Wound dressing and preparation method thereof

Abstract

The invention discloses a wound dressing and a preparation method thereof, and belongs to the technical field of medical wound dressing preparation. The wound dressing comprises the following components in percentage by mass: 10-20% of polyvinyl alcohol, 10-20% of starch, 2-6% of an antibacterial agent, 0.1-0.3% of nano titanium dioxide and the balance of water, the antibacterial agent is KH-560 modified amine organic molecular cage combined with nano silver. The preparation method comprises the following steps: mixing and dissolving polyvinyl alcohol, starch and nano titanium dioxide in water, uniformly stirring, then adding the antibacterial agent, and continuously stirring to obtain a solution A; and pouring the obtained solution A into a container, and further freezing-unfreezing to obtain the wound dressing. The antibacterial agent is added in the process of preparing the wound dressing, so that the dressing disclosed by the invention has excellent antibacterial performance and mechanical performance, is beneficial to promoting wound healing, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of preparation of medical wound dressings, and particularly to a wound dressing and a preparation method thereof. Background Art

[0002] The skin is an organ that covers the entire surface of the human body and is also the first layer of protective barrier of the human body, which can protect the body from the invasion of bacteria and microorganisms in the external environment. However, due to various internal and external factors, we will inevitably get injured, forming acute wounds or chronic wounds with different sizes and depths of wound surfaces. At this time, an ideal wound dressing is urgently needed, and it should have the following characteristics: (1) maintaining a high degree of wetness on the wound surface; (2) being able to absorb the exudate on the wound surface; (3) being able to carry out gas exchange in the wound microenvironment; (4) being antibacterial, non-toxic, non-adhesive, and non-fibrous shedding; (5) preventing bacteria, being able to insulate heat, and promoting skin tissue reconstruction.

[0003] Hydrogel is a class of hydrophilic materials with a three-dimensional network structure, which can wrap a large amount of water in its three-dimensional network. It has a high water content, can keep the wound moist, avoid secondary damage caused by the adhesion of the dressing to the wound, resist the infiltration of bacteria and dust, and its pore structure can absorb the tissue fluid exuded from the wound, avoiding the formation of fluid accumulation near the wound and causing infection, and is very popular in wound surface healing.

[0004] Patent CN113244443B provides a hydrogel dressing and its preparation method and application. This patent utilizes the adhesiveness and flexibility of polyvinyl alcohol, waxy starch and its porous derivatives. The prepared dressing has excellent elasticity, toughness, adhesiveness and antibacterial properties. In this patent, silver ions and curcumin are respectively used as antibacterial agents. The antibacterial property of silver ions is better than that of curcumin, but silver ions belong to small molecule antibacterial agents and there is a problem of easy precipitation during use, which affects the antibacterial ability of the hydrogel dressing. Summary of the Invention

[0005] The present invention provides a wound dressing and a preparation method thereof, which can solve the problem that silver ions belong to small molecule antibacterial agents and there is a problem of easy precipitation during use, which affects the antibacterial ability of the hydrogel dressing in the background art.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] In a first aspect, the present invention provides a wound dressing, comprising the following components in terms of mass percentage: 10-20% of polyvinyl alcohol, 10-20% of starch, 2-6% of antibacterial agent, 0.1-0.3% of nano-titanium dioxide, and the balance is water; the antibacterial agent is KH-560 modified amine organic molecular cage combined with nano-silver.

[0008] Further, the starch includes any one of waxy starch, amylopectin, and high amylose starch.

[0009] Further, the polyvinyl alcohol includes polyvinyl alcohol with any molecular weight and its derivatives.

[0010] Further, the preparation method of the antibacterial agent is as follows:

[0011] A1: Dissolve 2,5-thiophenedicarboxaldehyde in methanol to obtain solution a; dissolve (2,4,6-trimethylbenzene-1,3,5-triyl)trimethylamine in methanol to obtain solution b; drop solution b into solution a, react at room temperature for 24 - 48 h, filter, wash, and vacuum dry to obtain an imine organic molecular cage;

[0012] Among them, the dosage ratio of 2,5-thiophenedicarboxaldehyde to methanol is 63 mg:100 mL; the dosage ratio of (2,4,6-trimethylbenzene-1,3,5-triyl)trimethylamine to methanol is 62 - 93 mg:50 mL; the volume ratio of solution a to solution b is 2:1.

