Preparation method of antibacterial hydrogel loaded with paris polyphylla carbon quantum dots

Abstract

The invention relates to a paris polyphylla carbon quantum dot loaded antibacterial hydrogel preparation method, which comprises: accurately weighing 30-40 parts of paris polyphylla powder, and placing in a high pressure reaction kettle; discharging air therein, and then heating at 200-300 DEG C for 5-8 hours; cooling, taking out the solid in the reaction kettle, crushing, adding 100-110 parts of 50% ethanol, uniformly stirring, and filtering with a 0.22-0.28 [mu] m filter membrane; collecting liquid, freezing and drying to obtain the traditional Chinese medicine biomass carbon quantum dots. The paris polyphylla carbon quantum dot-loaded antibacterial hydrogel prepared by the preparation method has a good antibacterial effect, can delay the generation of drug-resistant bacteria, is biodegradable, small in environmental pollution, free of environmental protection pressure, good in skin repair effect and capable of effectively promoting skin repair, the paris polyphylla rhizome paris polyphylla is adopted to prepare carbon quantum dots, and the specific saponin carbonization product of the carbon quantum dots is used for production, so that the preparation method is simple, and the preparation cost is low. The porosity is improved to 82% by combining acetic acid pretreatment with PVA freeze-thaw crosslinking, carboxyl groups on the surfaces of the carbon quantum dots and PVA hydroxyl groups form a hydrogen bond network, the contradiction between antibiosis and mechanics is broken through, and the characteristic of sustainable release is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial hydrogels, and in particular to a method for preparing an antibacterial hydrogel loaded with parsley carbon quantum dots. Background Art

[0002] Polyvinyl alcohol (PVA) is produced through the alcoholysis and polymerization of vinyl acetate. It is a white, powdery, stable, non-toxic, biodegradable, water-soluble polymer that dissolves rapidly in water at room temperature to form a stable colloid. Water is a good solvent for PVA. PVA exhibits excellent film-forming properties, resulting in films with superior adhesion, solvent resistance, abrasion resistance, tensile strength, and oxygen barrier properties. PVA possesses both hydrophilic and hydrophobic functional groups, making it an interfacially active substance. Therefore, PVA can be used as a protective colloid in polymer emulsion and suspension polymerization reactions.

[0003] Carbon quantum dots (CQDs) are a type of carbon-based biomaterial with fluorescent properties, mainly composed of elements such as carbon, hydrogen, and oxygen. The synthesis of biomass carbon quantum dots is commonly done by hydrothermal and high-temperature pyrolysis methods. Since their discovery in 2004, carbon dots have been widely reported in the fields of light-emitting devices, imaging, catalysis, and biomedicine. Generally speaking, the core carbon atoms of carbon dots are sp2 hybridized, so the internal core can be doped with a variety of heteroatoms, such as N, O, and P atoms, resulting in an increase in delocalized electrons and a tunable band gap. At the same time, the exposed surface of CQDs can form various derivative functional groups, thereby achieving adjustable absorption, photoelectron generation, and transmission properties. In turn, the surface functional groups of carbon dots can be customized according to the properties of the precursor and have the ability to chelate with metals and react with various chemicals, making carbon dots a building block for biomaterials. It is reported that the antibacterial behavior of CQDs can be attributed to the following aspects:

[0004] (1) Rich surface groups give CQDs different charges. When CQDs come into contact with bacteria through electrostatic adsorption, they will cause excessive oxidative stress in the bacteria, destroy the membrane structure, and lead to bacterial death;

[0005] (2) Excellent photoelectron transfer performance, which can generate reactive oxygen species (ROS) or heat by absorbing photons. The large amount of ROS or high heat generated by CQDs can destroy bacterial proteins, biomolecules and outer membranes, leading to bacterial death. Therefore, CQDs can be used as a promising photodynamic and photothermal antibacterial agent;

[0006] (3) Due to their ultra-small particle size, CQDs are easily taken up by bacteria, interfering with the intracellular components of bacteria and inducing programmed cell death.

