A photodynamic antibacterial hydrogel material and its preparation method

Abstract

The present disclosure provides a photodynamic antibacterial hydrogel material, comprising: a hydrogel matrix, having self-healing properties, long-afterglow nanomaterials, which provide the light source required for photodynamic action through the afterglow effect under the excitation of natural light, and mesoporous nano-silica materials, loaded with photosensitizers. Among them, the afterglow emission wavelength range of the long-afterglow nanomaterials is within the excitation wavelength range of the photosensitizers, so that the photosensitizers generate reactive oxygen species under the light excitation provided by the long-afterglow nanomaterials. The present disclosure also provides a preparation method of the above-mentioned photodynamic antibacterial hydrogel material, comprising: dissolving a metal salt, and obtaining long-afterglow nanomaterials through hydrothermal reaction and heat treatment; performing stirring treatment on a mixed dispersion of mesoporous nano-silica materials and photosensitizers in the dark to obtain mesoporous nano-silica materials loaded with photosensitive materials; mixing and casting a dispersion of the foregoing materials and a hydrogel matrix to obtain a photodynamic antibacterial hydrogel material.

Description

Technical Field

[0001] The present disclosure relates to the field of photodynamic antibacterial technology, and relates to a photodynamic antibacterial hydrogel material and a preparation method thereof. Background Art

[0002] As the largest organ of the human body, the skin plays an important role in resisting the invasion of external pathogens. When the skin is injured, bacteria may invade and form an infectious wound. Bacteria at the wound site will cause the aggregation of immune cells in the body. However, if the bacteria cannot be cleared for a long time, continuous bacterial infection will lead to long-term chronic inflammation, delaying the wound healing process and turning it into a chronic wound. Therefore, in addition to using dressings to isolate the wound from external pathogens, it is also necessary to take measures to inhibit or kill bacteria.

[0003] Traditional wound dressings, such as bandages and gauzes, can isolate the wound surface and absorb wound exudate, but the dressings themselves do not have antibacterial effects, and traditional wound dressings will dry and cake after absorbing wound exudate, causing secondary damage to the wound when changing the dressings.

[0004] The discovery and application of antibiotics have greatly reduced the mortality rate of bacterial infections, but bacteria will develop drug resistance to antibiotics, even leading to the emergence of "super bacteria". The emergence and spread of drug-resistant strains endanger human safety. Therefore, it is very important to develop a safe and efficient antibacterial method that is not easy to cause drug resistance. Summary of the Invention

[0005] In view of this, in order to solve the problems in the related technologies that traditional wound dressings have the risk of secondary injury on the one hand, which is not conducive to wound recovery, and on the other hand, they cannot clear bacteria or produce drug-resistant pathogens, the present disclosure proposes a photodynamic antibacterial hydrogel material and a preparation method thereof.

[0006] In one aspect of the present disclosure, a photodynamic antibacterial hydrogel material is proposed, including:

[0007] A hydrogel matrix having self-healing properties;

[0008] A long afterglow nanomaterial that provides the light source required for photodynamic action through the afterglow effect under the excitation of natural light; and

[0009] A mesoporous nano-silica material loaded with a photosensitizer;

[0010] Wherein, the afterglow emission wavelength range of the long afterglow nanomaterial is within the excitation wavelength range of the photosensitizer, so that the photosensitizer generates reactive oxygen species under the light excitation provided by the long afterglow nanomaterial.

[0011] According to an embodiment of the present disclosure, the hydrogel matrix includes: carboxymethyl chitosan, dialdehyde cellulose nanocrystals; wherein,

[0012] The amino group of carboxymethyl chitosan is connected to the aldehyde group of dialdehyde cellulose nanocrystals to form a self-healing hydrogel with dynamic Schiff base bonds;

[0013] The long afterglow nanomaterials and mesoporous nano-silica materials are dispersed in the self-healing hydrogel at a mass ratio of 4:1.

[0014] According to an embodiment of the present disclosure, the long afterglow nanomaterials include zinc gallium germanate-based nanoparticles doped with chromium, and the afterglow emission wavelength range is 650 - 750 nm;

[0015] The photosensitizer includes dichlorosilicon phthalocyanine, and the excitation wavelength range of the photosensitizer is 650 - 750 nm.

[0016] In another aspect of the present disclosure, a preparation method of the above-mentioned photodynamic antibacterial hydrogel material is proposed, including:

[0017] Dissolve zinc salt, gallium salt, chromium salt and germanium salt, and obtain long afterglow nanomaterials through hydrothermal reaction and heat treatment;

[0018] Stir the mixed dispersion of mesoporous nano-silica material and photosensitizer in the dark to obtain mesoporous nano-silica material loaded with photosensitive material;

[0019] Add water to the long afterglow nanomaterials, the mesoporous nano-silica material loaded with photosensitive material, and the hydrogel matrix respectively to prepare dispersions, and mix and cast the dispersions to obtain the photodynamic antibacterial hydrogel material.

[0020] According to an embodiment of the present disclosure, the molar ratio of zinc salt, gallium salt, chromium salt and germanium salt is 3:2:1:0.005;

[0021] The conditions of the hydrothermal reaction include: the reaction temperature is 184 °C and the reaction time is 4 h;

[0022] The conditions of the heat treatment include: the treatment temperature is 800 °C and the treatment time is 1 h.

[0023] According to an embodiment of the present disclosure, the mesoporous nano-silica is prepared by the following method: mix an ethanol-water mixed solvent, a silicon source and a surfactant, and obtain nano-silica material through sol-gel method (Stober template method), and then perform heat treatment on the nano-silica material to obtain mesoporous nano-silica material;

[0024] The volume ratio of ethanol to water in the ethanol-water mixed solvent is preferably 1:50;

[0025] The silicon source preferably includes tetraethoxysilane;

[0026] The surfactant preferably includes cetyltrimethylammonium bromide;

[0027] The heat treatment of the nano-silica material preferably includes: reacting the nano-silica material at 550 °C for 4 h to obtain a mesoporous nano-silica material.

[0028] According to an embodiment of the present disclosure, the hydrogel matrix includes carboxymethyl chitosan and dialdehyde cellulose nanocrystals; the method further includes:

[0029] Mixing cellulose nanocrystal powder with sodium periodate solution and performing an oxidation reaction to obtain dialdehyde cellulose nanocrystals;

[0030] Mixing chitosan powder and an alkaline solution and performing an expansion treatment, adding an organic solvent to dissolve, obtaining a chitosan powder solution, and then adding chloroacetic acid for reaction to prepare carboxymethyl chitosan.

