Medical clay nanoparticles

Abstract

The present invention relates to a composition comprising a plurality of clay nanoparticles wherein each clay nanoparticle comprises an anionic component and a cationic component wherein the anionic component has the formula (I): [(Si8MgbLic) O20 (OH) 4] (I) wherein 5.5 < b < = 6, and wherein c > 0 and b / c > 12.

Description

Technical Field

[0001] The present invention relates to compositions comprising clay nanoparticles, methods for preparing such compositions, and their use in medical and cosmetic methods. The nanoclays can be used alone or in combination with therapeutic or diagnostic agents. For example, the nanoclays can be used to deliver therapeutic or diagnostic agents or in regenerative medicine. Background Art

[0002] Clay nanoparticles are layered mineral silicate nanoparticles with a wide range of applications, including cosmetics and coatings. They have also been used as excipients and active agents in the pharmaceutical industry. Clay nanoparticles are classified into several categories based on their chemical composition, crystal structure, and nanoparticle morphology, including montmorillonite, bentonite, smectite, cellulose potassium alum, hectorite, and halloysite.

[0003] Certain clay nanoparticles self-assemble into gels in aqueous environments (e.g., in vivo), and the resulting nanoclay gels have been found to be particularly suitable for providing a regenerative microenvironment or a drug delivery platform. Examples of nanoclays that have been used in medical and cosmetic formulations are Laponite TM (Synthetic smectite clay manufactured by BYK). Laponite TM It is a disc-shaped synthetic hectorite-type clay that is considered a potential nanomedicine for drug delivery, bioimaging, tissue engineering and regenerative medicine.

[0004] Important characteristics of some nanoclay gels for use as nanomedicines include ease of administration and high in vivo stability after administration. High stability is desirable so that, once the gel is at the target site, it provides a stable matrix structure in which new cells can grow or from which drugs can be delivered. Poor stability at the target site can cause the nanoclay gel to disperse throughout the subject, meaning it will not perform its intended purpose in the correct location and could potentially cause harmful effects elsewhere in the body.

[0005] Therefore, there is a need for a clay nanoparticle gel that can effectively localize to the target site, has high stability under physiological conditions (i.e., pH 7.35 to 7.45, 36.1°C to 37.5°C), and can be safely and conveniently administered to a subject and retained. Currently known clay nanoparticles do not meet these requirements.

[0006] Some attempts have been made to address issues related to gel stability by creating organic nanoclay composites. However, these employ cross-linkable polymer chemistries that are complex, difficult to regulate, and extremely time-sensitive. For clinical feasibility, more reliable and easily manufactured formulations are needed.

[0007] The present inventors have unexpectedly discovered that, compared to existing nanoclays, clay nanoparticles with an increased ratio of magnesium ions to lithium ions can be used to prepare transparent gels with high in vivo stability. Nanoclay gels produced from such particles can have good rheological properties, particularly exhibiting changes in rheological properties under physiological conditions, thereby facilitating administration of the gel by injection while providing a transparent and stable gel at physiological pH. Furthermore, formulations containing the clay nanoparticles of the present invention can self-assemble and can be easily manufactured. Summary of the Invention

[0008] The present invention develops a composition comprising a plurality of clay nanoparticles, wherein each clay nanoparticle comprises an anionic component and a cationic component, wherein the anionic component has formula (I):

[0009] [(Si8MgbLi c )O 20 (OH)4](I)

[0010] Wherein 5.5<b≤6, and wherein c>0 and b / c>12.

[0011] Surprisingly, the gel compositions described herein have been found to exhibit high stability at physiological pH. Such gels can generally be easily administered via syringe without causing significant discomfort or pain to the subject. Furthermore, the gels are stable under physiological conditions, thereby ensuring effective localization at the target site and reducing adverse effects caused by gel displacement.

[0012] The present invention also provides a method for preparing the composition of the present invention, wherein the method comprises mixing a lithium salt solution, a magnesium salt solution, a solution comprising a cationic component and a silicate solution, and heating the solutions together until a slurry is formed.

[0013] The present invention also provides compositions for use in therapy or diagnosis, particularly therapy, of the human or animal body. Specifically, the compositions can be used in methods of tissue repair and / or regeneration, and / or cell delivery. The compositions can also be used to treat or prevent infection.

[0014] The composition of the present invention can be used in cosmetic methods. In some embodiments, the composition is a cosmetic composition, in particular a tissue filler or a topical gel or cream.

[0015] The present invention also provides a composition of the invention for use in a method of delivering one or more therapeutic or diagnostic agents to a target site in the human or animal body, wherein the method comprises administering the composition to the human or animal body.

[0016] The present invention has, in particular, the features listed in the following numbered paragraphs:

[0017] 1. A composition comprising a plurality of clay nanoparticles, wherein each clay nanoparticle comprises an anionic component and a cationic component, wherein the anionic component has formula (I):

[0018] [(Si8MgbLi c )O 20 (OH)4](I)

[0019] Among them, 5.5<b≤6,

[0020] And wherein c>0 and b / c>12.

[0021] 2. A composition according to paragraph 1, wherein 12 < b / c ≤ 100.

[0022] 3. A composition according to paragraph 1 or paragraph 2, wherein 12 < b / c ≤ 18, preferably wherein 13 < b / c ≤ 18.

[0023] 4. A composition according to any one of paragraphs 1 to 3 wherein 0.2≤c≤0.5.

[0024] 5. A composition according to any one of paragraphs 1 to 4, wherein the cationic component comprises Na + .

[0025] 6. A composition according to any one of paragraphs 1 to 5, wherein symbols b and c are determined by elemental analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES).

[0026] 7. The composition of any of paragraphs 1 to 6, wherein the average size of the clay nanoparticles in their longest dimension is from about 15 nm to about 50 nm, and wherein the average size of the clay nanoparticles in their shortest dimension is from about 1 nm to about 3 nm.

[0027] 8. A composition according to any one of paragraphs 1 to 7, further comprising one or more therapeutic or diagnostic agents.

[0028] 9. A composition according to paragraph 8, wherein the one or more therapeutic or diagnostic agents are therapeutic or diagnostic agents suitable for use in regenerative medicine.

[0029] 10. The composition according to paragraph 8 or 9, wherein the one or more therapeutic or diagnostic agents are selected from small molecules, growth factors, antibodies, biological tissue substitutes, synthetic bone grafts, antimicrobials, antibiotics and cells.

[0030] 11. A composition according to any one of paragraphs 1 to 10, wherein the composition comprises BMP-2.

[0031] 12. A composition according to any one of paragraphs 1 to 11, wherein the composition is in solid form, preferably in powder form.

[0032] 13. A composition according to any one of paragraphs 1 to 11 wherein the composition is in the form of a gel or a film.

[0033] 14. The composition according to paragraph 13, wherein the gel exhibits a 50% change in zeta potential over a pH range of pH 6.5 to pH 8 when the zeta potential is measured using acid titration.

[0034] 15. A pharmaceutical composition comprising a composition according to any one of paragraphs 1 to 14, a pharmaceutically acceptable carrier or diluent, and optionally one or more pharmaceutically acceptable excipients.

[0035] 16. A kit comprising a syringe or a vial (eg, a sprayable vial), wherein the syringe or vial contains a composition according to paragraph 13 or paragraph 14, or a composition according to paragraph 15, wherein the composition is in the form of a gel.

[0036] 17. A kit comprising: a composition according to any one of paragraphs 1 to 7; and one or more therapeutic or diagnostic agents as defined in any one of paragraphs 8 to 11, preferably wherein: (a) the composition is in the form of a powder or gel; and / or (b) the therapeutic or diagnostic agent is in the form of a powder.

[0037] 18. A method of preparing the composition of any one of paragraphs 1 to 15, wherein the method comprises mixing a lithium salt solution, a magnesium salt solution, a solution comprising a cationic component, and a silicate solution, and heating the solutions together until a slurry is formed.

[0038] 19. The method according to paragraph 18, wherein the method further comprises a hydrothermal treatment step.

[0039] 20. The method according to paragraph 18 or paragraph 19, wherein the method further comprises the step of drying the slurry to form a solid, optionally wherein the method further comprises the step of grinding the solid to form a powder.

[0040] 21. The method according to paragraph 20, wherein the method further comprises adding water to the composition to form a gel.

[0041] 22. The method according to any one of paragraphs 18 to 21, wherein the method further comprises the step of adding one or more therapeutic or diagnostic agents to the composition, wherein the one or more therapeutic or diagnostic agents are defined in any one of paragraphs 8 to 11.

[0042] 23. A composition according to any one of paragraphs 1 to 15 for use in treating the human or animal body.