[0007] Bio-carbon dot-loaded polyethylene hydrogel combines polyvinyl alcohol (PVA) with bio-carbon quantum dots (Bio-CQDs). This technology leverages the biodegradability of PVA and the antibacterial, biocompatible, and environmentally friendly properties of CQDs. This approach is beneficial for mitigating microplastic pollution and alleviating environmental pressures.

[0008] Seven-leafed Polygonum multiflorum is the dried rhizome of Polygonum multiflorum (Tripterygium wilfordii) or Polygonum multiflorum (Tripterygium wilfordii), a plant of the Liliaceae family. It is harvested in autumn, the fibrous roots removed, washed, and sun-dried. It is a tuberous, flat-cylindrical, slightly curved, 5 to 12 cm long and 1.0 to 4.5 cm in diameter. Its surface is yellowish-brown or grayish-brown, with white where the outer skin has fallen off. It is densely covered with coarse, layered rings of protruding tubercles. One side has distinct tubercles with oval, sunken stem scars, while the other side has sparse fibrous roots or warty root scars. The apex bears the remains of scale leaves and stems. It is firm, with a flat cross-section, white to light brown, and powdery or horny. It has a faint odor and a slightly bitter, numb taste.

[0009] Currently, there is a lack of cases of preparing antibacterial hydrogels loaded with carbon quantum dots from Paris polyphylla by combining polyvinyl alcohol with Paridis chinensis. Therefore, there is an urgent need to propose a method for preparing antibacterial hydrogels loaded with carbon quantum dots from Paris polyphylla to fill this gap. Summary of the Invention

[0010] In response to the shortcomings of the existing technology, the present invention provides a method for preparing an antibacterial hydrogel loaded with Paris polyphylla carbon quantum dots. The hydrogel cling film loaded with biomass carbon dots has three major advantages: antibacterial, skin repair, good biocompatibility, and biodegradability. It reduces environmental pressure, accelerates the healing of skin wounds, and has certain application value in the field of skin repair. At the same time, it has water absorption and hydrophobicity, can be coated on the skin surface to form a protective layer, and has a wide range of uses.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing an antibacterial hydrogel loaded with carbon quantum dots, comprising the following steps:

[0012] Step 1: Preparation of Chinese medicine biomass carbon quantum dots

[0013] 1) Accurately weigh 30-40 parts of Parsley septempunctata powder and place it in an autoclave;

[0014] 2) Expel the air and then heat at 200-300℃ for 5-8h;

[0015] 3) After cooling, remove the solid from the reactor and crush it, add 100-110 parts of 50% ethanol, stir evenly, and filter through a 0.22-0.28 μm filter membrane;

[0016] 4) Collecting the liquid and freeze-drying it to obtain the Chinese medicine biomass carbon quantum dots;

[0017] Step 2: Preparation of polyvinyl alcohol hydrogel loaded with traditional Chinese medicine biomass carbon dots

[0018] 1) Accurately weigh 15-45 parts of polyvinyl alcohol and add 1% acetic acid and soak for 20-90 minutes;

[0019] 2) Add 1-2 parts of Chinese medicine biomass carbon quantum dots, heat and stir until the polyvinyl alcohol is completely dissolved;

[0020] 3) Add 1000-1500 μL of glycerol and centrifuge at 900-2000 rpm for 5-10 minutes to remove the foam;

[0021] 4) Add 5-10 parts of the liquid prepared in 3) into the mold and wait for cross-linking to form a hydrogel.

[0022] Furthermore, the lattice fringe spacing of the traditional Chinese medicine biomass carbon quantum dots is 0.21-0.38 nm, the XRD diffraction peak is located near 18-25°, and the particle size is 0-20 nm.

[0023] Furthermore, the degree of polymerization of the polyvinyl alcohol is 1200-3500, and the carbon quantum dots can be at least one of water-soluble, alcohol-soluble, and fat-soluble.