[0031] According to an embodiment of the present disclosure, the operation of the sodium periodate oxidation method includes ultrasonically dispersing cellulose nanocrystal powder in water, adding sodium periodate, adjusting the pH to 3, reacting in the dark at 40 °C for 4 h, and then adding ethylene glycol and continuing the reaction for 1 h to obtain dialdehyde cellulose nanocrystals.

[0032] According to an embodiment of the present disclosure, the expansion treatment includes expanding at -20 °C for 12 h;

[0033] The chloroacetic acid substitution treatment includes adding a chloroacetic acid solution to the chitosan powder solution, stirring at room temperature for 1.5 h, then heating and refluxing in an oil bath at 60 °C for 2 h, and then pouring it into anhydrous ethanol for precipitation, washing and drying to obtain carboxymethyl chitosan.

[0034] According to an embodiment of the present disclosure, the volume ratio of the dispersion of the long afterglow nanomaterial, the dispersion of the mesoporous nano-silica material loaded with a photosensitive material, the dispersion of the dialdehyde cellulose nanocrystals, and the dispersion of the carboxymethyl chitosan is 1:1:1:1;

[0035] The mass concentration ratio of the dispersion of the long afterglow nanomaterial and the dispersion of the mesoporous nano-silica material loaded with a photosensitive material is 4:1, wherein the concentration range of the dispersion of the long afterglow nanomaterial is 5-200 μg·mL -1 , and the mass fractions of the dispersion of the dialdehyde cellulose nanocrystals and the dispersion of the carboxymethyl chitosan are 4% respectively.

[0036] According to the embodiments of the present disclosure, a hydrogel material with photodynamic antibacterial properties is constructed. Among them, a self-healing hydrogel is used as the matrix, and persistent luminescence nanoparticles (PLNP) and mesoporous nano-silica materials loaded with photosensitizers (DMOS-SiPcCl2) are combined to achieve the photodynamic bactericidal function. The persistent luminescence nanoparticles are excited by natural light, and the afterglow generated by the excitation can be used as an energy source for the hydrogel material to excite the photosensitizer loaded in the mesoporous nano-silica, so that the photosensitizer generates reactive oxygen species under the photodynamic action provided by the persistent luminescence nanoparticles to kill bacteria. Precise light irradiation at the wound is achieved, and it is not limited by instruments and wound depth. At the same time, while absorbing tissue exudate, the loose and porous network structure of the hydrogel material allows bacteria to diffuse into the hydrogel matrix and be captured by the internal materials of the hydrogel through electrostatic interaction, and cooperate with reactive oxygen species to complete the bactericidal function, producing a continuous antibacterial effect on the bacteria-infected wound without the addition of external antibiotics, promoting wound healing. During the bactericidal process, no precise target is required, and it is not easy to cause bacterial drug resistance. Description of the Drawings

[0037] Figure 1 is the scanning electron microscope image of the photodynamic antibacterial hydrogel material in the present disclosure;

[0038] Figure 2 is the scanning electron microscope image of the unloaded hydrogel material in the present disclosure;

[0039] Figure 3 is the schematic diagram of the principle of the hydrogel material formed by crosslinking dialdehyde cellulose nanocrystals and carboxymethyl chitosan through Schiff base bonds in the present disclosure;

[0040] Figure 4 is the process flow chart of the method for preparing dialdehyde cellulose nanocrystals in the present disclosure;

[0041] Figure 5 is the transmission electron microscope image of the prepared persistent luminescence nanoparticles (PLNP) in the present disclosure;

[0042] Figure 6 is the transmission electron microscope image of the prepared dialdehyde cellulose nanocrystals (DACNC) in the present disclosure;

[0043] Figure 7 is the comparative transmission electron microscope image of the mesoporous nano-silica materials (DMOS-SiPcCl2) before and after loading in the present disclosure;

[0044] Figure 8 is the particle size distribution diagram of the prepared persistent luminescence nanoparticles (PLNP) in the present disclosure;

[0045] Figure 9It is the particle size distribution diagram of the mesoporous nano-silica material (DMOS) prepared in the present disclosure;

[0046] Figure 10 It is the afterglow emission curve diagram of the long afterglow nano-material prepared in the examples of the present disclosure;

[0047] Figure 11 It is the column chart of the change in absorbance in the singlet oxygen test in Test Example 3 of the present disclosure;

[0048] Figure 12A It is the scanning electron microscope image of carboxymethyl chitosan capturing Gram-negative bacterium Escherichia coli (E. coli) in Test Example 4 of the present disclosure;

[0049] Figure 12B It is the scanning electron microscope image of carboxymethyl chitosan (CMC) capturing Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 4 of the present disclosure;

[0050] Figure 12C It is the scanning electron microscope image of dialdehyde cellulose nanocrystals (DACNC) capturing Gram-negative bacterium Escherichia coli (E. coli) in Test Example 4 of the present disclosure;

[0051] Figure 12D It is the scanning electron microscope image of dialdehyde cellulose nanocrystals (DACNC) capturing Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 4 of the present disclosure;

[0052] Figure 13 It is the bactericidal effect diagram of long afterglow nano-material (PLNP) and mesoporous nano-silica material loaded with photosensitizer (DMOS-SiPcCl2) in the environment of Gram-negative bacterium Escherichia coli (E. coli) in Test Example 5 of the present disclosure;

[0053] Figure 14 It is the bactericidal effect diagram of long afterglow nano-material (PLNP) and mesoporous nano-silica material loaded with photosensitizer (DMOS-SiPcCl2) in the environment of Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 5 of the present disclosure;

[0054] Figure 15 It is the bactericidal effect diagram of long afterglow nano-material (PLNP) and mesoporous nano-silica material loaded with photosensitizer (DMOS-SiPcCl2) in the environment of drug-resistant bacterium methicillin-resistant Staphylococcus aureus (MRSA) in Test Example 5 of the present disclosure;

[0055] Figure 16 It is the column chart of the statistical bactericidal effect of different component hydrogel materials in Test Example 5 of the present disclosure. Detailed implementation manners

[0056] To make the objectives, technical solutions, and advantages of the present disclosure more clear and understandable, the following further elaborates on the present disclosure in detail with reference to specific embodiments and the accompanying drawings.

[0057] In the ranges disclosed in the present disclosure, the endpoints and any values of the ranges are not limited to the precise ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present disclosure.

