Preparation method of pH intelligent response hydrogel and pH intelligent response hydrogel

Abstract

The embodiment of the invention discloses a preparation method of pH intelligent response hydrogel and the pH intelligent response hydrogel. A specific embodiment of the method comprises the following steps: carrying out double-end aromatic aldehyde modification on a nonionic surfactant; the chitosan is converted into carboxymethyl chitosan; preparing a first mother solution and a second mother solution, and sub-packaging; and determining a solid fused by the first preparation mother liquor and the second preparation mother liquor released from the preset double-component injector and the mixing tube as the prepared pH intelligent response hydrogel. According to the embodiment, the condition of bacterial drug resistance can be reduced, the controllability of the release rate of the exosome loaded in the hydrogel and the adaptability of the release amount of the exosome loaded in the hydrogel and the clinically demanded dosage are improved, and the prepared pH intelligent response hydrogel can be used for preparing the hydrogel under the condition that the pH of the microenvironment of the hydrogel is changed. The effect of controllably releasing the loaded exosome in a self-response manner is achieved, and the mechanical performance and the self-repairing performance of the prepared pH intelligent response hydrogel are improved.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of hydrogel preparation, and specifically to a method for preparing a pH smart responsive hydrogel and a pH smart responsive hydrogel. Background Art

[0002] Hydrogel is a material that can load substances (drugs or bioactive substances) and controllably release substances. Therefore, hydrogel is widely used as a material for drug delivery systems. At present, when preparing hydrogels, the commonly used method is to use traditional hydrogel dressing preparation methods (for example, methods for preparing hydrogel dressings with only simple physical or chemical cross-linking) to prepare hydrogel dressings containing specific antibiotics or specific drugs.

[0003] However, it is found in practice that when the above method is used to prepare hydrogels, the following technical problems often occur:

[0004] The prepared hydrogel dressing uses antibiotics or specific drugs, which makes it easy for bacteria to resist the drug; and the uneven network structure of the prepared hydrogel dressing and the irreversibility of the chemical cross-linking bonds cause the prepared hydrogel dressing to have poor mechanical properties and self-healing properties, and poor antibacterial effect, resulting in poor effect of using the prepared hydrogel dressing; traditional hydrogel dressings cannot controllably release loaded substances under different pH environments, resulting in poor controllability of the release rate of the hydrogel loaded substances, resulting in poor compatibility between the amount of substance released in the hydrogel and the dosage of the substance required clinically.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0006] The content of this disclosure is used to introduce concepts in a brief form, which will be described in detail in the detailed implementation section below. The content of this disclosure is not intended to identify the key features or essential features of the technical solution claimed for protection, nor is it intended to limit the scope of the technical solution claimed for protection.

[0007] Some embodiments of the present disclosure propose a method for preparing a pH smart responsive hydrogel and a pH smart responsive hydrogel to solve one or more of the technical problems mentioned in the above background technology section.

[0008] In a first aspect, some embodiments of the present disclosure provide a method for preparing a pH smart responsive hydrogel, the method comprising: performing a double-ended aromatic aldehyde modification treatment on a nonionic surfactant to obtain a double-ended aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid; converting chitosan into carboxymethyl chitosan; configuring a first configuration mother liquor based on the nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration; configuring a second configuration mother liquor based on the carboxymethyl chitosan and the exosomes of the preset concentration; packaging the first configuration mother liquor and the second configuration mother liquor according to a preset configuration ratio, a preset two-component syringe and a mixing tube; and determining a solid fused with the first configuration mother liquor and the second configuration mother liquor released from the preset two-component syringe and the mixing tube as the prepared pH smart responsive hydrogel.

[0009] In a second aspect, some embodiments of the present disclosure provide an electronic device comprising: one or more processors; a storage device on which one or more programs are stored, and when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any implementation manner in the above-mentioned first aspect.

[0010] In a third aspect, some embodiments of the present disclosure provide a computer-readable medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method described in any one of the implementations in the first aspect above is implemented.

[0011] The above-mentioned embodiments of the present disclosure have the following beneficial effects: through the pH intelligent responsive hydrogel preparation method of some embodiments of the present disclosure, the occurrence of bacterial resistance can be reduced, the controllability of the release rate of substances loaded in the hydrogel can be improved, and the compatibility of the release amount of substances loaded in the hydrogel with the clinical required dose can be improved, and the effect of self-responsive and controllable release of loaded exosomes when the pH of its own microenvironment changes is achieved, and the mechanical properties and self-healing properties of the prepared hydrogel can be further improved. Specifically, the reasons for the emergence of bacterial resistance, poor controllability of the release rate of hydrogel-loaded substances, poor compatibility of the release amount of substances loaded in the hydrogel with the clinically required dosage, the inability of the prepared hydrogel to controllably release the loaded substances when the pH of its own microenvironment changes, and the poor mechanical properties and self-healing properties of the prepared hydrogel are: the prepared hydrogel dressing uses antibiotics or specific drugs, which makes bacterial resistance easy to occur; and the uneven network structure of the prepared hydrogel dressing and the irreversibility of chemical cross-linking bonds cause the mechanical properties and self-healing properties of the prepared hydrogel dressing to be poor, and the antibacterial effect is poor, resulting in poor effect of using the prepared hydrogel dressing; traditional hydrogel dressings cannot controllably release loaded substances under different pH environments, resulting in poor controllability of the release rate of hydrogel-loaded substances, resulting in poor compatibility of the release amount of substances in the hydrogel with the clinically required dosage of substances. In some embodiments of the present disclosure, the pH intelligent response hydrogel preparation method is as follows: first, a nonionic surfactant is subjected to a double-end aromatic aldehyde modification treatment to obtain a nonionic surfactant after double-end aromatic aldehyde modification treatment as a nonionic surfactant solid. Thus, the prepared nonionic surfactant solid can be obtained. Then, chitosan is converted into carboxymethyl chitosan. Thus, a hydrogel prepared using carboxymethyl chitosan with high solubility can be obtained. Afterwards, a first configuration mother liquor is configured according to the above nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration. Thus, a mother liquor of the configured corresponding nonionic surfactant solid can be obtained, which can be used to further prepare a hydrogel. Then, a second configuration mother liquor is configured according to the above carboxymethyl chitosan and the above preset concentration of exosomes. Thus, a mother liquor of the configured corresponding carboxymethyl chitosan can be obtained. Afterwards, the above first configuration mother liquor and the above second configuration mother liquor are subpackaged according to a preset configuration ratio, a preset two-component syringe and a mixing tube. Thus, the configured first configuration mother liquor and the second configuration mother liquor can be subpackaged into a two-component syringe. Finally, the solid fused by the first configuration mother solution and the second configuration mother solution released from the above-mentioned preset two-component syringe and mixing tube is determined as the prepared pH smart response hydrogel. Thus, the prepared pH smart response hydrogel can be obtained.Also, the antibacterial effect is not achieved by using antibiotics or specific drugs, but because the prepared pH smart response hydrogel contains gallic acid, which has biological activities such as anti-inflammatory, antibacterial, antioxidant and anti-free radical effects, and the prepared pH smart response hydrogel contains carboxymethyl chitosan converted from chitosan (CTS), which has antibacterial properties, and the prepared pH smart response hydrogel includes exosomes, which have antibacterial, anti-inflammatory, regenerative and repair capabilities, so the prepared pH smart response hydrogel can achieve antibacterial effects and reduce bacterial resistance. Also, the prepared pH smart response hydrogel contains a non-ionic surfactant solid modified with a double-ended aromatic aldehyde. Thus, the nonionic surfactant solid included in the prepared pH smart response hydrogel can be used as a macromolecular crosslinker, which can form an imine bond as a crosslinking point through the reaction of the terminal aldehyde group and the active amino group of the chitosan monomer unit to complete the construction of the hydrogel network structure. The imine bond can undergo a reversible reaction and has good mechanical properties and self-healing properties, thereby improving the mechanical properties and self-healing properties of the prepared pH smart response hydrogel. Because the constructed imine bond is sensitive to acid and alkali, the exosomes loaded in the prepared pH smart response hydrogel can be controlled and released by regulating the pH, and chitosan forms a cationic hydrogel network in water due to its primary amine group, and exhibits pH response behavior by swelling in acidic pH and shrinking in alkaline pH, so that the prepared pH smart response hydrogel can achieve the effect of self-responsive and controllable release of the loaded exosomes when the pH of its own microenvironment changes. Therefore, when using the prepared pH smart response hydrogel, the pH smart response hydrogel prepared during the acute infection period of the wound (pH<7.0) can accelerate the release of exosomes and prolong the retention time of exosomes in the wound. Thus, the prepared pH smart responsive hydrogel can reduce the occurrence of bacterial resistance, improve the controllability of the release rate of exosomes loaded in the hydrogel, and improve the adaptability of the release amount of exosomes loaded in the hydrogel to the clinical required dose. The prepared pH smart responsive hydrogel can achieve the effect of self-responsive and controllable release of loaded exosomes when the pH of its own microenvironment changes, and further improve the mechanical properties and self-healing properties of the prepared pH smart responsive hydrogel. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that components and elements are not necessarily drawn to scale.

