EA042836B1 - PREPARATION OF CYAN-BRIDGED METALLIC NANOPARTICLES IN IN SITU IN SITU INVERSED MICELLAR SYSTEM - Google Patents

Description

Fig. 1. Schematic overview of the steps for the in situ synthesis of RS nanoparticles in a reverse micellar system, HOBP means homogeneous oil phase, MSP means metal salt precursor, WP means aqueous phase, CMSP means cyanometallate salt precursor, RMS means reverse micellar system, and CBMNP means cyano bridging metal nanoparticles.

Fig. Fig. 2. FTIR (Fourier Transform InfraRed) spectra of (1) Fe(II)-CN-Fe(III) nanoparticles (sample A) in reverse micellar system and (2) ferrocyanide precursor (sample A6) in reverse micellar system.

Fig. Fig. 3. FTIR spectra of (1) ferrocyanide precursor (sample A6), (2) Fe(III)-CN{Mn(II), Zn(II)) nanoparticles (sample E), (3) Fe(III)-CN -Mn(II) (sample C) and (4) Fe(III)-CN-Zn(II) (sample B), all in reverse micellar system.

Fig. 4. UV-visible spectra of (1) RS nanoparticles (sample A), (2) ferrocyanide precursor (sample A6), (3) ferric chloride precursor (sample A3), all in reverse micellar system, and (4) sample A7.

Fig. 5. TEM (transmission electron microscopy) images of sample A containing PB nanoparticles in a reverse micellar system.

Fig. 6. Cs ⁺ isotherm of a reverse micellar system containing (1) in situ prepared RS nanoparticles according to the present invention and (2) commercial RS.

Fig. 7. Percentage of Cs ⁺ recovered after 4 days compared to the initial dose of Cs ⁺ 0.5 mg per rat in urine and feces for 4 groups (average of 4 rats): untreated, sample L gavage, sample M buccal administration and sample L rectal administration with a cumulative excretion dose of RV of 0-8-4-2 mg, respectively (standard error from the mean is represented by error bars).

Fig. 8. Percent efficiency of Cs ⁺ excretion in the heart compared to control groups for 7 gavage-treated groups (in 5 rats): samples O, P, Q & R with a cumulative excretion dose of RV 4-8-16-80 mg per rat , respectively, and samples S, T & U with a cumulative excretion dose of RV 4-8-16 mg per rat, respectively (standard error of the mean is represented by error bars).

Fig. 9. Percentage of recovered Cs ⁺ at days 2 and 4 compared to Cs ⁺ of the initial dose of 0.05 mg per rat in feces for 9 groups (average of 5 rats): water, samples O, P, Q & R with cumulative excretion RV dose of 4-8-16-80 mg per rat, respectively, and samples N, S, T & U with a cumulative excretion dose of RV from 0 to 4-8-16 mg per rat, respectively (standard error of the mean is represented by error bars) .

Detailed description of the invention

The first object of the invention is a method for in situ preparation of cyano-bridged coordination polymers in the form of nanoparticles in a biocompatible reverse micellar system.

The term cyano-bridged coordination polymer refers to the repetition of the sequential assembly of the M ^p+ metal cation and the [M'(CN) _n ] ^q- cyanometallate anions obtained by growing a cyano-bridged network (containing CN ligands) within a reverse micellar system. Typically, these polymers form a network of polymers. This polymer is called a coordination polymer when a metal precursor M is linked to another metal precursor M' via a CN ligand to form an M'-CN-M subunit, which subunit is repeated many times in the reaction medium.

The present method includes the following step, consisting of:

mixing (i) at least one biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, an aqueous solution containing at least one metal salt as a precursor, and water, with (ii) biocompatible reverse micellar a micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, an aqueous solution containing at least one cyanometallate salt as a precursor, and water.

According to the invention, a metal salt refers to a metal cation, usually with chloride or nitrogen anions as counter-anions and water molecules. It is preferred that the counteranion is chloride. The metal cation (Mp+) can be selected from transition metals and lanthanide cations. Metal cations may have one or more positive charges (p ⁺ ), p is usually an integer from 1 to 10, more specifically p is 2, 3, 4 or 5, and the number of counter-anions and water molecules depends on the number of positive charges.

The transition metal cations (referred to as M) may be selected from all existing transition metal cations. The transition metal cations used in accordance with the invention are iron, zinc and manganese. Preferably the transition metal cation used in the invention is iron.

The lanthanide cations (also referred to as M) may be selected from all existing lanthanide cations, including gadolinium (Gd), terbium (Tb), or ytterbium (Yb). The lanthanide cation more specifically used in accordance with the invention is gadolinium.

More specifically, the metal cation (Mp+) may be iron (Fe ²⁺ or Fe ³⁺ ), zinc (Zn ²⁺ ), manganese (Mn ²⁺ ) or gadolinium (Gd ³⁺ ), which forms respectively FeCl ₂ , 4H _2O ; FeCl ₃ ,

_6H2O ; ZnCl ₂ , 4H ₂ O; MnCl ₂ , 4H ₂ O; or Gd(NO ₃ ) ₃ , 6H ₂ O.

An aqueous solution containing at least one metal salt may contain one, two or three metal salts (ie one metal salt or a mixture of metal salts).

According to the invention, the cyanometallate salt (Alk ⁺ _x [M'(CN)n] ^q- ) refers to the metal cation (M'), usually with CN ligands and alkali cations (Alk ⁺ ). The metal cation (M') can be selected from transition metal cations which define the number of CN ligands and their associated alkali metal cations, q is usually an integer equal to x, more specifically q is 2, 3 or 4; and n is usually an integer, more specifically n is 4, 6 or 8; and x is usually an integer, more specifically x is 2, 3, or 4.

More specifically, the metal cation (M') may be iron (Fe ²⁺ or Fe ³⁺ ), cobalt (Co ²⁺ or Co ³⁺ ), nickel (Ni ²⁺ ), molybdenum (Mo ⁴⁺ , Mo ⁵⁺ ) or tungsten (W ⁴⁺ ). M' is preferably iron.

The alkali metal cation (Alk ⁺ ) may be lithium (Li ⁺ ), rubidium (Ru ⁺ ), sodium (Na ⁺ ), potassium (K ⁺ ) or cesium (Cs ⁺ ) (in case of excretion). The sodium cation is more preferred when the cyano-bridged metal nanoparticles are intended for medical and pharmaceutical applications.

The formula Alk ⁺ x[M'(CN)n] ^q- can be as follows: Na4[Fe(CN) ₆ ], Na ₃ [Fe(CN) ₆ ], Na ₂ [Ni(CN) ₄ ], Na ₄ [ Mo(CN) ₈ ] or Na ₄ [W(CN) ₈ ]. In the above formulas, sodium can be replaced by potassium.

Accordingly, the mixing of the method according to the invention allows the in situ synthesis of cyano-bridged metal nanoparticles in a reverse micellar system.

As a rule, the amounts of metal salts and cyanometallate salts in biocompatible reverse micellar systems (i) and (ii) can vary to a large extent. The amount of biocompatible reverse micellar systems (i) and (ii) to be mixed can also vary to a large extent. In specific embodiments, the mixing of said biocompatible reverse micellar systems (i) and (ii) is carried out in such a way that the metal salts and cyanometallate salts are in equivalent molar amounts.

According to specific embodiments of the invention (i) at least one biocompatible reverse micellar system may contain one or more (eg, 2 or 3) metal salts.

According to other embodiments, the at least one biocompatible reverse micellar system (i) may be one, two or three biocompatible reverse micellar systems, each containing a different metal salt from the other. Accordingly, biocompatible reverse micellar systems (i) containing at least one metal salt can be mixed together with biocompatible reverse micellar systems containing at least one cyanometallate salt (ii).

The term biocompatible system refers to compatibility with living cells, tissues, organs or systems; more specifically, it refers to a system that poses no risk of injury, toxicity, or rejection by the immune system of mammals and, more preferably, humans.

Those skilled in the art can easily determine the mixing conditions, in particular time and temperature. In practice, the temperature may vary from room temperature (1825°C) to 40°C at atmospheric pressure. The mixing time is such that a homogeneous reverse micellar system, and more particularly a visually clear composition, is obtained.

According to a specific embodiment, prior to mixing, said (i) and (ii) biocompatible reverse micellar systems can be prepared by a process comprising the following steps:

Step 1: separate preparation of aqueous solutions each containing at least one metal precursor (i.e. at least one aqueous solution contains at least one metal salt compound and the other aqueous solution contains at least one cyanometallate salt) by dissolving each metal precursor in water, preferably deionized water,

Stage 2: each of the aqueous solutions obtained in stage 1 is solubilized in an oil-based homogeneous phase containing at least one acylglycerol, sterol, lecithin and ethanol, and optionally water, to form a homogeneous reverse micellar system, where these homogeneous phases oil-based are preferably the same (in terms of quality and quantity, ie the same compounds in the same quantities).