[0058] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0059] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted to have a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0060] In the present disclosure, the term "photodynamic therapy" (PDT) refers to a treatment strategy in which a photosensitizer (PS) is excited by a suitable light source, and the excited photosensitizer converts substances such as oxygen molecules into reactive oxygen species (ROS) through energy transfer. There have been many studies on tumor treatment.

[0061] In the present disclosure, the term "persistent luminescence nanoparticles" (PLNP) is a kind of nanoparticle that can store energy when excited and slowly release energy in the form of light energy after removing the excitation source. Due to its unique optical properties, persistent luminescence nanoparticles are widely used in fields such as in vivo imaging and tumor treatment.

[0062] Traditional PDT antibacterial technology needs to be excited by a light source with a specific wavelength, and the operation is relatively cumbersome. At the same time, the limited penetration depth of the light source in human tissues limits the application of this therapy. Using PLNP as an internal light source can effectively avoid the above defects.

[0063] In the present disclosure, the term "hydrogel dressing" refers to a gel material that can maintain a moist environment required for wound healing while absorbing wound exudate. Compared with traditional dressings, hydrogel dressings cause less damage to the wound during replacement and can also be loaded with drugs, immune cells, cytokines, etc. to achieve combined treatment. However, during wound healing and limb movement, the framework of the hydrogel dressing is relatively fragile and prone to being damaged or even degraded.

[0064] As a new type of hydrogel material, self-healing hydrogel can repair the damaged hydrogel framework network without external force. Injectable self-healing hydrogel is liquid before gelation, can perfectly fit the wound surface, and has certain mechanical strength and self-healing ability after gelation, serving as a barrier for the wound to resist external infections.

[0065] In the process of implementing the present disclosure, it is found that a self-healing hydrogel formed by cross-linking carboxymethyl chitosan and dialdehyde cellulose nanocrystals through Schiff base bonds is used as a matrix, and a long afterglow nanomaterial is mixed as a light source to excite a photosensitive material to convert substances such as oxygen molecules into reactive oxygen species through energy transfer to achieve an antibacterial effect.

[0066] Figure 1 It is a scanning electron microscope image of the photodynamic antibacterial hydrogel material in the present disclosure. In one aspect of the present disclosure, a photodynamic antibacterial hydrogel material is proposed, including:

[0067] A hydrogel matrix having self-healing properties;

[0068] A long afterglow nanomaterial that provides the light source required for photodynamic action through the afterglow effect under the excitation of natural light; and

[0069] A mesoporous nano-silica material loaded with a photosensitizer;

[0070] Wherein, the afterglow emission wavelength range of the long afterglow nanomaterial is within the excitation wavelength range of the photosensitizer, so that the photosensitizer generates reactive oxygen species under the light excitation provided by the long afterglow nanomaterial.

[0071] According to an embodiment of the present disclosure, as Figure 1As shown, the present disclosure constructs a hydrogel material with photodynamic antibacterial properties. Among them, a self-healing hydrogel is used as the matrix, and persistent luminescence nanoparticles (PLNP) and mesoporous silica nanoparticles loaded with photosensitizer (DMOS-SiPcCl2) are combined to achieve the photodynamic bactericidal function. The persistent luminescence nanoparticles are excited by natural light, and the afterglow generated by the excitation can be used as an energy source for the hydrogel material to excite the photosensitizer loaded in the mesoporous silica, so that the photosensitizer generates reactive oxygen species under the photodynamic action provided by the persistent luminescence nanoparticles to kill bacteria. Precise light irradiation at the wound is achieved, and it is not limited by instruments and wound depth. At the same time, while absorbing tissue exudate, the loose and porous network structure of the hydrogel material allows bacteria to diffuse into the hydrogel matrix and be captured by the internal materials of the hydrogel through electrostatic interaction, and cooperate with reactive oxygen species to complete the bactericidal function, and continuously antibacterial effect on bacteria-infected wounds without adding external antibiotics, promoting wound healing.

[0072] Figure 2 It is a scanning electron microscope image of the unloaded hydrogel material in the present disclosure.

[0073] Figure 3 It is a schematic diagram of the principle of forming a hydrogel material by crosslinking dialdehyde cellulose nanocrystals and carboxymethyl chitosan through Schiff base bonds in the present disclosure;

[0074] According to an embodiment of the present disclosure, the hydrogel matrix includes: carboxymethyl chitosan, dialdehyde cellulose nanocrystals; as Figure 2 、 Figure 3 shown, wherein,

[0075] The amino group of carboxymethyl chitosan is connected to the aldehyde group of dialdehyde cellulose nanocrystals to form a self-healing hydrogel with dynamic Schiff base bonds;

[0076] The persistent luminescence nanoparticles and the mesoporous silica nanoparticles are dispersed in the self-healing hydrogel at a mass ratio of 4:1.

[0077] According to an embodiment of the present disclosure, the hydrogel matrix is synthesized from biogenic carboxymethyl chitosan and dialdehyde cellulose nanocrystals, and has good biocompatibility. The amino group carried by carboxymethyl chitosan can form dynamic Schiff base bonds with the aldehyde group on the dialdehyde cellulose nanocrystals to form a self-healing hydrogel. The rod-shaped cellulose nanocrystals with a certain rigidity endow the hydrogel matrix with higher strength and can stably exist after fitting with the wound. The loose and porous network structure inside the hydrogel allows bacteria to diffuse into the hydrogel matrix. The positively charged carboxymethyl chitosan can capture bacteria at the infected wound through electrostatic adsorption, and the photosensitizer generates reactive oxygen species under the photodynamic action provided by the persistent luminescence nanoparticles to kill bacteria.

[0078] According to an embodiment of the present disclosure, the long afterglow nanomaterial includes chromium-doped zinc gallium germanate-based nanoparticles, and the afterglow emission wavelength range is 650-750 nm;

[0079] The photosensitizer includes dichlorosilicon phthalocyanine, and the excitation wavelength range of the photosensitizer is 650-750 nm.

[0080] According to an embodiment of the present disclosure, as Figure 10 shown, the afterglow emission peak of the long afterglow nanomaterial is at 690 nm, and within the range of 650-750 nm, it can be adapted to the excitation wavelength of the photosensitizer so that the photosensitizer generates reactive oxygen species under the photodynamic action provided by the long afterglow nanomaterial.