[0024] Furthermore, the carbon quantum dots are particles with a negative potential, and the heating temperature used during the heating and stirring in step 2 is 160-350° C., and the heating time is 6-24 hours.

[0025] Furthermore, in the step 2, the concentration of the acetic acid solution is 0.5-2.5%, and the temperature range for heating and dissolving the polyvinyl alcohol is 65-100°C.

[0026] Furthermore, the centrifugal force range of the centrifugal removal of bubbles is 500-2000g.

[0027] Furthermore, the step 2 also includes polyvinyl alcohol pretreatment, and the specific steps are as follows:

[0028] 1) adding polyvinyl alcohol with a degree of polymerization of 1700-2500 to a 1.0-2.0% (v / v) acetic acid solution;

[0029] 2) Swell at 30±2°C for 45-60 minutes until the volume of the polyvinyl alcohol increases by 200-300%.

[0030] Furthermore, the step 2 also includes plasticizing and degassing:

[0031] 1) Add 5-10% propylene glycol to the total weight of the system and continue stirring for 30 minutes;

[0032] 2) Use step-by-step centrifugal degassing: first 500g×5min to remove large bubbles, then 1500g×8min to remove microbubbles.

[0033] Furthermore, the cross-linking molding specific steps are as follows:

[0034] 1) The mixed solution is injected into a polytetrafluoroethylene mold and cross-linked by freeze-thaw cycles:

[0035] 2) Stage 1: Freeze at -20±1°C for 1-2 hours to form the initial ice crystal template;

[0036] 3) Second stage: melting at 25±1°C for 1-1.5 hours to induce rearrangement of the polyvinyl alcohol molecular chains;

[0037] 4) Repeat steps 1) and 3) for 2-4 cycles to finally obtain a porous hydrogel with a porosity of 75-85%.

[0038] Compared with the existing technology, the technical solution of this application has the following beneficial effects:

[0039] 1. The preparation method of the antibacterial hydrogel loaded with Paris polyphylla carbon quantum dots has good antibacterial effect, can delay the generation of drug-resistant bacteria, is biodegradable, has little environmental pollution, has no environmental pressure, has a good effect on skin repair, and can effectively promote skin repair.

[0040] 2. The preparation method of the antibacterial hydrogel loaded with Paris polyphylla carbon quantum dots uses the rhizome of Paris polyphylla to prepare carbon quantum dots, and its unique saponin carbonization product is produced. Acetic acid pretreatment combined with PVA freeze-thaw cross-linking increases the porosity to 82%. The carboxyl groups on the surface of the carbon quantum dots form a hydrogen bond network with the hydroxyl groups of PVA, breaking through the contradiction between antibacterial and mechanical properties, and achieving sustainable release characteristics.

[0041] 3. The preparation method of the antibacterial hydrogel loaded with carbon quantum dots from Tripterygium wilfordii uses biodegradable materials combined with biomass carbon quantum dots to prepare an antibacterial and fresh-keeping hydrogel that can protect against ultraviolet rays. It uses biodegradable materials, has less environmental pollution pressure, is not restricted by the shape of the object, and can be directly coated and naturally dried to form a protective layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart for preparing the polyvinyl alcohol hydrogel loaded with biomass carbon dots;

[0043] Figure 2 This is a flow chart for preparing biomass carbon dots according to the present invention;

[0044] Figure 3 This is a TEM image of biomass carbon quantum dots derived from the rhizomes of Paris polyphylla of the present invention;

[0045] Figure 4 This is the antibacterial graph of the biomass carbon quantum dots derived from the rhizomes of Paris polyphylla of the present invention;

[0046] Figure 5These are SEM images of E. coli & S. aureus before and after treatment with the Paris polyphylla rhizome-derived carbon dot antibacterial hydrogel in the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] Example 1

[0049] See also Figure 1-5 In this embodiment, a method for preparing an antibacterial hydrogel loaded with carbon quantum dots comprises the following steps:

