precipitation and dispersion in matrices such as silica, alumina and polymers, has also attracted considerable research interest in recent years (ENIU, et al 2005 and RUIZ-HERNÁNDEZ, et al. 2006). These systems have been shown to be suitable for providing controllable particle size and morphology, as well as obtaining a narrow particle size distribution for nanoparticles (ABDEL-HAMEED, 2009).

[015] Currently, two classes of materials are of interest for localized hyperthermia using magnetic induction heating: ferromagnets and ferrites. The magnetic attributes of both materials are determined by a set of magnetic moments of interaction in a crystalline structure (KOTHIYAL, et al.

2009).

[016] The biological effects of magnetic microparticles, exposed to an alternating magnetic field, have been investigated in animal tumors (ENIU, et al. 2005).

[017] These studies show tumoricidal effects of magnetically heated particles with few side effects. However, the lack of consistency, and reproducibility of studies (or even scarcity of literature) of tumor models, modes of application, magnetic field excitation techniques and ferrimagnetic materials leave gaps and doubts about the clinical use of these materials. [018] Therefore, the potential of this heating technique has not been clearly defined so far. The heating efficiencies of different materials, the energy absorption mechanisms and the use of these materials still generate technical problems for HT therapy, such as the difficulty of uniformly heating the tumor region to the required temperature without damaging the surrounding normal tissue ( KOTHIYAL, et al. 2009 and ABDEL-HAMEED, et al. 2009), resulting in an unsuccessful treatment.

[019] The ideal response of a magnetic material to the external field for clinical applications in HT is the generation of sufficient heat at the lowest frequency and possible external magnetic field strength. This is due to the fact that eddy currents are induced in the patient's tissue by the external magnetic field, generating an undesirable nervous and muscular response (BRETCANU et al, 2016).

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5/25 [020] Successful implantation of magnetic material in a location on the body is also a challenge, because the immune system can consider the material as a foreign body and perform phagocytosis of these materials, removing them from the target location, thus decreasing the effectiveness of HT therapy (RAVAGNANI, 2003 and SOARES,

2010). Currently, two implantation routes have already been used: surgical implantation or injection (GLASWERKE, 1997 and PRADO & ZANOTTO, 2002).

[021] During HT therapy many aspects need to be considered, such as: the magnetic field applied to the patient, the loss of heat from the material and its particle size distribution, in order to minimize the mass of the magnetic material needed to a specific volume of the area to be treated (BARRERO, et al. 2001).

[022] Most magnetic materials of industrial interest are ferromagnetic.

[023] These materials can be categorized into two classes: soft and hard magnetic materials (ABDEL-HAMEED, 2009); this categorization will depend on its coercivity (SAMPAIO, et al. 2000), which is the intensity of the magnetic field to be applied to this material to reduce its magnetization to zero after it is magnetically saturated (SAMPAIO, et al. 2000).

[024] Other materials thought to assist in the treatment of HT are bioactive glasses and bio-glass-ceramics, which have demonstrated through numerous in vitro, in vivo and clinical studies, to be able to bind to the host's hard tissue and to increase the rate of formation of new bone tissue (ZANOTTO, et al. 2015 and HENCH, 2012). Bio-glass-ceramics appeared in medicine in 1980, with the objective of replacing bioactive glasses in applications that required greater mechanical resistance (VAHAK, 2015).

[025] Glass-ceramics have advantages compared to other materials, such as alloys, polymers or sintered ceramics (SAMPAIO, et al. 2000). Vitroceramics are very convenient for providing particle size and controllable morphology, as well as obtaining a narrow distribution of crystal sizes and achieving good biocompatibility (DA LI, et al. 2010 and LOTY, et al. 2001).

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6/25 [026] The doping of bioactive glass and glass ceramic with iron has been considered useful for the potential treatment of cancer via HT due to its magnetic properties (VAHAK, 2015). In principle, when they were implanted in tumors after surgical curettage, they developed heat under an oscillating magnetic field (mainly due to magnetic hysteresis and eddy current losses), destroying recurrent cancer cells. The generation of heat depends on the magnetic properties of the glass-ceramics, the parameters of the magnetic field (intensity and frequency) and the characteristics of the tissues (thermal conductivity, thermal capacity, local blood perfusion, etc.) (HENCH, 2010).

[027] The choice of magnetic material depends on its magnetic properties and its biocompatibility. The advantages that vitroceramics have over synthesized magnetic ceramic materials are less biological toxicity (HENCH, 2012). [028] In addition, the magnetic properties can, to a large extent, be changed continuously by the composition of the glass and heat treatment, thus making it easier to engineer the material to have a certain set of final properties (BRETCANU, et al. 2010).

[029] Several glass-ceramics used for hyperthermia are initially bioactive, however, the addition of Fe2Ü3 or other elements may interfere with this property, as reported in the study by Guang et al. (2009) for the glass ceramic developed in the CaO-P2O5-SiO2-MgO-CaF2-MnO2-Fe2O3 system, which showed a significant drop in the hydroxyapatite layer formation rate.

[030] Over the past few years, some bioactive / biocompatible glass ceramic systems have been explored for HT. Usually, using the incorporation of Fe2O3 in the base glass. However, increasing the content of this element decreases the rate of apatite formation in the SBF (Simulated Body Fluid) solution (HSI, et al. 2007). This is because the presence of Fe2O3 increases the chemical durability of glass and glass-ceramics, suppressing the dissolution of calcium, and thus inhibiting the formation of the HCA layer. Thus, the bioactivity of these materials is reduced (HSI, et al. 2007).