[0081] In another aspect of the present disclosure, a preparation method of the above-mentioned photodynamic antibacterial hydrogel material is proposed, including:

[0082] Dissolve zinc salt, gallium salt, chromium salt and germanium salt, and obtain long afterglow nanomaterials through hydrothermal reaction and heat treatment;

[0083] Stir the mixed dispersion of mesoporous nano-silica material and photosensitizer in the dark to obtain mesoporous nano-silica material loaded with photosensitive material;

[0084] Prepare the long afterglow nanomaterials, the mesoporous nano-silica material loaded with photosensitive material, and the hydrogel matrix into dispersions by adding water respectively, and mix and inject the dispersions to obtain the photodynamic antibacterial hydrogel material.

[0085] According to an embodiment of the present disclosure, a photodynamic antibacterial hydrogel material with appropriate synergistic effects is prepared by regulating reactants and reaction conditions.

[0086] According to an embodiment of the present disclosure, the molar ratio of zinc salt, gallium salt, chromium salt and germanium salt is 3:2:1:0.005;

[0087] The conditions of the hydrothermal reaction include: the reaction temperature is 184 °C and the reaction time is 4 h;

[0088] The conditions of the heat treatment include: the treatment temperature is 800 °C and the treatment time is 1 h.

[0089] According to an embodiment of the present disclosure, the long afterglow nanomaterials prepared under these conditions have good afterglow performance, the afterglow time can reach 24 h, and the doping ratio of chromium element is about 0.5%.

[0090] According to an embodiment of the present disclosure, mesoporous nano-silica is prepared by the following method: Mix an ethanol-water mixed solvent, a silicon source and a surfactant, and obtain nano-silica materials through sol-gel method (Stober template method), and then perform heat treatment on the nano-silica materials to obtain mesoporous nano-silica materials.

[0091] According to an embodiment of the present disclosure, the volume ratio of ethanol to water in the ethanol-water mixed solvent is preferably 1:50; the silicon source preferably includes tetraethoxysilane; the surfactant preferably includes cetyltrimethylammonium bromide; the heat treatment of the nano-silica material preferably includes: reacting the nano-silica material at 550 °C for 4 h to obtain a mesoporous nano-silica material.

[0092] According to an embodiment of the present disclosure, cetyltrimethylammonium bromide can be used as a pore-forming agent. The surfactant self-assembles into micelles in the solution and embeds into the silicon spheres. The surface organic surfactant micelles can be removed by high temperature, leaving voids to obtain a mesoporous nano-silica material.

[0093] According to an embodiment of the present disclosure, a diethanolamine solution needs to be added in the reaction for obtaining the mesoporous nano-silica material to adjust the pH and catalyze the reaction.

[0094] According to an embodiment of the present disclosure, the mesoporous nano-silica material prepared under these conditions has a pore structure suitable for loading photosensitizers, and the particle radius is about 50 nm.

[0095] According to an embodiment of the present disclosure, the hydrogel matrix includes carboxymethyl chitosan and dialdehyde cellulose nanocrystals; its preparation method further includes:

[0096] Mixing cellulose nanocrystal powder with sodium periodate solution and performing an oxidation reaction to obtain dialdehyde cellulose nanocrystals;

[0097] Mixing chitosan powder and an alkaline solution and performing an expansion treatment, adding an organic solvent to dissolve to obtain a chitosan powder solution, and then adding chloroacetic acid for reaction to prepare carboxymethyl chitosan.

[0098] According to an embodiment of the present disclosure, the carboxymethyl chitosan prepared by the method of the present disclosure belongs to carboxymethyl oxygen-substituted chitosan, which can effectively increase water solubility.

[0099] Figure 4 It is a process flow diagram for preparing dialdehyde cellulose nanocrystals in the present disclosure.

[0100] According to an embodiment of the present disclosure, as Figure 4 shown, the operation of the sodium periodate oxidation method includes ultrasonically dispersing cellulose nanocrystal powder (CNC) in water, adding sodium periodate, adjusting the pH to 3, reacting in the dark at 40 °C for 4 h, and then adding ethylene glycol and continuing the reaction for 1 h to obtain dialdehyde cellulose nanocrystals.

[0101] According to an embodiment of the present disclosure, as Figure 4As shown, cellulose nanocrystal powder (CNC) can be prepared through the following steps: Neutral filter paper is crushed and passed through a 20-mesh sieve to obtain cellulose powder; concentrated sulfuric acid is slowly added to an equal volume of ultrapure water to obtain a sulfuric acid solution. After cooling, the sulfuric acid solution is heated to 45 °C, and the cellulose powder is added with stirring to obtain a mixture. After reacting for 1 h, the mixture is poured into an ice-water mixture with a volume twice that of the mixture to terminate the hydrolysis reaction. The supernatant is discarded by centrifugation, and the precipitate is washed twice with ultrapure water. After dialysis against ultrapure water for 48 h, it is freeze-dried to obtain cellulose nanocrystal powder (CNC).

[0102] According to an embodiment of the present disclosure, the puffing treatment includes puffing at -20 °C for 12 h;

[0103] The chloroacetic acid substitution treatment includes adding a chloroacetic acid solution to a chitosan powder solution, stirring at room temperature for 1.5 h, then heating and refluxing in an oil bath at 60 °C for 2 h, and then pouring it into absolute ethanol for precipitation. After washing and drying, carboxymethyl chitosan is obtained.

[0104] According to an embodiment of the present disclosure, the volume ratio of the dispersion of the long afterglow nanomaterial, the dispersion of the mesoporous nano-silica material loaded with the photosensitive material, the dispersion of the dialdehyde cellulose nanocrystal, and the dispersion of the carboxymethyl chitosan is 1:1:1:1;

[0105] The mass concentration ratio of the dispersion of the long afterglow nanomaterial and the dispersion of the mesoporous nano-silica material loaded with the photosensitive material is 4:1, wherein the concentration range of the dispersion of the long afterglow nanomaterial is 5-200 μg·mL -1 , and the mass fractions of the dispersion of the dialdehyde cellulose nanocrystal and the dispersion of the carboxymethyl chitosan are 4% respectively.

[0106] The amino group carried by the carboxymethyl chitosan can form a dynamic Schiff base bond with the aldehyde group on the dialdehyde cellulose nanocrystal to form a self-healing hydrogel. The long afterglow nanomaterial and the mesoporous nano-silica material loaded with the photosensitive material are dispersed therein, jointly constituting a hydrogel material with photodynamic antibacterial properties.

