A polyvinyl alcohol-based antibacterial hydrogel with aggregation-induced luminescence properties, an antibacterial dressing, and a preparation method and application thereof

Abstract

The present invention provides a polyvinyl alcohol-based antibacterial hydrogel with aggregation-induced luminescence properties, an antibacterial dressing, and a preparation method and application thereof, wherein the antibacterial hydrogel comprises polyvinyl alcohol, a modifier, an AIE photosensitizer, and water, wherein the modifier is at least one of sorbitol and glycerol, and the AIE photosensitizer comprises at least one of berberine, TBP, and ASCP-TPA. The antibacterial hydrogel and antibacterial dressing of the present invention have good biocompatibility, good antibacterial effect, and excellent mechanical properties (high tensile strength, good flexibility, and good elasticity), and realize the application of PVA hydrogel in wound dressing.

Description

Technical Field

[0001] The invention belongs to the technical field of biological antibacterial materials, and relates to a polyvinyl alcohol-based antibacterial hydrogel with aggregation-induced luminescence properties, an antibacterial dressing, and a preparation method and application thereof. Background Art

[0002] The skin is the first barrier of the human body and the largest organ of the human body. When the skin is damaged by trauma, burns, surgery, chronic diseases, etc., bacteria may invade the human body, destroy the internal balance of the human body, and then cause inflammation, leading to wound infection. Bacteria at the wound will cause the body's immune cells to gather. However, if the bacteria cannot be eliminated for a long time, persistent bacterial infection will lead to long-term chronic inflammation, delay the wound healing process, and turn it into a chronic wound. In order to ensure the wound healing environment, wound dressings came into being and developed rapidly.

[0003] Although traditional wound dressings, such as bandages and gauze, can isolate the wound surface and absorb wound exudate, the dressings themselves do not have antibacterial effects. After absorbing wound exudate, traditional wound dressings will make the wound too dry, slowing healing. Due to their structural defects, they can cause adhesion at the wound, causing secondary damage to the wound when the dressing is removed.

[0004] Hydrogel is a swollen body with a large amount of water and a three-dimensional network structure obtained by cross-linking hydrophilic polymer compounds through covalent bonds, ionic bonds or hydrogen bonds. It has a certain compressive strength and good compatibility with biological tissues. Therefore, it has received great attention in biomedical engineering fields such as drug controlled release, tissue engineering scaffolds, and wound dressings, and has extremely good application prospects. In addition, hydrogel has good elasticity, can provide a moist environment for wounds, is easy to remove, and can relieve local pain. It is a relatively ideal wound dressing material.

[0005] Polyvinyl alcohol (PVA) is a high molecular polymer with good water solubility. Its molecular chain has a strict linear structure and contains a large number of hydrophilic hydroxyl groups in the chain structure, which makes the polyvinyl alcohol molecules and molecules have strong hydrogen bond interactions, so it has excellent adhesion, excellent solvent resistance and oil resistance, and good film-forming properties. It is widely used in the preparation of wound dressings, drug delivery systems, artificial organs, contact lenses, etc. However, the hydrogel prepared by using polyvinyl alcohol alone is poor in mechanical strength such as elasticity and hardness, and polyvinyl alcohol itself does not have antibacterial properties. In order to obtain hydrogels with antibacterial functions, antibiotics and their derivatives, antibacterial polymers, nanosilver and other antibacterial agents are usually added to the hydrogel system; however, antibiotics and their derivatives are prone to cross-resistance; antibacterial polymers have strong toxic side effects and poor solubility, and cannot be directly used for the treatment of infectious diseases; the stability, toxicity and in vivo drug metabolism mechanism of antibacterial particles such as nanosilver have not been fully clarified and need further study. The existing PVA antibacterial hydrogels are not ideal in terms of antibacterial effect and use effect. Therefore, it is very important to develop a safe, efficient and excellent antibacterial PVA antibacterial hydrogel in the application of polyvinyl alcohol medical dressings. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a polyvinyl alcohol-based antibacterial hydrogel with aggregation-induced luminescence properties, an antibacterial dressing, and a preparation method and application thereof. The antibacterial hydrogel of the present invention has good biocompatibility, good antibacterial effect, and excellent mechanical properties (high tensile strength, good flexibility, and good elasticity), thereby realizing the application of PVA hydrogel in wound dressings.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides an antibacterial hydrogel, comprising polyvinyl alcohol, a modifier, an AIE photosensitizer and water, wherein the modifier is at least one of sorbitol and glycerol, and the AIE photosensitizer comprises at least one of berberine, TBP and ASCP-TPA;

[0009] The structural formula of berberine is:

[0010]

[0011] TBP structure:

[0012]

[0013] ASCP-TPA structure:

[0014]

[0015] The AIE photosensitizer in the antibacterial hydrogel of the present invention can non-covalently bind to bacteria, generate reactive oxygen species (ROS) in situ under light of appropriate wavelength, induce irreversible oxidative damage to bacteria, and thus achieve antibacterial activity. The present invention forms a three-dimensional network structure by adding sorbitol and / or glycerol to the polyvinyl alcohol hydrogel system, and after modification by sorbitol and / or glycerol, the AIE photosensitizer molecules can be wrapped inside the structure, and the intramolecular motion of the AIE photosensitizer is restricted, thereby showing enhanced fluorescence and the ability to continuously generate ROS, effectively enhancing the photodynamic antibacterial effect, and showing excellent antibacterial effect.