[0013] Figure 1is a flow chart of some embodiments of the method for preparing a pH smart responsive hydrogel according to the present disclosure;

[0014] Figure 2 is a schematic diagram of the structure of an electronic device suitable for implementing some embodiments of the present disclosure;

[0015] Figure 3-Figure 5 It is a chemical bond characterization diagram of the prepared pH smart responsive hydrogel;

[0016] Figure 6 This is a microstructural characterization diagram of the prepared pH smart responsive hydrogel;

[0017] Figure 7 It is a characterization diagram of the injectability of the prepared pH smart responsive hydrogel;

[0018] Figure 8 It is a characterization diagram of the mobility of the prepared pH smart responsive hydrogel;

[0019] Fig. 9 This is a characterization diagram of the self-healing property of the prepared pH smart responsive hydrogel;

[0020] Fig.10 The experimental data show that the prepared pH-smart responsive hydrogel has the performance of exosome smart release under pH response;

[0021] Fig.11 It is the experimental data that the prepared pH smart responsive hydrogel has biocompatibility;

[0022] Fig.12 It is the experimental data that the prepared pH smart responsive hydrogel has in vitro antibacterial properties;

[0023] Fig.13 These are images of wound surfaces of mice with the prepared pH smart responsive hydrogel injected on the surface;

[0024] Fig.14 It is the experimental data of wound healing rate of the prepared pH intelligent responsive hydrogel;

[0025] Fig.15 These are the in vivo animal experimental data of the prepared pH smart responsive hydrogel. DETAILED DESCRIPTION

[0026] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0027] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0028] It should be noted that the concepts such as "first" and "second" mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0029] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0030] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0031] Figure 1 The process 100 of some embodiments of the method for preparing a pH smart responsive hydrogel according to the present disclosure is shown. The method for preparing a pH smart responsive hydrogel comprises the following steps:

[0032] Step 101, performing double-end aromatic aldehyde modification treatment on a nonionic surfactant to obtain the double-end aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid.

[0033] In some embodiments, a nonionic surfactant may be subjected to double-end aromatic aldehyde modification treatment to obtain a double-end aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid. The nonionic surfactant may be a polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) copolymer. The molecular formula structure of the obtained nonionic surfactant solid may be Thus, the obtained nonionic surfactant solid can be used as a macromolecular cross-linking agent, which can form an imine bond (Schiff base bond) as a cross-linking point through the reaction of the terminal aldehyde group and the active amino group of the chitosan monomer unit to complete the construction of the hydrogel network structure. The imine bond can undergo a reversible reaction, which can improve the mechanical properties and self-healing properties of the prepared pH smart response hydrogel. And the polymer micelles based on the Schiff base bond can be used as pH-responsive drug carriers. These micelles are stable at normal physiological pH values, but at acidic pH values, the hydrolysis of the Schiff base bond will cause the micelles to disintegrate, thereby accelerating drug release. In addition, the hydrogel can simulate the environment of the extracellular matrix, provide the physical and chemical signals required for cell attachment and proliferation, while maintaining the integrity and activity of the bioactive molecules (such as exosomes) it carries.

[0034] In some optional implementations of some embodiments, the nonionic surfactant may be subjected to double-end aromatic aldehyde modification treatment to obtain the double-end aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid by the following steps:

[0035] The first step is to place a nonionic surfactant of a first preset weight in a flask of a target volume. The target volume may be 250 ml. The first preset weight may be 10 g. It should be noted that the weight of the nonionic surfactant is set to 10 g because 10 g is a suitable amount in a small experiment, and can be used to multiply the nonionic surfactant in large-scale preparation.

[0036] The second step is to perform toluene azeotropic distillation drying on the nonionic surfactant in the flask of the target volume, and dissolve the nonionic surfactant in a first preset volume of anhydrous dichloromethane. The first preset volume may be 30 mL. It should be noted that the volume of anhydrous dichloromethane is not limited, and the volume of anhydrous dichloromethane added can initially dissolve the nonionic surfactant.

[0037] The third step is to add a second preset volume of anhydrous dichloromethane to the flask of the target volume to dissolve the solution in the flask of the target volume to obtain a hydrogel solution. The second preset volume can be 50 mL. It should be noted that a total of 80 mL of anhydrous dichloromethane was added, and the volume of anhydrous dichloromethane used is not limited. For example, the total amount of anhydrous dichloromethane used can be 100 mL or 120 mL, and the volume of anhydrous dichloromethane added can make the solution in the flask of the target volume conducive to subsequent reactions.

[0038] In the fourth step, the second preset weight of 4-formylbenzoic acid is dissolved in the third preset volume of anhydrous dichloromethane to obtain a dissolved solution. The dissolved solution may be a solution obtained by dissolving 1.6 g of 4-formylbenzoic acid in 5 mL of anhydrous dichloromethane. The second preset weight may be 1.6 g. The third preset volume may be 5 mL. The mass ratio between the weight of the 4-formylbenzoic acid and the volume of anhydrous dichloromethane may be 0.32 g / mL.

[0039] The fifth step is to add the third preset weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the above-mentioned dissolving solution to activate the carboxyl group of 4-formylbenzoic acid in the above-mentioned dissolving solution to obtain the target mixed solution. Wherein, the third preset weight can be 2.5g. The time for activating the carboxyl group of the above-mentioned 4-formylbenzoic acid can be 15 minutes. The above-mentioned target mixed solution can be a solution obtained after the carboxyl group of 4-formylbenzoic acid in the above-mentioned dissolving solution is activated.

[0040] The sixth step is to add the second preset weight of 4-dimethylaminopyridine to the target mixed solution to activate the target mixed solution to obtain activated 4-formylbenzoic acid. The activation time of the target mixed solution can be 15 minutes. The weight of the above-mentioned 4-formylbenzoic acid: the weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide: the weight of 4-dimethylaminopyridine can be 1.6:2.5:1.6. The reason for setting the weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to 2.5g and the weight of 4-dimethylaminopyridine to 1.6g is to fully activate 4-formylbenzoic acid.

[0041] The seventh step is to drip the activated 4-formylbenzoic acid into the hydrogel dissolving solution to obtain a hydrogel mixed solution. In practice, the activated 4-formylbenzoic acid can be dripped into the hydrogel dissolving solution drop by drop.

[0042] Step 8: subjecting the hydrogel mixed solution to a room temperature reaction according to a preset reaction time, wherein the preset reaction time may be 24 hours, and the room temperature may be 20 degrees Celsius to 25 degrees Celsius.

[0043] The ninth step is to perform a rotary evaporation treatment on the hydrogel mixed solution to evaporate and remove the dichloromethane in the hydrogel mixed solution. In practice, a rotary evaporator can be used to perform a rotary evaporation treatment on the hydrogel mixed solution to evaporate and remove the dichloromethane in the hydrogel mixed solution.