According to a preferred embodiment of step 1, the metal precursors are dissolved in water at appropriate concentrations to obtain the desired final concentration of nanoparticles in the reverse micellar system. Thus, a person skilled in the art will estimate the amount of metal precursors to be dissolved in order to obtain the desired final concentration of nanoparticles. An aqueous solution is defined as a solution in which the solvent is essentially water. The word aquatic is defined as inherent in water, referring to water, analogous to water, or dissolved in water.

More specifically, the reverse micellar systems obtained in step 2 are biocompatible reverse micellar systems (i) and (ii) which are then mixed together in accordance with the method of the invention, preferably the amount by weight of the biocompatible reverse micellar systems (i) is the same as the amount of biocompatible reverse micellar system (ii). Said biocompatible reverse micellar systems are preferably the same (in terms of quality and quantity, ie the same compounds in the same amounts), except for the metal precursors which are different in each biocompatible reverse micellar system.

More specifically, mixing according to the method of the invention allows the metal precursors to interact and therefore induce in situ formation of cyano-bridged metal nanoparticles in the resulting reverse micellar system.

The homogeneous oil-based phase of the invention used in step (2) can be obtained by any method known in the art. In particular, they can be obtained in the following way:

(a) contacting (i) an acylglycerol, preferably diacylglycerol, (ii) lecithin, (iii) ethanol (iv) sterol and (v) optionally water, preferably purified water, (b) the mixture obtained in step (a), stirred at 40° C. or less, and for a time sufficient to form a homogeneous oil-based phase.

The mixing parameters, more specifically the duration and speed of mechanical mixing, can be easily determined by any person skilled in the art and depend on the conditions of the experiment. In practice, these parameters are such that a homogeneous oil-based phase is obtained; the speed is determined so as to ensure the formation of a visually transparent composition, and the duration of mixing is such that mixing can be stopped after a few minutes (for example, 2, 3, 4, 5 or 6 minutes) after obtaining a visually transparent composition.

The term homogeneous or reverse micellar system refers to a system that is visually transparent.

In FIG. 1 provides an overview of the in situ preparation of specific cyano-bridged metal nanoparticles.

Typically, the method of the invention is carried out from room temperature (ie, 18 to 25°C) to 40°C, unless otherwise indicated.

Components of homogeneous oil phases or reverse micellar systems

Acylglycerols.

The acylglycerols used in the reverse micellar system or homogeneous oil phase according to the invention can be isolated from most animals and more preferably plants.

The acylglycerols used in accordance with the invention include mono-, di- and triacylglycerols of the following formula (I): CH ₂ (OR ₁ )-CH(OR ₂ )-CH ₂ (OR ₃ ), in which:

R1 is an acyl residue of a linear or branched unsaturated fatty acid having from 14 to 24 carbon atoms;

R ₂ is an acyl residue of a linear or branched unsaturated fatty acid having 2 to 18 carbon atoms or a hydrogen atom;

R ₃ is an acyl residue of a linear or branched unsaturated fatty acid having 14 to 24 carbon atoms, or a hydrogen atom.

According to a particular embodiment, R1 or R ₃ , preferably only one of R1 and R ₃ , in particular only R ₁ , is an oleic acid acyl residue (C18:1 [cis]-9).

In a particular aspect, R2 has 18 carbon atoms, preferably R2 is an oleic acid residue (oleoyl group), one of its positional isomers with respect to the double bond (cis-6,7,9,11 and 13) or one of its iso-branched isomers.

According to another specific aspect, R1 is an oleoyl group.

In accordance with another specific aspect, R3 is a hydrogen atom.

In accordance with another specific aspect, R2 and R3 are hydrogen atoms.

Typically, an oil containing a high concentration of oleic acid will be selected as a useful source of acylglycerols in accordance with the invention. Such an oil usually contains a high proportion of acylglycerols useful in accordance with the invention.

According to a specific aspect of the invention, the preferred acylglycerols are glycerol 1-monoleate and glycerol 1,2-dioleate.

Some of them, and especially those that are considered to be the most active in the applications sought, are also commercially available. For example, glycerol monooleate 40 contains 32% to 52% monoacylglycerol, 30% to 50% diacylglycerol, 5% to 20% triacylglycerol, and is pharmaceutically acceptable (European Pharmacopeia (8th edition), USP 25/NF20 and Japanese Standard for Dietary Supplements) .

Such a product is for example commercially available from Gattefosse under the name Peceol®. In particular, Peceol® may contain about 45.3 wt.% monoacylglycerol, about 44.5 wt.% diacylglycerol and about 8.6 wt.% triacylglycerol (the acyl fraction of Peceol® mainly consists of oleoyl: usually about 80% acyl residue is the oleol fraction).

As used herein, the weight of an acylglycerol corresponds to the total weight of a mixture, typically containing an acylglycerol or a mixture of acylglycerols, with glycerol and fatty acids derived from said acylglycerol(s), such as Peceol® described above.

Acylglycerols are natural compounds and can be extracted and/or obtained from renewable plant sources. Therefore, their use is advantageous in terms of biocompatibility and environmental concerns compared to synthetic compounds.

Sterol.

The homogeneous oil-based phase or reverse micellar system according to the invention contains at least one sterol, preferably a natural sterol such as cholesterol or phytosterol (plant sterols). Sitosterol and cholesterol are the preferred sterols that may be present in the reverse micellar system of the invention. Preferably, the reverse micellar system comprises sitosterol, such as beta-sitosterol.

Sitosterol and cholesterol are commercially available. In particular, commercial sitosterol, which is derived from soy, can be used. In such a product, sitosterol typically accounts for 50 to 80% by weight of the product, and is usually mixed with campesterol and sitostanol in appropriate proportions at 15% each. You can also use commercial sitosterol, which is extracted from a variety of pine called tall oil.

Lecithin.

In the present invention, the term lecithin refers to phosphatidylcholine. Phosphatidylcholine is also known as 1,2-diacyl-glycero-3-phosphocholine or PtdCho. It consists of choline, a phosphate group, glycerol and two fatty acids. It is actually a group of molecules in which the composition of fatty acids varies from one molecule to another. Phosphatidylcholine can be obtained from commercial lecithin, which contains phosphatidylcholine in mass fractions from 20 to 98%. The lecithin preferably used in accordance with the invention is Epikuron 200® (sold by Cargill) and contains more than 90% phosphatidylcholine. Preferably, the lecithin used in accordance with the invention contains more than 92% by weight of phosphatidylcholine.

Water.

The water suitable for preparing the reverse micellar system or oil-based homogeneous phase according to the invention is preferably purified water; more specifically distilled or deionized water.

Ethanol.

The ethanol is usually an ethanol-water solution, where the amount of ethanol is from about 90% to 99% by volume. In a more specific embodiment, the ethanol is absolute or anhydrous alcohol (which refers to low water ethanol). There are various grades with maximum water content ranging from 1% to several parts per million (ppm). Absolute ethanol is preferred.

Other components.

The homogeneous phase or reverse micellar system according to the invention may contain any additional components. As an example of an additional component, alcohols other than ethanol can be given.

The oil-based homogeneous phase or reverse micellar system according to the invention may contain at least one alcohol in addition to ethanol as defined above. The alcohols that can be used in accordance with the invention are preferably linear or branched monoalcohols with two to four carbon atoms. Examples of alcohols are 1-propanol, 2-propanol, 2-methyl-1-propanol, isopropanol, and any mixture thereof. The polyols that can be used in accordance with the invention are preferably glycerol and propylene glycol.

The amounts of components of the oil-based homogeneous phase or reverse micellar system can be adapted by one skilled in the art depending on the desired properties of the phase or system, such as, for example, appearance, viscosity and/or active agent concentration.

In a preferred embodiment, the oil-based homogeneous phase or reverse micellar system does not contain liposomes.

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In an embodiment of the invention, the amounts of the components of the homogeneous oil-based phase or reverse micellar system are adjusted so that the reverse micellar systems (i) or (ii) are in the form of a liquid. One skilled in the art can tailor the relative amounts of acylglycerol, sterol, lecithin, ethanol, and water in homogeneous oil phases or reverse micellar systems to produce a liquid with desired properties such as, for example, appearance, viscosity, and/or active agent concentration.

Example amounts for the various components of a biocompatible reverse micellar system containing cyano-bridged coordination polymers prepared in accordance with the invention are as follows:

The reverse micellar system may contain 1 to 30%, preferably 1 to 20%, in particular 5 to 15% lecithin.

