A method for preparing an injectable fast self-healing emulsion gel

Abstract

The application discloses a preparation method of an injectable quick self-healing emulsion gel. First, an emulsion is prepared by high-speed shearing of a surfactant and an oil phase, and then the emulsion is fully mixed with a crosslinking agent at room temperature to quickly form an emulsion gel. The functional groups in the surfactant and the crosslinking agent interact with each other to give the emulsion gel self-healing properties through reversible crosslinking. The method is simple, mild, green and safe, and the self-healing emulsion gel prepared by the method can quickly and spontaneously heal without any external stimulation, thereby prolonging the service life of the material and having stable structure and performance. In addition, the self-healing emulsion gel has shear thinning performance, thereby expanding the application range of the self-healing emulsion gel in the fields of food, medicine and cosmetics.

Description

Technical Field

[0001] This invention relates to the field of gel material preparation technology, and more specifically, to a method for preparing an injectable, rapid self-healing emulsion gel. Background Technology

[0002] Emulsion gels are gel-like solids or semi-solids formed by encapsulating a dispersed phase within a continuous phase, based on an emulsion and aided by certain induction methods. They possess strong water-holding and swelling capabilities. Compared to traditional oil-water emulsions, the network structure and superior mechanical properties of gels provide a more robust physical barrier for oil droplets, restricting the flow, migration, and oxygen diffusion of liquid oils, resulting in better storage stability. Therefore, they have attracted considerable attention in recent years. Because emulsion gels can improve emulsion stability, protect bioactive substances, and control their release, acting as encapsulators, protectors, and slow-release agents, they are among the most promising transport systems. Numerous studies have reported on the rich functionality of emulsion gels, indicating their promising application prospects in the food, pharmaceutical, and cosmetic fields.

[0003] Generally, the preparation process of emulsion gels can be divided into two steps: the preparation of the emulsion, and the induction of the emulsion through a series of induction methods such as heat, pH, salt, and enzymes to induce gelation, thereby obtaining the emulsion gel. Therefore, the preparation process of emulsion gels is cumbersome and has a long gelation cycle. Emulsion gels prepared by traditional methods lack the ability to self-repair after being damaged, resulting in limited practical applications despite their promising prospects.

[0004] The concept of self-healing materials was proposed in the 1980s. Conceptually, self-healing generally refers to the ability of a material to spontaneously heal or repair fractures and defects after being damaged, restoring its structure and function. Mechanistically, self-healing materials inherently possess the ability to restore the load-bearing capacity of the material. This restoration can occur autonomously or be achieved by applying specific stimuli (such as radiation, heat, or water). It is an emerging biomimetic material that mimics the self-healing mechanism of organisms after injury. Due to its self-healing ability, self-healing gels can significantly extend their service life and improve their reliability and durability. In the past decade, self-healing gels have attracted widespread attention and become one of the important hot topics in innovative materials research in recent years. More and more researchers are choosing to introduce self-healing properties into gels to enhance their application prospects.

[0005] However, the preparation process of emulsion gels is cumbersome, the gelation cycle is long, and there are no reports of emulsion gels that can self-repair after damage. Therefore, improving the preparation method of emulsion gels and introducing self-healing properties into emulsion gels to prepare a self-healing emulsion gel to overcome the shortcomings of conventional emulsion gels is of great significance in expanding the application fields of emulsion gels. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing an injectable, rapid self-healing emulsion gel.

[0007] The first objective of this invention is to provide a method for preparing an injectable, rapid self-healing emulsion gel.

[0008] A second objective of this invention is to provide an injectable rapid self-healing emulsion gel prepared by the method described above.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0010] A method for preparing an injectable, rapidly self-healing emulsion gel includes the following steps:

[0011] S1. Mix the surfactant with the oil phase at a volume ratio of 5-1:2-1 to obtain a mixture, and shear the mixture at high speed for 1-3 minutes to obtain a stable emulsion;

[0012] S2. The stable emulsion obtained in step S1 is thoroughly mixed with the crosslinking agent at a volume ratio of 19-4:5-1, and a self-healing emulsion gel is obtained after the crosslinking reaction.

[0013] Preferably, the oil phase in step S1 is vegetable oil.