[0013] In the above step, the aldehyde group of 2,5-thiophenedicarboxaldehyde and the amino group in (2,4,6-trimethylbenzene-1,3,5-triyl)trimethylamine undergo a Schiff base amine-aldehyde condensation reaction to obtain an imine organic molecular cage.

[0014] A2: Add the imine organic molecular cage to methanol, add sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add deionized water, continue stirring and reacting for 8 - 10 h, and the obtained product is filtered, washed, and dried to obtain an amine organic molecular cage;

[0015] Among them, the dosage ratio of the imine organic molecular cage, methanol, sodium borohydride, and deionized water is 0.5 g:25 mL:0.1 - 0.3 g:1 mL.

[0016] The imine organic molecular cage is reduced by sodium borohydride to obtain an amine organic molecular cage. The amine organic molecular cage has higher chemical stability than the imine organic molecular cage and can maintain the integrity of its structure in a humid environment.

[0017] A3: Add the amine organic molecular cage to methanol, then add AgNO3, stir and mix at room temperature for 2 - 3 h, add sodium borohydride at -5 - 0 °C, continue stirring for 20 - 30 min, and obtain amine organic molecular cage combined with silver nanoparticles through separation, freeze-drying, and grinding;

[0018] Among them, the dosage ratio of the amine organic molecular cage, methanol, AgNO3, and sodium borohydride is 20 g:100 mL:0.5 - 0.8 g:5 - 7 g.

[0019] Amine organic molecular cages have a large number of cavity structures and high chemical stability. Through the above steps, silver nanoparticles can be loaded inside the cavities of amine organic molecular cages, thereby reducing the aggregation of silver nanoparticles, improving the dispersion of silver nanoparticles, and preventing the precipitation of silver nanoparticles. Moreover, the amine organic molecular cages of the present invention contain thiophene groups, and there is a strong adsorption effect between thiophene and silver ions, which can further improve the dispersion of silver nanoparticles, thereby enhancing the antibacterial ability of the hydrogel.

[0020] A4: Add amine organic molecular cage combined with silver nanoparticles and KH-560 into absolute ethanol, react at 60 °C for 8 - 10 h, then wash and vacuum dry for 12 - 24 h to obtain the antibacterial agent.

[0021] Among them, the dosage ratio of amine organic molecular cage combined with silver nanoparticles, KH-560, and absolute ethanol is 3 g : 0.03 - 0.06 g : 30 mL.

[0022] In order to further improve the compatibility between amine organic molecular cage combined with silver nanoparticles and the raw materials of wound dressings, the present invention further modifies it on the basis of amine organic molecular cage combined with silver nanoparticles. By reacting with the epoxy groups in KH-560, an antibacterial agent is obtained. This antibacterial agent contains methoxysilane. During the subsequent preparation process of the hydrogel, methoxy will hydrolyze in water to generate silanol groups (Si-OH). The hydrolyzed silanol groups (Si-OH) can undergo a condensation reaction with the hydroxyl groups (-OH) on the surfaces of polyvinyl alcohol and starch to form siloxane bonds (Si-O-Si), thereby forming a relatively tight cross-linked network between the antibacterial agent and polyvinyl alcohol and starch, improving the mechanical properties and antibacterial properties of the dressing. Moreover, the silicon-oxygen bond in the siloxane chain has a relatively long bond length and a large bond angle, which can further enhance the flexibility of the dressing.

[0023] In the second aspect, the present invention provides a preparation method of a wound dressing, including the following steps:

[0024] S1: Mix polyvinyl alcohol, starch, and nano-titanium dioxide and dissolve them in water, stir evenly, then add the antibacterial agent and continue stirring to obtain solution A;

[0025] S2: Pour the solution A obtained in step S1 into a container and further freeze-thaw to obtain the wound dressing.

[0026] Furthermore, the temperature of the stirring in step S1 is 80 - 100 °C, and the time is 1 - 3 h.

[0027] Furthermore, the temperature of the freezing in step S2 is -25 - -20 °C, and the time is 12 - 24 h.

[0028] Furthermore, the thawing time in step S2 is 3 - 5 h.