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7/25 [031] According to Guang et al. (2009), the addition of oxides decreases the bioactive behavior of the material. These authors developed a glass ceramic in the CaO-SiO2-P2O5-MgO-CaF2-Fe2O3 system that presented a magnetic behavior under the action of an alternating magnetic field of 10 KOe. This magnetic behavior was attributed to the addition of magnesium ferrite; however, this addition also led to a heterogeneous growth of the hydroxyapatite layer, showing the decrease in the bioactivity of the material. Corroborating these results, Verne et al. (2010) demonstrated that the iron ions in the SiO2Na2O-CaO-P2O5-FeO-Fe2O3 system cause a decrease in the material's bioactivity.

[032] The use of Fe2O3 even in small quantities also suppressed the reactions for the formation of apatite in the glass ceramic developed by Ebisawa et al. (1997), in the CaO-SiO2-Fe2O ₃ -Na2O-B2O ₃ -P2O5 system.

[033] There are also ferrimagnetic products that have magnetic and bioactive properties. Saqlain et al. (2010) developed a glass ceramic in the matrix ZnO-Fe2O ₃ SiO2-CaO-P2O5-Na2O, and the content of ferrimagnetic ZnFe2O4 was enough to achieve both properties. Even with the amount of Fe that was 3036% by weight, bioactivity was achieved due to Zn ions, as these are of great importance in reactions involving metabolism and the stimulation of bone formation. In addition, the heat generation increased as the ZnO content in the glass increased.

[034] A glass-ceramic developed by the sol-gel route in the Si2O-CaO-MgOP2O5-CaF2-Fe2O3 system also showed the formation of the hydroxyapatite layer in 7 days in SBF solution (DA LI, et al. 2010). However, in this manufacturing route, the segregation of non-magnetic precipitates in the material was mentioned, such as the hematite phase (a-Fe2O ₃ ) (ARCOS, et al. 2002) In the work of Arcos et al. (2003), the results point to a mechanism for diffusing iron ions during heat treatment. This fact leads to an increase in the paramagnetic fraction, decreasing the ferromagnetic. Contradictorily, Singh et al. (2010) developed a glass ceramic in the matrix MgO-CaO-SiO2-P2O5-CaF2-Fe2O3, which showed bioactivity in a test with SBF and magnetic hysteresis that would be convenient for

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8/25 to HT, containing 5-20% by weight of Fe2Ü3, which material is probably capable of binding to human bone. According to the results reported in this work, bioactivity increases when the iron content is increased, and the compositions with a higher iron oxide content provided the formation of higher amounts of bone mineral phases, as well as the magnetic phase.

[035] Another exception reported for the addition of Fe in glass-ceramics without a significant change in its bioactivity, was the glass-ceramics developed by Kothiyal et al. (2009) in the SiO2-P2O5-CaO-Fe2O3-ZnOMgO system. These with magnesium oxide or zinc oxide additives are biologically active and can be heated under the action of an alternating magnetic field, the heat generated being sufficient for the use of the material in the treatment of cancer by the hyperthermia technique. After three weeks of immersion in SBF, the results indicated the formation of hydroxyapatite suggesting a certain bioactivity of the materials. [036] An analogous result was reported in the glass ceramic developed by Leenakul et al. (2010), in which additions of barium ferrite at levels between 5 and 40% by weight in the glass matrix of the SiO2-CaO-Na2O-P2O5 system led to the obtaining of a material that had bioactivity and magnetic properties suitable for its use in therapy of cancer by hyperthermia. In contrast, Verne et al. (2010) observed that the glass ceramic of the SiO2-Na2O-CaO-P2O5-FeO-Fe2O3 system, presented a slower bioactivity kinetics with the addition of ferrite, where the material composition was calculated to have a content of 45% by weight of magnetite. Guangda et al. (2010) similar results were also reported, where the addition of Mg or Fe2O3 decreased the bioactivity of the material and prevented the growth of hydroxyapatite on the entire surface of the material.

[037] In vitro cell tests were performed by Serrano et al. (2008). These authors performed biocompatibility tests with fibroblasts from Wistar rats of the L929s strain, and observed good adherence, cell growth, morphology and viability of cultured cells on glass-ceramic samples of the SiO2P2O5-CaO-Fe2O3 system. However, changes in the oxygen transport activity of the