[0050] Step 1: Preparation of Chinese medicine biomass carbon quantum dots

[0051] 1) Accurately weigh 30 parts of Parsley septempunctata powder and place them in an autoclave;

[0052] 2) Expel the air and then heat at 200°C for 5 hours;

[0053] 3) After cooling, the solid in the reactor was removed and crushed, and 100 parts of 50% ethanol was added, stirred evenly, and filtered through a 0.22 μm filter membrane;

[0054] The prepared traditional Chinese medicine biomass carbon quantum dots have a lattice fringe spacing of 0.21 nm, an XRD diffraction peak located near 18°, a particle size of 2 nm, and carbon quantum dots are particles with a negative potential. The heating temperature used during heating and stirring in step 2 is 160° C., and the heating time is 6 h.

[0055] 4) Collecting the liquid and freeze-drying it to obtain the Chinese medicine biomass carbon quantum dots;

[0056] Step 2: Preparation of polyvinyl alcohol hydrogel loaded with traditional Chinese medicine biomass carbon dots

[0057] 1) Accurately weigh 20 parts of polyvinyl alcohol and soak in 1.5% acetic acid for 20 minutes. The degree of polymerization of the polyvinyl alcohol is 1200, the concentration of the acetic acid solution is 0.5%, and the range of heating to dissolve the polyvinyl alcohol is 65°C.

[0058] 2) adding 1 portion of traditional Chinese medicine biomass carbon quantum dots, heating and stirring until the polyvinyl alcohol is completely dissolved. The carbon quantum dots can be at least one of water-soluble, alcohol-soluble, and fat-soluble;

[0059] 3) Add 1000 μL of glycerol and centrifuge at 900°C for 5 min to remove the foam. The centrifugal force range for removing bubbles is 500 g.

[0060] 4) Add 5 parts of the liquid prepared in 3) into the mold and wait for cross-linking to form a hydrogel. The specific steps of cross-linking are as follows:

[0061] 1) The mixed solution is injected into a polytetrafluoroethylene mold and cross-linked by freeze-thaw cycles:

[0062] 2) First stage: Freeze at -21°C for 1 hour to form the initial ice crystal template;

[0063] 3) Second stage: melting at 19°C for 1 hour to induce rearrangement of the PVA molecular chains;

[0064] 4) Repeat steps 1) and 3) for 2 cycles to finally obtain a porous hydrogel with a porosity of 75%.

[0065] Specifically, it also includes polyvinyl alcohol pretreatment, and the specific steps are as follows:

[0066] 1) Add polyvinyl alcohol with a degree of polymerization of 1700 to a 1.0% (v / v) acetic acid solution;

[0067] 2) Swell at 28°C for 45 minutes until the volume of the polyvinyl alcohol increases by 200%.

[0068] Specifically, it also includes plasticization and degassing:

[0069] 1) Add 5% propylene glycol to the total weight of the system and continue stirring for 30 minutes;

[0070] 2) Use step-by-step centrifugal degassing: first 500g×5min to remove large bubbles, then 1500g×8min to remove microbubbles.

[0071] Example 2

[0072] See also Figure 1-5 In this embodiment, a method for preparing an antibacterial hydrogel loaded with carbon quantum dots comprises the following steps:

[0073] Step 1: Preparation of Chinese medicine biomass carbon quantum dots

[0074] 1) Accurately weigh 35 parts of Parsley septempunctata powder and place them in an autoclave;

[0075] 2) Expel the air and then heat at 280°C for 6 hours;

[0076] 3) After cooling, the solid in the reactor was removed and crushed, 105 parts of 50% ethanol was added, stirred evenly, and filtered through a 0.25 μm filter membrane;

[0077] The prepared traditional Chinese medicine biomass carbon quantum dots have a lattice fringe spacing of 0.32 nm, an XRD diffraction peak located near 20°, a particle size of 10 nm, and carbon quantum dots are particles with a negative potential. The heating temperature used during heating and stirring in step 2 is 280° C., and the heating time is 12 h.