[0043] 24. A composition according to any one of paragraphs 1 to 15 or 23 for use in a method of regenerative medicine.

[0044] 25. A composition for use according to paragraph 24, wherein the composition is used in a method of tissue repair or regeneration and / or cell delivery.

[0045] 26. A composition according to any one of paragraphs 1 to 15 or 23 for use in treating or preventing an infection.

[0046] 27. The composition of any of paragraphs 1 to 15 or 23 for use in a method of delivering one or more therapeutic or diagnostic agents to a target site in the human or animal body, wherein the method comprises administering the composition to the human or animal body, wherein the composition comprises one or more therapeutic or diagnostic agents and / or wherein the one or more therapeutic or diagnostic agents are administered separately in a composition at the target site in the body.

[0047] 28. A cosmetic composition comprising a composition according to any one of paragraphs 1 to 14 and optionally one or more additives, preferably wherein the cosmetic composition is a tissue filler or a topical gel or cream. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Unless otherwise indicated, references to Renovite, Renovite 1.0, or Renovite analogs in the figures refer to the compositions of the present invention.

[0049] Figure 1 Shows Laponite TM Comparison of the element ratios between XLG and the composition of the invention (Renovite) listed in Table 1. +a [(Si8Mg b Li d )O 20 (OH)4] -a Scaling was performed to express empirically determined Mg, Li, and Na relative to empirically determined Si. Bars represent mean and SD. P values ​​were calculated using an unpaired T-test.

[0050] Figure 2 Shows Laponite TM Comparison of elemental ratios between XLG and a series of compositions of the present invention (Renovite analogues) listed in Table 2. Mg content was calculated from empirical Si, Li and Na values ​​according to the following formula: (Na +a [(Si8Mg b Li d )O 20 (OH)4] -a .Bars represent mean values.

[0051] Figure 3 The enhanced gelation of Renovite (AS-19, Table 1) in response to serum was shown. After external exposure to simulated serum (40 mg / ml bovine serum albumin in phosphate buffer, pH 7.4), the gelation of Renovite and Laponite TM (XLG) Rheological isotherm of the change in gel hardness (storage modulus) in suspension. An increase in gel hardness was observed for Renovite when exposed to simulated serum. Measurements were performed at 25°C.

[0052] Figure 4 The enhanced gelation of the composition of the invention (Renovite: average of all clay batches listed in Table 1) in response to serum is shown. Renovite and Laponite in their native state (a) and after 1 hour of external exposure to simulated serum (b; 40 mg / ml bovine serum albumin in phosphate buffer, pH 7.4) TM Rheological analysis of (XLG) suspensions. In its native state, Renovite exhibited comparable gel strength (yield stress (Pa)), hardness (storage modulus (G')), and viscosity (storage modulus (G")) to those of XLG. Upon exposure to simulated serum, a significant enhancement in the gel strength, hardness, and viscosity of Renovite was observed. Yield stress was calculated as the inflection point (>5%) based on the linear dependence of shear stress on shear strain. Mean values ​​are plotted as histograms. Error bars = SD, N = 6, ** and **** indicate P < 0.01 and P < 0.0001, respectively (unpaired t-test).

[0053] Figure 5 It is shown that the enhanced gelation of the compositions of the present invention (AS-13, AS-14, AS-15, AS-18, AS-19, AS-21, AS-22, AS-33) in response to serum is related to the Mg and Li content. The high and low Mg / Li compositions of the present invention and the reference samples listed in Table 2 are compared with Laponite TM After 1 hour of external exposure to simulated serum, the storage modulus and loss modulus of the (XLG) suspension showed a significant positive correlation with the Mg / Si ratio (a), a significant negative correlation with the Li / Si ratio (b), and a slightly positive correlation with the Mg / Li molar ratio. The Mg content was calculated based on the empirical Si, Li, and Na values ​​according to the following formula: (Na +a [(Si8Mg b Li d )O 20 (OH)4] -a P values ​​are reported as Pearson correlation coefficients, with significant correlations at P < 0.05. ns = not significant.

[0054] Figure 6 The Zeta Potential Half Maximum (PHM) and its significance for nanoclay gelation are shown. During titration with HCL, a sharp decrease in the negative zeta potential (ZP) of the nanoclay (here AS-14) between pH 8 and pH 5 was observed. The sharp decrease in the negative ZP coincides with an increase in particle (aggregate) size. This indicates a phase transition from repulsive to attractive interactions between the particles, leading to gel formation under diffusion and high nanoclay concentrations (>2 wt%). PHM The pH value at which the sharp drop in negative ZP occurs is obtained by measuring the pH value at which the negative ZP is 50% of the recorded mV value before the addition of the titrant. TM The assay was performed on an Ii instrument programmed to add 30 μl of 1 M HCL every 20 s.

[0055] Figure 7 The composition of the present invention (AS-14, labeled Renovite 1.0) and Laponite TM The zeta potential half-maximum (PHM) of Renovite appears near physiological pH 7.4 (grey shade), while Laponite TM Appears at pH 5.9. Titration and dynamic ZP measurement in Stabino TM Ii was performed and was programmed to add 30 μl of 1 M HCL to a 1 wt% nanoclay suspension every 20 seconds.

[0056] Figure 8 The Zeta potential half maximum (PHM) is shown to be related to the Mg and Li content. The 1 wt% high and low Mg / Li compositions of the present invention (AS-13, AS-14, AS-15, AS-18, AS-19, AS-21, AS-22, labeled Renovite 1.0) and the reference sample AS-33 are compared to Laponite TM pH value of (XLG) suspension under PHM (pH PHM ). Mg / Si and Mg / Li showed significant positive correlations, while Li / Si showed significant negative correlations. PHM Appears at pH values ​​close to physiological pH 7.4 (grey shading). Calculate Mg content based on empirical Si, Li, and Na values ​​according to the following formula: (Na +a [(Si8Mg b Li d )O 20 (OH)4] -aP values ​​are reported as Pearson correlation coefficients, with significant correlations at P < 0.05. DETAILED DESCRIPTION

[0057] Medical clay nanoparticles

[0058] The clay nanoparticles described herein are inorganic nanoparticles. The clay nanoparticles may include or consist of silicates. The silicates may include layered silicates.

[0059] The average size of the length of the clay nanoparticles in the longest direction may be about 15 nm to about 50 nm. The average size of the length of the clay nanoparticles in the longest direction may be about 20 nm to about 40 nm. For example, the average size of the length of the clay nanoparticles in the longest direction may be about 15 nm to about 40 nm, or about 20 nm to about 50 nm, or about 24 nm to about 36 nm.

[0060] The average thickness (dimension in the shortest direction) of the clay nanoparticles may be from about 1 nm to about 3 nm. For example, the average thickness of the clay nanoparticles may be from about 1 nm to about 2.5 nm, or from about 1.5 nm to about 2.5 nm, or from about 1.3 nm to about 2.2 nm.

[0061] The size of the clay nanoparticles can be determined by any suitable method known to those skilled in the art. Typically, the size is determined using small angle X-ray scattering. The size of the clay nanoparticles can be determined when they are dispersed in an aqueous environment.

[0062] The clay nanoparticles may have an aspect ratio of at least 1:5. For example, the clay nanoparticles may have an aspect ratio of at least 1:10, or at least 1:20, or at least 1:25. The clay nanoparticles may have an aspect ratio of less than 1:100. For example, the clay nanoparticles may have an aspect ratio of less than 1:50, or less than 1:30. The clay nanoparticles may have an aspect ratio of 1:10 to 1:50. For example, the clay nanoparticles may have an aspect ratio of 1:5 to 1:30, or 1:10 to 1:30.

[0063] Each clay nanoparticle of the present invention comprises an anionic component and a cationic component. The anionic component has formula (I):

[0064] [(Si8MgbLi c )O 20 (OH)4](I).

[0065] The anionic component of the clay nanoparticle carries a negative charge. Typically, this negative charge is a-, where a is equal to the positive charge carried by the cationic component. a is greater than 0 and is not necessarily an integer value.

[0066] In the above formula (I), b represents the number of Mg atoms present per unit of the anionic component. b is not necessarily an integer value. Typically, b ≤ 6.0. More typically, b ≤ 5.9. Typically, b ≥ 5.6, preferably 5.5 ≤ b ≥ 6.0, for example, 5.6 ≤ b ≥ 6.0 or 5.6 ≤ b ≥ 5.9.

