Method for synthesizing zeolite nanoparticles in phosphate-buffered saline, as well as related nanoparticles, suspensions, pharmaceutical compositions, and applications.

Abstract

The present invention relates to a method for synthesizing nanoparticles comprising or containing at least one zeolite nanocrystal, comprising: - preparing a first composition / solution 1 comprising an aluminum source and a source of alkali metal M, particularly Na ions; - preparing a second composition / solution 2 comprising a silicon source and a source of alkali metal M, particularly Na ions, wherein compositions / solutions 1 and 2 contain no organic structuring agents; - mixing the two compositions / solutions 1 and 2; - crystallizing the mixture; and - separating the nanoparticles thus formed. According to the present invention, both the first composition / solution 1 and the second composition / solution 2 comprise the sources and alkaline phosphate buffer (PBS). The present invention also relates to the obtained nanoparticles and compositions comprising them.

Description

[Technical Field]

[0001] The present invention relates to a method for synthesizing zeolite nanoparticles, the nanoparticles thus obtained, suspensions of these nanoparticles in water or PBS buffer, and pharmaceutical compositions and combination products containing these nanoparticles.

[0002] These nanoparticles can be used, in particular, in the medical field, and especially for the treatment of hypoxic solid tumors. [Background technology]

[0003] Zeolites are a type of crystalline microporous material. They are formed by a three-dimensional arrangement of TO4 (T = Si, Al, or other heteroatoms) that are bonded to each other by sharing an oxygen atom. In aluminosilicate zeolites, AlO4 5- The presence of ions creates a negative charge in the skeleton, and in order to maintain electrical neutrality, so-called compensating cations (alkali metals or alkaline earth metals), such as Na, are produced. + , K + Ca 2+ Sr 2+ This must be compensated for. The voids are defined by the aluminosilicate framework formed by these three-dimensional chains. The voids in the tetrahedral crystal lattice are interconnected and occupied by alkali ions and water molecules. Dehydration of the zeolite allows for the removal of any existing water molecules. Zeolites also possess a micropore network formed from cavities, channels connecting the cavities, and pores connecting the channels or cavities to the outside. Zeolites can be natural or synthetic. There are currently more than 250 types of zeolites.

[0004] Patent Document 1 discloses methods for synthesizing hojasite nanocrystals (FAU-type zeolite), hojasite single crystals, and colloidal suspensions thereof. The hojasite nanocrystals have dimensions in the range of 5 to 400 nm, a Si / Al molar ratio in the range of 1 to 2.5, and a Si / Na molar ratio of 1.1 to 1.5. The total pore volume is 0.50 to 1.5 cm³. 3 It is within the range of / g.

[0005] Patent Document 2 discloses FAU and EMT-type zeolite nanocrystals in which sodium ions are replaced by Fe or Gd ions and which can be filled with gaseous dioxygen. These nanocrystals may be used for the diagnosis and treatment of brain tumors, including glioblastoma.

[0006] Non-patent document 1 discloses a suspension of FAU-type nanozeolite in water. The zeolite nanocrystals disclosed in these documents are synthesized in water, which limits their medical applications. In fact, these nanocrystals may cause allergic problems over long periods and at high concentrations. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2015 / 101800 [Patent Document 2] International Publication No. 2019 / 030200 [Non-patent literature]

[0008] [Non-Patent Document 1] Anfray et al., “nanosized zeolites as a gas delivery platform in a glioblasma model” [Overview of the project] [Problems that the invention aims to solve]

[0009] One of the objects of the present invention is, therefore, to propose novel zeolite nanoparticles that can be used for the diagnosis and / or treatment of a certain medical condition, particularly solid brain tumors.

[0010] Another object of the present invention is to propose a novel method for synthesizing such nanoparticles.

[0011] Another object of the present invention is to propose a colloidal suspension of these nanoparticles.

[0012] Another object of the present invention is to propose zeolite nanoparticles with reduced toxicity and / or improved oxygen adsorption ability and / or oxygen release ability.

Means for Solving the Problems

[0013] The first aspect of the present invention is the following steps, namely, - preparing a first composition / solution 1 containing an aluminum source and a source of ions of an alkali metal M, especially Na (sodium); - preparing a second composition / solution 2 containing a silicon source and a source of ions of an alkali metal M, especially Na (sodium), wherein the composition / suspension 1 and 2 do not contain any organic structuring agent; - mixing the composition / solution 1 and 2 and leaving the mixture under stirring; - crystallizing the mixture at a temperature of 50°C or higher; and - optionally separating the nanoparticles thus formed relates to a method for synthesizing nanoparticles consisting of at least one zeolite nanocrystal or containing at least one zeolite nanocrystal.