[0078] 4) Collecting the liquid and freeze-drying it to obtain the Chinese medicine biomass carbon quantum dots;

[0079] Step 2: Preparation of polyvinyl alcohol hydrogel loaded with traditional Chinese medicine biomass carbon dots

[0080] 1) Accurately weigh 30 parts of polyvinyl alcohol and soak it in 1% acetic acid for 50 minutes. The degree of polymerization of the polyvinyl alcohol is 2100, the concentration of the acetic acid solution is 1.5%, and the range of heating to dissolve the polyvinyl alcohol is 85°C.

[0081] 2) adding 1.5 parts of traditional Chinese medicine biomass carbon quantum dots, heating and stirring until the polyvinyl alcohol is completely dissolved. The carbon quantum dots can be at least one of water-soluble, alcohol-soluble, and fat-soluble;

[0082] 3) Add 1200 μL of glycerol and centrifuge at 1800°C for 8 min to remove the foam. The centrifugal force range for removing bubbles is 1200 g.

[0083] 4) Add 8 parts of the liquid prepared in 3) into the mold and wait for cross-linking to form a hydrogel. The specific steps of cross-linking are as follows:

[0084] 1) The mixed solution is injected into a polytetrafluoroethylene mold and cross-linked by freeze-thaw cycles:

[0085] 2) First stage: Freeze at -20°C for 1.5 h to form the initial ice crystal template;

[0086] 3) Second stage: melting at 25°C for 1.2 h to induce rearrangement of the PVA molecular chains;

[0087] 4) Repeat steps 1) and 3) for 3 cycles to finally obtain a porous hydrogel with a porosity of 80%.

[0088] Specifically, it also includes polyvinyl alcohol pretreatment, and the specific steps are as follows:

[0089] 1) Add polyvinyl alcohol with a degree of polymerization of 2000 to a 1.8% (v / v) acetic acid solution;

[0090] 2) Swell at 30°C for 50 min until the volume of the polyvinyl alcohol increases by 220%.

[0091] Specifically, it also includes plasticization and degassing:

[0092] 1) Add 8% propylene glycol to the total weight of the system and continue stirring for 30 minutes;

[0093] 2) Use step-by-step centrifugal degassing: first 500g×5min to remove large bubbles, then 1500g×8min to remove microbubbles.

[0094] Example 3

[0095] See also Figure 1-5 In this embodiment, a method for preparing an antibacterial hydrogel loaded with carbon quantum dots comprises the following steps:

[0096] Step 1: Preparation of Chinese medicine biomass carbon quantum dots

[0097] 1) Accurately weigh 40 parts of Parsley septempunctata powder and place them in an autoclave;

[0098] 2) Expel the air and then heat at 300°C for 8 hours;

[0099] 3) After cooling, the solid in the reactor was removed and crushed, 110 parts of 50% ethanol was added, stirred evenly, and filtered through a 0.28 μm filter membrane;

[0100] The prepared traditional Chinese medicine biomass carbon quantum dots have a lattice fringe spacing of 0.38 nm, an XRD diffraction peak located near 25°, a particle size of 20 nm, and carbon quantum dots are particles with a negative potential. The heating temperature used during heating and stirring in step 2 is 350° C., and the heating time is 24 h.

[0101] 4) Collecting the liquid and freeze-drying it to obtain the Chinese medicine biomass carbon quantum dots;

[0102] Step 2: Preparation of polyvinyl alcohol hydrogel loaded with traditional Chinese medicine biomass carbon dots

[0103] 1) Accurately weigh 45 parts of polyvinyl alcohol (PVA), add 1% acetic acid and soak for 90 minutes. The degree of polymerization of the PVA is 3500, the concentration of the acetic acid solution is 2.5%, and the range of heating to dissolve the PVA is 100°C.

[0104] 2) adding 2 parts of traditional Chinese medicine biomass carbon quantum dots, heating and stirring until the polyvinyl alcohol is completely dissolved. The carbon quantum dots can be at least one of water-soluble, alcohol-soluble, and fat-soluble;

[0105] 3) Add 1500 μL of glycerol and centrifuge at 2000 g for 10 min to remove the foam. The centrifugal force range for removing bubbles is 2000 g.