[0107] It should be noted that the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, other embodiments obtained by those of ordinary skill in the art without creative efforts all belong to the scope of protection of the present disclosure. The steps of the preparation raw materials described in the present disclosure do not limit the order and only schematically show the preparation process.

[0108] Example

[0109] S1: Prepare the long afterglow nanomaterial (Zn3Ga2Ge2O 10 :C r 3+ , PLNP)

[0110] Put 0.5504 g of solid Zn(CH3COOH)2 and 0.5115 g of solid Ga(NO3)3·xH2O into a 50 mL beaker, add 15 mL of ultrapure water, and stir with a magnetic heating stirrer at room temperature to dissolve the solids. The stirring rate is 400 rpm. After complete dissolution, add 500 μL of a Cr(NO3)3 solution with a concentration of 0.01 mol·L -1 and 235 μL of GeCl4, and continue stirring until the solution becomes clear. Adjust the pH to 8 with 28% ammonia water by mass fraction to obtain the reaction solution.

[0111] After stirring the reaction solution for 3 h, transfer it to a 30 mL Teflon-lined hydrothermal reactor, and transfer the hydrothermal reactor to a muffle furnace for a hydrothermal reaction at 184 °C for 4 h. Centrifuge the suspension obtained from the hydrothermal reaction at 8000 rpm for 5 min, and wash it twice with ultrapure water and ethanol in sequence. Then place it in a vacuum drying oven to dry, and grind it with an agate mortar to obtain the crude product.

[0112] Transfer the crude product powder to a ceramic crucible, place it in a muffle furnace for heat treatment at 800 °C for 1 h, take it out after complete cooling, grind it again and perform ultrasonic dispersion, centrifuge at 2000 rpm for 4 min to discard the larger particles, and obtain a suspension of long afterglow nanomaterials with appropriate size. Finally, centrifuge at 6000 rpm for 8 minutes and dry it in vacuum to obtain the long afterglow nanomaterial powder (PLNP).

[0113] S2: Preparation of mesoporous nano-silica material (DMOS-SiPcCl2) loaded with photosensitive material dichlorosilicon phthalocyanine

[0114] Mix 5 mL of absolute ethanol and 25 mL of ultrapure water to obtain a mixed solvent. Transfer the mixed solvent to a 100 mL round-bottom flask, add 0.2 g of CTAB and 50 μL of diethanolamine, heat and reflux at 80 °C for 30 min, then add 2 mL of TEOS, and continue the reflux reaction for 2 h. Dialyze the product against ethanol and then rotary evaporate and dry to obtain the mesoporous nano-silica material (DMOS).

[0115] Ultrasonically disperse 30 mg of dry DMSO in 3 mL of ultrapure water, and dissolve 3 mg of silicon phthalocyanine dichloride in 3 mL of DMSO. Under stirring conditions, drop it into the DMOS dispersion, continuously stir in the dark for 24 h, and centrifuge at 10000 rpm for 10 min. Then wash it twice with ultrapure water and dry it to obtain DMOS-SiPcCl2, and store it in the dark.

[0116] S3: Preparation of dialdehyde cellulose nanocrystals (DACNC)

[0117] After crushing neutral filter paper with a pulverizer, pass it through a 20-mesh sieve to obtain filter paper powder. Slowly add 50 mL of concentrated sulfuric acid to 50 mL of ultrapure water. After cooling, transfer the sulfuric acid solution to a 250-mL beaker. Heat to 45 °C, and add 5 g of filter paper powder to the sulfuric acid solution under stirring. After reacting for 1 h, pour the mixture in the flask into 200 mL of ice-water mixture to terminate the hydrolysis reaction. Centrifuge at 8000 rpm for 7 min, discard the supernatant, wash the precipitate twice with ultrapure water, then dialyze against ultrapure water for 48 h and freeze-dry to obtain cellulose nanocrystal powder CNC.

[0118] Disperse 0.15 g of CNC powder ultrasonically in 10 mL of ultrapure water, add NaIO4, and adjust the pH to 3 with glacial acetic acid. React in the dark at 40 °C for 4 h, add ethylene glycol, and terminate the oxidation reaction after reacting for 1 h. Dialyze the reaction liquid against water and then rotary evaporate to dryness to obtain the product dialdehyde cellulose nanocrystals (DACNC).

[0119] Among them, the molecular weight cut-off of the dialysis bags used is 3500 Da. DACNC 1:3, DACNC 1:2.5, DACNC 1:2, and DACNC 1:1 were prepared according to different feeding ratios.

[0120] S4: Prepare carboxymethyl chitosan (CMC)

[0121] Mix 10 g of chitosan powder and 50 g of 50% sodium hydroxide solution, expand it in a -20 °C refrigerator for 12 h, and then add 50 mL of isopropanol and stir at room temperature.

[0122] Dissolve 28.5 g of chloroacetic acid in 38.5 mL of isopropanol, add it dropwise to the flask within 30 min, stir at room temperature for 1.5 h, and then transfer it to a 60 °C oil bath for reflux reaction for 2 h. After the reaction is completed, pour it into anhydrous ethanol and stir to precipitate. Dissolve the dried precipitate in 150 mL of ultrapure water, adjust the pH to 7.0 with acetic acid, and drop the solution into methanol with stirring to precipitate again. Filter by suction and dry to obtain the product carboxymethyl chitosan (CMC).

[0123] S5: Prepare a photodynamic antibacterial hydrogel material

[0124] Weigh 10 mg of the PLNP prepared in S1 and place it in a 5-mL centrifuge tube, add 1 mL of ultrapure water and disperse it ultrasonically.

[0125] Weigh 5 mg of the DMOS-SiPcCl2 prepared in S2 and place it in a 5-mL centrifuge tube, add 2 mL of ultrapure water and disperse it ultrasonically.

[0126] Weigh 0.4 g of the DACNC prepared in S3 and place it in a 25 mL flask. Add 9.6 mL of ultrapure water and stir for 12 h at 50 °C. After uniform dispersion, transfer it to a glass bottle for storage.

[0127] Weigh 0.4 g of the CMC prepared in S4 and place it in a 25 mL flask. Add 9.6 mL of ultrapure water and stir for 12 h at 50 °C. After dissolution, transfer it to a glass bottle for storage.

[0128] Dilute the dispersions of PLNP and DMOS-SiPcCl2 with ultrapure water. Among them, the concentration range of PLNP is between 4 mg / mL and 5 μg / mL, and the concentration of DMOS is one-fourth of the PLNP concentration.