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9/25 cancer cells were not significant, which indicates that the interaction between L929s fibroblasts and glass ceramic did not induce cancer cell death. [038] Arcos et al (2002) developed a material using the SiO2-CaOFe2Ü3-Na2O system and observed that it was bioactive and magnetic. Through the bioactivity test in SBF, it was observed that an apatite layer was formed on the surface of the material after three days and, therefore, good bone integration is expected when this material is implanted. In addition, the presence of Fe in the ceramic phase provided magnetic properties to the material, however, in the same study it was found that the sol-gel method used produced the segregation of a non-ferromagnetic phase. This caused the material to show a decrease in the saturation magnetization. Continuing the studies, Arcos, et al. (ARCOS, et al. 2003) developed glasses in the SiO2-P2O5-CaO systems by the sol-gel method, and SiO2CaO-Fe2O3 by the melting method, both were mixed and heated to a temperature of 1400 ° C. These glass-ceramics were then ground and sieved in the range of 32 to 63 pm. The results obtained with the material hysteresis cycles showed that the presence of gel affected the magnetic properties, and the results of XRD analyzes showed that this manufacturing method partially inhibits the formation of ferromagnetic phases. In a later study Concepción et al. (2002) also studied the effect of the glass ceramic manufacturing process for HT on its biological properties. The authors developed a glass ceramic in the P2O5-CaO-SiO2-Fe2O3 system by two processes, these being the sol-gel and “melting” (fusion). Through in vitro tests with the SBF solution, these authors verified that the sol-gel process causes important changes in the textural properties of the glass ceramic, which contribute significantly to its bioactivity.

[039] As previously explained, the processes used for the development of the magnetic material in glassy matrices, in most cases, lead to a glass ceramic with magnetic and biocompatible properties. However, the bioactivity shown, as well as the magnetic properties achieved by these materials developed so far are not suitable for their clinical application in HT therapy. Many challenges remain to be overcome and

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10/25 several studies have yet to be carried out to define the characteristics of “an ideal material” for the clinical treatment of cancer via HT.

[040] Identifying the lack of bioactive and magnetic material suitable for the HT technique, the present invention brings a new alternative to this treatment, with the obtaining of a biocomposite obtained through the encapsulation of magnetite particles by a glassy matrix, composed of F18 bioactive glass (ZANOTTO, et. al, 2013 WO2015021519), giving rise to a bioactive, magnetocaloric and magnetoestrictive material. The material has different concentrations of magnetite and has the ability to raise the temperature of the medium in the range used 39-45 ° C for treatment by HT (approximately 10 ° C). The combination of the bioactive properties of F18 glass and the magnetic properties of magnetite makes this biocomposite a promising material in the treatment of bone cancer through the technique of magnetic induction hyperthermia.

BACKGROUND OF THE INVENTION [041] In the current state of the art, some priorities are present that describe bioactive compounds and / or their process of obtaining, as well as solutions for the use of hyperemia for treatments. However, none of them describes a bioactive and magnetic composite for the treatment of tumors due to hyperemia, as described in the present patent application.

[042] Previously WO2004045652A2, entitled Biocompatible magnetic materials for treatment of cancer by means of hyperthermia, and processes for their production describes a biocompatible magnetic material for the thermal treatment of neoplasms comprising a magnetite crystalline phase and a biocompatible matrix in which said biocompatible matrix it is a bioactive glass. The process for the production of the material, comprises the fusion of a mixture of Na2CO3, CaCO3, SiO2, CaHPO4.2H2O, Fe2O3 and FeSO4.7H2O and subsequent cooling.

[043] Previous EP0040512B1, entitled Ceramic suitable for inducing localized heating in the presence of a radio frequency magnetic field, and use thereof provides a glass ceramic material, for use in reducing tumor mass by inducing localized hyperthermia, the material being characterized by have one

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11/25 basic composition chosen from phosphates, silicates and borates and incorporated in the same magnetic iron - containing crystals or magnetite or a ferrite selected from lithium, cobalt, nickel, manganese and barium ferrite, the crystals being of such size, composition, concentration and magnetic properties that 200 Oe are transmitted to the material and the localized heating is induced essentially only by heating by magnetic hysteresis.

[044] The previous US 2011/0301401 A1, entitled Compositions and methods for hermoradiotherapy provides superparamagnetic, ferromagnetic radioactive particles that heat the surrounding tissue after magnetic induction and its methods of use.

[045] Formerly US4042519, entitled Ferrimagnetic glass ceramic, describes glass-ceramics prepared by in situ thermal crystallization of nickel-zinc; manganese zinc; and crystalline manganese and magnesium ferrites in a residual glassy matrix.

[046] The previous US 2006/0111763 A1, entitled Heat generating article for hyperthermia and method for preparation thereof describes exothermic elements for the treatment with hyperthermia manufactured by heating after deposition of iron hydroxide in the nucleus particles by a liquid phase process.

[047] Priority EP061797B1, entitled Heat-generating body for hyperthermia and method of producing the same refers to a ceramic body that generates heat, particularly by hyperthermia, and methods for producing the same.

[048] Priority EP0132276B1, entitled Implantable hyperthermia device and system refers to a device to treat tumors in a living body and specifically to an implantable hyperthermia device and an electronic control circuit connected to it to control and maintain a condition of desired temperature in the tumor.

[049] The previous WO2006125452, entitled Injectable superparamagnetic nanoparticles by hyperthermia and use for an hyperthermic implant describes an injectable formulation for treatment by hyperthermia, comprising a liquid vehicle and heat-generating nanoparticles, the use of said injectable formulation to form an implant in situ hyperthermic in contact with a fluid

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12/25 body or tissue, said hyperthermic implant and a process for the preparation of silica beads containing nanoparticles for use in said injectable formulation.

[050] Previously WO2013073313, entitled Iron oxide nanoparticles and their synthesis by controlled oxidation describes iron oxide nanoparticles with an iron content in a metastable state that the iron content of the unexpectedly beneficial magnetic properties of wustite resulting from the size of nanoparticles are attractive for magnetic imaging applications.