[0014] More preferably, the oil phase in step S1 is one or more of rapeseed oil, sunflower seed oil, soybean oil, camellia seed oil, olive oil, sacha inchi oil, flaxseed oil, perilla oil, and gardenia oil.

[0015] Preferably, the surfactant in step S1 is one or more of carboxymethyl chitosan, carboxyethyl chitosan, quaternized chitosan, gallic acid-grafted chitosan, maleic acid-modified chitosan, and / or cationic gelatin.

[0016] More preferably, the concentration of the surfactant in step S1 is 0.5 wt% to 4 wt%.

[0017] Most preferably, the concentration of the surfactant in step S1 is 1 wt% to 4 wt%.

[0018] Preferably, the crosslinking agent in step S2 is one or more of the following: dialdehyde cellulose nanofibers, oxidized sodium alginate, oxidized pullulan, dialdehyde bacterial cellulose, oxidized pectin, oxidized dextran, oxidized leucovorin, oxidized starch, oxidized hyaluronic acid, and / or thiol-derived sodium alginate.

[0019] More preferably, the concentration of the crosslinking agent in step S2 is 0.5 wt% to 4 wt%.

[0020] Most preferably, the crosslinking agent in step S2 is one or more of dialdehyde cellulose nanofibers, oxidized pullulan polysaccharide, and / or dialdehyde bacterial cellulose.

[0021] More preferably, the concentration of the crosslinking agent in step S2 is 0.5 wt% to 2 wt%.

[0022] Preferably, in step S2, the stable emulsion obtained in step S1 is thoroughly mixed with the crosslinking agent at a volume ratio of 19-4:5-1 under high-speed shearing, wherein the reaction conditions for the high-speed shearing are: 10,000-20,000 rpm for 10-30 seconds.

[0023] More preferably, in step S2, the reaction conditions for high-speed shearing are: mixing at 10,000 rpm for 15 seconds.

[0024] Preferably, in step S2, the crosslinking reaction conditions are: standing at room temperature for 10s to 10min.

[0025] The injectable rapid self-healing emulsion gel prepared by the aforementioned method should also be within the scope of protection of this invention.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The method for preparing the injectable rapid self-healing emulsion gel provided by the present invention is simple and fast, the preparation conditions are mild, and the resulting injectable rapid self-healing emulsion gel has a stable structure and properties.

[0028] (2) The injectable rapid self-healing emulsion gel prepared by the present invention is constructed by reversible cross-linking of surfactant and cross-linking agent. It can form gel quickly in as little as 10 seconds and can self-heal quickly at room temperature without external stimulation. The self-healing emulsion gel can self-heal quickly in as little as 3.5 minutes after breaking and maintains a stable structure after self-healing. It will not break again unless external force is applied.

[0029] (3) The injectable rapid self-healing emulsion gel prepared by the present invention has shear-thinning properties compared with conventional emulsion gels. It can be squeezed out smoothly through a fine needle without clogging, and can form gel in situ. It has great application prospects in the fields of food, medicine, cosmetics and other fields. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the preparation process of an injectable, rapid self-healing emulsion gel.

[0031] Figure 2The images show the self-healing performance of the self-healing emulsion gel samples prepared in Examples 1-3 and Examples 7-9. A1-F1 are images of the gel after being cut into pieces; A2-F2 are images of the gel pieces adhering to each other; A3-F3 are images of the gel after healing under gravity; A1-A3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 1; B1-B3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 2; C1-C3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 3; D1-D3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 7; E1-E3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 8; and F1-F3 represent the self-healing performance of the self-healing emulsion gel prepared in Example 9.

[0032] Figure 3 The images show the alternating strain scanning test results of the self-healing emulsion gels prepared in Examples 1 to 3 and Examples 7 to 9, where a is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 1; b is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 2; c is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 3; d is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 7; e is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 8; and f is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 9.