[0067] In the above formula (I), c represents the number of Li atoms present per unit anionic component. c is greater than 0 and is not necessarily an integer value. Typically, c ≤ 2, more typically c ≤ 1. Preferably, c ≤ 0.5, more preferably, c ≤ 0.45, for example, c may be ≤ 0.4. Typically, c ≥ 0.2, more typically c ≥ 0.3. Therefore, typically, 0 < c ≤ 2, 0 < c ≤ 1, 0 < c ≤ 0.5, 0 < c ≤ 0.4, 0.2 < c ≤ 2, 0.2 < c ≤ 1, 0.2 < c ≤ 0.5, 0.2 < c ≤ 0.45, 0.3 < c ≤ 0.5 or 0.3 < c ≤ 0.45. In some preferred embodiments, 0.2 < c ≤ 0.5, and in particularly preferred embodiments, 0.3 < c ≤ 0.5.

[0068] The ratio b / c is greater than 12. Typically, the ratio is less than 100, such that typically 12 < b / c ≤ 100. In some embodiments, b / c ≥ 13. In some embodiments, b / c ≥ 14. Typically, b / c ≤ 18. In some preferred embodiments, b / c ≤ 16. Thus, preferably, 12 < b / c ≤ 18, preferably, 12 < b / c ≤ 18. In some embodiments, 13 ≤ b / c ≤ 18, 13 ≤ b / c ≤ 16, 14 ≤ b / c ≤ 18, or 14 ≤ b / c ≤ 16.

[0069] The symbols b and c are preferably determined by elemental analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES).Example 2 described herein provides further details of a suitable method for determining these values ​​using elemental analysis.

[0070] The cationic component of each clay nanoparticle typically comprises one or more metal cations. In some embodiments, the cationic component comprises one or more metal cations selected from alkali metal cations, alkaline earth metal cations, transition metal cations, and combinations thereof. Such metal cations may include one or more cations of lithium, sodium, calcium, copper, potassium, or magnesium. Sodium is preferred.

[0071] Typically, the metal cation may have the formula M n+ , wherein M is a metal and n is an integer, typically an integer from 1 to 6, more typically an integer from 1 to 4. Preferably, n is 1 or 2, more preferably 1. M n+ Preferably Na + .

[0072] Thus, typically, the clay nanoparticles comprise an anionic component and a cationic component such that the clay nanoparticles have the formula:

[0073] [(M n+ ) x (M2 p+ ) y ][(Si8MgbLi c )O 20 (OH)4] a-

[0074] wherein b, c, and a are as defined anywhere herein, and wherein M n+ and M2 p+ are different metal cations, n and p are the same or different and are integers from 1 to 6, typically 1 or 2. Typically, the charge is balanced so that nx+py=a. x and y do not have to be integers and can be the same or different. The sum of x and y is greater than 0. Typically, the sum of x and y (i.e., x+y) is ≤2, more typically ≤1. In some preferred embodiments, x+y≤0.7, more preferably x+y≤0.5. Typically, x+y≥0.3, more typically ≥0.4. Therefore, in some embodiments, 0<(x+y)≤2, for example, 0<(x+y)≤1, 0<(x+y)≤0.7, 0<(x+y)≤0.5, 0.2≤(x+y)≤0.7, 0.3≤(x+y)≤0.7, 0.4≤(x+y)≤0.7, 0.3≤(x+y)≤0.5, or 0.4≤(x+y)≤0.5. In some preferred embodiments, 0.2≤(x+y)≤0.7, more preferably wherein 0.3≤(x+y)≤0.5.

[0075] In some embodiments, the cationic component of the clay comprises only one metal cation, such that the clay nanoparticles have the formula:

[0076] (M n+ ) z [(Si8MgbLi c )O 20 (OH)4] a- ,

[0077] wherein n is an integer from 1 to 4, typically 1 or 2, more typically 1, and z is equal to a / n. In some preferred embodiments, M n+ for Na + , so that the clay nanoparticles have the formula:

[0078] (Na + ) a [(Si8MgbLi c )O 20 (OH)4] a- ,

[0079] wherein a, b and c are as defined anywhere herein.

[0080] The nanoparticles of the present invention may contain impurities and / or by-products. The purity of the nanoparticles is preferably 90%, more preferably 95%, more preferably 98% or 99%. Most preferably, the nanoparticles are of the formula [(Si8Mg b Li c )O 20 (OH)4] substantially pure particles.

[0081] Compositions of the present invention

[0082] The composition of the present invention comprises a plurality of clay nanoparticles, wherein each clay nanoparticle comprises an anionic component and a cationic component, wherein the anionic component has formula (I):

[0083] [(Si8MgbLi c )O 20 (OH)4](I)

[0084] Wherein 5.5<b≤6, and wherein c>0 and b / c>12.

[0085] A plurality of clay nanoparticles herein refers to two or more clay nanoparticles.

[0086] The compositions of the present invention may contain up to 100 wt% of the clay nanoparticles of the present invention. More typically, the compositions of the present invention comprise up to 85 wt% of the clay nanoparticles of the present invention, or up to 50 wt% of the clay nanoparticles of the present invention. Typically, the composition contains at least 0.1 wt% of the clay nanoparticles, e.g., 0.1 to 100 wt%, 0.1 to 85 wt%, or 0.1 to 50 wt%.

[0087] The clay nanoparticles described herein may contain coordinated water. Therefore, the clay nanoparticles of the present invention mentioned herein are intended to cover clay nanoparticles with coordinated water. In addition, the dry composition mentioned herein is intended to cover compositions comprising clay nanoparticles containing coordinated water. Therefore, the dry composition may contain up to 10 wt % water. More typically, the dry composition contains up to 7 wt % water. Typically, the composition contains at least 3 wt % water, or at least 5 wt % water. Therefore, typically, the composition may contain 3 wt % to 10 wt % water, for example, 5 wt % to 7 wt % water. In such an embodiment, the remainder of the composition may contain up to 100 wt % of the clay nanoparticles of the present invention, such that the composition contains, for example, 93 wt % to 95 wt % of the clay nanoparticles of the present invention.

[0088] Said composition can be made up of clay nanoparticles of the present invention, or be made up of clay nanoparticles of the present invention substantially.In this embodiment, composition is generally in dry form, for example powder, film, granule, coating, porous sponge or fiber.Said composition can for example comprise at least 90% clay nanoparticles, at least 95% clay nanoparticles, at least 98% or 99% clay nanoparticles or about 99.5% clay nanoparticles.Alternately, additional materials may be present in the composition, for example, including carrier or diluent (for example water or saline), excipient and / or therapeutic agent or diagnostic agent.For example, in the embodiment in which the composition is in powder form, the composition may also include additional materials, for example ions, proteins and polymers.

[0089] In some preferred embodiments, the composition of the present invention is in a dry form, such as a powder form. The composition can be freeze-dried, such as a freeze-dried powder. Another dry form is a film. In some embodiments, such as when water or saline is present in the composition, the composition is a liquid-solid fluid mixture, such as a slurry or a paste. In some embodiments, such as when water or saline is present in the composition, the composition is in a gel form. Gel is a preferred form of the composition of the present invention, and the composition is usually applied in this form.

[0090] The gel of the present invention can be formed by, for example, casting clay nanoparticles in water. The gel of the present invention can be dried to form a film, or lyophilized. When the composition is provided in a film or lyophilized form, it can be applied to a surface. Alternatively, it can be reconstituted with a diluent (e.g., water or saline) before use.

[0091] The composition may be a pharmaceutical composition, which is a composition suitable for pharmaceutical use. Pharmaceutical compositions typically comprise one or more pharmaceutically acceptable excipients. Preferred pharmaceutical compositions are sterile and pyrogen-free.

[0092] Suitable carriers and / or diluents for use in the present invention include pharmaceutically acceptable carriers, such as water and aqueous solutions, particularly saline. Isotonic solutions, particularly isotonic saline, are preferred. The carrier or diluent is typically sterile. Thus, sterile isotonic saline is a preferred carrier. Such carriers may be used in the case of compositions in the form of slurries or gels.

[0093] As needed, the composition may also include an excipient. Those skilled in the art are familiar with suitable excipients that may be useful for inclusion. In one embodiment, when the composition also includes a therapeutic and / or diagnostic agent, for example, a second carrier material for the therapeutic or diagnostic agent may be used. The second carrier may be a polymeric material. In some preferred embodiments, the second carrier is selected from carboxymethyl cellulose, gelatin, and collagen.