[051] Formerly BR1120140248265, entitled Bicompatible magnetic materials for treatment of cancer by means of hyperthermia, and processes for their production refers to dispersions of magnetic particles comprising single monocrystalline and / or polycrystalline nanoparticles coated with iron oxides and nanoparticulate aggregates ( multicore particles) with improved nonlinear magnetization behavior and better heating properties in alternating magnetic fields.

[052] The previous BR1020130223808, entitled microparticulate magnetic nanocomposites based on poly (vinyl pivalate) describes the development of multifunctional polymeric nanomaterials comprising basically nanostructured magnetic particles homogeneously dispersed in a thermoplastic matrix of poly (vinyl vinyl).

[053] Previously US20170089890, entitled Method for Preparing Magnetic Microsphere for Separation of Biological Protein and Use Thereof describes a method for preparing a magnetic microsphere for the separation of biological proteins. [054] A matrix of magnetic microspheres is treated by the formulation and use of an appropriate emulsified liquid, and the modification of the surface of the matrix of magnetic microspheres is carried out by emulsion polymerization, thus obtaining a magnetic microsphere coated with a layer of polyacrylate polymer. .

[055] Previously US20160354495, entitled Multicore Magnetic Particles describes a multicore magnetic particle. In one embodiment, the particle

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Magnetic 13/25 includes a plurality of superparamagnetic cores embedded in a non-magnetic matrix.

[056] The anterity US20140163305, entitled Device Including Moving Magnet Configurations, refers to devices and methods for the activation of nerve cells and muscles by magnetic induction, and in particular to devices that include moving magnets. The disclosed devices may also have other therapeutic, medical and industrial applications.

[057] The previous US20150371776, entitled Ferrofluid - MWCNT hybrid nanocomposite in liquid state describes the synthesis of a double-surface ferrofluid based on water with magnetite nanoparticles (2-18 nm) coated with primary and secondary surfactants. The hybrid fluid synthesized shows a magnetic response and self-sustained homogeneity in the presence of a magnetic field.

[058] Priority US20060182997, entitled Noble metal-magnetic metal oxide composite particle and method for producing same provides a method for the production of fine particles composed of noble metal / magnetic metal comprising the steps of dispersing fine particles of magnetic metal oxide in a solution containing a noble metal ion or by adding a metal ion to the solution that can form the magnetic metal oxide.

[059] Priority US20090110644, entitled Polymer nanoparticles coated by magnetic metal oxide and uses thereof provides nanoparticles consisting of a polymer that is a metal chelating agent coated with a magnetic metal oxide, in which at least one active agent is covalently bound to the polymer, said nanoparticles may optionally further comprise at least one active agent physically or covalently attached to the outer surface of the magnetic metal oxide. The pharmaceutical compositions comprising these nanoparticles can be used for the detection and treatment of tumors and inflammations.

[060] Previously US20090258073, entitled Magnetic carrier and medical preparation for controllable delivery and release of active substances, methods of their production and methods of treatment using thereof refers to magnetic vehicles and

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14/25 medical preparations for controllable administration and release of active substances. It has a magnetocaloric or electrocaloric effect sufficient to substantially vary the said rate of retention / release of the active substance from the carrier. It also provides methods for controllable administration and release of captive substances at a predetermined location and at a predetermined time, and treatment methods using these carriers.

[061] Previously US20090258073, entitled Magnetic carrier and medical preparation for controllable delivery and release of active substances, methods of their production and methods of treatment using thereof refers to magnetic vehicles and medical preparations for controllable administration and release of active substances. It has a magnetocaloric or electrocaloric effect sufficient to substantially vary the said rate of retention / release of the active substance from the carrier. It also provides methods for controllable administration and release of active substances at a predetermined location and at a predetermined time, and treatment methods using these carriers.

[062] Previously US20110027854, entitled Method for concentrating viruses, method for concentrating cells or bacteria and magnetic composite describes a method for virus concentration includes applying a magnetic force to a mixture containing magnetic metal nanoparticles immobilized on the structure of your sugar chain; each metallic nanoparticle immobilized in the sugar chain has a structure in which a ligand conjugate is linked to a metallic nanocycle through sulfur atoms.

[063] The previous US20050155779, entitled Coated substrate assembly describes a set consisting of a coating that has a relative magnetic permeability of at least 1.1 in the frequency range of about 10 MHz to 200 MHz.

[064] The previous US20060142853, entitled Coated substrate assembly describes a coated assembly with an inductance of about 0.1 to about 5 nanohenries and a capacitance of about 0.1 to about 10 nanofarads. When the assembly is exposed to radio frequency electromagnetic radiation with a

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15/25 frequency from 10 megahertz to about 200 megahertz, at least 90% of the electromagnetic radiation penetrates inside.

[065] Previously US201314650239, entitled Magnetic nanoparticles, composites, suspensions and colloids with high specific absorption rate (SAR) describes iron oxide nanoparticles and nanocomposites with organic molecules incorporated in their structure, with exceptionally high SAR values, are provided for biological, medical use (eg drug delivery, hyperthermia, etc.) and other uses.