The reverse micellar system may contain 0.1 to 20%, preferably 1 to 20%, in particular 5 to 15% water.

The reverse micellar system may contain 5 to 20%, preferably 5 to 15% alcohols, including ethanol.

The reverse micellar system may contain from 0.82 to 4.5% sterol.

The reverse micellar system may contain from 30 to 90%, preferably from 50 to 90%, acylglycerol.

In addition, the amount of cyano-bridged coordination polymers obtained is more preferably 0.4 to 10%, preferably 0.5 to 5%, more preferably 1-2% by weight of the total amount of water and cyano-bridged coordination polymers within systems.

Those skilled in the art will tailor the amounts of components in biocompatible reverse micellar systems containing precursors and hence homogeneous oil-based phases and aqueous solutions containing metal precursors to obtain the preferred amounts as indicated above.

Unless otherwise indicated, the percentages used in the present invention are weight percent based on the total weight of the named compounds or reverse micellar system.

In the present invention, the term reverse micellar system refers to a reverse phase system containing an aqueous phase dispersed in an oil phase. Preferably the reversed phase system includes reversed or reversed swollen micelles, but they can be organized into more ordered isotropic structures such as a water-in-oil microemulsion or anisotropic structures such as cubic, hexagonal, layered organizations.

Cyano-bridged metal nanoparticles.

According to the process of the invention described above, cyano-bridged metal nanoparticles were thus obtained.

Another embodiment of the invention relates to a biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, cyano-bridged metal nanoparticles, water, and said biocompatible reverse micellar system does not contain a stabilizing agent. More specifically, a biocompatible reverse micellar system can be obtained by the method described in detail in this document.

As mentioned above, the amounts of the various components of the biocompatible reverse micellar system containing cyano-bridged coordination polymers, more specifically prepared in accordance with the invention, are as follows:

The reverse micellar system may contain 1 to 30%, preferably 1 to 20%, in particular 5 to 15% lecithin.

The reverse micellar system may contain 0.1 to 20%, preferably 1 to 20%, in particular 5 to 15% water.

The reverse micellar system may contain 5 to 20%, preferably 5 to 15% alcohols, including ethanol.

The reverse micellar system may contain from 0.82 to 4.5% sterol.

The reverse micellar system may contain from 30 to 90%, preferably from 50 to 90%, acylglycerol.

In addition, the amount of cyano-bridged coordination polymers obtained is more preferably 0.4 to 10%, preferably 0.5 to 5%, more preferably 1-2% of the total amount of water and cyano-bridged coordination polymers within the system.

In accordance with another embodiment, the invention relates to a composition containing a biocompatible reverse micellar system according to the invention. The composition is more specifically used for treatment or diagnosis, as described below. According to a specific embodiment, the invention relates to a pharmaceutical composition comprising the biocompatible reverse micellar system of the invention in a pharmaceutically acceptable carrier or support.

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More specifically, the cyano-bridged metal nanoparticles included in the biocompatible reverse micellar system of the invention are advantageously stabilized by the reverse micellar system. Thus, the cyano-bridged metal nanoparticles contained in it do not require a special stabilizing agent.

The term stabilizing agent refers to any compound capable of stabilizing nanoparticles, more specifically their size. Typically, the stabilizing agent is polyethylene glycols (PEGs) or derivatives thereof such as PEG-amine or polysaccharides such as dextrans.

In the present invention, the term cyano-bridged metal nanoparticles refers to compounds in the form of nanoparticles (the size of nanoparticles is preferably in the range of 1 to 100 nm) comprising the metal cation Mp+ and cyanometallate anions [M'(CN) _n ] ^q- as defined above .

More specifically, cyano-bridged metal nanoparticles contain M'-CN-M bonds such as Fe(II)-CN-Fe(III), Fe(II)-CN-Zn(II), Fe(II)-CN- Mn(II), Fe(II)-CN-[Fe(III)Mn(II)] or Fe(II)-CN[Mn(II)Zn(II)].

The number of CN groups can vary from 4 to 8, depending on the transition metal cation used. For example, the number of CN groups is 4 with nickel, 6 with iron, and 8 with molybdenum.

The term cyano-bridged metal nanoparticles also includes PB and any PBA.

The term nanoparticles according to the invention refers in particular to particles whose size is from 0.5 to 20 nm, preferably from 1 to 10 nm, more preferably from 1 to 5 nm. For example, RE nanoparticles in reverse micellar systems prepared in accordance with the invention (see sample A of the examples) are recognized by transmission electron microscopy (referred to as TEM), which makes it possible to state that the RS nanoparticles according to the invention more specifically have a diameter in the range from 1 to 5 nm.

Areas of use

Cyano-bridged coordination polymers have their own vacancies, which can provide the sorption of ionic compounds. Depending on the nature of these ionic compounds, the fields of application are quite wide.

One of the objectives of the invention is the binding of cations of radionuclides in cyano-bridged metal nanoparticles in organic tissues, which is called excretion.

In particular, we can consider the option of removing cesium. Many cyano-bridged metal nanoparticles can be used for excretion with varying efficiencies (Vincent, 2014). Traditional cyano-bridged metal nanoparticles are RS, which are known to efficiently scavenge cesium (McCargar, 1988 and Henge, 2000). RV is not absorbed orally and the so-called Radiogardase® is a commercial cesium scavenger. In this case, as mentioned earlier, the RV particles remain in the gastrointestinal tract, waiting for the binding of cesium atoms, which follow the path of potassium. The RS nanoparticles in the reverse micellar system according to the invention can significantly increase, in particular by oral administration, the sorption of cesium with fewer doses and therefore prevent undesirable side effects.

Accordingly, it is an object of the invention to provide a biocompatible reverse micellar system containing cyano-bridged metal nanoparticles according to the present invention, in which the biocompatible reverse micellar system or the cyano-bridged metal nanoparticles contained therein are used to displace and/or bind a radionuclide and/or metal cation.

The terms radionuclide cations and metal cations in the present invention refer to any chemical form of said radionuclide and metal cations. For example, the radionuclide and/or metal cations that are displaced and/or captured in accordance with the present invention may be in ionic form, optionally with at least one counter-anion, or complexed with at least one other ligand, solvated or in oxide form, before substitution or bonding.

In accordance with the present invention, substitution and derivatives of this term refer to the replacement of one or more atoms from cyano-bridged metal nanoparticles with one or more radionuclides and/or metal cation(s) in the medium. More specifically, the term substitution is used for gadolinium and manganese cations.

According to the invention, bonding and derivatives of this term refer to the capture of one or more atoms by one or more vacancies of cyano-bridged metal nanoparticles in a medium. More specifically, the term binding is used for cesium and thallium cations.

For example, the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles contained therein, can be used to replace a metal cation, thereby facilitating the release of the metal cation contained in the patient's body. Said metal cation may be the result of, for example, external intoxication (exposure to the metal cation) or pathogenesis causing the accumulation of cations in the patient's body.

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The term excretion is used in the present invention in connection with a radionuclide cation to denote the removal of at least a portion of said radionuclide cation from the patient's body.

In one embodiment, the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles included therein in accordance with the invention, or a composition containing it, are used to remove at least one radionuclide cation and/or treat at least one metal cation intoxication. the patient's body. In this embodiment, the elimination or treatment of intoxication includes the replacement and/or binding of the metal cation and/or radionuclide using the biocompatible reverse micellar system of the invention or the cyano-bridged metal nanoparticles contained therein and the elimination and/or excretion of the substituted and/or associated cation metal or radionuclide from the patient's body. In a preferred embodiment, excretion is through natural routes such as urine or feces.

In the present invention, the terms treatment or elimination refer to any prophylactic and/or curative action that is capable of suppressing or reducing the duration or intensity of any symptom due to exposure to a radionuclide and/or metal cation or improving the health or comfort of a patient in any way.

In one embodiment, the metal cation or radionuclide is toxic to the patient, or the amount of said metal cation or radionuclide present in the patient is toxic.

The term radionuclide cation or radioactive nuclide cation refers to the cation of an atom with an unstable nucleus, characterized by excess energy available for transfer either to a newly emerging particle of radiation in the nucleus, or through internal conversion. During this process, the radionuclide cation is believed to undergo radioactive decay, resulting in the release of gamma rays and/or subatomic particles such as alpha or beta particles.

Depending on the nature of the cyano-bridged metal nanoparticles included in the inverted micellar system, this system is suitable for the removal of cations of any type of radionuclides. If the radionuclide cation is a specific isotope of an element, the reverse micellar system will not necessarily more selectively displace the radioactive isotope than other isotopes of the same element.