[0044] In the tenth step, a fourth preset volume of purified water is added to the hydrogel mixed solution to dissolve and precipitate the hydrogel mixed solution. The fourth preset volume may be 100 mL. It should be noted that the volume of purified water is not limited here, and the purified water added can fully dissolve the precipitate of the hydrogel mixed solution.

[0045] In the eleventh step, the hydrogel mixed solution is dialyzed into a dialysis bag using deionized water. The molecular weight of the dialysis bag is 8-15 kDa, so as to dialyze the hydrogel mixed solution to obtain a dialysis sample of the hydrogel mixed solution. The molecular weight of the dialysis bag is 8-15 kDa, which can remove small molecule impurities introduced by chemical reactions. It should be noted that the dialysis bag can be used to dialyze the hydrogel mixed solution for 3 to 5 days. When dialyzing the hydrogel mixed solution, the deionized water in the hydrogel is replaced at least three times and the deionized water in the hydrogel is used for at least one day.

[0046] In the twelfth step, the dialyzed sample of the hydrogel mixed solution is freeze-dried to obtain a non-ionic surfactant modified with a double-end aromatic aldehyde as a non-ionic surfactant solid.

[0047] Step 102, converting chitosan into carboxymethyl chitosan.

[0048] In some embodiments, chitosan can be converted into carboxymethyl chitosan. The molecular formula structure of the obtained carboxymethyl chitosan can be The reason for converting chitosan into carboxymethyl chitosan is to improve the water solubility of chitosan. The dissolution effect of carboxymethyl chitosan is better than that of chitosan, so that pH smart response hydrogel can be further configured.

[0049] In the process of adopting technical solutions to solve the above-mentioned technical problem one, the following technical problem two is often accompanied: the mechanical properties of the prepared hydrogel are improved by adjusting the preparation temperature and preparation time of the hydrogel, and the controllability of the preparation temperature and time is poor, resulting in poor biocompatibility and stability of the prepared hydrogel. In response to the above-mentioned technical problem two, the conventional solution is generally: directly adding chitosan to improve the mechanical properties of the prepared hydrogel. The inventors took into account the disadvantage that the mechanical properties of the prepared hydrogel are poor due to the low water solubility of chitosan. In combination with the inventors' advantages in preparing hydrogels, we decided to adopt the following solution:

[0050] In some optional implementations of some embodiments, chitosan can be converted into carboxymethyl chitosan by the following steps:

[0051] The first step is to add a fourth preset weight of chitosan to the target round-bottom flask. The fourth preset weight may be 5 g. The viscosity of the chitosan may be 20 mPa·s to 200 mPa·s. The volume of the target round-bottom flask may be 250 ml. It should be noted that the reason for setting the weight of the chitosan to 5 g is that 5 g is a more appropriate amount in small experiments, and it can be used to increase the amount of chitosan exponentially when it is prepared on a large scale. The reason why the viscosity of the chitosan used is 20 mPa·s to 200 mPa·s is that the use of chitosan within this viscosity range is conducive to the subsequent preparation of hydrogels.

[0052] The second step is to use a target beaker to weigh a fifth preset weight of solid sodium hydroxide, wherein the fifth preset weight may be 30 g, and the volume of the target beaker may be 150 mL.

[0053] The third step is to prepare a sodium hydroxide solution of a fifth preset concentration based on the solid sodium hydroxide. The fifth preset concentration may be 20%. In practice, deionized water may be added to prepare a sodium hydroxide solution corresponding to the solid sodium hydroxide so that the concentration of the obtained sodium hydroxide solution is 20%.

[0054] The fourth step is to add the sodium hydroxide solution into the target round-bottom flask, wherein the ratio between the weight of the chitosan and the volume of the sodium hydroxide solution can be 1:6.

[0055] The fifth step is to alkalize the chitosan of the fourth preset weight in the target round-bottom flask according to the preset speed and the preset alkalization time to obtain the alkalized chitosan solution. The preset speed can be 500r / min, and the preset alkalization time can be 2 hours. In practice, the chitosan of the fourth preset weight in the target round-bottom flask can be alkalized by a magnetic stirrer according to the preset speed and the preset alkalization time to obtain the alkalized chitosan solution.

[0056] The sixth step is to add a preset number of chloroacetic acid to the target round-bottom flask according to the preset interval time, and to heat the target round-bottom flask and stir the reaction process to make the temperature of the target round-bottom flask reach 50 degrees Celsius to obtain a mixed solution. The preset interval time can be 10 minutes. The time of the stirring reaction process can be 5 hours. The preset number of portions can be 5 portions. The weight of each portion of chloroacetic acid can be 4g. The ratio between the weight of the chloroacetic acid and the weight of the chitosan can be 4:1.

[0057] Step 7. Use an ice pack to cool the target round-bottom flask to room temperature.

[0058] Step 8: According to the glacial acetic acid solution of the sixth preset concentration, the pH of the mixed solution is adjusted to obtain an adjusted mixed solution. The sixth preset concentration may be 15% v / v. The pH of the adjusted mixed solution may be 7. It should be noted that the reason for using the glacial acetic acid solution of 15% v / v is to facilitate the adjustment of the pH of the mixed solution.

[0059] In the ninth step, the adjusted mixed solution is stirred according to the seventh preset concentration of methanol solution and the preset stirring time to obtain a stirred mixed solution. The seventh preset concentration may be 80% v / v. The preset stirring time may be 5 minutes. It should be noted that the reason for using a methanol solution with a concentration of 80% v / v is to facilitate the reaction with the adjusted mixed solution.

[0060] The tenth step is to filter the mixed solution to obtain carboxymethyl chitosan, wherein the carboxymethyl chitosan can be in the form of white powder. In practice, the mixed solution can be filtered through a Buchner funnel to obtain carboxymethyl chitosan.

[0061] The eleventh step is to perform vacuum freeze-drying on the carboxymethyl chitosan.

[0062] The twelfth step is to seal the carboxymethyl chitosan after vacuum freeze-drying and store it in bags.

[0063] The first to twelfth steps of the above technical solution are an inventive point of an embodiment of the present disclosure, which solves the second technical problem "the mechanical properties of the prepared hydrogel are poor due to the low water solubility of chitosan". The factors that lead to the poor mechanical properties of the prepared hydrogel due to the low water solubility of chitosan are often as follows: directly adding chitosan to improve the mechanical properties of the prepared hydrogel, and the water solubility of chitosan is low. If the above factors are solved, the effect of improving the mechanical properties of the prepared hydrogel can be achieved. In order to achieve this effect, when preparing the hydrogel, the present disclosure first needs to convert chitosan into carboxymethyl chitosan. Since the water solubility of carboxymethyl chitosan is higher than that of chitosan, the use of carboxymethyl chitosan converted from chitosan can better form an effective three-dimensional structure with a non-ionic surfactant, thereby improving the mechanical properties of the prepared hydrogel. Chitosan has an antibacterial effect, which can further improve the antibacterial properties of the prepared hydrogel.

[0064] Step 103, preparing a first preparation mother solution according to the non-ionic surfactant solid, the gallic acid solid and the exosomes of a preset concentration.