[066] The previous WO2004020042, entitled Heat generating article for hyperthermia and method for preparation thereof describes a heat generator for hyperthermia that has a layer of ferromagnetic material applied to the outer surface of a fine nuclear particle, in which the layer of ferromagnetic material comprises an oxide and has a magnetic domain structure consisting mainly of at least a single domain and a single pseudo-domain. It can be prepared by a method comprising the precipitation of iron hydroxide on the fine nuclear particle by the liquid phase method and subjecting the resulting iron hydroxide to heat treatment.

[067] Previous EP0040512, entitled Ceramic suitable for inducing localized heating in the presence of a radio frequency magnetic field, and use thereof describes a sintered glass ceramic that is suitable for inducing localized heating in the presence of a radiofrequency magnetic field, the field with a low enough frequency that essentially only heating by magnetic hysteresis. In general terms, the present invention is directed to a non-invasive tumor treatment modality that results in a reduction of the tumor mass and can lead to the complete eradication of a tumor. The method comprises RF induced hyperthermia, magnetically coupled and localized, mediated by a material that is non-toxic and, preferably, is compatible with animal tissue and has been incorporated into these crystals containing iron with magnetic properties.

[068] As much as the previous ones presented describe bioactive compounds that use magnetism and / or hyperthermia, none of them anticipates the present

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16/25 proposal, which brings as a solution to the problems present in the current state of the art the development of a biocomposite obtained through the encapsulation of magnetite particles by a vitreous matrix, composed of bioactive glass F18 and / or by Biosilicate, to obtain a bioactive and magnetic material, with a single magnetic phase, for application in hyperthermia (HT) processes for the treatment of tumors and related diseases.

[069] Currently, one of the most conservative alternatives for the treatment of tumors is the HT technique, which is very promising and promotes several studies in the area. HT is based on the elevation of the temperature of cells in the tumor area and, due to several factors, this increase in temperature leads cancer cells to death. In this technique, a material is usually used which, when exposed to an external magnetic field, generates heat leading to the destruction of the tumor without causing greater discomfort to the patient. Among the materials used for HT, we highlight the superparamagnetic and ferromagnetic nanoparticles, and the bioactive glass-ceramics that have also called attention to a potential use in HT due to their high bioactivity. However, until now, there has been no development of a composite material that adequately balances the magnetic properties and bioactivity for HT, as proposed in this patent application.

OBJECTIVE OF THE INVENTION [070] The present invention aims to provide a composite material F18 glass / magnetite or biosilicate / magnetite capable of adequately balancing, in its composition, the magnetic properties and bioactivity for the hyperthermia technique. OF THE INVENTION [071] The present invention originated from the combination of the established biological properties of bioactive glasses (high osteoconduction and osteoinduction, angiogenic potential and antibacterial activity) with the magnetic properties of magnetite already consolidated for the HT technique. In this sense, a bioactive and magnetocaloric composite is described, with the ability to achieve the thermal response required by the HT technique, raising the temperature of the medium in the range of 5 to 15 ° C when exposed to

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17/25 an external field. The material also has a magnetostrictive effect, which allows the generation of mechanical stimuli to the surrounding tissue after implantation. The combination of the bioactive properties of F18 glass and magnetite makes this biocomposite a promising material in the treatment of cancer, especially bone cancer, using the technique of hyperthermia by magnetic induction.

ADVANTAGES OF THE INVENTION [072] In short, the present invention has as main advantages:

Have a bioactive and magnetocaloric composite that presents an appropriate balance between magnetic properties and bioactivity for hyperthermia; Have a bioactive and magnetocaloric composite capable of achieving the necessary thermal response to the hyperthermia technique, raising the temperature of the medium in the range of 5 to 15 ° C when exposed to an external field;

Have a bioactive and magnetocaloric composite with a magnetostrictive effect, which allows the generation of mechanical stimuli to the surrounding tissue after implantation;

To dispose of a bioactive and magnetocaloric composite, a promising material in the treatment of cancer, especially bone cancer, through the technique of hyperthermia by magnetic induction;

Have a bioactive and magnetocaloric composite that presents a combination of the bioactive properties of F18 glass and biosilicate, such as high osteoconduction and osteoinduction, angiogenic potential and antibacterial activity, and magnetite, which are already consolidated magnetic properties for the hyperthermia technique.

DESCRIPTION OF THE FIGURES [073] The invention will be described in a preferred embodiment, thus, for better understanding, references will be made to the flowchart and figures:

Figure 1: Flowchart of the process for obtaining the bioactive magnetocaloric composite;

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18/25 c Figure 2: Diffracture of composites with glass matrix F18 and different concentrations of Fe ₃ Q4 with vacuum heat treatment for 2 hours with carbon black.

c Figure 3: SEM of the composite surface in the glass matrix F18. 2 h vacuum treatment with carbon black, with a) 5% Fe3Q4 and b) 10% Fe3Q4. Increase 1500x and 500x.

c Figure 4: Micrograph of the composite surface in the glass matrix F18 with 5% Fe3Q4, sintered for 2 hours under vacuum with carbon black, after a) 2 days and b) 7 days in SBF.

c Figure 5: Micrograph of the composite surface in the F18 glass matrix with 10% Fe3Q4, sintered for 2 hours under vacuum with carbon black, after a) 2 days and b) 7 days in SBF.

c Figure 6: Micrograph of the composite surface in the glass matrix F18 with 20% Fe3Q4, sintered for 2 hours under vacuum with carbon black, after a) 2 days and b) 7 days in SBF.