In embodiments of the invention, the radionuclide cation is selected from the group consisting ^of plutonium, e.g. ^{238 Pu} , ²³⁹ Pu or ^{240 Pu} , americium, e.g. ^{241 Am} , uranium, ^{e.g. 135} Cs or ¹³⁷ Cs, thallium, such as ²⁰¹ Tl or ²⁰⁴ Tl, indium, such as ^In, strontium, such as ⁸⁵ Sr, ⁸⁹ Sr or ⁹⁰ Sr, molybdenum, such as ⁹⁹ Mo or ¹⁰⁰ Mo, lead, such as ²¹⁰ Pb, chromium, eg ⁵¹ Cr, polonium, eg ²¹⁰ Rho, cobalt, eg ⁵⁷ Co, ⁵⁸ Co or ⁶⁰ Co, copper, eg ⁶⁴ Cu or ⁶⁷ Cu, gallium, eg ⁶⁷ Ga, technetium, eg ^99m Tc, and their degradation products. The radionuclide cation is more preferably cesium, thallium or some lanthanide cation.

The selectivity of the inverted micellar system according to the invention upon substitution or binding of radionuclide and/or metal cations is related to the selectivity of metal cations in cyano-bridged metal nanoparticles.

Accordingly, the cyano-bridged metal nanoparticles are preferably selective for two basic atoms such as cesium ( ¹³⁵ Cs or ¹³⁷ Cs) and thallium ( ²⁰¹ Tl or ²⁰⁴ Tl).

By way of example, PB is known to be suitable for binding cesium and/or thallium. Accordingly, when the cyano-bridged metal nanoparticles included in the biocompatible reverse micellar system of the invention are RS nanoparticles, the biocompatible reverse micellar system of the invention or the RS nanoparticles contained therein are used to capture at least one of cesium or thallium.

The metal cation that can be substituted and/or bonded by the cyano-bridged metal nanoparticles according to the invention can be any metal cation. For example, the metal cation may be a transition metal cation, a heavy metal cation, a lanthanide cation, or an alkali metal cation.

In one embodiment, the metal cation, which may be substituted and/or bonded, is selected from iron, aluminum, mercury, lead, arsenic, cadmium, cesium, copper, gold, beryllium, bismuth, cobalt, chromium, nickel, protactinium, polonium, silver , platinum, antimony, selenium, tin, technetium, titanium, zinc, manganese and thallium. In a specific embodiment, the metal cation is cesium.

In one embodiment, the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles contained therein, or a composition containing them, is used to reduce the cumulative radiation dose delivered to tissues by internalized radionuclide cations. Indeed, the only possibility is to eliminate the radionuclide cations by binding them in order to facilitate their excretion by natural means, such as urine or feces. In accordance with a specific embodiment of the invention, the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles contained therein, or a composition containing them, is intended to reduce the risk of developing diseases due to the cumulative radiation dose transmitted to tissues by radionuclide cations.

In accordance with a specific embodiment, the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles contained therein, or a composition containing them, is intended for the treatment of at least one disease associated with the accumulation and/or overdose of at least one radionuclide cation in a patient. in need of it.

Diseases (or pathologies) associated with the accumulation and/or overdose of at least one radionuclide cation may vary depending on the radiation exposure (duration and/or amount), may include gastrointestinal disorders such as nausea or vomiting, symptoms, associated, for example, with a predisposition to infection or bleeding, neurological disorders or various types of malignant neoplasms (eg leukemia or thyroid cancer).

Exposure to radionuclide cations and thus accumulation and/or overdose of radionuclide cations can have various origins, for example, from the injury of nuclear workers when the containment of the glove box is destroyed, to the contamination of many people by the widespread distribution of radionuclide cations in the environment, such as: incident / an accident or natural disaster affecting research facilities, production facilities, facilities for the operation or storage of nuclear materials, a military conflict with the use of nuclear weapons, a weapon containing radionuclide cations, a terrorist act directed at these facilities or characterized by an explosive device that disperses radionuclide cations, called dirty bomb.

Cations of internalized radionuclides are highly toxic and can cause both acute and chronic radiation injury. The most commonly encountered nuclides in these scenarios include actinide cations such as americium, plutonium or uranium and transition metal cations such as cesium or strontium. After internalization in the body, the nuclide is distributed to various tissues and/or organs (eg lungs, muscles, bone and/or liver).

In a specific embodiment, the cyano-bridged metal nanoparticles included in the biocompatible reverse micellar system of the invention are PB nanoparticles. The biocompatible reverse micellar system according to the invention, or the PB nanoparticles contained therein, or a composition containing it, is used to remove at least one of cesium or thallium or to treat at least one disease associated with the accumulation and/or overdose of cesium or thallium in a patient in need of it.

The patient to be treated may be any non-human or human mammal, and more particularly children.

Another object of the invention is a biocompatible reverse micellar system according to the invention or the cyano-bridged metal nanoparticles contained therein, or a composition containing them, is used as a contrast agent and/or as a diagnostic agent.

Cyano-bridged metal nanoparticles are well known as a contrast agent for magnetic resonance imaging (MRI) and imaging agent for scintigraphy. When delivered through the mucosa, the uptake and/or quality of cyano-bridged metal nanoparticles within the body can be increased, which can improve the quality of images obtained by imaging methods. In particular, a manganese-based contrast agent (Pan, 2011, Massaad, 2011 and Zhu, 2015) and a gadolinium-based contrast agent (Mohs, 2007 and Zhou, 2013) have been investigated for the use of MRI. However, both of these types are quite toxic at certain dose levels and the amounts administered must be reduced. Thus, the use of cyano-bridged metal nanoparticles containing Mn ²⁺ and Gd ³⁺ ions in a reverse micellar system should:

(i) improve longitudinal relaxation values allowing lower doses of contrast agent to be administered and/or (ii) improve pharmacokinetics by increasing circulation time in the body and/or (iii) reduce toxicity.

In addition, the advantage of using a transmucosal system is the passage through the blood-brain barrier. More specifically, cyano-bridged metal nanoparticles in a reverse micellar system can indeed provide brain imaging.

Depending on the nature of the metal cation involved in the cyano-bridged metal network, compounds presenting magnetic properties of interest for imaging techniques (such as MRI) can be formed in a reverse micellar system.

In accordance with a particular embodiment, the cyano-bridged metal nanoparticles included in the reverse micelle system of the invention are gadolinium or manganese substituted (containing) RS nanoparticles and can preferably be used as a contrast agent and/or as a diagnostic agent.

The contrast agent may be a magnetic contrast agent (eg, as for MRI), a scintigraphy imaging aid, a spectroscopic contrast agent, or a microscopic contrast agent. In this regard, the contrast agent can be used as a diagnostic tool or agent.

Another object of the invention is a method for imaging at least a portion of at least one organ of a patient, comprising administering a biocompatible reverse micellar system of the invention, or cyano-bridged metal nanoparticles included therein, or a composition containing them. Said imaging method advantageously further comprises the step of detecting the emitted radiation and/or signal, and preferably the step of forming an image therewith.

Another object of the invention is the use of the biocompatible reverse micellar system of the invention, or the cyano-bridged metal nanoparticles contained therein, or a composition containing them, in the preparation of a composition to be used in an imaging and/or diagnostic method.

The amount of reverse micellar system that needs to be introduced to implement the imaging method can be easily adapted by any person skilled in the art depending on the number of cyano-bridged metal nanoparticles, the area (s) to be imaged using this imaging method, and the imaging technique used.

The imaging method may be, for example, scintigraphy or MRI. In one embodiment, the imaging method is bone, kidney, liver, brain, and/or lung scintigraphy. The term contrast agent refers in the present invention to an agent that can advantageously be used in an imaging method to improve the quantity and/or quality of the emitted radiation and/or the signal or image formed therefrom.

Another object of the invention is thus a reverse micellar system for use as a contrast agent according to the invention, where the contrast agent is used in scintigraphy and/or MRI.

The contrast agent may also be used to study renal perfusion and/or urinary tract function or to determine glomerular filtration rate.

The imaging method according to the invention may be part of a diagnostic method for determining a pathology, preferably a pathology of the area being imaged, such as bone, kidney, brain and/or lung pathology. The term "diagnostic agent" refers in the present invention to an agent that can advantageously be used to determine the presence of a pathology or the risk of developing a pathology, such as bone, kidney, brain and/or lung pathology.

Introduction of reversed micellar systems.

The reverse micellar systems according to the invention are capable of being absorbed through the mucosa and vectorizing cyano-bridged metal nanoparticles in a protected form into any tissues and/or organs of the body.

The reverse micellar system can be administered in a variety of ways. In a preferred embodiment of the invention, the reverse micellar system is administered by topical, oral or transmucosal route.