[0065] In some embodiments, the first configuration mother solution can be configured according to the above-mentioned nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration. In practice, the above-mentioned nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration can be dissolved using a phosphate buffered saline solution to obtain a first configuration mother solution. Among them, the above-mentioned preset concentration can be greater than or equal to 500ug / ml. The concentration of the above-mentioned phosphate buffered saline solution can be 1×PBS. The concentration of the dissolved nonionic surfactant solid in the above-mentioned first configuration mother solution can be 10-40% w / v, the concentration of the dissolved gallic acid solid can be 0.01-10% w / v, and the concentration of the dissolved exosomes of the preset concentration can be 1-500ug / ml. It should be noted that the reason for using a concentration of exosomes greater than or equal to 500ug / ml is to meet the subsequent dilution requirements of the exosomes. Here, the ratio between the nonionic surfactant solid, gallic acid solid and the preset concentration of exosomes used to configure the above-mentioned first configuration mother solution is not specifically limited. The effect of the hydrogel configured by different ratios between the nonionic surfactant solid, gallic acid solid and the preset concentration of exosomes used to configure the above-mentioned first configuration mother solution is different. The ratio between the nonionic surfactant solid, gallic acid solid and the preset concentration of exosomes used to configure the above-mentioned first configuration mother solution can be determined according to the requirements for the hydrogel effect. The concentration range of the dissolved nonionic surfactant solid in the above-mentioned first configuration mother solution: the concentration range of the dissolved gallic acid solid: the concentration range of the dissolved exosomes of the preset concentration can be (10-40% w / v): (0.01-10% w / v): (1-500ug / ml). The effect of making the concentration of the dissolved nonionic surfactant solid in the above-mentioned first configuration mother solution 10-40% w / v is to form an effective three-dimensional structure with carboxymethyl chitosan, so that the prepared hydrogel is not a too hard solid and not a non-gelling liquid. The effect of making the concentration of the gallic acid solid dissolved in the above-mentioned first configuration mother solution to be 0.01-10% w / v is that the antibacterial / antimicrobial properties of the hydrogel can be ensured, and it will not affect the performance of the hydrogel too much or even cause damage to the wound. The effect of making the concentration of the preset concentration of exosomes dissolved in the above-mentioned first configuration mother solution to be 1-500ug / ml is that the effect of the prepared pH smart response hydrogel is adjustable, and different exosome concentrations can be selected according to different wound degrees to achieve the best effect. The concentration of the exosomes can be determined within the concentration range of 1-500ug / ml according to the severity of the wound.

[0066] Step 104, preparing a second preparation mother solution according to carboxymethyl chitosan and exosomes of a preset concentration.

[0067] In some embodiments, a second configuration mother solution can be configured according to the above carboxymethyl chitosan and the above preset concentration of exosomes. In practice, the above phosphate buffered saline solution can be used to dissolve the above carboxymethyl chitosan and the above preset concentration of exosomes to obtain a second configuration mother solution, wherein the concentration of the carboxymethyl chitosan solution in the above second configuration mother solution can be 1-40% w / v and the concentration of the exosomes at the preset concentration after dissolution can be 1-500ug / ml. It should be noted that the concentration of the carboxymethyl chitosan solution in the above second configuration mother solution is in the concentration range of: the concentration range of the exosomes at the preset concentration after dissolution can be (1-40% w / v): (1-500ug / ml). The effect of making the concentration of the carboxymethyl chitosan solution in the above second configuration mother solution 1-40% w / v is to form an effective three-dimensional structure with the dissolved non-ionic surfactant solid, so that the prepared hydrogel is not a too hard solid and not a non-gelling liquid.

[0068] It should be noted that the ratio between the concentration of the dissolved nonionic surfactant solid in the first mother solution and the concentration of the carboxymethyl chitosan solution in the second mother solution can form an effective three-dimensional structure, so that the prepared hydrogel is neither a too hard solid nor a non-gelatinous liquid.

[0069] Step 105, according to the preset configuration ratio, the preset two-component syringe and the mixing tube, the first configuration mother liquid and the second configuration mother liquid are packaged.

[0070] In some embodiments, the first configuration mother liquid and the second configuration mother liquid can be subpackaged according to a preset configuration ratio, a preset two-component syringe and a mixing tube. Among them, the preset two-component syringe may include two sub-packaging tubes. The preset configuration ratio can characterize the ratio between the volume of the first configuration mother liquid and the volume of the second configuration mother liquid. Here, there is no limitation on the specific numerical value of the preset configuration ratio. The preset configuration ratio can be 1:2 or 1:3. In practice, the first configuration mother liquid and the second configuration mother liquid can be respectively subpackaged into each sub-packaging tube of the preset two-component syringe. It should be noted that the effect of the pH smart response hydrogel configured when the preset configuration ratio is 1:2 and the preset configuration ratio is 1:3 is different, and different ratios of pH smart response hydrogels can be configured according to the needs of the wound.

[0071] In step 106, a solid obtained by fusing the first configuration mother solution and the second configuration mother solution released from the preset two-component syringe and the mixing tube is determined as the prepared pH intelligent response hydrogel.

[0072] In some embodiments, the solid fused by the first configuration mother liquid and the second configuration mother liquid released from the above-mentioned preset two-component syringe and mixing tube can be determined as the prepared pH smart response hydrogel. It should be noted that the specific size of the above-mentioned preset two-component syringe and mixing tube is not limited, and the specific size of the above-mentioned preset two-component syringe and mixing tube can be determined according to the requirements of preparing the pH smart response hydrogel.

[0073] Optionally, the exosomes of the preset concentration are cultured by the following steps:

[0074] The first step is to place the human umbilical cord mesenchymal stem cells in a target incubator for culture, wherein the target incubator may be a CO2 incubator.

[0075] In the second step, in response to determining that the density information of the P3-P8 generation cells is a preset density, the P3-P8 generation cells are starved to obtain the P3-P8 generation cells after starvation treatment, wherein the preset density may be 80%. It should be noted that the exosomes cultured using the P3-P8 generation cells with a preset density of 80% have the best effect.

[0076] The third step is to collect the supernatant of the P3-P8 cells after the above starvation treatment.

[0077] Step 4: ultracentrifugation to collect exosomes of a preset concentration corresponding to the above-mentioned P3-P8 generation cells. In practice, the exosomes of a preset concentration corresponding to the above-mentioned P3-P8 generation cells can be collected by ultracentrifugation.

[0078] The fifth step is to store the exosomes of the preset concentration collected by ultracentrifugation in separate tubes. The temperature for storing the exosomes of the preset concentration collected by ultracentrifugation can be minus 80 degrees Celsius. In practice, a preset number of storage tubes can be used to store the exosomes of the preset concentration collected by ultracentrifugation. Here, there is no limitation on the specific value of the preset number.

[0079] In order to demonstrate the effect of the pH smart responsive hydrogel prepared by the above-mentioned pH smart responsive hydrogel preparation method, the following experimental methods and experimental results are provided.

[0080] Experiment 1

[0081] The formation of chemical bonds can be characterized by Fourier transform infrared spectroscopy (FT-IR). Figure 3 The above shows that Figure 3 It can be characterized that for the PF127-CHO polymer, the peak at 1704 cm-1 indicates that the aldehyde group is successfully grafted onto PF127. Figure 3From top to bottom, the first broken line can represent the broken line of PF127, and the second broken line can represent the broken line of PF127-CHO. Figure 4 As shown, Figure 4 For CMCS, the peaks at 1717 cm-1, 1568 cm-1, and 1398 cm-1 can be characterized, indicating successful carboxymethylation. Figure 4 From top to bottom, the first line can represent the line of CTS, and the second line can represent the line of CMCS. Figure 5 As shown, Figure 5 It can be characterized that compared with the FT-IR spectrum of PF127-CHO, the -CHO peak at 1704cm-1 in the PF127 / CMCS / GA hydrogel almost disappeared, and the characteristic peak at 1600cm-1 corresponds to the -NH2 of CMCS and the newly formed Schiff base (-N=H-) of -CHO of PF127-CHO. Figure 5 From top to bottom, the first broken line can represent the broken line of PF127-CHO, the second broken line can represent the broken line of CMCS, and the third broken line can represent the broken line of PF127 / CMCS / GA. Therefore, these experimental results show that the PF127 / CMCS / GA hydrogel is successfully synthesized, and the above PF127 / CMCS / GA hydrogel is a pH smart response hydrogel prepared by the pH smart response hydrogel preparation method.

[0082] Experiment 2

[0083] The microstructure of the prepared pH smart responsive hydrogel was characterized using a scanning electron microscope (SEM) to obtain the microstructure of the prepared pH smart responsive hydrogel. Figure 6 As shown, the microstructure of the prepared pH smart responsive hydrogel is porous and neatly arranged.