[0094] For solid form medications: diluents such as lactose, glucose, sucrose, cellulose, corn starch, or potato starch; rheology modifiers such as carboxymethylcellulose, gelatin, and collagen; lubricants such as silicon dioxide, talc, stearic acid, magnesium or calcium stearate, and / or polyethylene glycol; binders such as starch, acacia, gelatin, methylcellulose, carboxymethylcellulose, or polyvinylpyrrolidone; deagglomerators such as starch, alginic acid, alginates, or sodium starch glycolate; effervescent mixtures; dyes; wetting agents such as lecithin, polysorbates, lauryl sulfate; dispersants such as sodium polyacrylate and pyrophosphate; and non-toxic and pharmacologically inactive substances generally used in pharmaceutical formulations.

[0095] For liquid forms such as syrups: rheology modifiers such as carboxymethylcellulose, gelatin and collagen; carriers such as sucrose, or sucrose with glycerol and / or mannitol and / or sorbitol.

[0096] For suspensions and emulsions: carriers such as natural gums, agar, sodium alginate, pectin, methylcellulose, carboxymethylcellulose, or polyvinyl alcohol.

[0097] For injection forms, in addition to the sterile water mentioned above, there are: rheology modifiers such as carboxymethyl cellulose, gelatin and collagen; olive oil; ethyl oleate; glycols such as propylene glycol; and, if necessary, an appropriate amount of lidocaine hydrochloride.

[0098] Preferred compositions of the present invention comprise nanoparticles of the present invention and water, wherein the nanoparticles are present in an amount of from about 0.1 wt % to about 50 wt % based on the total weight of the composition. Preferred compositions comprise nanoparticles of the present invention in an amount of from about 0.5 wt % to about 40 wt % based on the total weight of the composition. For example, the composition may comprise from about 1 wt % or about 2 wt % to about 40 wt % of the nanoparticles of the present invention. The composition typically also comprises water or saline. The composition may optionally comprise one or more other additives. The composition may consist of, or essentially consist of, the nanoparticles of the present invention and water or saline.

[0099] Preferred compositions of the present invention are gels, particularly pharmaceutically acceptable gels. The gels typically comprise from about 2 wt% to about 12 wt% of the nanoparticles of the present invention, based on the total weight of the gel. The gels may also comprise from about 80 wt% to about 98 wt% water, for example, from about 85 wt% to about 96 wt% water or from about 88 wt% to about 94 wt% water.

[0100] When the amount of nanoparticles of the present invention included in the gel is higher than 7wt%, the nanoparticles may not be fully dispersed. In this case, the gel may also include a dispersant, such as pyrophosphate or sodium polyacrylate. In embodiments where a dispersant is present in the gel, the gel may include nanoparticles of the present invention in an amount of up to about 12wt% of the total weight of the gel. For example, when a dispersant is present, the gel may include nanoparticles of the present invention in an amount of from about 2wt% to about 12wt%, from about 4wt% to about 10wt%, or from about 7wt% to about 10wt%. Such gels may also include water in an amount of from about 80wt% to about 98wt%, for example, from about 85wt% to about 96wt% or from about 88wt% to about 93wt%.

[0101] Compositions that do not contain a dispersant, such as compositions consisting of or consisting essentially of nanoparticles of the present invention and water, typically form gels when the nanoparticles are present in an amount of up to about 7 wt % based on the total weight of the gel. Thus, in embodiments in which no dispersant is present, such as when the composition consists of or consists essentially of nanoparticles of the present invention and water, the gel typically comprises from about 2 wt % to about 7 wt % of the nanoparticles of the present invention, based on the total weight of the gel. Typically, the gel comprises from about 2 wt % to about 4 wt % of the nanoparticles of the present invention, based on the total weight of the gel. In one embodiment, the gel comprises from about 4 wt % to about 5 wt % of the nanoparticles of the present invention. In another embodiment, the gel comprises from about 5 wt % to about 6 wt % of the nanoparticles of the present invention. In this case, the water content of the gel can be from about 93 wt % to about 98 wt %, such as from about 96 wt % to about 98 wt %, based on the total weight of the gel.

[0102] Alternatively, the composition of the present invention may be a paste. Typically, when the composition is a paste, the composition comprises 7 to 50 wt% of the nanoparticles of the present invention, such as 10 to 40 wt%, or 20 to 30 wt%, based on the total weight of the composition.

[0103] Alternatively, the composition of the present invention may be a sol. Typically, when the composition of the present invention is a sol, the composition comprises 0.1 wt% to 2 wt% of the nanoparticles of the present invention, such as 0.5 wt% to 2 wt%, or 1 wt% to 2 wt%, based on the total weight of the composition.

[0104] The composition of the present invention is generally biodegradable. The term "biodegradable" is understood to mean that the composition has the ability to decompose over time in the tissues or bodies of humans or animals and / or in the environment. The time for complete degradation can be at least 1 week, at least one month, at least 2 months, at least 6 months or at least 12 months. The time for complete degradation can be no more than 12 months, also no more than 6 months. For example, the time for complete degradation can be 1 week to 12 months, 1 week to 6 months, 1 month to 12 months, 1 month to 6 months, 2 months to 12 months or 2 months to 6 months. The degradation time may affect the speed at which the drug is released from the gel in situ in the body. Therefore, the degradation time can vary according to any therapeutic agent or diagnostic agent present in the composition.

[0105] When the composition is a gel, the gel preferably exhibits a 50% change in zeta potential over a pH range of pH 6.5 to pH 8. A 50% change in zeta potential is defined as a change of at least 50% in the measured zeta potential compared to the baseline zeta potential after titration with an acid. The baseline zeta potential is the zeta potential of the gel without a pH change (i.e., before the addition of acid). The baseline zeta potential is typically measured at pH 9 to pH 11, more typically at pH 9.5 to pH 10.5, and even more typically at about pH 10.

[0106] A change in zeta potential is typically a decrease in the magnitude of the zeta potential value, meaning that the absolute value of the zeta potential moves toward zero. This indicates an increase in gel stability. Zeta potential values ​​can be positive or negative. In either case, a decrease in the absolute value indicates a move closer to zero.

[0107] Preferably, 50% of the change in zeta potential occurs within the pH range of pH 7 to pH 7.8, more preferably within the pH range of pH 7.2 to pH 7.8. In a particularly preferred embodiment, 50% of the change in zeta potential of the gel occurs within the pH range of pH 7.3 to pH 7.5.

[0108] Typically, the change in zeta potential is measured by titrating the gel with an acid (e.g., hydrochloric acid). The change in zeta potential can be determined using any suitable method known in the art. For example, a dedicated zeta potential measuring device (e.g., Stabino Zeta) can be used. TMTypically, the zeta potential is measured using an aqueous solution of the nanoparticles (typically a 1 wt% ultrapure solution of the nanoparticles in water). The zeta potential is a measure of the electrokinetic potential of particles in a colloidal system and can be used as an indicator of gel stability. Particles with a large negative zeta potential will tend to repel each other. However, a low negative zeta potential indicates a low repulsive force between particles. Therefore, at a pH within the physiological range, the particles of the present invention preferably have a negative zeta potential, where the value is less than 50% of the absolute value. This means that the gel is most stable within the physiological pH range.

[0109] The gels of the present invention typically have a pH of about 10 in the absence of rheological agents or pH adjusters. At this pH, the gel typically has a very large negative zeta potential, which means that the particles repel each other and flow more easily, making it relatively easy to administer, for example, by injection. However, when exposed to body fluids or other physiological pH environments, the zeta potential changes, typically reducing the repulsive forces between the particles. As a result, the stability or hardness of the gel increases, providing a harder, more stable gel at the site of delivery. This further gelation may be the result of new attractive interactions due to increased ionicity. In addition, when in contact with body fluids, proteins that diffuse into the gel may bind and form bridges between the particles, further stabilizing the gel. The increase in stability helps to retain the gel at the site of administration and avoid off-target side effects.

[0110] Therapeutic or diagnostic agents

[0111] The compositions of the present invention can also include one or more therapeutic agents or diagnostic agents. Therapeutic agents or diagnostic agents can be small molecule therapeutic agents or diagnostic agents, including small molecule drugs, prodrugs or dyes or colorants. Alternatively, therapeutic agents or diagnostic agents can be biological agents, wherein the biological agent can be amino acids, signal molecules, peptides, proteins (wherein the protein can be a recombinant protein or a natural protein), antibodies, nucleic acids, oligonucleotides (such as aptamers) or cells. Alternatively, therapeutic agents or diagnostic agents can be polymeric materials. The combination of one or more therapeutic agents or diagnostic agents can be used.