[0129] Take 250 μL of the PLNP dispersion, 250 μL of the DMOS-SiPcCl2 dispersion, 250 μL of the CMC solution, and 250 μL of the DACNC dispersion respectively, and inject them into a polytetrafluoroethylene mold. After 2 min, a hydrogel with the same shape as the mold is formed.

[0130] Transfer the hydrogel to a 5 mL syringe and inject it into the mold again. After 30 min, the hydrogel returns to its original state through self-healing. It shows that the prepared photodynamic antibacterial hydrogel material of the present disclosure has self-healing performance.

[0131] Figure 1 It is the scanning electron micrograph of the photodynamic antibacterial hydrogel material in the present disclosure.

[0132] Figure 2 It is the scanning electron micrograph of the unloaded hydrogel material in the present disclosure.

[0133] As Figure 1 、 Figure 2 shown, compared with the scanning electron micrographs of the hydrogels without loaded long afterglow nanomaterials (PLNP) and mesoporous nanosilica materials loaded with photosensitizers (DMOS-SiPcCl2), it can be seen that the photodynamic antibacterial hydrogel material in the present disclosure contains nanoparticles of long afterglow nanomaterials (PLNP) and mesoporous nanosilica materials loaded with photosensitizers (DMOS-SiPcCl2), showing a rougher internal network surface.

[0134] Test Example 1 Morphology Characterization

[0135] Use a transmission electron microscope to observe the microscopic morphologies of the long afterglow nanomaterials (PLNP), mesoporous nanosilica materials loaded with photosensitive material dichlorosilaphthalocyanine (DMOS-SiPcCl2), and dialdehyde cellulose nanocrystals (DACNC) prepared in the examples of the present disclosure.

[0136] Figure 5 It is the transmission electron microscopy image of the long afterglow nanomaterial (PLNP) prepared in the present disclosure.

[0137] As Figure 5 shown, the particle size of the PLNP nanoparticles is about 50 nm, and the morphology is relatively uniform.

[0138] Figure 6 It is the transmission electron microscopy image of the dialdehyde cellulose nanocrystals (DACNC) prepared in the present disclosure.

[0139] As Figure 6 shown, the dialdehyde cellulose nanocrystals (DACNC) are rod-shaped. The length of a single nanorod is about 100 nm, and the diameter is in the range of 10 - 20 nm. Moreover, the nanorods will form rod-shaped clusters.

[0140] Figure 7 It is the comparative transmission electron microscopy image of the mesoporous nano-silica material (DMOS-SiPcCl2) before and after loading in the present disclosure.

[0141] As Figure 7 shown, the morphology of the mesoporous nano-silica material is uniform, presenting a porous spherical shape with a radius of about 50 nm. There is no obvious change in the morphology and size before and after loading dichlorosilicon phthalocyanine.

[0142] The particle size and monodispersity of the long afterglow nanomaterial (PLNP) and the mesoporous nano-silica material (DMOS-SiPcCl2) loaded with the photosensitive material dichlorosilicon phthalocyanine prepared in the present disclosure were measured using a dynamic light scattering nanolaser particle size analyzer.

[0143] Figure 8 It is the particle size distribution diagram of the long afterglow nanomaterial (PLNP) prepared in the present disclosure.

[0144] As Figure 8 shown, the average particle size of the long afterglow nanomaterial prepared in the examples of the present disclosure is 185.09 nm, and the PDI is 0.173.

[0145] Figure 9 It is the particle size distribution diagram of the mesoporous nano-silica material (DMOS) prepared in the present disclosure.

[0146] As Figure 9 shown, the particle size of the mesoporous nano-silica material prepared in the examples of the present disclosure is 151.03 nm, and the PDI is 0.237.

[0147] It shows that the sizes of these two kinds of particles meet the expected requirements, and the particle size distributions are uniform.

[0148] Test Example 2

[0149] The long afterglow nanomaterials prepared in the embodiments of the present disclosure were measured using an ultraviolet-visible spectrometer to obtain the emission spectrum.

[0150] Figure 10 It is the afterglow emission curve diagram of the long afterglow nanomaterials prepared in the embodiments of the present disclosure.

[0151] As Figure 10 shown, the afterglow emission wavelength of PLNP is within 650 - 750 nm, and the peak value is 690 nm.

[0152] Test Example 3 Characterization of the Photodynamic Ability of the Nanoparticle System (Singlet Oxygen Detection)

[0153] Spectrophotometry was used to verify that under natural light, the long afterglow nanomaterials excited the photosensitizer dichlorosilicon phthalocyanine to generate singlet oxygen content. The principle is that the light emitted by the light source will pass through oxygen and be received by the instrument, and the concentration of oxygen can be obtained through absorbance photometry testing.

[0154] 1,3 - diphenylisobenzofuran (DPBF) was dissolved in mesoporous nanosilica material (DMOS) to prepare a solution with a concentration of 10 -6 mol·L -1 . Fifteen 1.5 mL centrifuge tubes were taken, and 500 μL of the DPBF solution was added to each tube and divided into three groups, with 8 samples in each group. Different concentrations of PLNP / DMOS - SiPcCl2 with different PLNP concentrations were added to the 8 centrifuge tubes in each group. Among them, the concentrations of PLNP were 0 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.5 mg / mL, 1 mg / mL, 5 mg / mL, and 10 mg / mL respectively.

[0155] The three groups of centrifuge tubes were respectively irradiated with light for 10 min, 20 min, and 30 min. After the irradiation ended, centrifugation was performed, and 100 μL of the supernatant was taken and placed in a 96 - well plate to measure its absorbance at a wavelength of 415 nm.

[0156] Figure 11 It is the column chart of the absorbance change in the singlet oxygen test in Test Example 3 of the present disclosure.

[0157] As Figure 11 shown, the proposed photodynamic system of the present disclosure has the ability to generate singlet oxygen through the oxidation fading of DPBF and the absorbance change.

[0158] Test Example 4 Bacteria Capture Experiment

[0159] The bacteria used in this test example were Gram - negative bacteria Escherichia coli (E.coli) and Gram - positive bacteria Staphylococcus aureus (S.aureus).

[0160] Two kinds of bacteria revived and cultured on solid MH agar medium were inoculated on liquid MH agar medium and cultured in an incubator at 37 °C until the plateau phase.