[0033] Figure 4 The images show the injectability of the self-healing emulsion gel samples prepared in Examples 1 to 3 and Examples 7 to 9, where a is an actual injection image of the gel in Example 1; b is an actual injection image of the gel in Example 2; c is an actual injection image of the gel in Example 3; d is an actual injection image of the gel in Example 7; e is an actual injection image of the gel in Example 8; and f is an actual injection image of the gel in Example 9. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0035] Example 1: A method for preparing a carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel

[0036] The preparation process of the carboxymethyl chitosan-dialdehyde cellulose nanocrystal self-healing emulsion gel is as follows: Figure 1As shown, the specific steps are as follows:

[0037] Method 1:

[0038] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0039] S2. At room temperature, dialdehyde cellulose nanocrystals were dispersed in distilled water to prepare a dispersion with a dialdehyde cellulose nanocrystal concentration of 2wt%.

[0040] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0041] S4. Add the dispersion prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 5:2. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 2 minutes to obtain a carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel.

[0042] Method 2:

[0043] Steps S1 and S2 are the same as in Method 1;

[0044] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:2. After mixing and stirring at 10000 rpm for 2 minutes, a carboxymethyl chitosan stabilized emulsion is obtained.

[0045] S4. Add the dispersion prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 19:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 50 seconds to obtain a carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel.

[0046] Method 3:

[0047] Steps S1 and S2 are the same as in Method 1;

[0048] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 1:1 and mixed and stirred at 10,000 rpm for 2 minutes to obtain a carboxymethyl chitosan stabilized emulsion.

[0049] S4. Add the dispersion prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 4:1. Mix and shear at 10,000 rpm for 15 seconds, and let stand at room temperature for 10 seconds to obtain carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel.

[0050] Method 4:

[0051] S1. At room temperature, carboxymethyl chitosan is dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 2 wt%.

[0052] Step S2 is the same as in method 1;

[0053] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0054] S4. Add the dispersion prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 4 minutes to obtain a carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel.

[0055] Method 5:

[0056] S1. At room temperature, carboxymethyl chitosan is dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 1 wt%.

[0057] Step S2 is the same as in method 1;

[0058] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0059] S4. Add the dispersion prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 10 minutes to obtain a carboxymethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel.

[0060] Example 2: A method for preparing a carboxymethyl chitosan-sodium oxidized alginate self-healing emulsion gel

[0061] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0062] S2. Dissolve sodium oxidized alginate in distilled water at room temperature to prepare a solution with a sodium oxidized alginate concentration of 2 wt%.

[0063] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0064] S4. Add the solution prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 4 minutes to obtain carboxymethyl chitosan-sodium oxidized alginate self-healing emulsion gel.

[0065] Example 3: A method for preparing a carboxymethyl chitosan-oxidized pullulan polysaccharide self-healing emulsion gel

[0066] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0067] S2. Dissolve oxidized pullulan in distilled water at room temperature to prepare a solution with an oxidized pullulan concentration of 2 wt%.

[0068] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0069] S4. Add the solution prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 1 minute to obtain a carboxymethyl chitosan-oxidized pullulan polysaccharide self-healing emulsion gel.

[0070] Example 4: A method for preparing a carboxymethyl chitosan-dialdehyde bacterial cellulose self-healing emulsion gel

[0071] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0072] S2. At room temperature, the dialdehyde bacterial cellulose was dispersed in distilled water to prepare a solution with a dialdehyde bacterial cellulose concentration of 2 wt%.

[0073] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0074] S4. Add the solution prepared in step S2 to the carboxymethyl chitosan stabilized emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stabilized emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 2 minutes to obtain carboxymethyl chitosan-dialdehyde bacterial cellulose self-healing emulsion gel.

[0075] Example 5: A method for preparing a carboxymethyl chitosan-oxidized pectin self-healing emulsion gel

[0076] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0077] S2. Dissolve oxidized pectin in distilled water at room temperature to prepare a solution with an oxidized pectin concentration of 2 wt%.

[0078] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0079] S4. Add the solution prepared in step S2 to the carboxymethyl chitosan stabilized emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stabilized emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 6 minutes to obtain a carboxymethyl chitosan-oxidized pectin self-healing emulsion gel.

[0080] Example 6: A method for preparing a carboxymethyl chitosan-oxidized dextran self-healing emulsion gel

[0081] S1. At room temperature, carboxymethyl chitosan was dissolved in deionized water to prepare a carboxymethyl chitosan solution with a concentration of 4 wt%.

[0082] S2. At room temperature, dissolve oxidized dextran in distilled water to prepare a solution with an oxidized dextran concentration of 2 wt%.