[0084] Experiment 3

[0085] like Figure 7 As shown, the prepared pH smart responsive hydrogel extruded from the mixing tube can instantly form an ideal shape, which can indicate that the prepared pH smart responsive hydrogel has surface injectability. And the prepared pH smart responsive hydrogel can adhere to the wound and will not break or fall off when the wound is active, and has mobility, such as Figure 8 As shown in the figure, when the finger moves at 180°, 135°, 90° and 45°, the prepared pH smart response hydrogel does not break or fall off on the finger, thus, the prepared pH smart response hydrogel has mobility. Fig. 9As shown, the prepared pH smart responsive hydrogel can be self-healed into a complete hydrogel after being cut and contacted at room temperature for 3 minutes. Therefore, the prepared pH smart responsive hydrogel has self-healing properties.

[0086] Experiment 4

[0087] In a transwell chamber at 37°C, the release rate of exosomes at different pH values ​​(pH 6.0, pH 7.4) was measured using a protein assay method, proving that the prepared pH-smart responsive hydrogel can achieve the intelligent release of exosomes under pH response. Fig.10 As shown in Figure 2, the release rate of exosomes varies at different pH values. Fig.10 As shown, the release rate of exosomes at acidic pH is faster than that at neutral pH.

[0088] Experiment 5

[0089] The experiment was divided into four groups, namely control group (NC), hydrogel group (H), exosome group (EV), and pH smart responsive hydrogel group (HE). The prepared pH smart responsive hydrogel can be characterized by the following steps to have good biocompatibility:

[0090] The first step is to prepare a hydrogel extract. In practice, first, the prepared pH smart response hydrogel can be freeze-dried. Then, it is irradiated with ultraviolet light for 1 hour and sterilized by soaking in 75% ethanol. After that, the excess 75% ethanol is washed away with culture medium. Finally, the culture medium is soaked for 24 hours and filtered through a 0.22 μm filter membrane to obtain the prepared hydrogel extract.

[0091] In the second step, the prepared pH smart responsive hydrogel was tested to be free of toxic components and to promote the proliferation of mouse embryonic fibroblasts (NIH 3T3). Fig.11 As shown in (G), the absorbance of the HE group is higher, which indicates that the prepared pH smart responsive hydrogel can promote the proliferation of mouse embryonic fibroblasts (NIH 3T3). Fig.11 (F) shows that the absorbance of the HE group is higher, which indicates that the prepared pH smart responsive hydrogel can promote the proliferation of HUVEC cells. Fig.11 (G) and Fig.11 As shown in (F), the absorbance of the HE group was higher than that of the control group (NC), which can indicate that the prepared pH smart responsive hydrogel does not contain toxic components.

[0092] In the third step, a scratch experiment was performed to verify that the prepared pH smart responsive hydrogel could promote the migration of mouse embryonic fibroblasts (NIH 3T3). Fig.11 (H) and Fig.11 (I) is the experimental result of the scratch test, such as Fig.11 (H) and Fig.11 As shown in (I), the relative migration rate of the HE group is the highest. Therefore, it can be characterized that the prepared pH smart responsive hydrogel can promote the migration of mouse embryonic fibroblasts (NIH 3T3).

[0093] In the fourth step, angiogenesis experiments were performed to verify that the prepared pH-smart responsive hydrogel could promote the tube formation of human umbilical vein endothelial cells (HUVEC). Fig.11 (K) Fig.11 (L) and Fig.11 (J) is the experimental result of angiogenesis experiment. Fig.11 (K) and Fig.11 (L) respectively characterize Fig.11 (J) The total number of vascular nodes and total length of vessels in each group. Fig.11 As shown in (K), the total number of vascular nodes in the HE group was higher. Fig.11 As shown in (L), the total length of blood vessels in the HE group was the longest. Therefore, it can be characterized that the prepared pH smart responsive hydrogel can promote the tube formation of human umbilical vein endothelial cells (HUVEC).

[0094] Therefore, through Experiment 7, it can be characterized that the prepared pH smart responsive hydrogel is non-toxic, can promote the proliferation of mouse embryonic fibroblasts (NIH 3T3), can promote the migration of mouse embryonic fibroblasts (NIH 3T3), and can promote the tube formation of human umbilical vein endothelial cells (HUVEC), so that the prepared pH smart responsive hydrogel is biocompatible.

[0095] Experiment 6

[0096] The prepared pH smart responsive hydrogels can be characterized to have in vitro antibacterial properties by the following steps:

[0097] The experiment was divided into 4 groups, namely control group (NC), PF127 / CMCS group, PF127 / CMCS / GA group (prepared pH smart responsive hydrogel group), and ampicillin group (Ampicilin 200 μg / mL).

[0098] First, 10^6 of methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) were cultured with the control group (NC), the PF127 / CMCS group, the PF127 / CMCS / GA group, and the ampicillin (Ampicilin 200 μg / mL) group for 12 hours. Then, each group was diluted 500 times and plated. After 15 hours, the growth of bacteria in the culture dish was observed and photographed to verify the antibacterial effect of the hydrogel. Fig.12As shown, compared with the control group (NC), the PF127 / CMCS group had no significant antibacterial activity, while the PF127 / CMCS / GA group achieved nearly 100% antibacterial activity. Thus, it can be characterized that the prepared pH smart responsive hydrogel has in vitro antibacterial properties.

[0099] Experiment 7

[0100] In the first step, after disinfecting the back skin of each mouse, a circular full-thickness wound was made on the back skin of each mouse using a biopsy puncture needle with a diameter of about 7 mm, and the circular full-thickness wound was fixed with a silicone sheet. The total number of mice was 24.

[0101] In the second step, the mice were randomly divided into 4 groups (n=6), with 6 mice in each group, namely control group (NC), hydrogel group (H), exosome group (EV), and pH smart responsive hydrogel group (HE).

[0102] In the third step, first, on the first day, all mice in each group were infected with methicillin-resistant Staphylococcus aureus (MRSA). Then, the wounds of each group of mice were treated as follows every 3 days: 100uL of phosphate buffered saline was applied to each mouse in the control group (NC), 400uL of hydrogel was replaced for each mouse in the hydrogel group (H), 100ug of exosomes was applied to the exosome group (EV), and 400uL of the prepared pH smart response hydrogel containing 100ug of exosomes was injected into the pH smart response hydrogel group (HE). The wounds of mice in all groups were covered with transparent dressings (Tegaderm TM , 1624W, USA) and then a digital camera was used to capture the wound surface images of any mouse in each group, such as Fig.13 As shown, each wound image of the target mouse in each group was taken using a digital camera on the first day, the third day, the seventh day, the tenth day, and the fourteenth day. Then, Image J software (NIH, ImageJ1.8, USA) was used to calculate the wound area of ​​the target mouse in each group on the third day, the seventh day, the tenth day, and the fourteenth day based on each wound image of the target mouse in each group. Then, based on the obtained wound area of ​​each target mouse in each group, the wound healing rate of the target mouse in each group on the third day, the seventh day, the tenth day, and the fourteenth day was calculated, as shown in FIG. Fig.14 As shown, the wound healing rate of the pH smart responsive hydrogel group (HE) was the highest. The target mice in each group were pre-selected mice by arbitrary selection.

[0103] In the fourth step, blood was collected on the 7th and 14th day after surgery, mice were killed, wound samples were taken, and heart, liver, spleen, lung and kidney samples were taken.

[0104] Step 5: HE staining of the heart, liver, spleen, lung and kidney specimens, and blood routine and blood biochemistry tests to detect liver (ALT, AST) and kidney (BUN, CREA) functions. Fig.15 As shown, Fig.15 (Group A) represents the experimental results of HE staining of heart, liver, spleen, lung and kidney specimens. Fig.15 (Panel B) Experimental data representing routine blood tests. Fig.15 (C) Group c1 and c2 can represent the experimental data of liver function test. Fig.15 (C) Group c3 and c4 can represent the experimental data of renal function test. Fig.15 As shown, the experimental data of blood routine test, the experimental data of liver function test and the experimental data of kidney function test of the HE group were all within the normal range.

[0105] After the preparation of the pH smart responsive hydrogel is completed, it is necessary to verify the efficacy of the prepared pH smart responsive hydrogel by testing the application effect of the prepared pH smart responsive hydrogel, so as to provide doctors with guidance on the use of the pH smart responsive hydrogel.