[0112] The nanoclay compositions of the present invention can be used to deliver a variety of different therapeutic or diagnostic agents, and the nature of the agents used is not particularly limited. Exemplary therapeutic agents include antimicrobials (e.g., antibiotics), growth factors, antibodies, nutrients, enzymes, hormones, steroids, biological tissue substitutes, synthetic tissue substitutes, aptamers, and cells. Exemplary diagnostic agents include dyes, colorants, radioisotopes (which can be used for X-ray detection and / or monitoring degradation), contrast agents (e.g., contrast agents for CT, such as iodine-containing contrast agents and barium sulfate; contrast agents for MRI, such as gadolinium (III), iron oxide, iron platinum, and manganese; or contrast agents for ultrasound) or fluorescent molecules. A combination of two or more therapeutic agents can be used. A combination of two or more diagnostic agents can be used. One or more therapeutic agents can be used in combination with one or more diagnostic agents.

[0113] In one embodiment, the one or more therapeutic or diagnostic agents are agents useful in regenerative medicine. In some embodiments, the one or more therapeutic or diagnostic agents are selected from growth factors, antibodies, biological tissue substitutes, synthetic bone grafts, and cells. The composition may also include an antimicrobial agent to supplement or replace such therapeutic agents. Any antimicrobial agent may be used. Examples include antibiotics such as vancomycin, gentamicin, tobramycin, and chlorhexidine.

[0114] Typically, biological tissue substitutes can be substitutes for soft tissue (such as bone marrow or plasma) or hard tissue (such as bone). Examples of biological tissue substitutes include platelet-rich plasma (PRP) and biological bone graft substitutes.

[0115] Typically, the synthetic tissue substitute can be a synthetic bone graft. Synthetic bone grafts include calcium salts, such as calcium sulfate or calcium phosphate, used alone or in combination. Beta-tricalcium phosphate (β-TCP) is a preferred calcium phosphate. Hydroxyapatite (HA) is another preferred calcium phosphate.

[0116] Typically, the cells can be somatic cells, such as chondrocytes; progenitor cells; or stem cells, such as mesenchymal stem cells. The cells can also be provided as bone marrow aspirate (BMA).

[0117] Typically, the protein is a recombinant protein. Any protein for regenerative medicine can be used. Typically, the recombinant protein is a growth factor, such as bone morphogenetic protein (BMP), platelet-derived growth factor (PDGF), transforming growth factor (TGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF) or insulin-like growth factor (IGF). A combination of two or more such growth factors can be used.

[0118] As used herein, an aptamer is a short synthetic ssDNA or ssRNA sequence. Aptamers can be therapeutic or diagnostic, such as those that interact with a biomarker. Aptamers can also contain diagnostic features, such as fluorescent labels or radioactive isotopes.

[0119] In some preferred embodiments, the composition comprises a BMP or a BMP analog, such as an AMP. Examples include BMP-2, BMP-3, BMP-4, BMP-6, BMP-7, and BMP-8, or heterodimers thereof. AMP-2 is an example of a suitable BMP-2 analog. More preferably, the composition comprises BMP-2 and / or BMP-7, and analogs thereof, particularly BMP-2 and / or BMP-7. Most preferably, the composition comprises BMP-2 and analogs thereof, particularly BMP-2.

[0120] Alternatively, one or more therapeutic agents or diagnostic agents can be used to treat or diagnose diseases and conditions other than those associated with regenerative medicine. For example, the compositions of the present invention can be used to deliver therapeutic and / or diagnostic agents suitable for treating or diagnosing cancer. For example, diagnostic agents that exhibit chemiluminescence, fluorescence, or contain radioactive isotopes can be used. Suitable therapeutic agents include one or a combination selected from doxorubicin, β-lapachone, or methotrexate.

[0121] The composition generally comprises a diagnostically detectable amount and / or a therapeutically effective amount of one or more diagnostic agents or therapeutic agents, respectively. Such amounts can be determined by those skilled in the art based on the nature of the drug and the size and weight of the subject.

[0122] In embodiments where a BMP is provided as a therapeutic agent, the BMP can be provided at a total dose of about 0.01 μg to about 50 mg, such as about 0.1 μg to about 20 mg, or about 1 μg to about 15 mg. One skilled in the art will appreciate that the dosage may depend on the clinical situation, such as the size of the area to be treated or the total volume of the composition.

[0123] The use of clay nanoparticles for BMP delivery provides dosage control, allowing the use of low doses of BMP (e.g., 0.1 to 300 μg) to promote bone formation at the defect, or allowing the use of higher doses (e.g., 10 μg to about 25 mg, or 300 μg to about 15 mg) to reduce the risk of off-target effects. Studies have shown that the use of higher doses of BMP and its poor local retention can produce serious adverse reactions, such as heterotopic ossification, osteolysis, and swelling. Therefore, allowing low doses of BMP or ensuring that the protein is retained at the target site can help fracture healing and joint fusion without serious adverse reactions. The high stability and hardness of the gel provided by the present invention are conducive to the targeted administration of BMP, while also reducing the off-target and adverse side effects of BMP.

[0124] When the composition comprises one or more therapeutic agents and / or diagnostic agents, the therapeutic agent and / or diagnostic agent can be provided in combination with a pharmaceutically acceptable carrier (herein referred to as a second carrier). Any suitable pharmaceutical carrier can be used, and those skilled in the art are familiar with selecting suitable carriers and excipients for the therapeutic agents and diagnostic agents that can be used in the present invention. Typically, the carrier can be selected from carboxymethyl cellulose, gelatin, and collagen. Other excipients may optionally be included.

[0125] In some embodiments, the composition does not comprise other diagnostic and / or therapeutic agents.

[0126] Reagent test kit

[0127] Also provided herein are kits comprising the compositions or pharmaceutical compositions according to the present invention.

[0128] In some embodiments, the kit of the present invention comprises a syringe, such as a pre-filled syringe, wherein the syringe contains a composition as described herein, wherein the composition is in the form of a gel. In some embodiments, the kit can separately comprise the syringe and the composition of the present invention. In such embodiments, the composition can be in the form of a gel, stored in a container such as a pouch. In other such embodiments, the composition can be a precursor to the form of a gel, typically in a solid form, such as a powder, typically a lyophilized powder, which can be hydrated to form a gel.

[0129] In some embodiments, a kit of the invention comprises a vial, which can be a sprayable vial, such as a pre-filled vial containing a composition of the invention as described herein.

[0130] In some embodiments, the kits of the invention may comprise one or more therapeutic agents or diagnostic agents as defined anywhere herein.The therapeutic and / or diagnostic agents may be provided separately from the compositions of the invention, or they may be provided within the compositions of the invention.

[0131] Preferably, the composition is in powder form or gel form; and / or the therapeutic agent or diagnostic agent is in powder form. When the composition is in powder form, use of the kit may involve hydrating the powder to form a gel.

[0132] The compositions of the present invention and the therapeutic and / or diagnostic agents may be provided in a form suitable for separate administration.

[0133] Alternatively, one or more therapeutic agents and / or diagnostic agents may be provided in a form suitable for addition to a gel prior to administration to a subject. Alternatively, the drugs and compositions may be pre-mixed in dry form, and use of the kit may involve hydration of the mixture to form a gel suitable for administration.

[0134] The kit may include a bioimplant and a composition of the present invention. In one embodiment, the bioimplant is pre-coated with a gel or dry film, as described herein. Alternatively, the composition (e.g., gel or dry film) and the implant may be provided separately. The bioimplant referred to herein may be a medical device, such as a pacemaker, implantable defibrillator, or contraceptive implant; or a prosthetic implant, such as a knee, hip, or shoulder replacement, or a medical screw or other fixator.

[0135] The kit may comprise the gel of the invention in the form of a dehydrated film. The kit may also comprise a device for hydrating the film. Use of such a kit may involve application of the film, for example by application to the skin, and subsequent hydration of the film.

[0136] In some embodiments, the kit may contain the composition in the form of particles or microparticles.

[0137] The kit may also include instructions for use.

[0138] Therapeutic uses

[0139] The compositions described anywhere herein may be used to treat the human or animal body.

[0140] In one aspect, the subject is a mammal, particularly a human. However, it may not be a human. Preferred non-human animals include, but are not limited to, primates, such as marmosets or monkeys, commercially farmed animals, such as horses, cattle, sheep, or pigs, and pets, such as dogs, cats, mice, rats, guinea pigs, ferrets, gerbils, or hamsters.

[0141] In one embodiment, the composition is used in a regenerative medicine method.

[0142] Therefore, the present invention also provides the use of the composition of the present invention in the manufacture of a medicament for use in a regenerative medicine method.

[0143] The present invention also provides a regenerative medicine method comprising administering an effective amount of the composition of the present invention to a subject.