[0083] S3. The carboxymethyl chitosan solution prepared in step S1 and rapeseed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxymethyl chitosan stabilized emulsion.

[0084] S4. Add the solution prepared in step S2 to the carboxymethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxymethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 4 minutes to obtain a carboxymethyl chitosan-oxidized dextran self-healing emulsion gel.

[0085] Example 7: A method for preparing a carboxyethyl chitosan-dialdehyde bacterial cellulose self-healing emulsion gel

[0086] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0087] S2. At room temperature, the dialdehyde bacterial cellulose was dispersed in distilled water to prepare a dispersion with a dialdehyde bacterial cellulose concentration of 2wt%.

[0088] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0089] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the dispersion is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 2 minutes to obtain carboxyethyl chitosan-dialdehyde bacterial cellulose self-healing emulsion gel.

[0090] Example 8: A method for preparing a carboxyethyl chitosan-oxidized pectin self-healing emulsion gel

[0091] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0092] S2. Dissolve oxidized pectin in distilled water at room temperature to prepare a solution with an oxidized pectin concentration of 2 wt%.

[0093] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0094] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the solution is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 6 minutes to obtain carboxyethyl chitosan-oxidized pectin self-healing emulsion gel.

[0095] Example 9: A method for preparing a carboxyethyl chitosan-oxidized dextran self-healing emulsion gel

[0096] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0097] S2. At room temperature, dissolve oxidized dextran in distilled water to prepare a solution with an oxidized dextran concentration of 2 wt%.

[0098] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0099] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the solution is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 4 minutes to obtain a carboxyethyl chitosan-oxidized dextran self-healing emulsion gel.

[0100] Example 10: A method for preparing a carboxyethyl chitosan-dialdehyde cellulose nanofiber self-healing emulsion gel

[0101] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0102] S2. At room temperature, dialdehyde cellulose nanocrystals were dispersed in distilled water to prepare a solution with a dialdehyde cellulose nanocrystal concentration of 2wt%.

[0103] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0104] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the solution is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 2 minutes to obtain a carboxyethyl chitosan-dialdehyde cellulose nanocrystal self-healing emulsion gel.

[0105] Example 11: Preparation method of a carboxyethyl chitosan-sodium oxidized alginate self-healing emulsion gel

[0106] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0107] S2. Dissolve sodium oxidized alginate in distilled water at room temperature to prepare a solution with a sodium oxidized alginate concentration of 2 wt%.

[0108] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0109] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the solution is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 4 minutes to obtain carboxyethyl chitosan-sodium oxidized alginate self-healing emulsion gel.

[0110] Example 12: A method for preparing a carboxyethyl chitosan-oxidized pullulan polysaccharide self-healing emulsion gel

[0111] S1. At room temperature, carboxyethyl chitosan is dissolved in deionized water to prepare a carboxyethyl chitosan solution with a concentration of 4 wt%.

[0112] S2. Dissolve oxidized pullulan in distilled water at room temperature to prepare a solution with an oxidized pullulan concentration of 2 wt%.

[0113] S3. The carboxyethyl chitosan solution prepared in step S1 and sunflower seed oil are placed in a high-speed shear machine at a volume ratio of 5:1 and mixed and stirred at 10000 rpm for 2 min to obtain a carboxyethyl chitosan stabilized emulsion.

[0114] S4. Add the dispersion prepared in step S2 to the carboxyethyl chitosan stable emulsion prepared in step S3. The volume ratio of the carboxyethyl chitosan stable emulsion to the solution is 12:5. After mixing and shearing at 10,000 rpm for 15 seconds, let it stand at room temperature for 1 minute to obtain carboxyethyl chitosan-oxidized pullulan polysaccharide self-healing emulsion gel.

[0115] Example 13: A method for preparing a cationic gelatin-oxidized lecithin polysaccharide self-healing emulsion gel.

[0116] S1. At room temperature, cationic gelatin is dissolved in deionized water to prepare a cationic gelatin solution with a cationic gelatin concentration of 2wt%.

[0117] S2. At room temperature, dissolve oxidized white powder and polysaccharide in distilled water to prepare a solution with an oxidized white powder and polysaccharide concentration of 1 wt%.