[0106] 4) Add 10 parts of the liquid prepared in 3) into the mold and wait for cross-linking to form a hydrogel. The specific steps of cross-linking are as follows:

[0107] 1) The mixed solution is injected into a polytetrafluoroethylene mold and cross-linked by freeze-thaw cycles:

[0108] 2) First stage: Freeze at -19°C for 2 h to form the initial ice crystal template;

[0109] 3) Second stage: melting at 20°C for 1.5 h to induce rearrangement of the PVA molecular chains;

[0110] 4) Repeat steps 1) and 3) for 4 cycles to finally obtain a porous hydrogel with a porosity of 85%.

[0111] Specifically, it also includes polyvinyl alcohol pretreatment, and the specific steps are as follows:

[0112] 1) Add polyvinyl alcohol with a degree of polymerization of 2500 to a 2.0% (v / v) acetic acid solution;

[0113] 2) Swell at 32°C for 60 min until the volume of the polyvinyl alcohol increases by 300%.

[0114] Specifically, it also includes plasticization and degassing:

[0115] 1) Add 10% propylene glycol to the total weight of the system and continue stirring for 30 minutes;

[0116] 2) Use step-by-step centrifugal degassing: first 500g×5min to remove large bubbles, then 1500g×8min to remove microbubbles.

[0117] By using the above embodiment, the hydrogel performance test was carried out, and the test content was as follows:

[0118] Mechanical properties (ASTM standard): compression modulus: 28.4 kPa (strain rate 10% / min), tensile strength: 2.1 MPa (tensile rate 50 mm / min), elongation at break: 520%.

[0119] Swelling properties:

[0120] Swelling rate: 625% in PBS (pH 7.4, 37°C) for 24 h;

[0121] Swelling kinetics: conformed to the Fickian diffusion model (n = 0.45);

[0122] Antibacterial properties (GB / T31402-2015):

[0123] Inhibition rate: Staphylococcus aureus (24h): 99.4%, Escherichia coli (24h): 98.7%, MIC value (CLSI standard), Staphylococcus aureus: 35μg / mL, Escherichia coli: 45μg / mL;

[0124] Biocompatibility: Cytotoxicity (CCK-8 method): L929 cell survival rate 96.3% (72h), hemolysis rate: 2.1% (GB / T16886.4-2017).

[0125] Effects of different carbon quantum dot loadings on hydrogel properties

[0126] Variable setting: fixed PVA20g, changing the amount of carbon quantum dots added (0.1g, 0.3g, 0.5g);

[0127] Key Results:

[0128] Carbon quantum dot addition amount Antibacterial rate (S. aureus) Tensile strength (MPa) Cell survival rate (%) 0.1g 92.5％ 1.8 98.1 0.3g 98.3％ 2.0 96.8 0.5g 99.6％ 1.7 94.2

[0129] The model was established by physical experiment verification and the specific steps are as follows:

[0130] 1) SD rats (n=6) were selected and diabetic rats were induced with streptozotocin (STZ);

[0131] 2) Create a full-thickness skin defect with a diameter of 1 cm on the back.

[0132] Experimental groups:

[0133] Blank control group (no treatment);

[0134] commercially available silver dressing group;

[0135] hydrogel group of the present invention (0.3 g of carbon quantum dots);

[0136] Results (14 days):

[0137]

[0138] In summary, the preparation method of the antibacterial hydrogel loaded with Paris polyphylla carbon quantum dots has good antibacterial effect, can delay the production of drug-resistant bacteria, is biodegradable, has little environmental pollution, has no environmental pressure, has a good effect on skin repair, and can effectively promote skin repair. The carbon quantum dots are prepared using the rhizome of Paris polyphylla, and its unique saponin carbonization product is produced. The acetic acid pretreatment combined with PVA freeze-thaw cross-linking increases the porosity to 82%. The carboxyl groups on the surface of the carbon quantum dots form a hydrogen bond network with the hydroxyl groups of PVA, breaking through the contradiction between antibacterial and mechanical properties, and has sustainable release characteristics. The use of biodegradable materials combined with biomass carbon quantum dots has prepared an antibacterial and fresh-keeping hydrogel that can protect against ultraviolet rays, uses biodegradable materials, has less environmental pollution pressure, is not restricted by the shape of the object, and can be directly coated and naturally dried to form a protective layer.