[0029] The beneficial effects of the present invention:

[0030] In the process of preparing the wound dressing of the present invention, an antibacterial agent is added, and the antibacterial agent is an amine organic molecular cage modified by KH-560 combined with nano silver. This antibacterial agent has good dispersibility in the system and can form a relatively tight cross-linked network between polyvinyl alcohol and starch, so that the prepared wound dressing has excellent antibacterial properties and mechanical properties, which is beneficial to promoting wound healing. Specific Embodiments

[0031] The following describes the specific embodiments of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0032] Example 1

[0033] This example provides a wound dressing, which contains the following components by mass percentage:

[0034] 10% polyvinyl alcohol, 10% waxy starch, 2% antibacterial agent, 0.1% nano titanium dioxide, and the balance is water; the antibacterial agent is an amine organic molecular cage modified by KH-560 combined with nano silver.

[0035] Its preparation steps are as follows: Mix polyvinyl alcohol, starch and nano titanium dioxide and dissolve them in water, stir at 80°C for 1 h, then add the antibacterial agent and continue stirring to obtain solution A; pour solution A into a container, freeze it at -20°C for 12 h, take it out and thaw it for 3 h to obtain the wound dressing.

[0036] The preparation method of the antibacterial agent is as follows:

[0037] A1: Dissolve 63 mg of 2,5-thiophene dialdehyde in 100 mL of methanol to obtain solution a; dissolve 62 mg of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in 50 mL of methanol to obtain solution b; drop 50 mL of solution b into 100 mL of solution a, react at room temperature for 24 h, filter, wash, and vacuum dry to obtain an imine organic molecular cage;

[0038] A2: Add 0.5 g of the imine organic molecular cage to 25 mL of methanol, add 0.1 g of sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add 1 mL of deionized water and continue stirring for 8 h. The obtained product is filtered, washed, and dried to obtain an amine organic molecular cage;

[0039] A3: Add 20 g of the amine organic molecular cage to 100 mL of methanol, then add 0.5 g of AgNO3, stir and mix at room temperature for 2 h, then add 5 g of sodium borohydride at -5°C and continue stirring for 20 min. Through separation, freeze-drying and grinding, an amine organic molecular cage combined with nano silver is obtained;

[0040] A4: Add 3 g of amine organic molecular cage combined with nano silver and 0.03 g of KH-560 to 30 mL of absolute ethanol. After reacting at 60 °C for 8 h, wash and vacuum dry for 12 h to obtain the antibacterial agent.

[0041] Example 2

[0042] This example provides a wound dressing, containing the following components by mass percentage:

[0043] 15% polyvinyl alcohol, 15% waxy starch, 3% antibacterial agent, 0.2% nano titanium dioxide, and the balance is water; the antibacterial agent is KH-560 modified amine organic molecular cage combined with nano silver.

[0044] The preparation steps are as follows: Mix polyvinyl alcohol, starch and nano titanium dioxide and dissolve them in water. Stir at 90 °C for 2 h, then add the antibacterial agent and continue stirring to obtain solution A; Pour solution A into a container, freeze at -25 °C for 20 h, take it out and thaw for 4 h to obtain the wound dressing.

[0045] The preparation method of the antibacterial agent is as follows:

[0046] A1: Dissolve 63 mg of 2,5-thiophene dicarboxaldehyde in 100 mL of methanol to obtain solution a; Dissolve 78 mg of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in 50 mL of methanol to obtain solution b; Drop 50 mL of solution b into 100 mL of solution a, react at room temperature for 36 h, filter, wash and vacuum dry to obtain the imine organic molecular cage;

[0047] A2: Add 0.5 g of imine organic molecular cage to 25 mL of methanol, add 0.2 g of sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add 1 mL of deionized water and continue stirring and reacting for 9 h. The obtained product is filtered, washed and dried to obtain the amine organic molecular cage;

[0048] A3: Add 20 g of amine organic molecular cage to 100 mL of methanol, then add 0.7 g of AgNO3, stir and mix at room temperature for 3 h, then add 6 g of sodium borohydride at 0 °C and continue stirring for 30 min. Through separation, freeze drying and grinding, obtain amine organic molecular cage combined with nano silver;

[0049] A4: Add 3 g of amine organic molecular cage combined with nano silver and 0.05 g of KH-560 to 30 mL of absolute ethanol. After reacting at 60 °C for 10 h, wash and vacuum dry for 24 h to obtain the antibacterial agent.