[0014] The features of the present invention are that the first composition / solution 1 and the second composition / suspension 2 are each composed of the supply source and an aqueous buffer (PBS) consisting of water and 137 mM / L NaCl, 2.7 mM / L KCl, 10 mM / L Na2HPO4, and 1.76 mM / L KH2PO4, with a pH of 7.2, and the mixture of solutions 1 and 2 has the following molar composition (I) [ka] It is having.

[0015] The method of the present invention is easy to implement and makes it possible to obtain zeolite nanoparticles that form a stable colloidal suspension in PBS.

[0016] Preferably, solutions 1 and 2 are prepared.

[0017] According to this implementation, it is sometimes necessary to heat the mixture of PBS buffer and other reagents in order to obtain a clear or transparent suspension.

[0018] Regarding temperature, the first composition / solution 1 can be prepared at room temperature. The second composition / solution can be prepared, for example, at a temperature below 30°C, particularly at 25°C. The mixing of the two compositions / solutions can be advantageously carried out at a temperature between 0°C and 30°C, particularly at 0°C. The mixture must then be left to stand under stirring for at least 2 hours, particularly 24 hours, at a temperature between 0°C and 30°C, particularly at 25°C. The mixture can be crystallized at a temperature of 50°C or higher. [Brief explanation of the drawing]

[0019] The features and advantages of this invention will become clear from the drawings and the following description.

[0020] [Figure 1] Figure 1 shows the dimensional distribution of the Na-FAU-PBS nanoparticles of the present invention, which are dispersed in a PBS solution. [Figure 2]Figure 2A shows scanning electron microscope images of Na-FAU-PBS and Gd-FAU-PBS type nanoparticles (nanocrystals), with a scale of 500 nm. Figure 2B shows transmission electron microscope images of Na-FAU-PBS type nanoparticles (nanocrystals), with scales of 100 nm and 40 nm. [Figure 3] Figure 3 shows the amount of adsorbed dinitrogen as a function of the relative pressure obtained for Na-FAU-PBS type nanoparticles under the operating conditions described below. [Figure 4] Figure 4 shows a comparison of the viability of U87-MG cells exposed to two colloidal suspensions containing 10 μg / ml and 100 μg / ml Na-FAU-water or Gd-FAU-water nanoparticles, respectively, with the viability obtained for Na-FAU-PBS and Gd-FAU-PBS nanoparticles of the same concentration. [Figure 5] Figure 5 shows the percentage of hemolysis as a function of the dose (in μg / ml) of Na-FAU- and Gd-FAU type nanoparticles synthesized in water or PBS on the left side. [Figure 6] Figure 6A shows the change in oxygen concentration in water obtained by contacting Na-FAU-water and Gd-FAU-water particles pre-filled with O2, and Figure 6B shows the change in oxygen concentration in PBS obtained by contacting Na-FAU-PBS and Gd-FAU-PBS particles of the present invention, which are pre-filled with O2. [Modes for carrying out the invention]

[0021] The aluminum source can be selected from any aluminum source capable of providing monomeric oxyhydroxide species. For the purposes of the present invention, "any aluminum source capable of providing monomeric oxyhydroxide species" means that the aluminum source does not provide polymeric oxyhydroxide species of aluminum and makes all of the aluminum soluble in a clear aqueous solution 1. In particular, the aluminum source can be selected from alumina, hydrated alumina, aluminum powder, Al, Al2(SO4)3, aluminum hydroxide Al(OH)3, sodium aluminate (NaAlO2), potassium aluminate (KAlO2), and kaolin clay.

[0022] The silicon source can be selected from all silicon sources that can provide the monomeric oxyhydroxide species of Si2-Si6. Therefore, a larger unit [SiOOH] n The amount is limited in the composition / suspension 2.

[0023] In particular, the silicon source can be selected from silica hydrogel, silicic acid, colloidal silica, calcined silica, tetraalkyl orthosilicate, silica hydroxide, precipitated silica, silica smoke, and clay. Colloidal silica is preferred in all embodiments of the method of the present invention.

[0024] The source of alkali metal M can be selected from sources of Na (sodium) and K (potassium). Hydroxides of these two alkali metals are preferred as alkali metal sources.

[0025] According to a particular embodiment, M is Na (M=Na), the aluminum source is aluminum powder, solution 1 and solution 2 are prepared, and the mixture of solution 1 and solution 2 is dehydrated under vacuum before crystallization, and the remaining solid fraction is then crystallized at a temperature of 30°C to 100°C, particularly 50°C, for a period of 6 hours or more and 30 hours or less, especially 25 hours.