[0144] As described herein, regenerative medicine includes tissue repair and regeneration, wherein tissue repair and regeneration may include tissue formation and / or fusion. This may include the repair or regeneration of soft tissue, wherein soft tissue includes muscle (smooth muscle, skeletal muscle, and myocardium), fat, fibrous tissue (connective tissue, cartilage, tendons, and ligaments), synovial tissue, blood vessels (arteries, veins, and capillaries), lymphatic vessels, skin, and nerves. Regenerative medicine also includes the repair and regeneration of hard tissue, wherein hard tissue includes bone, tooth enamel, dentin, and cementum.

[0145] Tissue repair and regeneration also include tissue replacement, such as filling gaps left by tumors.

[0146] Preferably, the regenerative medicine approach is the repair or regeneration of skin, bone and / or cartilage.

[0147] Regenerative medicine methods can be wound repair methods. For example, one or more drugs that can be included in the composition can be used for wound repair, as well as preventing or treating complications that often occur in people who need wound repair, such as inflammation, infection, and pain.

[0148] In certain instances, regenerative medicine may involve cell delivery, such as delivery of cells to regenerate tissue, such as delivery of somatic cells (such as chondrocytes), progenitor cells, or stem cells (such as mesenchymal stem cells).

[0149] Thus, the compositions of the present invention may be used in methods of tissue repair or regeneration and / or cell delivery.

[0150] Therefore, the present invention also provides use of the composition of the present invention in the manufacture of a medicament for tissue repair or regeneration and / or cell delivery.

[0151] The present invention also provides a method of tissue repair or regeneration and / or cell delivery, wherein the method comprises administering to a subject an effective amount of the composition of the present invention.

[0152] In certain cases, the compositions of the invention may be used to treat or prevent infection.

[0153] Therefore, the present invention also provides use of the composition of the present invention in the manufacture of a medicament for treating or preventing infection.

[0154] The present invention also provides a method for treating or preventing infection, wherein the method comprises administering to a subject an effective amount of a composition of the present invention.

[0155] The composition of the present invention can also be used in a method for delivering one or more therapeutic agents or diagnostic agents to a target site of the human or animal body, wherein the method comprises administering the composition to the human or animal body, wherein the composition comprises one or more therapeutic agents or diagnostic agents and / or wherein one or more therapeutic agents or diagnostic agents are separately administered to a composition at the target site in vivo. The therapeutic agent or diagnostic agent for delivery can be any therapeutic agent or diagnostic agent as described herein. In some embodiments, the therapeutic agent or diagnostic agent is a cell. In some embodiments, the therapeutic agent or diagnostic agent is a reagent for regenerative medicine. In some embodiments, the therapeutic agent or diagnostic agent is used to treat cancer, i.e., a cancer therapeutic agent such as doxorubicin, β-lapachone or methotrexate. In such an embodiment, the target site can generally be a tumor.

[0156] The compositions and pharmaceutical compositions of the present invention can be administered in a variety of dosage forms. The compositions and pharmaceutical compositions of the present invention can be administered, for example, parenterally, whether subcutaneously, intravenously, intramuscularly, intrasternally or transdermally. Typically, the compositions of the present invention are administered by injection or applied to an exposed target site. For example, the composition can be applied directly to the surface of the object to be treated, that is, the surface is coated with the composition of the present invention (e.g., by spraying the surface to be treated); or the composition can be applied directly to the void in the tissue of the object, that is, filling or partially filling the void. Alternatively, the compositions of the present invention can be delivered through a fixed entry point, for example, by cannula delivery.

[0157] When the composition of the present invention is in the form of a gel or dry film, it can be applied directly to a wound, such as a skin wound or burn, by covering the wound with the gel or film. Alternatively, the composition of the present invention can be applied to the wound by spraying. A further dressing, such as gauze and / or a bandage can then be applied. Alternatively, the gel or film can be included in a dressing, i.e., a bandage can include the gel or dry film of the present invention.

[0158] The composition can also be applied as a coating on a medical device and provided to a subject along with the device. If the composition is provided as a dry film, the composition can be rehydrated after insertion into the device. Suitable medical devices include pacemakers, implantable defibrillators, or contraceptive implants; or prosthetic implants, such as knee, hip, or shoulder replacements, or medical screws or other fixators.

[0159] In embodiments where one or more therapeutic or diagnostic agents are used, the one or more therapeutic or diagnostic agents can be administered as a single composition comprising nanoparticles as described herein and a therapeutic and / or diagnostic agent. Alternatively, the one or more therapeutic or diagnostic agents can be administered separately from the gel, subsequently to the gel, or sequentially with the gel. The separate, subsequent, or sequential administration of one or more therapeutic or diagnostic agents can include administration to a gel on the target surface or injection into a gel at the target site.

[0160] In such an embodiment, one or more therapeutic agents or diagnostic agents can be added in a therapeutically effective amount. One or more therapeutic agents or diagnostic agents can be added by single administration or multiple administration. In some embodiments, one or more therapeutic agents or diagnostic agents can be added to the target site in situ to provide the sustained delivery of one or more therapeutic agents or diagnostic agents. One or more therapeutic agents or diagnostic agents can be added in 1 to 10 administrations, usually 1 to 6 administrations, more usually 1 to 4 administrations. As long as the composition is unsaturated, the number of administrations that can be provided is unrestricted. Therefore, administration can continue until the treatment of the object is completed.

[0161] In some embodiments, the compositions of the invention do not comprise any other therapeutic and / or diagnostic agent. In such embodiments, the composition can be administered by multiple administrations, e.g., 1 to 10 administrations, typically 1 to 6 administrations, more typically 1 to 4 administrations.

[0162] When one or more therapeutic or diagnostic agents are added to the composition in multiple administrations, there is no specific time interval between each administration. The time interval between each administration can be determined by the skilled practitioner administering the one or more therapeutic or diagnostic agents and depends on factors such as the half-life of the therapeutic or diagnostic agent in question and the rate of release from the gel.

[0163] A therapeutically effective amount of the composition of the present invention is administered to the patient. Typical dosages can be determined by those skilled in the art based on the activity of the specific composition, the age, weight and condition of the subject to be treated, the type and severity of the disease, and the frequency and route of administration.

[0164] Cosmetic uses

[0165] The compositions described herein can be used in cosmetic methods. Suitable methods include methods of using the composition as a cosmetic topical cream or gel, or as a cosmetic tissue filler (e.g., a lip filler or dermal filler) to moisturize the skin, improve skin tone, prevent or reduce wrinkles or skin spots. In some preferred embodiments, the composition is used as a cosmetic tissue filler. Alternatively, the composition can also be used in a cosmetic topical cream.

[0166] Thus, a composition described anywhere herein may be a cosmetic composition, which is a composition suitable for cosmetic use. Cosmetic compositions typically comprise one or more additives used to formulate cosmetic compositions. The cosmetic composition may be a tissue filler, or a topical cream or gel.

[0167] Typically, when the composition of the invention is a cosmetic composition or is for use in a cosmetic method, it does not comprise additional diagnostic or therapeutic agents.

[0168] The cosmetic compositions of the present invention may optionally include an anti-inflammatory agent to reduce swelling. In some embodiments, no anti-inflammatory agent is present in the cosmetic composition. In some embodiments, the cosmetic composition does not include any therapeutic agent.

[0169] Preparation method of clay nanoparticles and composition thereof

[0170] Also provided herein are methods of making the clay nanoparticles and compositions of the present invention.

[0171] Typically, the method comprises mixing a lithium salt solution, a magnesium salt solution, a solution comprising a cationic component and a silicate solution.The salt solution used in the method of the present invention may be any suitable aqueous solution known to those skilled in the art.

[0172] The molar ratio of magnesium to lithium (Mg 投入 / Li 投入 ) is 2 to 30, for example, 5 to 25, or 10 to 25.

[0173] As the lithium salt solution, lithium sulfate solution, lithium chloride solution, lithium hydroxide solution, lithium nitrate solution, and combinations thereof can be used. Typically, lithium sulfate solution is used. The method for preparing the clay nanoparticles and compositions of the present invention may first involve dissolving a lithium salt in water to form an aqueous solution. The salt may be a hydrated salt, such as a monohydrate. In some embodiments, the method involves dissolving lithium sulfate monohydrate in water.

[0174] As the magnesium salt solution, magnesium sulfate solution, magnesium chloride solution, magnesium nitrate solution, and combinations thereof can be used. Magnesium sulfate solution is typically used. The method for preparing the clay nanoparticles and compositions of the present invention may first involve dissolving a magnesium salt in water to form an aqueous solution. The salt may be a hydrated salt, such as a monohydrate or heptahydrate. In some embodiments, the method involves dissolving magnesium sulfate heptahydrate in water.