[0050] Example 3

[0051] This example provides a wound dressing, containing the following components by mass percentage:

[0052] 20% polyvinyl alcohol, 20% waxy starch, 4% antibacterial agent, 0.3% nano-titanium dioxide, the balance being water; the antibacterial agent is an amine organic molecular cage modified by KH-560 combined with nano-silver.

[0053] The preparation steps are as follows: Mix polyvinyl alcohol, starch and nano-titanium dioxide and dissolve them in water, stir at 100 °C for 3 h, then add the antibacterial agent and continue stirring to obtain solution A; Pour solution A into a container, freeze at -25 °C for 24 h, take it out and thaw for 3 - 5 h to obtain the wound dressing.

[0054] The preparation method of the antibacterial agent is as follows:

[0055] A1: Dissolve 63 mg of 2,5-thiophene dialdehyde in 100 mL of methanol to obtain solution a; dissolve 93 mg of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in 50 mL of methanol to obtain solution b; Drop 50 mL of solution b into 100 mL of solution a, react at room temperature for 48 h, filter, wash, and vacuum dry to obtain the imine organic molecular cage;

[0056] A2: Add 0.5 g of the imine organic molecular cage to 25 mL of methanol, add 0.3 g of sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add 1 mL of deionized water and continue stirring and reacting for 10 h. The obtained product is filtered, washed, and dried to obtain the amine organic molecular cage;

[0057] A3: Add 20 g of the amine organic molecular cage to 100 mL of methanol, then add 0.8 g of AgNO3, stir and mix at room temperature for 3 h, then add 7 g of sodium borohydride at -5 °C and continue stirring for 30 min. Through separation, freeze-drying and grinding, the amine organic molecular cage combined with nano-silver is obtained;

[0058] A4: Add 3 g of the amine organic molecular cage combined with nano-silver and 0.06 g of KH-560 to 30 mL of absolute ethanol, react at 60 °C for 10 h, then wash and vacuum dry for 24 h to obtain the antibacterial agent.

[0059] Example 4

[0060] The difference between this example and Example 3 is as follows:

[0061] A wound dressing comprising the following components by mass percentage:

[0062] 20% polyvinyl alcohol, 20% waxy starch, 5% antibacterial agent, 0.3% nano-titanium dioxide, the balance being water. The remaining raw materials and steps are the same as in Example 3.

[0063] Example 5

[0064] In comparison with Example 3, the difference in this example is as follows:

[0065] A wound dressing contains the following components by mass percentage:

[0066] 20% polyvinyl alcohol, 20% waxy starch, 6% antibacterial agent, 0.3% nano titanium dioxide, and the balance is water. The remaining raw materials and steps are the same as those in Example 3.

[0067] Comparative Example 1

[0068] In comparison with Example 1, the difference in this comparative example is that KH-560 is omitted from the antibacterial agent. The specific steps are as follows:

[0069] The preparation method of the antibacterial agent is as follows:

[0070] A1: Dissolve 63 mg of 2,5-thiophenedicarboxaldehyde in 100 mL of methanol to obtain solution a; dissolve 62 mg of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in 50 mL of methanol to obtain solution b; add 50 mL of solution b dropwise to 100 mL of solution a, react at room temperature for 24 h, filter, wash, and vacuum dry to obtain an imine organic molecular cage;

[0071] A2: Add 0.5 g of the imine organic molecular cage to 25 mL of methanol, add 0.1 g of sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add 1 mL of deionized water, and continue stirring and reacting for 8 h. The obtained product is filtered, washed, and dried to obtain an amine organic molecular cage;

[0072] A3: Add 20 g of the amine organic molecular cage to 100 mL of methanol, then add 0.5 g of AgNO3, stir and mix at room temperature for 2 h, add 5 g of sodium borohydride at -5°C, continue stirring for 20 min, and obtain the antibacterial agent through separation, freeze-drying, and grinding.

[0073] The remaining raw materials and steps are the same as those in Example 1.