[0026] According to a certain alternative embodiment, 5 ≦ x1 ≦ 8.8, 0.3 ≦ y ≦ 1.5, and 40 ≦ z ≦ 200, and according to a further specific alternative embodiment, x1 = 8.3, y = 1.1, and z = 55.6.

[0027] The FAU-type zeolite nanoparticles are thus obtained. It should also be noted that the method of the present invention can directly obtain a suspension of zeolite nanoparticles in PBS.

[0028] Advantageously, the purification of the nanoparticles is carried out using a membrane, particularly a dialysis membrane. The operation of this method is simple, inexpensive, and is usually carried out using a commercially available membrane (dialysis membrane), and it can also save water. This technique also makes it possible to retain PBS in the nanoparticles.

[0029] The second aspect of the present invention relates to a method for producing a colloidal suspension of nanoparticles, according to which the nanoparticles are synthesized according to the method of the present invention, and the synthesized nanoparticles are dispersed in water that may be sterilized, or in an aqueous buffer solution that may be sterilized and consists of water and 137 mM / L of NaCl, 2.7 mM / L of KCl, 10 mM / L of Na2HPO4, and 1.76 mM / L of KH2PO4 and has a pH of 7.2. Thus, a suspension of zeolite nanoparticles is obtained in water or in PBS. In the case of a suspension in water, pre-filtered zeolite nanoparticles are dispersed to remove PBS.

[0030] The present invention also relates to nanoparticles composed of or containing zeolite nanocrystals and obtainable according to the method of the present invention. According to the present invention, the zeolite is a FAU-type aluminosilicate, and it contains PBS ions, namely, Na + , K + , H2PO4 - , HPO4 2- , H3O + and Cl -It contains ions, and optionally water molecules. These ions are located on the surface of the crystal lattice and / or in the gaps of the crystal lattice and / or within the porous network of particles. The surface of the crystal lattice can be the surface of a particle. Na + and K + The ions can be found, in particular, as compensating ions within the interstitial spaces of the crystal lattice. The nanozeolite may advantageously contain at least two of the above ions. Depending on the pH, it may contain HPO4 2- H3O + H2PO4 - It may contain different amounts of ions. These ions are located on the surface of the crystal lattice, whichever they may be, within its porous network and / or on its surface and / or within the gaps of its crystal lattice and / or on the surface of the particles.

[0031] The inventors have demonstrated that nanoparticles synthesized in PBS physiological saline buffer have low cytotoxicity and are therefore readily accepted by living organisms.

[0032] PBS has the same salt concentration as the human body. It also contains a dihydrogen phosphate / hydrogen phosphate ion pair that allows it to maintain the pH of blood in the human body. Although the inventors have not related this to the explanation, it appears that certain ions of PBS contained within the crystal lattice and / or porous network and / or on the surface of nanoparticles can stabilize the nanoparticles and prevent their degradation in the biological environment, thereby reducing their toxic potential. In addition, ions in PBS can also modulate the charge on the surface of nanoparticles, which may affect the behavior of the nanoparticles and their interaction with living cells and tissues. Therefore, nanoparticles obtained according to the method of the present invention avoid or mitigate the aforementioned allergic phenomena.

[0033] Nanoparticles can be nanocrystals.

[0034] These nanocrystals may have an average diameter of 10 nm or more and 100 nm or less, particularly equal to 30 nm. According to a particular embodiment, the zeolite has the following chemical composition: [ka]

[0035] The number of moles of water is measured by thermogravimetric analysis. The number of atoms of Na, K, Si, and Al is measured by ICP, and the number of moles of oxygen is determined from the number of moles of metal using stoichiometric formulas.

[0036] Regardless of the embodiment, the nanoparticles of the present invention are 0.4 cm 3 / g or more and 1.5cm 3 Total pore volume of less than / g, and / or 200m 2 / g or more and 1,000m 2 Specific surface area S less than or equal to / g BET It may have.

[0037] According to a particular alternative embodiment, the nanoparticles are 0.6 cm 3 / g or more and 1.3 cm 3 Less than / g, especially 0.93cm 3 Total pore volume (cavities + pores + channels) equal to / g, and / or 300m 2 / g or more and 800m 2 / g or less, especially 600 or 428m 2 Specific surface area S equal to / g BET This nanocrystal may have chemical formula (II).

[0038] The pore network of the zeolite of this invention extends along three directions in space.