[0161] Take 3 mL of the bacterial solution, centrifuge it, wash it once with phosphate buffered saline (PBS), and resuspend it with 3 mL of PBS. Take 4 1.5-mL centrifuge tubes, set up 4 control groups, and add the following to the centrifuge tubes respectively:

[0162] (A) 500 μL of 4% (mass fraction) CMC solution and 500 μL of E. coli bacterial suspension;

[0163] (B) 500 μL of 4% (mass fraction) CMC solution and 500 μL of S. aureus bacterial suspension.

[0164] (C) 500 μL of 4% (mass fraction) DACNC dispersion and 500 μL of E. coli bacterial suspension;

[0165] (D) 500 μL of 4% (mass fraction) DACNC dispersion and 500 μL of S. aureus bacterial suspension;

[0166] After co-incubating each group for 4 h, centrifuge at low speed, where the rotation speed is 5000 rpm and the time is 3 min. After centrifugation, fix the precipitate with glutaraldehyde, dehydrate it with gradient ethanol, prepare a specimen, and observe it through a scanning tunneling microscope.

[0167] Observe the morphology of bacteria in the 4 control groups through a scanning tunneling microscope.

[0168] Figure 12A It is the scanning electron microscope image of carboxymethyl chitosan capturing Gram-negative bacterium Escherichia coli (E. coli) in Test Example 4 of the present disclosure.

[0169] Figure 12B It is the scanning electron microscope image of carboxymethyl chitosan (CMC) capturing Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 4 of the present disclosure.

[0170] Figure 12C It is the scanning electron microscope image of dialdehyde cellulose nanocrystal (DACNC) capturing Gram-negative bacterium Escherichia coli (E. coli) in Test Example 4 of the present disclosure.

[0171] Figure 12D It is the scanning electron microscope image of dialdehyde cellulose nanocrystal (DACNC) capturing Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 4 of the present disclosure.

[0172] As Figures 12A - 12DAs shown, positively charged carboxymethyl chitosan (CMC) can capture bacteria at the infected wound through electrostatic adsorption, forming bacterial aggregates; dialdehyde cellulose nanocrystals (DACNC) intertwine into a network-like structure as a rigid structure to wrap and bind bacteria.

[0173] Test Example 5 Antibacterial Experiment

[0174] 1. Resuscitation of Bacterial Strains and Preparation of Bacterial Suspensions

[0175] The bacteria used in this test example are Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus), and drug-resistant Methicillin-resistant Staphylococcus aureus (MRSA).

[0176] Take the cryopreserved bacteria, thaw them, and resuscitate them on solid MH agar medium. After 24 h, inoculate the resuscitated colonies onto liquid MH agar medium and culture them in an incubator at 37 °C until the stationary phase.

[0177] Inoculate 100 μL of the bacterial suspension into 4 mL of MH liquid agar medium, culture it in an incubator at 37 °C until the logarithmic growth phase, centrifuge it, and resuspend it with phosphate buffered saline (PBS). The resuspended bacterial suspension is diluted with PBS solution to obtain bacterial suspension A, and diluted with liquid MH agar medium to obtain bacterial suspension B, with a concentration of 10 8 CFU·mL -1 .

[0178] 2. Bactericidal Experiments of PLNP and DMOS-SiPcCl2

[0179] Add 25 μL of PLNP dispersion with a concentration of 200 μg / mL and 25 μL of DMOS-SiPcCl2 dispersions with different concentrations into the experimental wells of a 96-well plate as the test groups. Set the experimental control groups as a negative control with 50 μL of 50 μg / mL gentamicin solution and a positive control with 50 μL of PBS solution. Add 100 μL of the above-mentioned bacterial suspension A and 50 μL of PBS solution into the wells, place them in an incubator at 37 °C, and culture them under light for 4 h and then in the dark for 20 h.

[0180] Take out the culture solutions of each group, dilute them 100 times, and then take 60 μL from each and inoculate them onto MH agar plates. Incubate them upside down in an incubator at 37 °C for 24 h and then observe the experimental results.

[0181] Among them, the concentration of PLNP is 50 μg / mL, and the concentrations of the DMOS-SiPcCl2 dispersions are 100, 80, 60, 40, 20, 10, 0 μg / mL respectively.

[0182] Figure 13 It is the bactericidal effect diagram of the long persistent phosphor nanomaterials (PLNP) and mesoporous nanosilica materials loaded with photosensitizers (DMOS-SiPcCl2) in the environment of Gram-negative bacterium Escherichia coli (E. coli) in Test Example 5 of the present disclosure;

[0183] Figure 14 It is the bactericidal effect diagram of the long persistent phosphor nanomaterials (PLNP) and mesoporous nanosilica materials loaded with photosensitizers (DMOS-SiPcCl2) in the environment of Gram-positive bacterium Staphylococcus aureus (S. aureus) in Test Example 5 of the present disclosure;

[0184] Figure 15 It is the bactericidal effect diagram of the long persistent phosphor nanomaterials (PLNP) and mesoporous nanosilica materials loaded with photosensitizers (DMOS-SiPcCl2) in the environment of drug-resistant bacterium methicillin-resistant Staphylococcus aureus (MRSA) in Test Example 5 of the present disclosure;

[0185] As Figures 13 - 15 shown, the survival rate of the colonies in the test group decreased with the increase of the concentration of DMOS-SiPcCl2. When the concentration of DMOS-SiPcCl2 reached 80 μg / mL, no obvious colonies appeared on the agar plate, verifying the reliability of using the PLNP and DMOS-SiPcCl2 mixed system as a photodynamic bactericidal method.

[0186] 3. Hydrogel antibacterial experiment

[0187] Add 50 μL of PLNP dispersion liquids with different concentrations, 50 μL of DMOS-SiPcCl2 dispersion liquids with different concentrations, 50 μL of DACNC dispersion liquid with a mass fraction of 4%, and 50 μL of CMC solution with a mass fraction of 4% into the experimental wells of a 48-well plate to form a gel at the bottom of the well plate, and the total volume of the hydrogel is 200 μL. After the gel is formed, add 200 μL of the above-mentioned bacterial suspension B and 100 μL of PBS solution into the wells, place them in an incubator at 37 °C, culture under light for 4 h, and then culture in the dark for 20 h. Take 100 μL of each group of culture solutions and place them in a sterile 96-well plate, and measure their absorbance at 600 nm.