[0106] Optionally, after step 106, the following steps may also be performed:

[0107] The first step is to capture the surface injection image information of each corresponding target wound. The target wound surface is injected with the pH smart response hydrogel prepared above. The wound surface injection image information in the above-mentioned individual wound surface injection image information may be an image of the target wound surface injected with the pH smart response hydrogel prepared above, captured within a preset time. The above-mentioned preset time may characterize the number of days that the target wound surface is injected with the pH smart response hydrogel prepared above. For example, the preset time may be the second day. The target wound may be any skin wound. For example, the surface injection image information of each wound may be: "The image of the target wound surface injected with the pH smart response hydrogel prepared above, captured on the first day, the image of the target wound surface injected with the pH smart response hydrogel prepared above, captured on the second day, the image of the target wound surface injected with the pH smart response hydrogel prepared above, captured on the third day".

[0108] The second step is to upload the above-mentioned injection image information of each wound surface to the hydrogel application effect detection server to determine whether the above-prepared pH intelligent response hydrogel meets the preset application effect conditions, wherein the above-mentioned hydrogel application effect detection server is configured to perform the following steps:

[0109] The third step is to perform enhancement processing on the received injection image information of each wound surface to obtain the enhanced injection image information of each wound surface.

[0110] In the fourth step, the enhanced surface injection image information of each wound is input into the pre-trained wound healing time-consuming detection model to obtain the wound healing time-consuming information corresponding to the pH intelligent response hydrogel prepared above. Among them, the wound healing time-consuming information can characterize the time consumed for the healing of the above-mentioned target wound. The wound healing time-consuming detection model can be a model that takes the surface injection image information of each wound as input and the wound healing time-consuming information corresponding to the above-mentioned target wound as output. The wound healing time-consuming detection model can be a convolutional neural network model. It should be noted that the training data used for training the above-mentioned wound healing time-consuming detection model can be a set of wound surface injection image information groups corresponding to each wound and the wound healing time corresponding to each wound in the above-mentioned wounds. The above-mentioned wounds can be any skin wounds. The wounds in the above-mentioned wounds can correspond to the wound surface injection image information group in the above-mentioned wound surface injection image information group set. The shooting time corresponding to each wound surface injection image information group in the wound surface injection image information group set is the same as the shooting time corresponding to each wound surface injection image information of the target wound. For example, if the shooting time corresponding to each wound surface injection image information of the target wound is the first day, the second day and the third day, then the shooting time corresponding to each wound surface injection image information group in the wound surface injection image information group set can be the first day, the second day and the third day. And the wound healing time-consuming detection model can be trained using a batch training method.

[0111] The fifth step is to determine that the obtained wound healing time information satisfies the preset wound healing time condition, and to determine that the pH smart response hydrogel prepared above meets the preset application effect condition. Among them, the above-mentioned preset wound healing time condition can be that the time represented by the wound healing time information is less than the preset wound healing time. Here, there is no limitation on the specific value of the above-mentioned preset wound healing time. The above-mentioned preset application effect condition can be that the prepared pH smart response hydrogel meets the above-mentioned preset wound healing time condition.

[0112] In the process of adopting technical solutions to solve the above-mentioned technical problem one, the following technical problem three is often accompanied: when using the conventional wound healing time-consuming experiment (injecting the prepared hydrogel into the wound surface every day until the wound heals) to detect the application effect of the prepared hydrogel, it is necessary to inject the prepared hydrogel into the wound surface every day until the wound heals, and the wound healing takes a long time, resulting in more steps and longer time for detecting the application effect of the prepared hydrogel. For the above-mentioned technical problem three, the conventional solution is generally: directly use the image information of each wound surface injection taken to predict the application effect of the prepared hydrogel. The inventors took into account that when the skin is damaged and the wound has been coated with hydrogel, the image quality of the image information of each wound surface injection taken is often poor. If the image information of each wound surface injection taken is directly used to predict the application effect of the prepared hydrogel, the accuracy of the predicted application effect of the hydrogel is low. The inventor's unit has experience in solving image quality problems, and combined with the situation of the cooperative unit commissioned for development, we decided to adopt the following solution:

[0113] The hydrogel application effect detection server is further configured to perform enhancement processing on the above-mentioned wound surface injection image information through the following steps to obtain enhanced wound surface injection image information:

[0114] The first sub-execution step is to initialize the preset moving speed information, preset position information and cropping factor information. Among them, the preset moving speed information can characterize the speed of the particle group. The preset position information can characterize the position of the particle group. The cropping factor information can characterize the cropping factor. In practice, first, the execution subject can change the preset moving speed information to the initial speed. Then, change the preset position information to the initial position. After that, change the cropping factor information to the initial cropping factor. To initialize the preset moving speed information, the preset position information and the cropping factor information. Here, there is no limitation on the specific value of the initial speed. There is no limitation on the specific position of the initial position. There is no limitation on the specific value of the initial cropping factor.

[0115] The second sub-executing step is to execute the following steps for each wound surface injection image information in the above wound surface injection image information:

[0116] The first execution step is to perform the following division steps on the wound surface injection image information:

[0117] In the first division step, the wound surface injection image information is divided and processed according to the preset number of division areas to obtain images of each division area. The preset number of division areas may represent the number of images of each division area into which the wound surface injection image information is divided. For example, the preset number of division areas may be 6. Here, there is no limitation on the specific value of the preset number of division areas. The images of each division area may represent images divided from the wound surface injection image information.

[0118] In the second division step, for each of the obtained divided area images, the following steps are iterated:

[0119] The first sub-step is to determine the histogram information of the divided region image. The histogram information may represent the histogram of the divided region image. In practice, the execution subject may determine the histogram information of the divided region image through the cv2.calcHist() function in the OpenCV library.

[0120] The second sub-step is to perform equalization processing on the above histogram information to obtain the histogram information after equalization processing. The above grayscale information can represent the grayscale level of the above divided area image.

[0121] The third sub-step is to perform grayscale value mapping processing on the obtained histogram information after the equalization processing to obtain the grayscale level corresponding to the above-mentioned divided area image.

[0122] The fourth sub-step is to determine the threshold information corresponding to the above-mentioned divided area image according to the obtained grayscale level, the quantity information of the above-mentioned divided area image and the above-mentioned cropping factor information. The above-mentioned threshold information can represent the histogram cropping threshold. The quantity information of the above-mentioned divided area image can represent the number of pixels in the divided area image. In practice, first, the above-mentioned execution entity can determine the ratio of the number of pixels of the above-mentioned divided area image to the above-mentioned grayscale level as the target ratio. Then, the product of the above-mentioned target ratio and the above-mentioned cropping factor information is determined as the threshold information.

[0123] The fifth sub-step is to update the divided region image according to the threshold information. In practice, the execution subject can perform cropping on the divided region image according to the threshold information by using a threshold segmentation algorithm to obtain a cropped divided region image. Then, an interpolation algorithm can be used to perform pixel allocation processing on each pixel in the cropped divided region image to obtain a pixel allocated divided region image as the updated divided region image.

[0124] In the sixth sub-step, a histogram equalization process is performed on the divided region image after the update process to obtain the divided region image after the histogram equalization process as the divided region image.

[0125] The seventh sub-step is to update the number of iterations to obtain the updated number of iterations as the number of iterations. The number of iterations may be the number of times the execution subject executes the iterative step. In practice, the execution subject may add 1 to the number of iterations to update the number of iterations.

[0126] The second execution step is to fuse the obtained divided area images to obtain the fused images of the divided areas as fused image information. In practice, the execution subject may fuse the obtained divided area images through an image fusion algorithm to obtain the fused images of the divided areas as fused image information. For example, the image fusion algorithm may be a spatial domain fusion algorithm.

[0127] The third execution step is, in response to determining that the number of iterations is less than the preset number of iterations, using the fused image information as wound surface injection image information, and executing the above division step again. Here, the specific value of the above preset number of iterations is not limited.

[0128] The fourth execution step is, in response to determining that the number of iterations is greater than or equal to the preset number of iterations, determining the fused image information as the wound surface injection image information after enhancement processing.