[0039] According to a fourth aspect of the present invention, the present invention relates to nanoparticles further comprising, in particular, a cation of a metal selected from Fe, Gd, Cu, and Ce in the cavities of the crystal lattice of the nanoparticles, in an amount of 0.2% by weight or more and 5% by weight or less, and / or a gas selected from oxygen, dinitrogen, carbon dioxide, and mixtures thereof contained in the pore volume. Some of these nanoparticles can be used in diagnostics, particularly in magnetic resonance imaging (MRI), and in treatment when they are filled with oxygen. In fact, these nanoparticles then supply oxygen to cells and thus increase the responsiveness of solid cancer cells to anticancer drugs.

[0040] In another aspect of the present invention, the present invention relates to a suspension comprising or consisting of the nanoparticles of the present invention and water, a buffer (PBS) comprising water and 137 mM / L NaCl, 2.7 mM / L KCl, 10 mM / L Na2HPO4, and 1.76 mM / L KH2PO4 having a pH of 7.2, alcohol, and a dispersant selected from mixtures thereof.

[0041] In another aspect, the present invention relates to a pharmaceutical composition comprising nanoparticles according to the present invention, which may be suspended in a dispersant, as a contrast agent or as an active pharmaceutical agent.

[0042] The amount of nanoparticles is appropriate for obtaining a therapeutic effect or for obtaining contrast that enables diagnosis.

[0043] The dispersant is selected from pharmaceutical-grade solvents, particularly water, PBS, alcohol, and mixtures thereof.

[0044] The compositions of the present invention can be administered orally, mucosally (particularly intranasally), or parenterally.

[0045] The present invention also relates to nanoparticles according to the present invention for use as pharmaceuticals, particularly for the treatment of hypoxic solid brain tumors, especially glioblastoma, or as diagnostic agents, particularly as MRI contrast agents.

[0046] The present invention also relates to a combination product comprising or consisting of a pharmaceutical composition or suspension according to the present invention and an anticancer agent, for administration simultaneously or at time intervals. The nanoparticles according to the present invention preferably contain oxygen in their pore network and may optionally be suspended in a pharmaceutically acceptable dispersant. The dispersant is preferably selected from water, PBS, and mixtures thereof. The anticancer agent and pharmaceutical composition of the combination product of the present invention can be administered simultaneously or at time intervals, with the anticancer agent being advantageously administered first. The anticancer agent can be selected from temozolomide® (4-methyl-5-oxo-2,3,4,6,8-pentazabicyclo[4.3.0]nona-2,7,9-triene-9-carboxamide metazolastone), doxorubicin (8S,10S)-10-(4-amino-5-hydroxy-6-methyl-tetrahydro-2H-pyran-2-yloxy)-6,8,11-trihydroxy-8-(2-hydroxyacetyl)-1-methoxy-7,8,9,10-tetrahydrotetracene-5,12-dione), and cisplatin (cis-diaminedichloroplatinum(II)).

[0047] definition For the purposes of this invention, the predicate “average dimension” means the average dimension (in number or intensity) measured by dynamic light scattering (DLS). The average dimension is the diameter of spheres that scatter at the same rate as the particles being measured. The basic dimensional distribution obtained by DLS is the intensity distribution. The operating conditions are as defined in the remainder of this application. For the purposes of this invention, the predicate “nanoparticle” means a solid particle with a maximum dimension of less than 100 nm. This may be a single crystal or an aggregate of crystals.

[0048] The term "PBS" refers to phosphate-buffered saline, which is an aqueous solution of NaCl (0.137 M), KCl (0.002 M), disodium hydrogen phosphate (0.01 M), and potassium dihydrogen phosphate (0.0018 M). Its pH is 7.2.

[0049] The term "FAU-type nanoparticle" refers to nanoparticles that contain or consist of FAU-type zeolite single crystals.

[0050] The term "FAU-type zeolite" refers to an aluminosilicate crystallized in a face-centered cubic lattice. According to the present invention, this term includes X FAU-type zeolite having a Si / Al molar ratio of 1 or more and 1.5 or less, and Y FAU-type zeolite having a Si / Al molar ratio of 1.5 or more and 2.6 or less. Therefore, the chemical formula of the FAU-type zeolite nanocrystal is as follows: [ka] And here, Na + Ions and K + Ions are present to ensure the electrical neutrality of the nanocrystals. Water molecules do not necessarily need to be present in the nanocrystals.

[0051] The term "transparent suspension" refers to an aqueous suspension having a refractive index substantially identical to that of water, i.e., a refractive index of approximately 1.333 ± 0.030 as measured under standard conditions.