As used herein, the terms mucosal and mucosal refer to mucosal tissue, such as respiratory, digestive, or genital tissue. Transmucosal delivery, mucosal delivery, transmucosal administration, and similar terms used herein refer to administration of the composition through mucosal tissue. Transmucosal delivery, transmucosal delivery, transmucosal administration, and similar terms include, but are not limited to, delivery of the composition through the bronchi, gingiva, lingual, nasal, oral, buccal, esophageal, vaginal, rectal, and gastrointestinal mucosal tissues.

In a specific embodiment, the introduction of the mucosa occurs through buccal mucosal tissue.

According to another embodiment, the reverse micellar system of the invention may be administered orally for active use in the gastrointestinal tract. More specifically, this is the case for the RE particles of the invention.

The reverse micellar system can be administered according to the invention at any time with respect to exposure to and/or contamination with metal and/or radionuclide cation(s).

In one embodiment, the reverse micellar system is administered preemptively, which means prior to exposure to and/or contamination by radionucleotide and/or metal cation(s).

In another embodiment, the reverse micellar system is administered on the first day, preferably in the first hours, in particular the first 20 minutes, after exposure to and/or contamination with radionucleotide and/or metal cation(s).

In another embodiment, the reverse micellar system is administered more than 24 hours, preferably more than 48 hours, in particular more than 96 hours, after exposure to the radionucleotide and/or metal cation(s) has ended.

The reverse micellar system of the invention can be effective in removing the radionuclide cation when treatment is initiated immediately after 1 hour, 4 days after and even 7 days after contamination, preferably internal contamination.

The practitioner will be able to adapt the number of daily administrations, the amount of substances administered, the frequency of administration, and/or the start of treatment depending on the amount of active agent present in the reverse micellar system and the type and intensity of metal cation or radionuclide contamination.

In an embodiment in which a biocompatible reverse micellar system is used to treat a pathology associated with accumulation of at least one metal cation in a patient in need thereof, the pathology is not necessarily initiated by exposure to said metal cation. Pathology can also be associated with chronic metal cation exposure.

The biocompatible reverse micellar system may be in the form of a composition which may further comprise a pharmaceutically acceptable carrier.

Another object of the invention is a pharmaceutical composition comprising a pharmaceutically acceptable carrier or carrier and a biocompatible reverse micellar system of the invention.

The term pharmaceutically acceptable carrier or carrier refers to any pharmaceutically acceptable excipient, medium or carrier well known to those skilled in the art. Other additives well known to the person skilled in the art, such as stabilizers, desiccants, binders, or pH buffers, may also be used. Preferred excipients according to the invention promote adhesion of the finished product to the mucous membrane.

According to specific embodiments, the pharmaceutical composition is a capsule, caplet, aerosol, spray, solution, soft elastic gelatin capsule or syrup.

In accordance with the invention, the term includes(include) or including may be generally interpreted to include all specifically mentioned features and any optional additional and unspecified features; it can also be interpreted more specifically as the expression consists of, in which only the specified features are included, unless otherwise indicated.

The present invention includes specific embodiments as described above and any combination thereof.

In the present invention, percentages are weight percentages unless otherwise indicated.

The term around or about refers to a range of ±10% of the value.

The following examples are given only as illustrative and not limiting of the invention.

Examples

Example 1 Transition metal hexacyanometallate nanoparticles were prepared in situ and stabilized in a reverse micellar system.

Sample A.

A1: 0.11 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 9.89 g of HPLC water at room temperature after 10 seconds of vortexing.

A2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring with a magnetic stirrer was carried out at 700 rpm and 37° C. to form an oily homogeneous phase (or an oil-based homogeneous phase).

A3: 1.20 g of A1 was added to 8.80 g of A2 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

A4: 0.15 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.85 g of HPLC water at room temperature after 10 seconds of vortexing.

A5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

A6: 1.20 g of A4 was added to 8.80 g of A5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

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A: 2.00 g of A3 and 2.00 g of A6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PB nanoparticles.

Another reverse micellar system without any active compound or precursor was prepared as follows: 1.20 g of HPLC water was added to 8.80 g of A2 at room temperature and the mixture was vortexed for 10 seconds to obtain isotropic and homogeneous reverse micellar micellar system (sample A7).

Get a sample B.

B1: 0.04 g of commercially available zinc chloride tetrahydrate with a purity greater than 98% was dissolved in 9.96 g of HPLC water at room temperature after 10 seconds of vortexing.

B2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

B3: 1.20 g B1 was added to 8.80 g B2 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

B4: 0.07 g of commercially available potassium (III) hexacyanoferrate with a purity greater than 99% was dissolved in 9.93 g of HPLC water at room temperature after 10 seconds of vortexing.

B5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

B6: 1.20 g B4 was added to 8.80 g B5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing a second PBA precursor.

B: 2.00 g B3 and 2.00 g B6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Get sample C.

C1: 0.06 g of commercially available manganese chloride tetrahydrate with a purity greater than 99% was dissolved in 9.94 g of HPLC water at room temperature after 10 seconds of vortexing.

C2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

C3: 1.20 g C1 was added to 8.80 g C2 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

C4: 0.07 g of commercially available potassium (III) hexacyanoferrate with a purity greater than 99% was dissolved in 9.93 g of HPLC water at room temperature after 10 seconds of vortexing.

C5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

C6: 1.20 g C4 was added to 8.80 g C5 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

C: 2.00 g C3 and 2.00 g C6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Receipt of sample D (5%)

D1: 0.008 g of commercially available manganese chloride tetrahydrate of greater than 99% purity and 0.199 g of commercially available iron(III) chloride hexahydrate of greater than 97% purity were dissolved in 9.793 g of HPLC water at room temperature after 10 seconds of vortexing.

D 2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then added

5.75 g of Peceol® and stirred with a magnetic stirrer at 700 rpm and 37°C with the formation of an oily homogeneous phase.

D3: 1.20 g D1 was added to 8.80 g D2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

D4: 0.317 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.683 g of HPLC water at room temperature after 10 seconds of vortexing.

D5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D6: 1.20 g D4 was added to 8.80 g D5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

D (5%): 4.00 g D3 and 4.00 g D6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Receipt of Sample D (10%)

D1: 0.016 g of commercially available manganese chloride tetrahydrate with a purity above 99% and 0.188 g of commercially available iron (III) chloride hexahydrate, with a purity above 97%, were dissolved in 9.796 g of HPLC water at room temperature after 10 seconds of vortexing,

D2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D3: 1.20 g D1 was added to 8.80 g D2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

D4: 0.317 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.683 g of HPLC water at room temperature after 10 seconds of vortexing.

D5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D6: 1.20 g D4 was added to 8.80 g D5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

D (10%): 4.00 g D3 and 4.00 g D6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Receipt of sample D (25%)

D1: 0.040 g of commercially available manganese chloride tetrahydrate of greater than 99% purity and 0.157 g of commercially available iron(III) chloride hexahydrate of greater than 97% purity were dissolved in 9.803 g of HPLC water at room temperature after 10 seconds of vortexing.

D2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D3: 1.20 g D1 was added to 8.80 g D2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

D4: 0.317 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.683 g of HPLC water at room temperature after 10 seconds of vortexing.

D5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with magnetic stirring at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then added

5.75 g of Peceol® and stirred with a magnetic stirrer at 700 rpm and 37°C with the formation of an oily homogeneous phase.

D6: 1.20 g D4 was added to 8.80 g D5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

D (25%): 4.00 g D3 and 4.00 g D6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Receipt of sample D (50%)

D1: 0.080 g of commercially available manganese chloride tetrahydrate of greater than 99% purity and 0.105 g of commercially available iron(III) chloride hexahydrate of greater than 97% purity were dissolved in 9.815 g of HPLC water at room temperature after 10 seconds of vortexing.

D2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D3: 1.20 g D1 was added to 8.80 g D2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

D4: 0.317 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.683 g of HPLC water at room temperature after 10 seconds of vortexing.

D5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D6: 1.20 g D4 was added to 8.80 g D5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

D (50%): 4.00 g D3 and 4.00 g D6 were shaken together for 10 seconds at room temperature to obtain spontaneous formation of PBA nanoparticles in situ.

Sample D received (75%)

D1: 0.120 g of commercially available manganese chloride tetrahydrate of greater than 99% purity and 0.052 g of commercially available iron(III) chloride hexahydrate of greater than 97% purity were dissolved in 9.828 g of HPLC water at room temperature after 10 seconds of vortexing.

D2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D3: 1.20 g D1 was added to 8.80 g D2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

D4: 0.317 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 9.683 g of HPLC water at room temperature after 10 seconds of vortexing.