[0129] The above technical solution, as an inventive point of an embodiment of the present disclosure, solves the technical problem that "the predicted application effect of the hydrogel is low in accuracy". The factors that lead to the low accuracy of the predicted application effect of the prepared hydrogel are often as follows: when the skin is damaged and the wound has been coated with hydrogel, the image quality of the image information of the wound surface injection taken is often poor, and the application effect of the prepared hydrogel is directly predicted by using the image information of the wound surface injection taken. If the above factors are solved, the accuracy of the predicted application effect of the prepared hydrogel can be improved. In order to achieve this effect, when predicting the application effect of the prepared hydrogel, the present disclosure first uploads the above-mentioned wound surface injection image information to the hydrogel application effect detection server. Then, the hydrogel application effect detection server is used to divide the image area of ​​each wound surface injection image information, and then cropping and histogram equalization processing are performed on each image area to achieve image enhancement processing of each wound surface injection image information, thereby improving the quality of the image. Finally, the image after image enhancement processing is used by the hydrogel application effect detection server to predict the application effect of the prepared hydrogel. Thereby, the image quality of each wound surface injection image information can be improved, so that the application effect of the prepared hydrogel can be further predicted using the wound surface injection image information with higher image quality, thereby improving the accuracy of predicting the application effect of the prepared hydrogel.

[0130] The first to fifth steps of the above technical solution are an inventive point of the embodiment of the present disclosure, which solves the above technical problem three "the steps for detecting the application effect of the prepared hydrogel are many and time-consuming". The factors that lead to the steps for detecting the application effect of the prepared hydrogel being many and time-consuming are often as follows: when the conventional wound healing time-consuming experiment (injecting the prepared hydrogel into the wound surface every day until the wound heals) is used to detect the application effect of the prepared hydrogel, it is necessary to inject the prepared hydrogel into the wound surface every day until the wound heals, and the wound healing takes a long time. If the above factors are solved, the steps for detecting the application effect of the prepared hydrogel can be simplified and the time consumption can be shortened. In order to achieve this effect, when predicting the application effect of the prepared hydrogel, the present disclosure first shoots the injection image information of each wound surface corresponding to the target wound. Then, the above-mentioned injection image information of each wound surface is uploaded to the hydrogel application effect detection server to determine whether the pH intelligent response hydrogel prepared above meets the preset application effect conditions. Therefore, the hydrogel application effect detection server can be used to perform image enhancement processing on the injection image information of each wound surface and predict the wound healing time according to the pre-trained wound healing time detection model. Therefore, it is possible to determine whether the prepared pH smart response hydrogel meets the preset application effect conditions according to the wound healing time of the corresponding prepared pH smart response hydrogel. Also, because the effect of the prepared pH smart response hydrogel is not determined by using the wound healing time experiment, but by uploading the above-mentioned wound surface injection image information to the hydrogel application effect detection server, the wound healing time of the prepared pH smart response hydrogel is detected by the hydrogel application effect detection server using the pre-trained wound healing time detection model and the wound surface injection image information with high image quality. Therefore, the application effect of the prepared pH smart response hydrogel is determined according to the wound surface injection image information with high image quality. The accuracy of the determined application effect can be improved, and there is no need to inject the prepared hydrogel into the wound surface every day until the wound is healed, thereby simplifying the steps of detecting the application effect of the prepared hydrogel and shortening the time of detecting the application effect of the prepared hydrogel.

[0131] The above-mentioned embodiments of the present disclosure have the following beneficial effects: through the pH intelligent responsive hydrogel preparation method of some embodiments of the present disclosure, the occurrence of bacterial resistance can be reduced, the controllability of the release rate of substances loaded in the hydrogel can be improved, and the compatibility of the release amount of substances loaded in the hydrogel with the clinical required dose can be improved, and the effect of self-responsive and controllable release of loaded exosomes when the pH of its own microenvironment changes is achieved, and the mechanical properties and self-healing properties of the prepared hydrogel can be further improved. Specifically, the reasons for the emergence of bacterial resistance, poor controllability of the release rate of hydrogel-loaded substances, poor compatibility of the release amount of substances loaded in the hydrogel with the clinically required dosage, the inability of the prepared hydrogel to controllably release the loaded substances when the pH of its own microenvironment changes, and the poor mechanical properties and self-healing properties of the prepared hydrogel are: the prepared hydrogel dressing uses antibiotics or specific drugs, which makes bacterial resistance easy to occur; and the uneven network structure of the prepared hydrogel dressing and the irreversibility of chemical cross-linking bonds cause the mechanical properties and self-healing properties of the prepared hydrogel dressing to be poor, and the antibacterial effect is poor, resulting in poor effect of using the prepared hydrogel dressing; traditional hydrogel dressings cannot controllably release loaded substances under different pH environments, resulting in poor controllability of the release rate of hydrogel-loaded substances, resulting in poor compatibility of the release amount of substances in the hydrogel with the clinically required dosage of substances. In some embodiments of the present disclosure, the pH intelligent response hydrogel preparation method is as follows: first, a nonionic surfactant is subjected to a double-end aromatic aldehyde modification treatment to obtain a nonionic surfactant after double-end aromatic aldehyde modification treatment as a nonionic surfactant solid. Thus, the prepared nonionic surfactant solid can be obtained. Then, chitosan is converted into carboxymethyl chitosan. Thus, a hydrogel prepared using carboxymethyl chitosan with high solubility can be obtained. Afterwards, a first configuration mother liquor is configured according to the above nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration. Thus, a mother liquor of the configured corresponding nonionic surfactant solid can be obtained, which can be used to further prepare a hydrogel. Then, a second configuration mother liquor is configured according to the above carboxymethyl chitosan and the above preset concentration of exosomes. Thus, a mother liquor of the configured corresponding carboxymethyl chitosan can be obtained. Afterwards, the above first configuration mother liquor and the above second configuration mother liquor are subpackaged according to a preset configuration ratio, a preset two-component syringe and a mixing tube. Thus, the configured first configuration mother liquor and the second configuration mother liquor can be subpackaged into a two-component syringe. Finally, the solid fused by the first configuration mother solution and the second configuration mother solution released from the above-mentioned preset two-component syringe and mixing tube is determined as the prepared pH smart response hydrogel. Thus, the prepared pH smart response hydrogel can be obtained.Also, the antibacterial effect is not achieved by using antibiotics or specific drugs, but because the prepared pH smart response hydrogel contains gallic acid, which has biological activities such as anti-inflammatory, antibacterial, antioxidant and anti-free radical effects, and the prepared pH smart response hydrogel contains carboxymethyl chitosan converted from chitosan (CTS), which has antibacterial properties, and the prepared pH smart response hydrogel includes exosomes, which have antibacterial, anti-inflammatory, regenerative and repair capabilities, so the prepared pH smart response hydrogel can achieve antibacterial effects and reduce bacterial resistance. Also, the prepared pH smart response hydrogel contains a non-ionic surfactant solid modified with a double-ended aromatic aldehyde. Thus, the nonionic surfactant solid included in the prepared pH smart response hydrogel can be used as a macromolecular crosslinker, which can form an imine bond as a crosslinking point through the reaction of the terminal aldehyde group and the active amino group of the chitosan monomer unit to complete the construction of the hydrogel network structure. The imine bond can undergo a reversible reaction and has good mechanical properties and self-healing properties, thereby improving the mechanical properties and self-healing properties of the prepared pH smart response hydrogel. Because the constructed imine bond is sensitive to acid and alkali, the exosomes loaded in the prepared pH smart response hydrogel can be controlled and released by regulating the pH, and chitosan forms a cationic hydrogel network in water due to its primary amine group, and exhibits pH response behavior by swelling in acidic pH and shrinking in alkaline pH, so that the prepared pH smart response hydrogel can achieve the effect of self-responsive and controllable release of the loaded exosomes when the pH of its own microenvironment changes. Therefore, when using the prepared pH smart response hydrogel, the pH smart response hydrogel prepared during the acute infection period of the wound (pH<7.0) can accelerate the release of exosomes and prolong the retention time of exosomes in the wound. Thus, the prepared pH smart responsive hydrogel can reduce the occurrence of bacterial resistance, improve the controllability of the release rate of exosomes loaded in the hydrogel, and improve the adaptability of the release amount of exosomes loaded in the hydrogel to the clinical required dose. The prepared pH smart responsive hydrogel can achieve the effect of self-responsive and controllable release of loaded exosomes when the pH of its own microenvironment changes, and further improve the mechanical properties and self-healing properties of the prepared pH smart responsive hydrogel.