[0188] Among them, 50 μL of PLNP dispersion liquid, 50 μL of DMOS-SiPcCl2 dispersion liquid (the concentration ratio of PLNP to DMOS-SiPcCl2 is 4:1), 50 μL of DACNC, and 50 μL of CMC are added to each experimental group. The concentrations of each group of dispersion liquids (calculated by PLNP) are 0 mg / mL, 100 μg / mL, 500 μg / mL, 1 mg / mL, 5 mg / mL, and 10 mg / mL respectively; the control group adds 200 μL of PBS solution.

[0189] Figure 16 It is a statistical bar chart of the bactericidal effects of different component hydrogel materials in Test Example 5 of the present disclosure.

[0190] As Figure 16 shown, the results show that a large number of bacteria grow in the control group without hydrogel and antibacterial substances. The bacterial concentration in the supernatant of the group containing the hydrogel matrix but no antibacterial substances (i.e., long afterglow nanomaterials and mesoporous nano-silica materials loaded with photosensitizers) is low, but there are still a large number of live bacteria in the hydrogel matrix, proving that the hydrogel has the effect of capturing bacteria. There are no bacteria in the supernatant of the group containing the hydrogel matrix and low-concentration antibacterial substances, and there are a small number of bacteria in the hydrogel solution, proving the effectiveness of the antibacterial substances but a certain concentration is required to achieve a better bactericidal effect. There are no bacteria in both the supernatant and the hydrogel solution of the group containing the hydrogel matrix and high-concentration antibacterial substances, proving its good bactericidal effect.

[0191] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not used to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A photodynamic antibacterial hydrogel material, comprising: A hydrogel matrix with self-healing properties, the hydrogel matrix comprising: carboxymethyl chitosan, dialdehyde cellulose nanocrystals, wherein the amino group of the carboxymethyl chitosan is connected to the aldehyde group of the dialdehyde cellulose nanocrystals to form a self-healing hydrogel with dynamic Schiff base bonds; A long afterglow nanomaterial that provides the light source required for photodynamic action through the afterglow effect under the excitation of natural light, the long afterglow nanomaterial comprising zinc gallium germanate-based nanoparticles doped with chromium, and the afterglow emission wavelength range is 650-750 nm; and A mesoporous nano-silica material loaded with a photosensitizer, the photosensitizer comprising dichlorosilicon phthalocyanine, and the excitation wavelength range of the photosensitizer is 650-750 nm; Wherein, the afterglow emission wavelength range of the long afterglow nanomaterial is within the excitation wavelength range of the photosensitizer, so that the photosensitizer generates reactive oxygen species under the light excitation provided by the long afterglow nanomaterial.

2. The material according to claim 1, wherein, The long afterglow nanomaterial and the mesoporous nano-silica material are dispersed in the self-healing hydrogel at a mass ratio of 4:

1.

3. A preparation method of the photodynamic antibacterial hydrogel material according to any one of claims 1 or 2, comprising: Dissolving zinc salt, gallium salt, chromium salt and germanium salt, and obtaining the long afterglow nanomaterial through hydrothermal reaction and heat treatment; Stirring the mixed dispersion of the mesoporous nano-silica material and the photosensitizer in the dark to obtain the mesoporous nano-silica material loaded with the photosensitive material; Respectively adding water to the long afterglow nanomaterial, the mesoporous nano-silica material loaded with the photosensitive material, and the hydrogel matrix to prepare dispersions, and mixing and casting the dispersions to obtain the photodynamic antibacterial hydrogel material.

4. The method according to claim 3, wherein, The molar ratio of the zinc salt, the gallium salt, the chromium salt and the germanium salt is 3:2:1:0.005; The conditions of the hydrothermal reaction include: the reaction temperature is 184 °C, and the reaction time is 4 h; The conditions of the heat treatment include: the treatment temperature is 800 °C, and the treatment time is 1 h.

5. The method according to claim 3, wherein, The mesoporous nano-silica is prepared by the following method: mixing an ethanol-water mixed solvent, a silicon source and a surfactant, and obtaining a nano-silica material through sol-gel method treatment, and then performing heat treatment on the nano-silica material to obtain the mesoporous nano-silica material; The silicon source includes tetraethoxysilane; The surfactant includes cetyltrimethylammonium bromide; The heat treatment of the nano-silica material includes: reacting the nano-silica material at 550 °C for 4 h to obtain the mesoporous nano-silica material.

6. The method according to claim 5, wherein, The volume ratio of ethanol to water in the ethanol-water mixed solvent is 1:

50.

7. The method according to claim 3, wherein The hydrogel matrix includes carboxymethyl chitosan, dialdehyde cellulose nanocrystals; the method further includes: Mixing the cellulose nanocrystal powder with a sodium periodate solution and performing an oxidation reaction to obtain dialdehyde cellulose nanocrystals; Mix chitosan powder and an alkaline solution and conduct an expansion treatment. Add an organic solvent to dissolve it to obtain a chitosan powder solution, and then add chloroacetic acid for reaction to prepare carboxymethyl chitosan.

8. According to the method described in claim 7, wherein the operation of mixing the cellulose nanocrystal powder and the sodium periodate solution and conducting an oxidation reaction includes ultrasonically dispersing the cellulose nanocrystal powder in water, adding sodium periodate, adjusting the pH to 3, reacting in the dark at 40 °C for 4 h, then adding ethylene glycol and continuing the reaction for 1 h to obtain dialdehyde cellulose nanocrystals.

9. According to the method described in claim 7, wherein the expansion treatment includes expanding at -20 °C for 12 h; the reaction for preparing carboxymethyl chitosan includes adding a chloroacetic acid solution to the chitosan powder solution, stirring at room temperature for 1.5 h, then heating under reflux in an oil bath at 60 °C for 2 h, and then pouring it into anhydrous ethanol for precipitation. After washing and drying, the carboxymethyl chitosan is obtained.

10. According to the method described in claim 7, wherein the volume ratio of the dispersion of the long-afterglow nanomaterial, the dispersion of the mesoporous nano-silica material loaded with the photosensitive material, the dispersion of the dialdehyde cellulose nanocrystals, and the dispersion of the carboxymethyl chitosan is 1:1:1:1; The mass concentration ratio of the dispersion of the long-afterglow nanomaterial to the dispersion of the mesoporous nano-silica material loaded with the photosensitive material is 4:1, wherein the concentration range of the dispersion of the long-afterglow nanomaterial is 5-200 μg·mL -1 , and the mass fractions of the dispersion of the dialdehyde cellulose nanocrystals and the dispersion of the carboxymethyl chitosan are 4% respectively.

Images