D5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

D6: 1.20 g D4 was added to 8.80 g D5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

D (75%): 4.00 g D3 and 4.00 g D6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Sample E.

E1: 0.06 g of commercially available manganese chloride tetrahydrate with a purity greater than 99% soluble

- 17 042836 li in 9.94 g of HPLC water at room temperature after 10 seconds of vortexing.

E2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

E3: 1.20 g E1 was added to 8.80 g E2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

E4: 0.04 g of commercially available zinc chloride tetrahydrate with a purity greater than 98% was dissolved in 9.96 g of HPLC water at room temperature after 10 seconds of vortexing.

E5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

E6: 1.20 g E4 was added to 8.80 g E5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

E7: 0.07 g of commercially available potassium (III) hexacyanoferrate with a purity greater than 99% was dissolved in 9.93 g of HPLC water at room temperature after 10 seconds of vortexing.

E8: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

E9: 1.20 g E7 was added to 8.8 g E8 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

E: 2.00 g E3, 2.00 g E6 and 4.00 g E9 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Example 2 Transition Metal Tetracyanometallate Nanoparticles in a Reverse Micellar System.

Sample F received.

F1: 0.06 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 9.94 g of HPLC water at room temperature after 10 seconds of vortexing.

F2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Added 5.75 g of Peceol® and conducted stirring with a magnetic stirrer at 700 rpm and 37°C with the formation of an oily homogeneous phase.

F3: 1.20 g F1 was added to 8.80 g F2 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

F4: 0.07 g of commercially available potassium tetracyanonicolate with a purity greater than 99% was dissolved in 9.93 g of HPLC water at room temperature after 10 seconds of vortexing.

F5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. 5.75 g Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

F6: 1.20 g F4 was added to 8.80 g F5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

F: 2.00 g F3 and 2.00 g F6 are shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Example 3 Transition Metal Octacyanometallate Nanoparticles in a Reverse Micellar System.

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Sample G received.

G1: 0.11 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 9.89 g of HPLC water at room temperature after 10 seconds of vortexing.

G2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Added 5.75 g of Peceol® and conducted stirring with a magnetic stirrer at 700 rpm and 37°C with the formation of an oily homogeneous phase.

G3: 1.20 g of G1 was added to 8.80 g of G2 at room temperature and the mixture was stirred for 10 seconds in order to obtain an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

G4: 0.09 g of molybdenum or tungsten octacyanide was dissolved in 9.91 g of HPLC water at room temperature after 10 seconds of vortexing.

G5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. 5.75 g Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

G6: 1.20 g of G4 was added to 8.80 g of G5 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing a second PBA precursor.

G: 2.00 g of G3 and 2.00 g of G6 are shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Example 4 Lanthanide hexacyanometallate nanoparticles were prepared in situ and stabilized in a reverse micellar system.

Get sample H.

H1: 0.09 g of commercially available gadolinium (III) nitrate hexahydrate with a purity greater than 99.9% was dissolved in 9.91 g of HPLC water at room temperature after 10 seconds of vortexing.

H2: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

H3: 1.20 g H1 was added to 8.80 g H2 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the first PBA precursor.

H4: 0.07 g of commercially available potassium hexacyanoferrate with a purity greater than 99% was dissolved in 9.93 g of HPLC water at room temperature after 10 seconds of vortexing.

H5: 1.50 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.30 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.25 g of beta-sitosterol was dissolved in the mixture under the same conditions. Then 5.75 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

H6: 1.20 g H4 was added to 8.80 g H5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PBA precursor.

H: 2.00 g H3 and 2.00 g H6 were shaken together for 10 seconds at room temperature to obtain spontaneous in situ formation of PBA nanoparticles.

Example 5 Visual Observations of In Situ Produced and Stabilized Cyano-Bridged Metal Nanoparticles in a Reverse Micellar System.

After in situ formation of cyano-bridged metal nanoparticles, visual observations show that all samples are stable, homogeneous and isotropic. A unique phase is observed and there is no haze.

Example 6 FTIR characterization of in situ formation of cyano-bridged metal nanoparticles in a reverse micellar system.

Samples A, B, C, D and E can be characterized by infrared measurements. This method has been used to analyze stretching vibrations and bonding vibrations of M'-CN-M bonds, which are signatures of nanoparticle formation. In particular, CN stretching vibrations are observed in the wavenumber range 2000-2100 cm ^-1 .

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In the case of Fe(II)-CN-Fe(III) bond pattern A, one peak is induced and a stretching vibration is detected at 2086 cm ^-1 as reported by Ghosh, 1974 and Ellis, 1981.

In the case of the Fe(III)-CN-Zn(II) B bond sample, a single broad peak is induced and a stretching vibration is detected at 2092 cm ^-1 as reported by Denisova, 2009 and Vincent, 2014.

In the case of the Fe(III)-CN-Mn(II) C bond pattern, a thin peak is induced and a stretching vibration is detected at 2071 cm ^-1 as reported by Chugh, 2012.

The FTIR spectra are shown in Fig. 2 and 3.

Example 7 UV-Visible Characterization of In Situ Produced and Stabilized RS Nanoparticles in a Reverse Micellar System.

Sample A is the only sample that can be characterized using the UV-visible measurement method. Indeed, cyano-bridged metallic RS nanoparticles absorb in the visible region. This is due to intercellular charge transfer between Fe ²⁺ and Fe ³⁺ through the CN bond at a wavelength of 685 to 695 nm (Riter, 1998, Uemura, 2004). The absorption spectra are shown in Fig. 4.

Example 8 Microscopic Characterization of In Situ Obtained and Stabilized RS Nanoparticles in a Reverse Micellar System.

Sample A was analyzed by microscopy (TEM) to highlight the presence and structure of the nanoparticles. Microscopic images are shown in Fig. 5. Under the conditions of the invention, particles smaller than 5 nm are distinguishable. Particles larger than 5 nm should be clearly visible, so the available nanoparticles in sample A have a diameter of 1 to 5 nm.

Example 9 In Vitro Cesium Adsorption Study Using Commercial or In Situ Produced PB Nanoparticles in a Reverse Micellar System.

An in vitro study was achieved using two different systems. The goal was to compare the efficiency of cesium uptake by different RS nanoparticles.

The first system tested is comparative and is a surrogate for Radiogardase® using an available commercial RS in a reverse micellar system.

The second test system contains PB nanoparticles obtained and stabilized in a reverse micellar system according to the invention.

Receipt of sample I.

30.00 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 26.00 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. Then, under the same conditions, 5.00 g of beta-sitosterol was dissolved. 129.00 g Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase. Finally, 10.00 g HPLC water was added to form a homogeneous reverse micellar system. Then 0.04 g of commercial RS was dispersed in a homogeneous reverse micellar system at room temperature and mixed on a vortex mixer.

Receipt of Sample J.

J1: 0.11 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 9.89 g of HPLC water at room temperature after 10 seconds of vortexing.

J2: 15.00 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1300 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 2.50 g of beta-sitosterol was dissolved in the mixture under the same conditions. 64.50 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

J3: 5.00 g J1 was added to 95.00 g J2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

J4: 0.15 g of commercially available sodium hexacyanoferrate with a purity greater than 99% was dissolved in 9.85 g of HPLC water at room temperature after 10 seconds of vortexing.

J5: 15.00 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1300 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 2.50 g of beta-sitosterol was dissolved in the mixture under the same conditions. 64.50 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form an oily homogeneous phase.

J6: 5.00 g J4 was added to 95.00 g J5 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

J: 100.00 g J3 and 100.00 g J6 were shaken together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Obtaining cesium-containing samples K.

- 20 042836

K1: 0.4 mols-1 from Cs ⁺ was obtained by dissolving 0.004 g of CsCl with a purity greater than 99% in 44.996 g of HPLC water.

K2: 1.0 mols-1 from Cs ⁺ was prepared by dissolving 0.008 g of CsCl with a purity greater than 99% in 44.992 g of HPLC water.

K3: 2.0 mols-1 from Cs ⁺ was prepared by dissolving 0.016 g of CsCl with a purity greater than 99% in 44.984 g of HPLC water.

K4: 4.0 mols' ¹ from Cs ⁺ was obtained by dissolving 0.034 g of CsCl with a purity greater than 99% in 44.966 g of HPLC water.

K5: 6.0 mol^l-1 from Cs ⁺ was prepared by dissolving 0.050 g of CsCl with a purity greater than 99% in 44.950 g of HPLC water.

The experiment consisted of contacting 24.00 g of samples I and J with 7.00 g each of five samples K.