c Figure 7: Micrograph of the composite surface in the glass matrix F18 with 30% Fe3Q4, sintered for 2 hours under vacuum with carbon black, after a) 2 days and b) 7 days in SBF.

c Figure 8: Micrograph of the composite surface in the glass matrix F18 with 40% Fe3Q4, sintered for 2 hours under vacuum with carbon black, after a) 2 days and b) 7 days in SBF.

c Figure 9: Infrared spectroscopy of the composite in the glass matrix F18, with heat treatment for 2 hours in vacuum with carbon black, with different levels of Fe3Q4 after 7 days in SBF.

c Figure 10: Infrared spectroscopy of the composite in the glass matrix F18, with heat treatment for 2 hours under vacuum with carbon black, with different Fe3Q4 contents after 2 days in SBF.

c Figure 11: Magnetization curve as a function of the magnetic field applied for vacuum sintered samples at 580 ° C of the composite in the glass matrix

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F18 with different concentrations of magnetite (5 to 40% by weight) magnetization.

J Figure 12: Representation of cell function

J Figure 13: Experimental setup of the magnetocaloric test

J Figure 14: ΔΤ in 5 and 10 minutes applying magnetic field to samples heat treated in vacuum at 580 ° C of the composite in the glass matrix F18 with different concentrations of magnetite (5 to 40% by weight and pure Fe3Ü4).

DETAILED DESCRIPTION OF THE INVENTION [074] The process of obtaining the bioactive and magnetocaloric composite (Fig. 1) takes place from the fusion (E1) of the biosilicate (1), prepared according to patent application WO2004074199A1, and / or glass F18 (2), according to patent application BR102013020961-9A2, to obtain the glass matrix (V) to encompass the particles of magnetite, which is carried out at temperatures between 1050 and 1450 ° C for the period from 1 to 4 hours to homogenize the glasses. After melting (E1), the glassy matrix (V) is poured (E2), representing a proportion between 5 and 95% by weight of the product, with the “splat cooling” procedure (E3) being performed and, then, it is done the grinding (E4) of the matrix to obtain particles between 1 to 500 pm. After grinding (E4), the magnetite (3), Fe3O4, is added (E5) in concentrations gradually in the range of 5 to 40% by weight to the mixture (4) which is taken to the mill for homogenization (E6). Then, the powders (5) are pressed (E7) between 100 to 1250 MPa, without the addition of binders. Then, the obtained tablets (6) are sintered (E8), in a controlled atmosphere oven (vacuum), for a period between 1 and 6 hours, between 500 to 900 ° C. After the end of the heat treatment, the bioactive and magnetocaloric composite (C) is obtained, and it can also be ground (E9), so that its particles reach ranges between 50 nanometers to 1 millimeter of granulometry.

[075] The bioactive and magnetocaloric composite (C) obtained consists of a ferromagnetic crystalline phase dispersed in a bioactive glass or bioactive glass ceramic matrix. Being understood by sintering a mixture of powders, consisting of 5-20% by weight of a magnetic crystalline phase and 80-95% by weight of the bioactive glass matrix or bioactive glass ceramic, which can be ground, for use in treatments

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20/25 HT, where they are normally used in the form of particles. The particles of the bioactive and magnetocaloric composite (C) can be introduced into the tumor by different techniques conventionally employed, where the powders have a size in the range of 50 nanometers to 1 millimeter.

[076] Biosilicate (1) is a totally crystalline material developed at the Vitreous Materials Laboratory (LaMaV-DEMa-UFSCar, patent application WO2004074199A1) characterized by being composed of between 40 and 60% of SiO2, between 0 and 30 % K2O, between 0 and 30% Na2O, between 0 and 15% NaF, between 15 and 30% CaO, between 0 and 15% CaF2, between 0 and 10% U2O, between 0 and 10% SnO, between 0 and 10% SrO, between 0 and 8% P2O5, between 0 and 6% Fe2O3, between 0 and 3% MgO, between 0 and 3% B2O3, between 0 and 3% AEO3 and between 0 and 3% ZnO. The composition called F18 (2), on the other hand, presents greater stability in the face of crystallization, maintaining its high bioactivity which makes it more suitable for the process of forming complex parts and susceptible to thermal processes without significant crystallization, developed at the Materials Laboratory Vitreous (LaMaV-DEMa-UFSCar, patent application BR 10 2013 020961 9 A2), being characterized by being comprised of between 43 and 52% of SiO2; between 4 and 9.5% Na2O; between 20.5 and 32% K2O; between 0.5 and 2.5% MgO; between 15 and 20% CaO; between 0.1 and 3.5% of Au; between 0, and 3.5% of Ag; between 1.5 and 4% of B2O3; between 1 and 6% P2O5; between 0.1 and 3.5% ZnO; between 0.1 and 3.5% SrO. Magnetite (3) was chosen due to its magnetic properties to achieve a saturation magnetization that favors its use for the treatment of cancer via HT. In addition, there are no reports in the literature on the use of magnetite in a glassy matrix, which gives the present invention originality.

[077] X-ray diffraction, XRD analyzes were performed to identify the resulting phases after thermal treatments [078] In the diffractogram (Fig. 2) it is possible to observe that the major crystalline phase of the composite is magnetite in all samples analyzed (JPSD 75-33). The presence of magnetite gives the material its magnetic property even after TT.