[0074] Comparative Example 2

[0075] In comparison with Example 1, the difference in this comparative example is that KH-560 is omitted from the antibacterial agent, and 2,5-thiophenedicarboxaldehyde is replaced by isophthalaldehyde. The specific steps are as follows:

[0076] The preparation method of the antibacterial agent is as follows:

[0077] A1: Dissolve 60 mg of isophthalaldehyde in 100 mL of methanol to obtain solution a; dissolve 62 mg of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in 50 mL of methanol to obtain solution b; add 50 mL of solution b dropwise to 100 mL of solution a, react at room temperature for 24 h, filter, wash, and dry under vacuum to obtain the imine organic molecular cage;

[0078] A2: Add 0.5 g of the imine organic molecular cage to 25 mL of methanol, add 0.1 g of sodium borohydride under vigorous stirring, react at room temperature for 20 h, then add 1 mL of deionized water, and continue stirring and reacting for 8 h. The resulting product is filtered, washed, and dried to obtain the amine organic molecular cage;

[0079] A3: Add 20 g of the amine organic molecular cage to 100 mL of methanol, then add 0.5 g of AgNO3, stir and mix at room temperature for 2 h, add 5 g of sodium borohydride at -5 °C, and continue stirring for 20 min. The antibacterial agent is obtained by separation, freeze-drying, and grinding.

[0080] The remaining raw materials and steps are the same as those in Example 1.

[0081] Comparative Example 3

[0082] The difference between this comparative example and Example 1 is that the antibacterial agent is replaced with silver nanoparticles purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd. The remaining raw materials and steps are the same as those in Example 1.

[0083] Comparative Example 4

[0084] The difference between this comparative example and Example 1 is that 2% of the antibacterial agent is replaced with 1.5% of the antibacterial agent. The remaining raw materials and steps are the same as those in Example 1.

[0085] Comparative Example 5

[0086] The difference between this comparative example and Example 5 is that 6% of the antibacterial agent is replaced with 6.5% of the antibacterial agent. The remaining raw materials and steps are the same as those in Example 5.

[0087] Perform performance tests on Examples 1 - 5 and Comparative Examples 1 - 5. The test items are as follows, and the results are shown in Table 1:

[0088] I. Antibacterial performance test: Single colonies of Staphylococcus aureus and Escherichia coli on solid LB agar plates were immersed in 40 mL of fresh LB solution at a fixed temperature (37°C) with gentle shaking (75 rpm) for 24 h. Then, the obtained bacterial suspension was diluted to 105 CFU / mL. The sample was added to 2 mL of the bacterial suspension, and the suspension was incubated at 37°C with a shaking speed of 75 rpm. After 24 h of incubation, the number of colonies was counted and the antibacterial rate was evaluated using the following equation: Antibacterial rate (%) = (Number of bacteria in the control group - Number of bacteria in the experimental group) / Number of bacteria in the control group × 100%.

[0089] II. Wound healing rate test: Ten adult male mice weighing 18 - 22 g were prepared. A skin wound with a diameter of 8 mm was made on the back of each mouse and tightly covered with the sample gel. After 10 days, the wound size of the mice was measured. The wound healing rate was calculated using the following formula: Wound healing rate (%) = (S0 - S10) / S0 × 100%, where S0 represents the initial wound area size and S10 represents the wound area size on the 10th day.

[0090] III. Mechanical properties: The sample was prepared into dumbbell-shaped tensile test specimens. The test was carried out according to the method of the standard "GB / T1040.3 - 2006". Specifically, a 2 kN fixture was selected, the inlet force was 0.1 N, the tensile rate was 30 mm / min, and 6 specimen splines were stretched in each group to take the average value.

[0091] Table 1

[0092]

[0093]

[0094] As can be seen from Table 1, the comprehensive performance of the dressings prepared in Examples 1 - 5 is better than that of Comparative Examples 1 - 5.

[0095] In Comparative Example 1, KH-560 was not contained, and its antibacterial rate, wound healing rate, and tensile strength were all lower than those in Example 1. This shows that KH-560 can form a relatively tight cross-linked network between the antibacterial agent, polyvinyl alcohol, and starch, improving the mechanical properties and antibacterial performance of the dressing. Moreover, the silicon-oxygen bond in the siloxane chain has a relatively long bond length and a large bond angle, which can further enhance the flexibility of the dressing.