[0052] The technical terms "porous volume" or "porous network" refer to a collection of structures formed from cavities, channels connecting these cavities to one another, and pores connecting the channels and cavities to the outside of the nanoparticle.

[0053] The term "pharmaceutically active agent" refers to an agent that imparts therapeutic properties, such as therapeutic or preventive effects, to a composition containing it, and even if the agent has harmful side effects, these side effects do not outweigh the therapeutic and / or preventive effects.

[0054] The term "pharmaceutical-acceptable agent" means any agent that does not cause adverse effects or adverse effects of a magnitude that would impair the health of the patient, and that can be taken orally, injected, or applied in contact with the skin and mucous membranes.

[0055] The term "composition" means any homogeneous or heterogeneous mixture of at least two compounds that may be in different physical states. Therefore, this term "composition" includes, in particular, solutions, suspensions, and dispersions. [Examples]

[0056] Synthesis and characterization of nanoparticles The raw materials used in the following examples are listed below. That is, - Sodium hydroxide (Sigma Aldrich, 98%) - Potassium hydroxide (Sigma Aldrich, 90%) - Aluminum hydroxide (Type A2100, Alfa Aesar, 76.5% by mass Al(OH)3, 23.5% by mass H2O) - Aluminum powder (325 mesh, Alfa Aesar 99.5%) - Colloidal silica (SiO2 (Ludox HS-30, 30 wt% SiO2, pH=9.5-10.2 Sigma Aldrich)) - Colloidal silica (SiO2 (Ludox SM-30, 30 wt% SiO2, pH=9.7-10.3 Sigma Aldrich)) - Gadolinium nitrate Gd(NO3)3,6H2O (Aldrich, 99.9%) - Phosphate-buffered saline (PBS) (Sigma Aldrich, pH=7.15-7.25) These starting reagents were used as received from the manufacturer and were not further purified.

[0057] Analytical methods and operating conditions used The various zeolite materials obtained in the examples were characterized using various dimensional scales.

[0058] Imaging using scanning electron microscopes and transmission electron microscopes (SEM / TEM): The morphology of the nanoparticles was observed using a scanning electron microscope (SEM) at a voltage of 20 kV with a Tescan Mira I LMH system.

[0059] Transmission electron microscopy (TEM): The colloidal suspension was sonicated for 15 minutes, and then 2-3 drops of the particulate suspension were dried on a 300-mesh copper electron microscope grid covered with a carbon film. Images were obtained using a Tecnai G2 30 FEI microscope (Vacc=300kV, LaB6).

[0060] Dynamic light scattering (DLS) analysis: The hydrodynamic diameters of zeolite materials in various suspensions were measured using a Malvern Zetasizer Nano instrument. The surface charge of the samples was measured by the zeta potential of the suspensions. The analysis was performed on purified samples with a solid concentration of 1 wt% dispersed in PBS solution at pH 7.2. The backscatter configuration (HeNe laser with a scattering angle of 173° and a wavelength of 632.8 nm with an output power of 3 mW) allows for measurements at high sample concentrations because complete transmission of incident light through the sample is not required.

[0061] Chemical analysis by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) The chemical composition of the zeolite samples was characterized by inductively coupled plasma mass spectrometry using an Agilent Technologies 7900 instrument. The samples were prepared according to the following procedure: (i) 50 mg of the zeolite sample was dissolved in 3 mL of hydrofluoric acid (HF) (Sigma-Aldrich 40-45%), (ii) 0.5 mL of solution (HNO3 / HCl = 1:3 vol / vol) was added, and the mixture was then heated at 110°C for 1 hour in a polytetrafluoroethylene (PTFE) bottle (100 mL), and then (iii) 96.5 mL of distilled water and 2 g of boric acid (H3BO3) were added. The resulting solution was stirred overnight to promote the dissolution of boric acid. Finally, 10 mL of the suspension was diluted 10-fold with distilled water before analysis.

[0062] Example 1: Synthesis of FAU-type nanocrystals in PBS solution (Na-FAU-PBS) A colloidal suspension of FAU was synthesized by hydrothermal method from the molar composition referenced with reference to the first embodiment of the method of the present invention.

[0063] Aluminum powder solution A is prepared by dissolving 2.3 g of NaOH in 3 g of PBS, and then slowly adding 0.29 g of aluminum powder.

[0064] Silicate solution B was prepared by mixing 10 g of colloidal silica (LUDOX® HS-30) with 1.1 g of NaOH and 1 g of PBS. This turbid solution (suspension B) was heated in an oven at 100°C for 6-7 minutes to convert it to a clear solution. Solution B was then added dropwise to solution A at a temperature of 0-3°C with rapid stirring, and the mixture was then aged at room temperature for 24 hours.