Two-phase systems were induced, which were continuously stirred for 24 hours in closed vessels. After 24 hours of agitation, all biphasic systems were centrifuged to recover aqueous phases containing remaining cesium ions. The cesium concentrations were then analyzed using ion chromatography to show the sorption of cesium for various initial Cs concentrations, the so-called isotherms shown in FIG. 6. The results show that in situ prepared and stabilized RS nanoparticles are more efficient than commercial RS for cesium adsorption.

In the next table. 1 shows the examples detailed above.

Table 1

In situ synthesis of cyano-bridged metal nanoparticles Sample First predecessor(s) Second predecessor(s) Short Formula nanoparticles A FeCE, 6H ₂ O Na4[Fe(CN) ₆ l' Yun ₂ O Fe[Fe(CN) ₆ ] IN ZnCl _{2,4H 2} O K ₃ [Fe(CN) ₆ ] Zn[Fe(CN) ₆ ] WITH MPC1 ₂ , 4H ₂ O K ₃ [Fe(CN) ₆ ] Mn[Fe(CN) ₆ ] D (5%) 5% MnC1 ₂ + 95% FeCE Na4[Fe(CN) ₆ ]' Yun ₂ O MnFe[Fe(CN) ₆ ] D (10%) 10% MnC1 ₂ + 90% FeCE Na4[Fe(CN) ₆ ]' Yun ₂ O MnFe[Fe(CN) ₆ ] D (25%) 25% MnC1 ₂ + 75% FeCE Na4[Fe(CN)6]' Yun ₂ O MnFe[Fe(CN) ₆ ] D (50%) 50% MnC1 ₂ + 50% FeCE Na4[Fe(CN) ₆ ]' Yun ₂ O MnFe[Fe(CN) ₆ ] D (75%) 75% MnC1 ₂ + 25% FeCE Na4[Fe(CN) ₆ ]' Yun ₂ O MnFe[Fe(CN) ₆ ] E 50% MnCl ₂ + 50% ZnCl ₂ K ₃ [Fe(CN) ₆ ] MnZn[Fe(CN) ₆ ] F FeCE, 6H ₂ O K ₂ [Ni(CN) ₄ ] Fe[Ni(CN) ₆ ] G FeCE, 6H ₂ O [MoorW](CN) ₈ Fe[Mo(CN) ₆ ] H Gd (NO ₃ ) _{3,6H 2} O K ₃ [Fe(CN) ₆ ] Gd[Fe(CN)61 In vitro study of cesium uptake on cyano-bridged metal nanoparticles I Fe [Fe(CN) ₆ ] Commercial PB J _FeCl3 Na 4 [Fe(CN) ₆ ] Fe[Fe(CN) ₆ ] TO Aqueous solutions of cesium chloride

Example 10 In vivo study of cesium incubation using in situ prepared cyano-bridged metal RS nanoparticles in a reverse micellar system.

Receipt of sample L.

L1: 0.17 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 3.83 g of HPLC water at room temperature after 10 seconds of vortexing.

L2: 3.60 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 3.24 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.90 g of beta-sitosterol was dissolved in the mixture under the same conditions. 26.10 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

L3: 2.16 g L1 was added to 33.84 g L2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

L4: 0.23 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 3.77 g of HPLC water at room temperature after 10 seconds of vortexing.

L5: 3.60 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 3.24 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.90 g of beta-sitosterol was dissolved in the mixture under the same conditions. 26.10 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

L6: 2.16 g L4 was added to 33.84 g L5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

- 21 042836

L: 35.00 g L3 and 35.00 g L6 were shaken together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Get sample M.

M1: 0.34 g of commercially available iron(III) chloride hexahydrate, with a purity greater than 97%, was dissolved in 3.66 g of HPLC water at room temperature after 10 seconds of vortexing.

M2: 1.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.08 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.30 g of beta-sitosterol was dissolved in the mixture under the same conditions. 8.70 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

M3: 0.72 g M1 was added to 11.28 g M2 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

M4: 0.45 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 3.55 g of HPLC water at room temperature after 10 seconds of vortexing.

M5: 1.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 1.08 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.30 g of beta-sitosterol was dissolved in the mixture under the same conditions. 8.70 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

M6: 0.72 g M4 was added to 11.28 g M5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

M: 10.00 g M3 and 10.00 g M6 were vortexed together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Materials and methods.

After a 3-day acclimatization, 16 unrelated Sprague-Dawley rats 7 to 8 weeks old at the start of treatment (i.e., 250 +/- 30 g body weight) were housed in separate metabolic cages to allow separate collection of urine and feces with a constant temperature of 22°DC and a daily diet containing AO4C granules from S.A.F.E. and tap water ad libitum.

All rats were contaminated using an intraperitoneal injection of 500 µg cesium. Treatment was started one hour after Cs contamination (except for untreated group A rats); rats were injected for 4 days with sample L once a day (group B) and twice a day (group D) or sample M twice a day (group C). For the buccal and rectal routes, rats were anesthetized under gaseous isoflurane to provide a more reproducible administration.

Urine and feces for each rat were collected separately and cumulatively over 4 days, and cesium doses were analyzed by ICP-MS after mineralization.

Next table. 2 shows the corresponding study design of this in vivo study:

table 2

Groups A IN WITH D Number of rats 4 4 4 4 Identification of the agent for withdrawal Pattern L Sample M Pattern L Path gastric tube buccal rectal The concentration of RS nanoparticles 1 mg/g 2 mg/g 1 mg/g Dose per injection 8 mg/kg 2 mg/kg 1 mg/kg Duration once a day for 4 consecutive days twice a day for 4 consecutive days twice a day for 4 consecutive days Cumulative dose received by the rat 250 g 8 mg 4 mg 2 mg

The percentage of recovered cesium in faeces for each group is shown in FIG. 7.

This figure shows that RE nanoparticles created in a reverse micellar system enhance cesium excretion in feces. In Le Gall et al. similar efficacy results have been described at lower Cs contamination and higher doses of RS (Legall, 2006). This suggests that the cyano-bridged metal RS nanoparticles produced in situ according to the invention can improve cesium excretion at a lower RS dose.

Example 11 In vivo study of cesium excretion with in situ prepared cyano-bridged metal nanoparticles of RS in a reverse micellar system compared to commercially available RS.

Receipt of sample N.

N1: 6.00 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 5.40 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 1.50 g of beta-sitosterol was dissolved in the mixture under the same conditions. 43.50 g Peceol was added thereto and stirred with a magnetic stirrer at 700 rpm and 37° C. to form an oil-based homogeneous phase.

N: 3.60 g of HPLC water was added to 56.40 g of N1 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase without any active ingredients.

Obtaining samples O, P, Q, R.

O, P, Q, R were prepared by suspension of available commercial RS in distilled water. All samples were mixed on a magnetic stirrer for 30 minutes to obtain suspensions of RS from 0.5 to 1-2-10 mg/g, respectively.

Sample S received.

S1: 0.06 g of commercially available iron(III) chloride hexahydrate with a purity greater than 97% was dissolved in 2.94 g of HPLC water at room temperature after 10 seconds of vortexing.

S2: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

S3: 1.92 g S1 was added to 30.08 g S2 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

S4: 0.09 g of commercially available sodium hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 2.91 g of HPLC water at room temperature after 10 seconds of vortexing.

S5: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

S6: 1.92 g S4 was added to 30.08 g S5 at room temperature and the mixture was vortexed for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

S: 30.00 g S3 and 30.00 g S6 were shaken together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Sample T.

T1: 0.12 g of commercially available iron(III) chloride hexahydrate, greater than 97% purity, was dissolved in 2.88 g of HPLC water at room temperature after 10 seconds of vortexing.

T2: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

T3: 1.92 g T1 was added to 30.08 g T2 at room temperature and the mixture was stirred for 10 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the first PB precursor

T4: 0.18 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 2.82 g of HPLC water at room temperature after 10 seconds of vortexing.

T5: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

T6: 1.92 g T4 was added to 30.08 g T5 at room temperature and the mixture was stirred for

- 23 042836 seconds to obtain an isotropic and homogeneous reverse micellar phase containing the second precursor PB.

T: 30.00 g T3 and 30.00 g T6 were mixed together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Receipt of sample U.

U1: 0.24 g of commercially available iron(III) chloride hexahydrate, greater than 97% purity, was dissolved in 2.76 g of HPLC water at room temperature after 10 seconds of vortexing.

U2: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

U3: 1.92 g U1 was added to 30.08 g U2 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the first PB precursor.

U4: 0.36 g of commercially available sodium (II) hexacyanoferrate decahydrate with a purity greater than 99% was dissolved in 2.64 g of HPLC water at room temperature after 10 seconds of vortexing.