[0118] S3. The cationic gelatin solution prepared in step S1 is mixed with olive oil in a volume ratio of 5:1 in a high-speed shear machine and stirred at 10,000 rpm for 2 minutes to obtain the cationic gelatin stabilized emulsion.

[0119] S4. Add the solution prepared in step S2 to the cationic gelatin stabilized emulsion prepared in step S3. The volume ratio of the cationic gelatin stabilized emulsion to the solution is 12:5. Mix and shear at 10000 rpm for 10 seconds, and let stand at room temperature for 2 minutes to obtain cationic gelatin-oxidized white and polysaccharide self-healing emulsion gel.

[0120] Example 14: A method for preparing a quaternized chitosan-oxidized hyaluronic acid self-healing emulsion gel

[0121] S1. At room temperature, quaternized chitosan is dissolved in deionized water to prepare a quaternized chitosan solution with a concentration of 3 wt%.

[0122] S2. At room temperature, oxidized hyaluronic acid is dissolved in distilled water to prepare a solution with an oxidized hyaluronic acid concentration of 0.5 wt%.

[0123] S3. The quaternized chitosan solution prepared in step S1 is mixed with olive oil in a volume ratio of 5:1 in a high-speed shear machine and stirred at 10,000 rpm for 2 minutes to obtain a quaternized chitosan stabilized emulsion.

[0124] S4. Add the solution prepared in step S2 to the quaternized chitosan stabilized emulsion prepared in step S3. The volume ratio of the quaternized chitosan stabilized emulsion to the solution is 12:5. After mixing and shearing at 10000 rpm for 10 seconds, let it stand at room temperature for 5 minutes to obtain quaternized chitosan-oxidized hyaluronic acid self-healing emulsion gel.

[0125] Example 15: A method for preparing a gallic acid-grafted chitosan-oxidized starch self-healing emulsion gel

[0126] S1. At room temperature, gallic acid-grafted chitosan was dissolved in deionized water to prepare a gallic acid-grafted chitosan solution with a concentration of 4 wt%.

[0127] S2. Dissolve oxidized starch in distilled water at room temperature to prepare a solution with an oxidized starch concentration of 3 wt%.

[0128] S3. The gallic acid-grafted chitosan solution prepared in step S1 is mixed with olive oil in a volume ratio of 5:1 in a high-speed shear machine and stirred at 10,000 rpm for 2 minutes to obtain a stable gallic acid-grafted chitosan emulsion.

[0129] S4. Add the solution prepared in step S2 to the gallic acid-grafted chitosan stabilized emulsion prepared in step S3. The volume ratio of the gallic acid-grafted chitosan stabilized emulsion to the solution is 12:5. Mix and shear at 10000 rpm for 10 seconds, and let stand at room temperature for 2 minutes to obtain gallic acid-grafted chitosan-oxidized starch self-healing emulsion gel.

[0130] Example 16: A method for preparing a maleylated chitosan-thiol-derived sodium alginate self-healing emulsion gel

[0131] S1. At room temperature, maleylated chitosan was dissolved in deionized water to prepare a maleylated chitosan solution with a concentration of 4 wt%.

[0132] S2. At room temperature, dissolve sodium thiosulfate derivatized in distilled water to prepare a solution with a sodium thiosulfate derivatized in 1 wt% solution;

[0133] S3. The maleylated chitosan solution prepared in step S1 is mixed with olive oil in a volume ratio of 5:1 in a high-speed shear machine and stirred at 10,000 rpm for 2 minutes to obtain a maleylated chitosan stabilized emulsion.

[0134] S4. Add the solution prepared in step S2 to the maleylated chitosan stabilized emulsion prepared in step S3. The volume ratio of the maleylated chitosan stabilized emulsion to the solution is 12:5. After mixing and shearing at 10000 rpm for 10 seconds, let it stand at room temperature for 2 minutes to obtain maleylated chitosan-thiol-derived sodium alginate self-healing emulsion gel.

[0135] Example 17 Performance Test of Self-Healing Emulsion Gel

[0136] The self-healing emulsion gel prepared in Example 1 of this embodiment is the self-healing emulsion gel prepared using method 1 of Example 1.