[0065] The initial molar composition of the mixture is as follows: [ka]

[0066] The resulting mixture is dehydrated by freeze-drying and then crystallized in a 50°C oven for 25 hours. The suspension is purified to a pH of 7.2 using a dialysis membrane (Visking Dialysis Tubing, code number DTV.12000.08, size No. 8 (25.4 mm, 30 m), molecular weight 12-14000 Daltons). A colloidal suspension of 60-75 mL (1.6-1.9 g) containing 2.5% by mass of Na-FAU type zeolite nanocrystals in PBS is obtained. The nanoparticles contain PBS ions within their pore network, and Na is inserted into the network as an alkali ion. + and K + Contains ions. The final suspension was sonicated for 2 hours.

[0067] The crystallization yield is in the range of 53% to 63% (the crystallization yield is defined as (mass of the obtained product × 100) / (mass of SiO2 contained in solution B)).

[0068] The chemical formula of the Na-FAU-PBS zeolite nanocrystals obtained by the ICP method is as follows: [ka]

[0069] The formulas in parentheses correspond to the crystal lattice, and the number of moles of compensating ions and water are shown between the vertical lines.

[0070] Example 2: Synthesis of a colloidal suspension of nanoparticles according to the present invention Each given amount of the nanoparticle type from Example 1 was dispersed in 10 mL of PBS under sonication for 2 hours. Colloidal solutions containing 1% by mass, 2% by mass, 3% by mass, and 4% by mass of the Na-FAU-PBS type nanoparticles dispersed in PBS were obtained.

[0071] These nanoparticles are stable in colloidal suspension at room temperature for at least one week.

[0072] Example 3: Synthesis of zeolite nanoparticles charged with metal ions Five ml each of the two colloidal suspensions obtained in Example 2, each containing 2.5% by mass of nanoparticles, was separately added to 25 ml of a 0.03 mM gadolinium(III) nitrate hexahydrate (Gd(NO3)3·6H2O) solution. The suspensions were then left to stand at room temperature for 1 hour with stirring. This ion exchange process was performed twice. The final suspensions were then washed three times with PBS to finally obtain a Gd-FAU-PBS zeolite suspension in PBS at pH=7.2.

[0073] Example 4: Incorporation of dioxygen and / or CO2 into the pore network of nanoparticles Each colloidal aqueous suspension obtained in Example 2 or Example 3 was then splashed with O2, CO2, or carbogen at a flow rate of 800 mL / min for 30 minutes.

[0074] In this way, nanoparticles are obtained in which the pore network is at least partially filled with O2 and / or CO2.

[0075] Example 5: Morphological property evaluation of nanoparticles obtained in Examples 1, 2, and 4 The morphology and dimensions of synthesized Na-FAU-PBS and Gd-FAU-PBS nanoparticles were measured using scanning / transmission electron microscopy (SEM) / (TEM). Figure 1 shows the curve representing the dimensional distribution of nanoparticles dispersed in PBS for Na-FAU-PBS nanoparticles.

[0076] Regarding Na-FAU-PBS type nanoparticles, the hydrodynamic dimensions of nanoparticle aggregates in PBS solution, measured by DLS (dynamic light scattering), are between 50 and 200 nm. This distribution has been observed to be monodisperse.

[0077] Scanning electron microscope images of Na-FAU-PBS or Gd-FAU-PBS zeolite nanoparticles (see Figure 2A) show nearly spherical nanoparticles with a uniform particle size distribution, and transmission electron microscope (TEM) images (see Figure 2B) show nanoparticles (nanocrystals) with an average size of 30 nm.

[0078] In addition, high-resolution transmission electron microscope images show that the nanoparticles are highly crystalline. These are nanoparticles formed from individual nanocrystals.

[0079] Example 6: Chemical analysis of Na-FAU nanoparticles The chemical formulas of the zeolite materials of Na-FAU-PBS and Gd-FAU-PBS nanoparticles are as follows (determined by ICP method): [ka]

[0080] The formulas in parentheses correspond to the tetrahedral crystal lattice, and the number of moles of compensating cations and water are shown between the vertical lines.

[0081] Example 7: Measurement of porosity by dinitrogen adsorption / desorption The porosity of the Na-FAU-PBS and Gd-FAU-PBS zeolites synthesized in the above examples was characterized by adsorption / desorption measurements of gaseous nitrogen.