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21/25 [079] The scanning electron microscopy analysis, SEM, was used to observe the sample degradation after the SBF tests, checking the formation of the hydroxyapatite layer, as well as analyzing the microstructure of the samples (Fig. 3), obtained after heat treatment.

[080] In the post-test analysis in vitro in SBF solution, it was possible to observe a thick layer of HCA (globular formation characteristic of the HCA phase), mainly for samples with lower concentrations of magnetite (Figs. 4 to 8).

[081] In vitro bioactivity tests provide information on the rate of formation of HCA on the surface of the materials under study, the same being then related to the bioactivity of the material. These are preliminary and selective tests carried out prior to in vivo tests, which involve high costs and specialized professionals for raising animals, placing implants and sacrificing animals to collect samples for analysis. In addition, in vitro tests are more practical and can be performed in shorter times.

[082] Fourier transform infrared spectroscopy, FTIR, made it possible to identify and monitor the surface transformations occurring in the bioactive glass used. The diffuse reflectance infrared spectroscopy technique was applied to monitor the reactions in the samples in the form of tablets. The tablets were analyzed using the diffuse reflectance mode, with sweeping in the range of 400 to 4000 cm ^-1 and resolution of 4 cm ^-1 .

[083] In figure 9, it is possible to observe the formation of hydroxyapatite on the surfaces of all samples after 7 days. And on samples that contained lower concentrations of magnetite, this layer can be identified with 2 days of immersion (Fig. 10).

[084] Compared to pure F18 glass, which has formation of hydroxyapatite in 12 hours, the developed composite showed a slight drop in bioactivity, but still presenting bioactivity compatible with the desired application.

[085] However, all the samples of the developed composite showed bioactivity in up to 7 days, even in those that contained higher additions of magnetite.

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22/25 [086] The composites obtained and described in this application were produced through simple execution steps, easy to reproduce and which culminated in the preservation of the composite's bioactivity.

[087] By analyzing Hysteresis Curves with Vibrating Sample Magnetometer (MAV), the vibrating sample magnetometer measured the electromotive force induced when a ferromagnetic sample was vibrating at a constant frequency under the presence of a static DC magnetic field, generated by coils of an electromagnet.

[088] Figure 11 shows the hysteresis curve obtained for composites with different concentrations of magnetite (the values found vary from 22.59 to 58.75 emu / g for the saturation magnetization and 152.78 to 172 Oe for the coercive field). All samples had magnetic properties. The results found for our composites corroborate those found in the studies by Bretcanu et al. (2005 and 2006) and Vallet-regi. et al. (2006) for other magnetic glass-ceramics. The reported value ranges vary from 0.012 to 90 emu / g for the saturation magnetization and 0.0218 to 4298 Oe for the coercive field. Most authors used frequencies of 100 KHz, for the material developed, the field studied was -10 kOe to +10 kOe, with a constant frequency of vibration of 12 Hz. As mentioned earlier, the ideal for a material that will be used in HT procedures is that it presents magnetic and magnetocaloric responses with the application of the lowest possible frequency and external magnetic field strength, as this would decrease the eddy currents that are induced in the patient's tissue by the external magnetic field, which can generate an undesirable nervous and muscular response (RUIZ-HERNÁNDEZ et al., 2006). Therefore, using a frequency approximately 10 times lower, the magnetic response found in the glass-ceramics reported in the literature was obtained with our biocomposites.

[089] The essence of the magnetostrictive effect is that an electrical pulse can be converted into a mechanical pulse and vice versa, this effect involves the interaction between magnetization and mechanical stress. To obtain the response measures

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23/25 composite magnetostrictive, the samples were placed in a capacitive cell. A simplified test scheme is presented in (Fig. 12).

[090] Through the measurement of magnetostriction it was possible to verify the mechanical deformation of the systems when placed under the action of a magnetic field. With this measure it was possible to observe that, with the increase in the amount of Fe ₃ O4 in the composite, the expansion saturation value increased in smaller fields, with a peak for samples of 30% by weight of Fe ₃ O4. According to E. W Lee. (1955), in composites that have the addition of magnetic metals, the magnetostrictive effect depends on the amount of element added and its history of thermal processing in a linear relationship (GUALDI et al., 2010). The results can be better observed in Table 1.

Sample Magnetic field (kOe) Maximum expansion (AL / L) F18 + Fe3O4 5% 8 2.23 x 10 ^-6 F18 + Fe3O4 10% 5.44 2.35 x 10 ^-6 F18 + Fe3O4 20% 4.39 3.6 x 10 ^-6 F18 + Fe3O4 30% 3.7 9.09 x 10 ^-6 F18 + Fe3O4 40% 6.49 8.7 x 10 ^-6

Table 1: Expansion saturation for magnetic composites.

[091] A very positive point in this finding is the possible effect of piezoelectricity when the composite is applied to bone tissue during HT treatment. Currently, it is known that the piezoelectric effect occurs due to mechanotransduction; which is a process of producing biochemical reactions from a mechanical stimulus. [092] This phenomenon acts at the cellular level and can cause inhibition of apoptosis, increased cell proliferation, changes in cell migration, among other effects (BUARQUE DE GUSMÃO et al., 2009). Therefore, it is known that the application of a mechanical stimulus during the treatment of HT would be extremely valuable in the recovery of bone tissue.