[0137] I. Macroscopic self-healing performance test

[0138] (1) Experimental methods

[0139] First, the self-healing emulsion gels from Examples 1-3 and Examples 7-9 were cut in half with a knife, and then the cut surfaces were immediately bonded together at room temperature to test the self-healing performance of the gel by gravity.

[0140] (2) Experimental Results

[0141] Figure 2 Figures A through F represent the self-healing performance of the self-healing emulsion gels prepared in Examples 1 through 3 and Examples 7 through 9 of this invention. Specifically, A1 through F1 are images of the gel after it has been cut into pieces; A2 through F2 are images of the gel pieces adhered together; and A3 through F3 are images of the gel after it has healed under gravity. The self-healing properties of the self-healing emulsion gel prepared in Example 1 are shown in Figures B1-B3; the self-healing properties of the self-healing emulsion gel prepared in Example 2 are shown in Figures C1-C3; the self-healing properties of the self-healing emulsion gel prepared in Example 3 are shown in Figures D1-D3; the self-healing properties of the self-healing emulsion gel prepared in Example 7 are shown in Figures E1-E3; the self-healing properties of the self-healing emulsion gel prepared in Example 8 are shown in Figures F1-F3; and the self-healing properties of the self-healing emulsion gel prepared in Example 9 are shown in Figures F1-F3.

[0142] Depend on Figure 2 It can be seen that when the self-healing hydrothermal gel and the unstained self-healing emulsion gel of the same volume are cut into two pieces and then brought into contact, and left to stand at room temperature for 3.5 to 10 minutes, the self-healing emulsion gel does not separate or fall off under the action of gravity, showing rapid self-repair, indicating that the self-healing emulsion gel has excellent self-healing properties.

[0143] The self-healing emulsion gel raw materials and their self-healing properties prepared in Examples 1-12 of this invention are shown in Table 1. As can be seen from Table 1, when the surfactant, oil phase, surfactant concentration, and crosslinking agent concentration are the same, different crosslinking agents result in different self-healing times for the self-healing emulsion gel. The self-healing time of the self-healing emulsion gel is related to the gelation time; the shorter the gelation time, the shorter the self-healing time. Using oxidized pullulan, dialdehyde cellulose nanocrystals, and dialdehyde bacterial cellulose as crosslinking agents, the preparation time of the self-healing emulsion gel is even shorter, and the prepared self-healing emulsion gel also exhibits rapid self-healing properties.

[0144] Table 1. Self-healing emulsion gel raw materials and self-healing properties prepared in Examples 1-12

[0145] 1 Carboxymethyl chitosan rapeseed oil Dialdehyde cellulose nanocrystals 2min 4min 2 Carboxymethyl chitosan rapeseed oil Sodium alginate 4min 6min 3 Carboxymethyl chitosan rapeseed oil Oxidized pullulan 1min 3.5min 4 Carboxymethyl chitosan rapeseed oil Dialdehyde bacterial cellulose 2min 4min 5 Carboxymethyl chitosan rapeseed oil Oxidized pectin 6min 10min 6 Carboxymethyl chitosan rapeseed oil Oxidized dextran 4min 6min 7 Carboxyethyl chitosan Sunflower seed oil Dialdehyde bacterial cellulose 2min 4min 8 Carboxyethyl chitosan Sunflower seed oil Oxidized pectin 6min 10min 9 Carboxyethyl chitosan Sunflower seed oil Oxidized dextran 4min 6min 10 Carboxyethyl chitosan Sunflower seed oil Dialdehyde cellulose nanocrystals 2min 4min 11 Carboxyethyl chitosan Sunflower seed oil Sodium alginate 4min 6min 12 Carboxyethyl chitosan Sunflower seed oil Oxidized pullulan 1min 3.5min

[0146] II. Quantitative Self-Healing Test

[0147] (1) Experimental methods

[0148] The self-healing properties of the self-healing emulsion gel in the examples were microscopically tested using a rheometer; Ti diameter: 50 mm; stress scan fixed frequency: 10 Hz; test temperature: 25 °C; a suitable stress value was selected to perform time scanning on the gel for 7 cycles.

[0149] (2) Experimental Results

[0150] Figure 3 Figures a through f are alternating strain scanning test results of the self-healing emulsion gel samples prepared in Examples 1 through 3 and Examples 7 through 9 of this invention. Specifically, a is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 1; b is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 2; c is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 3; d is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 7; e is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 8; and f is the alternating strain scanning test result of the self-healing emulsion gel prepared in Example 9.