[0082] The texture properties of the nanoparticles obtained in Examples 1, 2, and 4 were determined by nitrogen adsorption / desorption isotherms measured using a "Micromeritics 3Flex" surface characterization instrument at a temperature of -196°C. All samples were degassed overnight under vacuum at 250°C before analysis. The outer surface volume of the zeolite nanoparticles and the volume of the micropores of the zeolite nanoparticles were evaluated by the t-plot method.

[0083] Nitrogen adsorption / desorption measurements of two types of zeolites yielded hybrid isotherms of types I and IV according to the IUPAC classification (see Figure 3). Specific surface area S of zeolite nanoparticles. BET The measurement results for total pore volume and micropore volume are grouped in Table 1 below. Micropores are defined as pores with dimensions of less than 0.08 mm.

[0084] [Table 1]

[0085] Table 2 below groups the chemical compositions of the Na-FAU-PBS and Gd-FAU-PBS nanoparticles of the present invention.

[0086] [Table 2]

[0087] The pharmacological properties of the nanoparticles of the present invention were studied. The results are shown in the following examples.

[0088] Example 8: Human culture cytotoxicity test The cells used were derived from the human glioblastoma cell line U87-MG, purchased from the American Type Culture Collection (ATCC). These cells were cultured in DMEM 1 g / L glucose (Sigma-Aldrich) supplemented with 10% fetal bovine serum (Eurobio), 2 mM glutamine (Sigma-Aldrich), and penicillin (100 U / mL) / streptomycin (100 μg / mL) (Sigma-Aldrich). The cells were cultured at 37°C, 5% CO2, and 95% humidity.

[0089] Cell viability was assessed 72 hours after exposure to zeolite nanoparticles using the WST-1 test (Rock) according to the manufacturer's instructions. The results can be seen in Figure 4. This figure also shows the percentage of cell viability after exposure to nanoparticles synthesized in water instead of PBS. With respect to the Na-FAU-PBS and Gd-FAU-PBS nanoparticles of the present invention, a higher percentage of viable cells was observed compared to nanoparticles synthesized from the same mixture but using water instead of PBS (Na-FAU-LTL-water and Gd-FAU-water).

[0090] Example 9: Red blood cell viability test To confirm the lack of toxicity of the nanoparticles of the present invention, red blood cells were exposed to increasing concentrations of nanoparticles according to the present invention (from Examples 1, 2 and 4). The results can be seen in Figure 5. Accordingly, with respect to nanoparticles synthesized in water, the maximum percentage of hemolysis was observed to be 1.85% for Na-FAU-water nanoparticles and 1.19% for Gd-FAU-water nanoparticles. This percentage decreased to 0.408% and 0.590% for Na-FAU-PBS and Gd-FAU-PBS particles, respectively.

[0091] Furthermore, in the presence of a large amount of nanoparticles (500 μg / ml), the maximum percentage of hemolysis obtained for Gd-FAU-water nanoparticles was 2%. This decreased to 1% for Gd-FAU-PBS nanoparticles.

[0092] These results confirm that using PBS during nanoparticle synthesis reduces its toxicity.

[0093] Example 10: Study on oxygen release by zeolite nanoparticles in aqueous solution and low-oxygen conditions Using a hypoxia chamber (IN VIVO2,500 (trademark), 3M), a stable and precisely controlled atmospheric gas composition was achieved with an accuracy of 0.1% O2 by adjusting the amount of N2. PBS solution (Sigma-Aldrich) was equilibrated with the gas mixture contained in the hypoxia chamber over 1 hour prior to the experiment. A sealed tube containing 12 ml of equilibrated PBS at 37°C and a dissolved oxygen sensor (SevenGo (Duo) pro (trademark) / OptiOx (trademark), Mettler Toledo) were used inside the hypoxia chamber. Prior to the experiment, a baseline was established by measuring the oxygen content of PBS for 30 minutes.

[0094] Nanoparticles of various types of embodiments, pre-filled with oxygen, were then added to the system, and the oxygen dissolved in the PBS solution was measured continuously for 1 hour. The results can be seen in Figures 6A and 6B. It was observed that the Gd-FAU-PBS nanoparticles of the present invention, pre-filled with oxygen, had better carbon dioxide release compared to nanoparticles prepared in water (Gd-FAU-water). In addition, the release rate was also increased, which is of interest for in vivo use. Oxygen release accelerated after 30 minutes, which is of considerable interest for in vivo use because the particles reach the brain and deliver oxygen there. With respect to Na-FAU-PBS nanoparticles, it was observed that the carbon dioxide release rate was slower compared to Na-FAU-water.