[0175] As the silicate solution, a sodium silicate solution, a potassium silicate solution, or a combination thereof can be used. Typically, a sodium silicate solution is used. The method for preparing the clay nanoparticles and compositions of the present invention may first involve dissolving a silicate in water to form an aqueous solution. In some embodiments, the method involves dissolving sodium silicate in water.

[0176] As a salt solution containing the cationic component, any suitable solution can be used. These include, for example, carbonate solutions, phosphate solutions, sulfate solutions, nitrate solutions, or combinations thereof. Typically, carbonate solutions are used, so when the cationic component includes sodium, sodium carbonate solutions can be used. The method for preparing the clay nanoparticles and compositions of the present invention can first involve the step of dissolving the cationic component salt in water to form an aqueous solution. In some embodiments, the method of the present invention includes the step of dissolving sodium carbonate to form an aqueous solution.

[0177] Once the solution is combined, the method of the present invention generally includes heating the combined solution together.Heating generally continues until a slurry is formed.Relative to the gross weight of the slurry, the weight % of the solid in the slurry is generally about 1wt% to 15wt%, generally about 3wt% to 12wt%.Sometimes, relative to the gross weight of the slurry, the weight % of the solid in the slurry is about 3wt% to about 5wt%.Sometimes, relative to the gross weight of the slurry, the weight % of the solid in the slurry is about 8wt% to about 10wt%.Conventionally the combined solution is heated to the boiling point (i.e., about 100 DEG C) of the slurry.Conventionally heated at this temperature under reflux, generally continued for about 30 minutes to about 2 hours, generally about 1 hour.

[0178] The method of the present invention may include a further step comprising subjecting the slurry to a hydrothermal treatment. Hydrothermal treatment as referred to herein is any treatment comprising heating the composition (in this case, the slurry) in the presence of water. For example, the hydrothermal treatment may include autoclaving. Typically, the hydrothermal treatment may be carried out at a temperature of 60 to 500° C. The hydrothermal treatment may be carried out under high pressure (i.e., above standard atmospheric pressure (about 100,000 Pa)). Hydrothermal treatment under high pressure may be referred to as autoclaving. Therefore, the method of the present invention may include an autoclaving step.

[0179] Typically, the hydrothermal treatment step occurs at a temperature of about 100° C. to about 300° C., typically about 150° C. to about 250° C., preferably about 180° C. to about 220° C. Typically, the hydrothermal treatment step occurs at a pressure of 30 psi to about 1800 psi, typically about 60 psi to about 600 psi, preferably about 100 psi to about 400 psi. Typically, the hydrothermal treatment step lasts for about 1 hour to 24 hours, preferably 2 hours to 12 hours, 4 hours to 8 hours, and most preferably about 6 hours.

[0180] The method of the present invention may also include a drying step, wherein the slurry is dried to form a solid. The drying of the slurry can be carried out using any suitable method known to those skilled in the art, such as rotary evaporation, oven dry or vacuum filtration. Preferably, vacuum filtration (e.g., using a Buchner funnel) is used.

[0181] The method may also include the steps of washing and re-drying the dried product. Any suitable solvent may be used to wash the product. Deionized water is typically used. Vacuum filtration (e.g., using a Buchner funnel) may be used in this step.

[0182] The washing step is particularly useful for removing soluble salt impurities (e.g., sulfate). To assess whether all impurities have been removed, BaCl2 can be added to the filtrate. If a precipitate forms, further washing is usually necessary.

[0183] Typically, more than one drying method is used, such as vacuum filtration combined with oven drying. The oven drying typically occurs at a temperature not much different from the standard temperature. Typically, the oven drying occurs at a temperature of about 40°C to about 80°C, more typically at a temperature of about 55°C to about 65°C.

[0184] The drying step may last from about 1 hour to 24 hours, typically from about 6 hours to 14 hours.

[0185] The method of the present invention may further comprise the step of grinding the dried product to form a powder. Grinding may be performed using any suitable method, for example using a pestle and mortar.

[0186] The method of the present invention may further comprise the step of adding water to the composition to form a gel.

[0187] When water is added to the composition, the composition can be vigorously stirred, i.e., stirred with a magnetic stirrer at a rate of 300 rpm to 1000 rpm, e.g., 500 rpm to 800 rpm. Stirring can be carried out at any temperature, e.g., 0° C. to 100° C., or 10° C. to 40° C. Typically, stirring occurs at standard atmospheric pressure (SATP), e.g., about 25° C. and about 15 psi.

[0188] In some embodiments, no further steps are required to obtain the gel. In some embodiments of the present method, the gel can then be sterilized, optionally by autoclaving. Autoclaving typically occurs at a temperature of about 100° C. to about 140° C., for example, about 120° C. Autoclaving typically lasts from 10 minutes to 1 hour, for example, 30 minutes. Autoclaving typically occurs at a pressure of between 13 psi and 20 psi, for example, between 15 psi and 20 psi.

[0189] The method of the present invention can also include the step of adding one or more therapeutic agents or diagnostic agents to the composition. One or more therapeutic agents or diagnostic agents can be added to the composition in any step of the method of the present invention. One or more therapeutic agents or diagnostic agents can also be added to the composition before gel formation. One or more therapeutic agents or diagnostic agents can be added after the composition is in gel form, but before being applied to the object. One or more therapeutic agents or diagnostic agents can be applied to the object alternatively or separately from the gel, such as by applying one or more therapeutic agents or diagnostic agents to the gel at the target site in the body, or by adding one or more therapeutic agents or diagnostic agents as coatings to the gel, particularly when the gel itself is coated on the surface of a medical device (such as an implant, a stent or a balloon). Typically, one or more therapeutic agents or diagnostic agents are added after the composition is in gel form, but before being applied to the object.

[0190] Example

[0191] Example 1 - Synthesis of Clay Nanoparticles

[0192] At room temperature, 2.65 g of Li₂SO₄.H₂O was dissolved in 170 mL of deionized water using a stirrer. After the Li₂SO₄.H₂O dissolved, 56.10 g of MgSO₄.7H₂O was added. The mixed salt solution was then transferred to a round-bottom flask (RBF) in the assembled reactor and heated to 60 ± 10°C.

[0193] In another container, 21.95 g of Na2CO3 was dissolved in 130 mL of DI water at room temperature with stirring.

[0194] When the RBF contents reached 60°C (±10°C), Na2CO3 solution was added at a rate of approximately 1 drop per second using a stoppered self-balancing dropping funnel.

[0195] Using a new dropping funnel, 69.7 g of sodium silicate solution was added to the RBF at a rate of approximately 1 drop per second.

[0196] A reflux condenser was then installed on the reactor and the temperature of the reactor was raised to 100° C. The mixed salt solution was then boiled under reflux at atmospheric pressure for 1 hour.

[0197] After one hour, the reaction mixture was cooled to 60°C, keeping all other conditions unchanged. A resulting slurry was formed.

[0198] Preheat the oven to 200°C with the fan set to maximum and the damper set to 40%.

[0199] The slurry was transferred to autoclave containers (120 mL per container). The autoclave containers were then placed in an oven and subjected to hydrothermal treatment (HT) at 200° C. for 6 hours. The oven was then closed and the containers were allowed to cool.

[0200] Once cooled, the slurry was rinsed out of the autoclave vessels. The contents of each autoclave vessel were then transferred to a Buchner funnel and the filter cake was washed with deionized water. 400 mL of deionized water was used per autoclave vessel.

[0201] Empty the Büchner flask periodically and test the filtrate with BaCl₂ solution. If a precipitate forms, sulfate is still being washed out of the filter cake. Continue washing until no more precipitate forms.

[0202] The filter cake is then transferred to a container suitable for the drying process. The filter cake is then left to dry for a minimum of 8 to 12 hours, but can be left to dry for up to 72 hours. Drying is performed in an oven set at 60°C, fan at 100%, and damper at 40%.

[0203] The dried cake was then powdered by grinding it with a mortar and pestle for about 10 minutes to obtain fine particles.

[0204] Example 2 - Chemical composition of clay nanoparticles

[0205] The composition of the clay nanoparticles prepared using the method of Example 1 was then analyzed by elemental analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES). TM XLG was also evaluated using the same method. The results are summarized in Table 1 below, where the empirically determined Mg, Li, and Na are expressed relative to the empirically determined Si according to the following chemical formula ratios (Na + ) a [(Si8Mg b Li c )O 20 (OH)4] -a The results are summarized in Table 1 below:

[0206] Table 1:

[0207]

[0208] Figure 1 Laponite is also shown graphically TM Comparison of element ratios between the compositions listed in Table 1 (collectively referred to as Renovite).