[0151] Depend on Figure 3 It can be seen that the self-healing emulsion gels prepared in Examples 1-3 and 7-9 of the present invention all exhibited a gel-sol-gel transition under alternating strain tests from small to large and then from large to small at a fixed angular frequency (1Hz). This indicates that when strain is applied to the gel, the internal structure of the gel is destroyed, causing the gel to dissolve into a sol. After the strain disappears, the gel can reform and restore its original structure and properties. That is, the self-healing emulsion gels prepared in Examples 1-3 and 7-9 of the present invention exhibit excellent self-healing properties.

[0152] III. Injectability Test

[0153] (1) Experimental methods

[0154] The self-healing emulsion gels prepared in Examples 1-3 and Examples 7-9 were loaded into a syringe with a 23G needle. The gel sample in the syringe was squeezed into a culture dish by external force and the letter "GEL" was written at room temperature. After the gel was squeezed out of the needle, it healed again to form a complete whole.

[0155] (2) Experimental Results

[0156] Figure 4 a to f are injection performance diagrams of the self-healing emulsion gels prepared in Examples 1 to 3 and Examples 7 to 9 of the present invention, wherein a is an actual injection diagram of the gel in Example 1; b is an actual injection diagram of the gel in Example 2; c is an actual injection diagram of the gel in Example 3; d is an actual injection diagram of the gel in Example 7; e is an actual injection diagram of the gel in Example 8; and f is an actual injection diagram of the gel in Example 9.

[0157] The results are as follows Figure 4 As shown in Figures a to f, the injected pattern is clearly “GEL”, indicating that the healing emulsion gels prepared in Examples 1 to 3 and Examples 7 to 9 of this invention all have shear-thinning properties, can be squeezed out smoothly through a fine needle without clogging, and can form gel in situ. This shows that the self-healing emulsion gel prepared using the preparation method of the self-healing emulsion gel described in this invention has good injectability.

[0158] The self-healing emulsion gels prepared in Examples 4-6 and 10-16 have the same properties as those prepared in Examples 1-3 and 7-9.

[0159] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an injectable, rapidly self-healing emulsion gel, characterized in that, Includes the following steps: S1. A surfactant with a volume ratio of 5-1:2-1 is mixed with an oil phase to obtain a mixture. The mixture is then subjected to high-speed shearing for 1-3 minutes to obtain a stable emulsion. The oil phase is vegetable oil. The surfactant is one or more of carboxymethyl chitosan, carboxyethyl chitosan, quaternized chitosan, gallic acid-grafted chitosan, maleic acid-modified chitosan, and / or cationic gelatin. The concentration of the surfactant is 0.5wt%-4wt%. S2. The stable emulsion obtained in step S1 is thoroughly mixed with a crosslinking agent at a volume ratio of 19–4:5–1, and a self-healing emulsion gel is obtained after the crosslinking reaction. The crosslinking agent is one or more of the following: dialdehyde cellulose nanocrystals, oxidized sodium alginate, oxidized pullulan, dialdehyde bacterial cellulose, oxidized pectin, oxidized dextran, oxidized leucovorin, oxidized starch, oxidized hyaluronic acid, and / or thiol-derived sodium alginate. The concentration of the crosslinking agent is 0.5 wt%–4 wt%.

2. The preparation method according to claim 1, characterized in that, The crosslinking agent mentioned in step S2 is one or more of dialdehyde cellulose nanofibers, oxidized pullulan polysaccharide, and / or dialdehyde bacterial cellulose.

3. The preparation method according to claim 1, characterized in that, The stable emulsion obtained in step S1 is thoroughly mixed with the crosslinking agent at a volume ratio of 19-4:5-1 under high-speed shearing. The reaction conditions for the high-speed shearing are: 10,000-20,000 rpm for 10-30 seconds.

4. The preparation method according to claim 1, characterized in that, The conditions for the crosslinking reaction in step S2 are: standing at room temperature for 10 seconds to 10 minutes.

5. A self-healing emulsion gel prepared by any one of the preparation methods according to claims 1 to 4.

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