[0139] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0140] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial hydrogel loaded with carbon quantum dots, characterized in that: The steps include: Step 1: Preparation of Chinese medicine biomass carbon quantum dots 1) Accurately weigh 30-40 parts of Parsley septempunctata powder and place it in an autoclave; 2) Expel the air and then heat at 200-300℃ for 5-8h; 3) After cooling, remove the solid from the reactor and crush it, add 100-110 parts of 50% ethanol, stir evenly, and filter through a 0.22-0.28 μm filter membrane; 4) Collecting the liquid and freeze-drying it to obtain the Chinese medicine biomass carbon quantum dots; Step 2: Preparation of polyvinyl alcohol hydrogel loaded with traditional Chinese medicine biomass carbon dots 1) Accurately weigh 15-45 parts of polyvinyl alcohol and add 1% acetic acid and soak for 20-90 minutes; 2) Add 1-2 parts of Chinese medicine biomass carbon quantum dots, heat and stir until the polyvinyl alcohol is completely dissolved; 3) Add 1000-1500 μL of glycerol and centrifuge at 900-2000 rpm for 5-10 minutes to remove the foam; 4) Add 5-10 parts of the liquid prepared in 3) into the mold and wait for cross-linking to form a hydrogel.

2. The method for preparing a polysaccharide-loaded carbon quantum dot antibacterial hydrogel according to claim 1, characterized in that: The lattice fringe spacing of the traditional Chinese medicine biomass carbon quantum dots is 0.21-0.38 nm, the XRD diffraction peak is located near 18-25 degrees, and the particle size is 0-20 nm.

3. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The degree of polymerization of the polyvinyl alcohol is 1200-3500, and the carbon quantum dots can be at least one of water-soluble, alcohol-soluble, and fat-soluble.

4. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The carbon quantum dots are particles with a negative potential. The heating temperature used during the heating and stirring in step 2 is 160-350° C., and the heating time is 6-24 hours.

5. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The concentration of the acetic acid solution in step 2 is 0.5-2.5%, and the temperature range of heating and dissolving the polyvinyl alcohol is 65-100°C.

6. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The centrifugal force range of the centrifugal air bubble removal is 500-2000g.

7. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The step 2 also includes polyvinyl alcohol pretreatment, and the specific steps are as follows: 1) adding polyvinyl alcohol with a degree of polymerization of 1700-2500 to a 1.0-2.0% (v / v) acetic acid solution; 2) Swell at 30±2°C for 45-60 minutes until the volume of the polyvinyl alcohol increases by 200-300%.

8. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The second step also includes plasticizing and degassing: 1) Add 5-10% propylene glycol to the total weight of the system and continue stirring for 30 minutes; 2) Use step-by-step centrifugal degassing: first 500g×5min to remove large bubbles, then 1500g×8min to remove microbubbles.

9. The method for preparing an antibacterial hydrogel loaded with carbon quantum dots according to claim 1, characterized in that: The specific steps of cross-linking molding are as follows: 1) The mixed solution is injected into a polytetrafluoroethylene mold and cross-linked by freeze-thaw cycles: 2) Stage 1: Freeze at -20±1°C for 1-2 hours to form the initial ice crystal template; 3) Second stage: melting at 25±1°C for 1-1.5 hours to induce rearrangement of the polyvinyl alcohol molecular chains; 4) Repeat steps 1) and 3) for 2-4 cycles to finally obtain a porous hydrogel with a porosity of 75-85%.

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