[0132] Reference below Figure 2 , which shows a schematic structural diagram of an electronic device 200 (eg, a computing device) suitable for implementing some embodiments of the present disclosure. Figure 2 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0133] like Figure 2As shown, the electronic device 200 may include a processing device 201 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 202 or a program loaded from a storage device 208 to a random access memory (RAM) 203. In the RAM 203, various programs and data required for the operation of the electronic device 200 are also stored. The processing device 201, the ROM 202, and the RAM 203 are connected to each other via a bus 204. An input / output (I / O) interface 205 is also connected to the bus 204.

[0134] Typically, the following devices may be connected to the I / O interface 205: an input device 206 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 207 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 208 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 209. The communication device 209 may allow the electronic device 200 to communicate with other devices wirelessly or by wire to exchange data. Although Figure 2 The electronic device 200 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead. Figure 2 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0135] In particular, according to some embodiments of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, some embodiments of the present disclosure include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In some such embodiments, the computer program can be downloaded and installed from the network through the communication device 209, or installed from the storage device 208, or installed from the ROM 202. When the computer program is executed by the processing device 201, the above-mentioned functions defined in the method of some embodiments of the present disclosure are executed.

[0136] It should be noted that the computer-readable medium recorded in some embodiments of the present disclosure may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In some embodiments of the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In some embodiments of the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0137] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperText Transfer Protocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0138] The computer-readable medium may be included in the electronic device; or it may exist independently without being assembled into the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: performs enhancement processing on each wound surface injection image information received to obtain each wound surface injection image information after enhancement processing; inputs each wound surface injection image information after enhancement processing into a pre-trained wound healing time detection model to obtain wound healing time information corresponding to the prepared pH smart response hydrogel; in response to determining that the obtained wound healing time information meets the preset wound healing time condition, determines that the prepared pH smart response hydrogel meets the preset application effect condition.

[0139] Computer program code for performing the operations of some embodiments of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0140] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0141] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0142] The present disclosure also provides a pH intelligent response hydrogel. The pH intelligent response hydrogel is prepared through the above steps 101-106.

[0143] The above descriptions are only some preferred embodiments of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) and the technical solutions formed.

Claims

1. A method for preparing a pH intelligent responsive hydrogel, comprising: The nonionic surfactant is subjected to double-end aromatic aldehyde modification treatment to obtain the double-end aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid; converting chitosan into carboxymethyl chitosan; According to the nonionic surfactant solid, gallic acid solid and exosomes of a preset concentration, a first configuration mother solution is configured; According to the carboxymethyl chitosan and the exosomes of the preset concentration, a second configuration mother solution is configured; According to a preset configuration ratio, a preset two-component syringe and a mixing tube, the first configuration mother liquid and the second configuration mother liquid are packaged; The solid formed by fusing the first configuration mother solution and the second configuration mother solution released from the preset two-component syringe and the mixing tube is determined as the prepared pH smart responsive hydrogel.

2. The method according to claim 1, wherein: The nonionic surfactant is a polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) copolymer.

3. The method according to claim 1, wherein: The method of performing double-end aromatic aldehyde modification on a nonionic surfactant to obtain the double-end aromatic aldehyde modified nonionic surfactant as a nonionic surfactant solid comprises: Placing a first preset weight of a nonionic surfactant in a flask of a target volume, wherein the target volume is 250 ml and the first preset weight is 10 g; Performing toluene azeotropic distillation drying treatment on the nonionic surfactant in the flask of the target volume, and dissolving the nonionic surfactant in anhydrous dichloromethane of a first preset volume, wherein the first preset volume is 30 mL; Adding a second preset volume of anhydrous dichloromethane into the flask of the target volume to dissolve the solution in the flask of the target volume to obtain a hydrogel dissolved solution, wherein the second preset volume is 50 mL; Dissolving a second preset weight of 4-formylbenzoic acid in a third preset volume of anhydrous dichloromethane to obtain a dissolved solution, wherein the second preset weight is 1.6 g and the third preset volume is 5 mL; Adding a third preset weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the dissolved solution to activate the carboxyl group of 4-formylbenzoic acid in the dissolved solution to obtain a target mixed solution, wherein the third preset weight is 2.5 g, and the activation time of the carboxyl group of the 4-formylbenzoic acid is 15 minutes; Adding the second preset weight of 4-dimethylaminopyridine to the target mixed solution to activate the target mixed solution to obtain activated 4-formylbenzoic acid, wherein the activation time of the target mixed solution is 15 minutes; dropping the activated 4-formylbenzoic acid into the hydrogel dissolving solution to obtain a hydrogel mixed solution; According to a preset reaction time, the hydrogel mixed solution is subjected to room temperature reaction treatment, wherein the preset reaction time is 24 hours; Performing a rotary evaporation treatment on the hydrogel mixed solution to evaporate and remove dichloromethane in the hydrogel mixed solution; Adding a fourth preset volume of purified water to the hydrogel mixed solution to perform a dissolution and precipitation process on the hydrogel mixed solution, wherein the fourth preset volume is 100 mL; Using deionized water to dialyze the hydrogel mixed solution into a dialysis bag, wherein the molecular weight of the dialysis bag is 8-15 kDa, so as to perform dialysis treatment on the hydrogel mixed solution to obtain a dialysis sample of the hydrogel mixed solution; The dialyzed sample of the hydrogel mixed solution is freeze-dried to obtain a non-ionic surfactant modified with a double-end aromatic aldehyde as a non-ionic surfactant solid.

4. The method according to claim 1, wherein: The first mother solution is prepared according to the non-ionic surfactant solid, the gallic acid solid and the exosomes of a preset concentration, comprising: A phosphate buffered saline solution is used to dissolve the nonionic surfactant solid, the gallic acid solid and the exosomes of a preset concentration to obtain a first configuration mother solution, wherein the preset concentration is greater than or equal to 500 ug / ml, the concentration of the phosphate buffered saline solution is 1×PBS, and the concentration of the dissolved nonionic surfactant solid in the first configuration mother solution is 10-40% w / v, the concentration of the dissolved gallic acid solid is 0.01-10% w / v, and the concentration of the dissolved exosomes of the preset concentration is 1-500 ug / ml.

5. The method according to claim 4, wherein: The step of preparing a second preparation mother solution according to the carboxymethyl chitosan and the exosomes at the preset concentration comprises: The phosphate buffered saline solution is used to dissolve the carboxymethyl chitosan and the exosomes of the preset concentration to obtain a second configuration mother solution, wherein the concentration of the carboxymethyl chitosan solution in the second configuration mother solution is 1 to 40% w / v and the concentration of the exosomes of the preset concentration after dissolution is 1 to 500 ug / ml.

6. The method according to claim 1, wherein: The exosomes at the preset concentration are cultured by the following steps: placing human umbilical cord mesenchymal stem cells in a target incubator for culturing, wherein the target incubator is a CO2 incubator; In response to determining that the density information of the P3-P8 generation cells is a preset density, starving the P3-P8 generation cells to obtain the starved generation cells, wherein the preset density is 80%; Collecting the supernatant of P3-P8 cells after the starvation treatment; Collecting exosomes of a preset concentration corresponding to the P3-P8 generation cells by ultracentrifugation; The exosomes of the preset concentration collected by ultracentrifugation are stored in separate containers, wherein the temperature for storing the exosomes of the preset concentration collected by ultracentrifugation is minus 80 degrees Celsius.

7. A pH-smart responsive hydrogel, wherein: The pH smart response hydrogel is prepared by the pH smart response hydrogel preparation method as described in any one of claims 1-6.

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