Claims

1. The following steps, namely, - A first composition / solution 1 is prepared, comprising an aluminum source and a source of alkali metal M, particularly Na ions; - A second composition / solution 2 is prepared, comprising a silicon source and a source of alkali metal M, particularly Na ions, wherein compositions / solutions 1 and 2 contain no organic structuring agents; - The compositions / solutions 1 and 2 are mixed, and the mixture is left to stand under stirring; - The mixture is crystallized at a temperature of 50°C or higher; and - The nanoparticles formed in this manner may be separated. A method for synthesizing nanoparticles consisting of at least one zeolite nanocrystal, or containing at least one zeolite nanocrystal, The first composition / solution 1 and the second composition / solution 2 are each supplied with the aforementioned source, water, and 137 mM / L NaCl, 2.7 mM / L KCl, and 10 mM / L Na ２ HPO ４ , 1.76 mM / L KH ２ PO ４ It consists of an aqueous buffer solution (PBS) having a pH of 7.2, and the mixture of the composition / suspension 1 and 2 has the following molar composition (I), i.e., 【Chemistry 1】 A method characterized by having the following:

2. The method according to claim 1, characterized in that M is Na, the aluminum source is aluminum powder, the mixture of composition / solution 1 and 2 is dehydrated under vacuum before crystallization, and the remaining solid fraction is then crystallized at a temperature of 30°C to 100°C, particularly 50°C, for a period of 6 hours or more and 30 hours or less, particularly 25 hours.

3. The method according to claim 1 or 2, characterized in that M is Na, and 5 ≤ X1 ≤ 8.8, 0.3 ≤ Y ≤ 1.5 and 40 ≤ Z ≤ 200, in particular X1 = 8.3, Y = 1.1 and Z = 55.

6.

4. The method according to any one of claims 1 to 3, characterized in that the nanoparticles are separated by membrane filtration.

5. The zeolite is a FAU-type aluminosilicate and contains Na ＋ , K ＋ , HPO ４ ２－ , H ３ O ＋ , H ２ PO ４ － and Cl － ions, and is composed of at least one zeolite nanocrystal obtainable according to the method according to any one of claims 1 to 4, or a nanoparticle containing the at least one zeolite nanocrystal.

6. The aforementioned nanocrystals are represented by the following formula (II), that is, 【Chemistry 2】 Alternatively, the following formula, that is, 【Transformation 3】 The nanoparticles according to claim 5, characterized by having the following features.

7. 0.4 cm ３ / g or more and 1.5cm ３ Total pore volume of less than / g, and / or 200 m ２ / g or more and 1,000m ２ Specific surface area S less than or equal to / g ＢＥＴ The nanoparticles according to claim 5 or 6, characterized by having the following features.

8. The nanoparticle according to any one of claims 5 to 7, characterized in that the crystal lattice further contains a cation of a metal selected from Fe, Gd, Cu, and Ce, in particular in an amount of 0.2% by weight or more and 5% by weight or less, and / or a gas selected from oxygen, dinitrogen, carbon dioxide, and mixtures thereof, contained in the pore volume.

9. Nanoparticles according to any one of claims 5 to 8, and water, water and 137 mM / L NaCl, 2.7 mM / L KCl, 10 mM / L Na ２ HPO ４ , 1.76 mM / L KH ２ PO ４ A suspension comprising, or consisting thereof, a buffer having a pH of 7.2, an alcohol, and a dispersant selected from mixtures thereof.

10. A pharmaceutical composition comprising nanoparticles according to any one of claims 5 to 8 or a suspension according to claim 9, which may be suspended in a dispersant, as a contrast agent or as an active pharmaceutical agent.

11. The dispersant is water, water and 137 mM / L NaCl, 2.7 mM / L KCl, and 10 mM / L Na ２ HPO ４ , 1.76 mM / L KH ２ PO ４ A pharmaceutical composition according to claim 10, characterized by being selected from a buffering agent having a pH of 7.2, an alcohol, and a mixture thereof.

12. A combination product comprising, or consisting of, the pharmaceutical composition according to claim 10 or 11 or the suspension according to claim 9 and an anticancer agent, for administration simultaneously or at time intervals.

13. Nanoparticles according to any one of claims 5 to 8, for use as pharmaceuticals, particularly for the treatment of solid tumors, especially brain tumors, especially glioblastoma, or for use as contrast agents, particularly as contrast agents in magnetic resonance imaging (MRI).

14. The suspension according to claim 9, particularly in PBS, for use as a pharmaceutical for the treatment of solid tumors, especially brain tumors, especially glioblastoma.

15. A suspension according to claim 9, particularly in PBS, for use as a contrast agent in magnetic resonance imaging.

Images