U5: 3.20 g of commercially available lecithin containing more than 97% phosphatidylcholine was dissolved in 2.88 g of absolute ethanol with stirring with a magnetic stirrer at 300 rpm and room temperature. 0.80 g of beta-sitosterol was dissolved in the mixture under the same conditions. 23.20 g of Peceol® was added and stirring was carried out with a magnetic stirrer at 700 rpm and 37° C. to form a homogeneous oil-based phase.

U6: 1.92 g U4 was added to 30.08 g U5 at room temperature and the mixture was vortexed for 10 seconds to achieve an isotropic and homogeneous reverse micellar phase containing the second PB precursor.

U: 30.00 g U3 and 30.00 g U6 were shaken together for 10 seconds at room temperature to obtain spontaneous formation of PB nanoparticles in situ.

Materials and methods.

After a 3-day acclimatization, 45 unrelated Sprague-Dawley rats aged 7 to 8 weeks at the start of treatment (i.e. 250 +/- g body weight) were housed in individual metabolism cages to allow separate fecal collection, at a constant temperature of 22°C. DC and a daily diet containing AO4C granules from S.A.F.E. and tap water ad libitum.

All rats were contaminated with intraperitoneal injection of 50 μg of cesium. Treatment was started three hours after Cs contamination; rats were then administered orally via gavage twice daily for four consecutive days with distilled water (group A), sample N (group B), sample O (group C), sample P (group D), sample Q (group E) , sample R (group F), sample S (group G), sample T (group H), sample U (group I).

Feces from each rat were collected separately and cumulatively over 48 hours (0 to 48 hours and 48 to 96 hours). Hearts were harvested after sacrificing at the end of processing.

Cesium doses in feces and hearts were analyzed by ICP-MS after mineralization.

Next table. 3 summarizes the research design of this in vivo study.

Table 3

Groups A IN WITH D E F G H I Number of Rats 5 5 5 5 5 5 5 5 5 Identification of the agent for withdrawal Distilled water Sample N Sample About Example P Example Q Sample R Example S Sample T sample and Path gastric tube The concentration of RS nanoparticles 0.5 mg/g 1 mg/g 2 mg/g 10 mg/g 0.5 mg/g 1 mg/g 2 mg/g Dose per administration 2 mg/kg 4 mg/kg 8 mg/kg 40 mg/kg 2 mg/kg 4 mg/kg 8 mg/kg Duration Twice daily for 4 consecutive days Cumulative dose obtained by treatment with a rat weighing 250 g 4 mg 8 mg 16 mg 80 mg 4 mg 8 mg 16 mg

The percentage clearance efficiency in the hearts for each group is shown in FIG. 8.

It was demonstrated that long-term treatment with RS nanoparticles reduced the retention

- 24 042836 cesium in the heart compared to control (0% efficiency). In addition, at the same dosage, the in situ cyano-bridged metal RS nanoparticles obtained in accordance with the invention are more efficient (35 to 53%) than the available commercial RS in suspension in distilled water (9 to 12%).

The percentage of recovered cesium in the feces for each group is shown in FIG. 9.

It has been confirmed that, at the same dosage, the removal of cesium is more efficient in the case of cyano-bridged metal RS nanoparticles obtained in situ in accordance with the invention, compared to the available commercial RS in suspension in distilled water.

In addition, the cesium excretion rate is higher within 48 hours in the case of cyano-bridged metal nanoparticles of RS prepared in situ in accordance with the invention compared to commercially available RS in suspension in distilled water.

Claims (14)

1. A method for producing a biocompatible reverse micellar system comprising cyano-bridged metal nanoparticles, said method comprising the following step consisting of: mixing (i) at least one biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol and an aqueous solution containing at least one metal salt as a precursor and water, where the metal salt is a salt a metal cation (M ^p+ ) selected from transition metal cations and lanthanide cations, with (ii) a biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol and an aqueous solution containing a cyanometallate salt as a precursor, and water, where the cyanometallate salt has the formula: (Alk ⁺ _x [M'(CN)n] ^q ), where M' is a metal cation with CN ligands, and Alk ⁺ is an alkaline cation, the metal cation (M') is a transition metal cation that specifies the number of CN ligands and their associated alkali cations, q is an integer equal to 2, 3 or 4 and equal to x, n is 4, 6 or 8 and x is 2, 3 or 4 , and said system does not contain a stabilizing agent. 2. The method according to claim 1, characterized in that the metal salt contains chloride or nitrate anions and water molecules. 3. The method according to claim 1 or 2, characterized in that the transition metal cation is selected from the group consisting of iron, zinc, manganese and mixtures thereof. 4. The method according to any one of claims 1 to 3, wherein the transition metal cation is selected from the group consisting of gadolinium (Gd), terbium (Tb), ytterbium (Yb), and mixtures thereof. 5. The method according to any one of claims 1 to 4, characterized in that the metal salt is a metal chloride or nitrate selected from the group consisting of FeCl ₂ , 4H2O; FeCl ₃ , 6H ₂ O; ZnCl ₂ , 4H2O; MnCl2, 4H2O; Gd(NO3)3, 6H2O; and their mixtures. 6. The method according to any one of claims 1 to 5, characterized in that the metal cation (M') is iron, cobalt, nickel or molybdenum or tungsten; preferably M' is an iron cation. 7. The method according to any one of claims 1 to 6, characterized in that the cyanometallate salt is selected from the group consisting of Na ₄ Fe(CN) ₆ , Na ₃ Fe(CN) ₆ , Na ₂ Ni(CN) ₄ , Na ₄ Mo (CN) ₈ or Na ₄ W (CN) ₈ , as well as compounds, - 28 042836 corresponding to the above formulas, in which sodium atoms are replaced by potassium atoms. 8. The method according to any one of claims 1 to 7, characterized in that, before the mixing step, the biocompatible reverse micellar systems (i) and (ii) are obtained by a method comprising the following steps: step 1: separate preparation of aqueous solutions each containing at least one metal precursor by dissolving each metal precursor in water, preferably deionized water step 2: each of the aqueous solutions obtained in step 1 is solubilized in a homogeneous phase on an oily a base containing at least one acylglycerol, sterol, lecithin and ethanol, and optionally water, to form a homogeneous reverse micellar system, where the homogeneous oil-based phases are preferably the same. 9. Biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, cyano-bridged metal nanoparticles and water, and said system does not contain a stabilizing agent, where cyano-bridged metal nanoparticles contain a metal cation (M ^p+ ) , selected from transition metal cations and lanthanide cations, and a cyanometallate salt having the formula: (Alk ⁺ _x [M'(CN)n] ^q ), where Alk ⁺ is an alkali cation, M' is a transition metal metal cation with CN- ligands, which specifies the number of CN ligands and their associated alkali cations, q is an integer equal to 2, 3 or 4 and equal to x, n is 4, 6 or 8, and x is 2, 3 or 4. 10. Use of a biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, cyano-bridged metal nanoparticles and water, wherein said system does not contain a stabilizing agent, where the cyano-bridged metal nanoparticles contain a metal cation (M ^p+ ) , selected from transition metal cations and lanthanide cations, and a cyanometallate salt having the formula: (Alk ⁺ _x [M'(CN)n] ^q- ), where Alk ⁺ is an alkali cation, M' is a transition metal metal cation with CN ligands , which specifies the number of CN ligands and their associated alkali cations, q is an integer equal to 2, 3, or 4 and equal to x, n is 4, 6, or 8, and x is 2, 3, or 4, as contrast agent. 11. Use of a biocompatible reverse micellar system containing at least one acylglycerol, sterol, lecithin, ethanol, cyano-bridged metal nanoparticles and water, wherein said system does not contain a stabilizing agent, where the cyano-bridged metal nanoparticles contain a metal cation (M ^p+ ) , selected from transition metal cations and lanthanide cations, and a cyanometallate salt having the formula: (Alk ⁺ _x [M'(CN) _n ] ^q -), where Alk ⁺ is an alkali cation, M' is a transition metal metal cation with CN ligands , which specifies the number of CN ligands and their associated alkali cations, q is an integer equal to 2, 3, or 4 and equal to x, n is 4, 6, or 8, and x is 2, 3, or 4, for substitution and/or binding of cations of radionuclides and/or metals. 12. A biocompatible reverse micellar system according to claim 9, characterized in that this biocompatible reverse micellar system is obtained by a method according to any one of claims 1 to 8. 13. Use according to claim 10 or 11, characterized in that the biocompatible reverse micellar system is obtained by the method according to any one of claims 1 to 8. 14. A pharmaceutical composition for binding radionuclide and/or metal cations, comprising a biocompatible reverse micellar system according to claim 9 or 12 in a pharmaceutically acceptable carrier or support.