[0209] To illustrate further variations in the elemental composition of the nanoclays of the present invention, the method of Example 1 was repeated with modifications to the synthesis scheme, as shown in Table 2 below. For each modified synthesis, ICP-OES analysis data for the resulting nanoclays are provided, as compared to Laponite TM For comparison, the Mg / Si and Mg / Li element ratios are as follows: Figure 2 shown.

[0210] Table 2:

[0211]

[0212] *Mg content calculated from empirical Si, Li and Na values ​​according to Equation I; HT = hydrothermal treatment.

[0213] Example 3 - Gel Production Protocol

[0214] The gels of the present invention were prepared according to the weight percentage (wt.%) of nanoclay / water, where 1% is equivalent to 1 g / 100 ml or 10 mg / ml. Gels were prepared using the nanoclay of the present invention at concentrations ranging from 2 wt% to 7 wt%. For comparison, corresponding amounts of Laponite TM A reference gel was prepared as a nanoclay. The mixing procedure was designed to ensure complete wetting and dispersion of the clay particles.

[0215] 1) Deionized water (18.2 MΩ, pH 7) was added to a glass bottle with a magnetic stir bar and placed on a stirrer to create a stable vortex that extended close to the bottom of the bottle but did not expose the stir bar to air.

[0216] 2) Add powdered nanoclay gradually to the vortex over 5-10 seconds.

[0217] 3) Stir the suspension at room temperature for 1-2 minutes, then mix briefly on a vortex to remove any powder that has stuck to the sides or formed clumps. Continue stirring for an additional 25 minutes, or until the colloidal solution is clear.

[0218] 4) Measure the total weight of the bottle containing the gel, then autoclave it at 121°C and 15 psi for approximately 30 minutes using a tabletop autoclave suitable for liquid sterilization. After cooling, weigh the bottle again, replace any lost water, and vortex mix. To maintain the sterility of the gel of the present invention, the process is performed under aseptic conditions, and sterile deionized water is used to replace any lost water.

[0219] Example 4: Rheological measurements and gelation reaction to serum

[0220] The rheological properties of the inventive gels were characterized in their native state and after addition to a simulated serum bath (40 mg / ml bovine serum albumin in phosphate buffered saline, pH 7.4) to assess their response in physiological fluids (eg, after injection in vivo).

[0221] All rheological measurements were performed on a MCR 92 rheometer (Anton Paar, UK) using a 12 mm parallel plate geometry (PP12 probe) where 117 μl of gel suspension were loaded onto the rheometer plate preset at 25 °C with a 1 mm gap.

[0222] At a constant oscillatory strain of 0.005% and 1 rad s -1 Isothermal measurements of the storage modulus and loss modulus in response to serum were performed over 60 minutes at an angular frequency of 1.5 Å. After 5 minutes, a serum reservoir was applied to the level of the lower surface of the upper plate. Figure 3 It is shown that the Laponite with corresponding nanoclay concentrationTM The storage modulus observed in the gels of the present invention increased in response to serum addition compared to the gels of WT.

[0223] In 1 rad s -1 At a constant angular frequency of 1.5 Å, an amplitude sweep covering the strain range of 0.01-100% was used to measure the storage and loss moduli within the linear viscoelastic range (LVR) and define the yield strain and stress. To calculate the yield stress and yield strain, a plot of elastic stress (τ) versus shear strain (γ) was plotted, and the yield stress and yield strain were calculated for each treatment at the inflection point (>5%) based on the linear dependence of τ on γ. Figure 4 It is shown that the gel of the present invention can have the same properties as Laponite with corresponding nanoclay concentration in its natural state. TM Gel strength (yield stress (Pa)), hardness (storage modulus (G')) and viscosity (storage modulus (G")) of the gels ( Figure 4 a, top), but in simulated serum, the increase in gel strength, hardness and viscosity of the gel of the present invention was significantly enhanced ( Figure 4 b, bottom). Figure 5 The present invention reports a series of high and low Li / Mg gels and their analogs compared to Laponite in simulated serum. TM The storage modulus and loss modulus of the suspensions showed a significant positive correlation with the Mg / Si(a) molar ratio of various nanoclays and a significant negative correlation with the Li / Si(b) molar ratio.

[0224] Example 5: Protocol for measuring Zeta potential half-maximum (PHM) and gelation in response to pH

[0225] Gels of the present invention prepared according to Example 3 were measured to evaluate the zeta potential dynamics in response to pH. Zeta potential is the electrical potential at the sliding plane. This plane is the interface that separates the flowing fluid from the fluid that remains attached to the surface. Zeta potential describes the electrokinetic potential in a colloidal dispersion and is a function of the specific surface chemistry of the dispersion, which is affected by changes in pH, salt and surfactant concentrations. At the minimum zeta potential of the colloid (i.e., the absolute lowest value), the colloid is most stable as a dispersion because the repulsion between the particles is greater than the attraction. As the zeta potential approaches the isoelectric point, the attraction increases, causing the particles to aggregate.

[0226] 1M HCl (30ul, 20 seconds interval) was used in Stabino TM Titrations were performed on a ELISA® II kit, allowing for dynamic measurement of the zeta potential (P) as the pH value decreases. All titrations were performed on a 1 wt% solution of clay in filtered ultrapure water, prepared on the day of the test.

[0227] Figure 6 The data show a sharp drop in negative zeta potential (ZP) between pH 8 and pH 5 during titration with HCl. This is characteristic of all nanoclays tested and coincides with an increase in particle (aggregate) size, indicating a shift from repulsive to attractive particle interactions. At high nanoclay concentrations (>2 wt%), the increased attraction leads to gel formation. The pH at which the sharp drop in potential occurs corresponds to the zeta potential half-maximum (PHM), defined as the point at which the negative ZP is 50% of the mV recorded before titrant addition. Figure 7 It shows that the pH value (pH PHM ) averages 7.33 – close to physiological pH. This is similar to Laponite TM In contrast, Laponite TM Average pH PHM It is much lower at 5.9. Figure 8 Shown, with Laponite TM Compared with other high lithium analogs of the gel of the present invention, the physiologically optimized pH of the gel of the present invention is PHM This is related to its higher Mg content and lower Li content.

Claims

1. A composition comprising a plurality of clay nanoparticles, wherein each clay nanoparticle comprises an anionic component and a cationic component, wherein the anionic component has formula (I): [(Si8MgbLi c )O 20 (OH)4](I) Among them, 5.5<b≤6, And wherein c>0 and b / c>12.

2. The composition according to claim 1, wherein 12 < b / c ≤ 18, preferably wherein 13 < b / c ≤ 18.

3. The composition according to claim 1 or 2, wherein 0.2≤c≤0.

5.

4. The composition according to any one of claims 1 to 3, wherein the cationic component comprises Na + .

5. The composition of any one of claims 1 to 4, further comprising one or more therapeutic or diagnostic agents.

6. The composition of claim 5, wherein the one or more therapeutic or diagnostic agents are therapeutic or diagnostic agents suitable for use in regenerative medicine.

7. The composition of claim 5 or 6, wherein the one or more therapeutic or diagnostic agents are selected from the group consisting of small molecules, growth factors, antibodies, biological tissue substitutes, synthetic bone grafts, antimicrobials, antibiotics, and cells.

8. The composition of any one of claims 1 to 7, wherein the composition comprises BMP-2.

9. The composition according to any one of claims 1 to 8, wherein the composition is in the form of a gel or a film.

10. The composition of claim 9, wherein the gel exhibits a 50% change in zeta potential over a pH range of pH 6.5 to pH 8 when zeta potential is measured using acid titration.

11. A kit comprising a syringe or a vial, wherein the syringe or the vial comprises the composition according to claim 9 or 10.

12. A method of preparing the composition of any one of claims 1 to 10, wherein the method comprises mixing a lithium salt solution, a magnesium salt solution, a solution comprising a cationic component, and a silicate solution, and heating the solutions together until a slurry is formed; optionally subjecting the slurry to a hydrothermal treatment; optionally drying the slurry to form a solid; as well as The solid is optionally ground to form a powder.

13. The method of claim 12, further comprising adding water to the composition to form a gel.

14. The composition of any one of claims 1 to 10 for use in a regenerative medicine method, a tissue repair or regeneration method, a cell delivery method, or for treating or preventing infection.

15. A composition as claimed in any one of claims 1 to 10 for use in a method of delivering one or more therapeutic or diagnostic agents to a target site in the human or animal body, wherein the method comprises administering the composition to the human or animal body, wherein the composition comprises the one or more therapeutic or diagnostic agents and / or wherein the one or more therapeutic or diagnostic agents are administered separately in a composition at the target site in the body.

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