[093] The magnetocaloric effect (EMC) is an intrinsic property of magnetic materials, with their heating or cooling occurring when they are

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24/25 subjected to an external magnetic field variation; this phenomenon is directly associated with the spin-network coupling, so that the application of the magnetic field promotes the alignment of the spins.

[094] For the knowledge of ΔΪ (temperature variation) and the capacity of the composite to heat a body of water, an experimental setup was proposed (Fig. 13). The results found in the tests to verify the magnetocaloric effect of biocomposites treated for 1 hour are shown in Table 2. [095] The temperature variation ^ T) is shown in figure 13.

Sample Temperature reached in 5 minutes (° C) Temperature reached in 10 minutes (° C) F18 + Fe3O4 5% 23.5 23.7 F18 + Fe3O4 10% 25 26.2 F18 + Fe3O4 20% 28.2 31.9 F18 + Fe3O4 30% 29.2 34 F18 + Fe ₃ O4 40% 31.2 36.5 Fe ₃ O4 Pure 32.9 40.2

Table 2. Temperature data reached as a function of time for biocomposites with different magnetite concentration.

[096] From these results it is possible to observe that the temperature variation is greater as the amount of magnetite in biocomposites increases. Pure magnetite, as expected, exhibits the greatest temperature variation.

[097] During the clinical hyperthermia procedure, a moderate rise in temperature is desired, in the range of 39 to 45 ° C; therefore, a variation of 3 to 9 ° C in relation to the body temperature. Such a temperature range has been successfully achieved in the case of the composite described in the present patent application.

[098] The composite obtained was produced using a simple and easy reproduction process, which culminated in the preservation of both the bioactivity of the vitreous matrix and the magnetic property of the magnetite, even in different concentrations. [099] This synthesis method allowed to obtain a composite with balanced magnetic and bioactive properties for applications in HT.

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25/25 [100] With the verification of all of the properties of bioactivity, magnetocalorie and magnetostriction, the developed composites have a potential application for hyperthermia in the treatment of tumors, especially bone cancer, due to the thermal response presented. With the gradual degradation of the vitreous phase and the permanence of the magnetic phase at the site, the possibility of reheating processes is envisioned, which is very important if the patient experiences a recurrence of the disease. It is important to mention that the magnetostrictive property in HT materials has not been previously reported, which solves the problem present in the current state of the art, being the PROCESS OF OBTAINING BIOACTIVE AND MAGNETOCALORIC COMPOSITES FOR THE TREATMENT OF TUMORS BY HYPERTHERMIA AND PRODUCT OBTAINED deserving of the patent privilege of invention.

Claims (5)

1) PROCESS OF OBTAINING BIOACTIVE AND MAGNETOCALORIC COMPOSITES FOR THE TREATMENT OF TUMORS BY HYPERTERMIA, characterized by taking place from the fusion (E1) of the biosilicate (1) and / or the F18 glass (2) to obtain the vitreous matrix (V ), which is carried out at temperatures between 1050 and 1450 ° C for a period of 1 to 4 hours; after melting (E1), the glass matrix (V), in a proportion between 5 and 95% of the product by weight, is poured (E2), the splat cooling procedure (E3) is carried out and then it is grinded (E4), to obtain particles between 1 and 500 pm; after grinding (E4), the magnetite (3), Fe3Ü4, is added (E5) in concentrations gradually in the range of 5 to 40% by weight; then, the mixture (4) is taken to the mill for homogenization (E6); then, the powders (5) are pressed (E7), between 100 to 1250 MPa; then, the obtained tablets (6) are sintered (E8), in a controlled atmosphere oven, for a period between 1 and 6 hours, between 500 to 900 ° C; thus, the bioactive and magnetocaloric composite (C) obtained; after obtaining it, it can still be milled (E9), so that its particles reach ranges between 50 nanometers and 1 millimeter of granulometry. 2) BIOACTIVE AND MAGNETOCALORIC COMPOSITE FOR THE TREATMENT OF TUMORS BY HYPERTERMIA, according to claim 1, characterized by being made up of a ferromagnetic crystalline phase dispersed in a glassy matrix (V). 3) BIOACTIVE AND MAGNETOCALORIC COMPOSITE FOR THE TREATMENT OF TUMORS BY HYPERTERMIA, according to any one of claims 1 or 2, characterized in that the bioactive glass matrix (V) consists of F18 glass (2) or biosilicate (1) and the phase magnetic crystalline being constituted by magnetite (3). 4) BIOACTIVE AND MAGNETOCALORIC COMPOSITE FOR THE TREATMENT OF TUMORS BY HYPERTERMIA, according to any one of claims 1, 2 or 3, characterized in that it consists of 5-20% by weight of a magnetic crystalline phase and 80-95% by weight of the glassy matrix (V). 5) BIOACTIVE AND MAGNETOCALORIC COMPOSITE FOR THE TREATMENT OF TUMORS BY HYPERTERMIA, according to any one of claims 1, 2 Petition 870180069526, of 08/09/2018, p. 33/45 2/2 or 3, characterized by being used in the treatment of tumors by hyperthermia, by introducing the particles of the bioactive and magnetocaloric composite (C) into the tumor by different techniques conventionally employed.