[0096] In Comparative Example 2, KH-560 and thiophene were not contained, and the performance was lower than that in Example 1. This shows that there is a strong adsorption effect between thiophene and silver ions, which can further improve the dispersion of silver nanoparticles, thereby enhancing the antibacterial ability of the hydrogel.

[0097] In Comparative Example 3, the antibacterial agent was nano silver particles, with poor dispersibility, easy precipitation, and poor performance.

[0098] The performances of Comparative Example 4 and Comparative Example 5 were both lower than those of Example 1 and Example 5, indicating that too much or too little addition of the antibacterial agent would affect the performance of the dressing, and the addition amount of the antibacterial agent in the present invention was the optimal amount.

[0099] The above-disclosed are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A wound dressing, characterized in that, Comprising the following components by mass percentage: 10-20% polyvinyl alcohol, 10-20% starch, 2-6% antibacterial agent, 0.1-0.3% nano titanium dioxide, and the balance being water; the antibacterial agent is an amine organic molecular cage modified by KH-560 combined with nano silver.

2. The wound dressing according to claim 1, characterized in that, The starch includes any one of waxy starch, amylopectin, and high amylose starch.

3. A wound dressing according to claim 1, wherein, The polyvinyl alcohol includes polyvinyl alcohol with any molecular weight and its derivatives.

4. A wound dressing according to claim 1, wherein The preparation method of the antibacterial agent is as follows: A1: Dissolve 2,5-thiophene dicarboxaldehyde in methanol to obtain solution a; dissolve (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine in methanol to obtain solution b; drop solution b into solution a, react at room temperature for 24-48 h, filter, wash, and vacuum dry to obtain an imine organic molecular cage. A2: Add the imine organic molecular cage to methanol, add sodium borohydride under stirring, react at room temperature for 20 h, then add deionized water, and continue stirring and reacting for 8-10 h. The obtained product is filtered, washed, and dried to obtain an amine organic molecular cage. A3: Add the amine organic molecular cage to methanol, then add AgNO3, stir and mix at room temperature for 2-3 h, add sodium borohydride at -5-0 °C, continue stirring for 20-30 min, and obtain an amine organic molecular cage combined with nano silver through separation, freeze drying, and grinding. A4: Add the amine organic molecular cage combined with nano silver and KH-560 to absolute ethanol, react at 60 °C for 8-10 h, wash, and vacuum dry for 12-24 h to obtain the antibacterial agent.

5. A wound dressing according to claim 4, characterized in that, In step A1, the dosage ratio of 2,5-thiophene dicarboxaldehyde to methanol is 63 mg:100 mL; the dosage ratio of (2,4,6-trimethylbenzene-1,3,5-triyl) trimethylamine to methanol is 62-93 mg:50 mL; the volume ratio of solution a to solution b is 2:

1.

6. A wound dressing according to claim 4, characterized in that, In step A2, the dosage ratio of the imine organic molecular cage, methanol, sodium borohydride, and deionized water is 0.5 g:25 mL:0.1-0.3 g:1 mL.

7. A wound dressing according to claim 4, characterized in that, In step A3, the dosage ratio of the amine organic molecular cage, methanol, AgNO3, and sodium borohydride is 20 g:100 mL:0.5-0.8 g:5-7 g.

8. A wound dressing according to claim 4, characterized in that, In step A4, the dosage ratio of the amine organic molecular cage combined with nano silver, KH-560, and absolute ethanol is 3 g:0.03-0.06 g:30 mL.

9. A method for preparing a wound dressing according to any one of claims 1-8, characterized in that, Including the following steps: S1: Mix polyvinyl alcohol, starch, and nano titanium dioxide and dissolve them in water, stir evenly, then add the antibacterial agent, and continue stirring to obtain solution A. S2: Pour the solution A obtained in step S1 into a container, and further freeze-thaw to obtain the wound dressing.

10. The preparation method of a wound dressing according to claim 9, characterized in that, The temperature of the stirring in step S1 is 80-100 °C, and the time is 1-3 h; the temperature of the freezing in step S2 is -25--20 °C, and the time is 12-24 h; the time of the thawing in step S2 is 3-5 h.

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