[0016] Preferably, the alcoholysis degree of the polyvinyl alcohol is 85%-100%, for example 85%, 88%, 90%, 92%, 94%, 96%, 98%, 98.5%, 98.8%, 99%, 99.5%, 99.8% or 100%; and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, preferably 95%-100%.

[0017] Preferably, the viscosity of the polyvinyl alcohol (viscosity is measured using an Oswald capillary viscometer, test conditions: 4% aqueous solution, 20°C) is 18-35 mPa·S, for example, 18 mPa·S, 20 mPa·S, 23 mPa·S, 25 mPa·S, 27 mPa·S, 29 mPa·S, 30 mPa·S or 31 mPa·S; and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, preferably 20-31 m Pa·S.

[0018] Preferably, the antibacterial hydrogel comprises the following components by weight:

[0019] Polyvinyl alcohol 1.25-2.5 parts (e.g., 1.25 parts, 1.3 parts, 1.35 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts or 2.5 parts), modifier 4-8 parts (e.g., 4 parts, 4.5 parts, 4.8 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts or 8 parts), AIE photosensitizer 0.0125-1.25 parts (e.g., 0.0125 parts, 0.015 parts, 0. 0.018 parts, 0.02 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.3 parts, 0.5 parts, 0.8 parts, 1 parts, 1.1 parts, 1.2 parts or 1.25 parts), 17-20 parts of water (for example, 17 parts, 17.5 parts, 18 parts, 18.5 parts, 19 parts, 19.5 parts or 20 parts); and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0020] In the present invention, when the modifier is sorbitol, the preferred content is 4-6 parts; when the polyol is glycerol, the preferred content is 4-8 parts.

[0021] In another aspect, the present invention provides a method for preparing the antibacterial hydrogel as described above, the method comprising the following steps:

[0022] The AIE photosensitizer and polyvinyl alcohol are added to water, heated and stirred, and after being evenly dispersed, a modifier is added, the pH of the solution is adjusted, and stirring is continued until the reaction system presents a uniform sol state, heating is stopped, and then a cycle of freezing and thawing is performed to obtain the antibacterial hydrogel.

[0023] Preferably, the heating and stirring is heating and stirring for 3h-4h (for example 3h, 3.3h, 3.5h, 3.8h or 4h, and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range) under 90℃-95℃ (for example 90℃, 92℃, 94℃ or 95℃, and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range) water bath conditions.

[0024] Preferably, the pH of the solution is adjusted to a pH of 6.5-8, for example 6.5, 6.8, 7.0, 7.3, 7.5, 7.8 or 8.

[0025] Preferably, the continued stirring is maintaining the temperature at 90°C-95°C (eg, 90°C, 91°C, 92°C, 93°C, 94°C or 95°C) and stirring for 2.5h-3.5h (eg, 2.5h, 2.8h, 3h, 3.3h or 3.5h).

[0026] Preferably, the cyclic freezing-thawing is: freezing at -20°C to -80°C (for example, -20°C, -25°C, -28°C, -30°C, -35°C, -40°C, -45°C, -50°C, -55°C, -60°C, -65°C, -70°C, -75°C or -80°C) for 10h-16h (for example, 10h, 12h, 14h or 16h), and then thawing, repeating freezing and thawing 2-4 times (for example, 2 times, 3 times or 4 times), and then placing at room temperature for 12h-24h (for example, 12h, 14h, 16h, 18h, 20h, 22h or 24h).

[0027] In the present invention, the specific operation of the cyclic freezing-thawing can be: after stopping heating, taking out the sol and pouring it into a mold, the thickness of the colloid is about 4 mm, after cooling, covering the mold, putting it in a -20°C refrigerator and freezing it for 12 hours, taking out the mold and thawing it at room temperature, repeating freezing and thawing twice, and then placing it at room temperature for 24 hours to form a hydrogel.

[0028] In another aspect, the present invention provides an antibacterial dressing, comprising the antibacterial hydrogel as described above.

[0029] In another aspect, the present invention provides use of the antibacterial hydrogel or antibacterial dressing as described above in the preparation of medical materials.

[0030] The hydrogel of the invention can be used for the care of traumatic wounds such as wounds and burns and diabetic foot wounds.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The polyvinyl alcohol-based antibacterial hydrogel of the present invention, by adding an AIE photosensitizer and sorbitol and / or glycerol modifiers, can form a three-dimensional network structure to wrap the AIE photosensitizer molecules inside the structure, restrict the intramolecular movement of the AIE photosensitizer, achieve aggregation-induced luminescence, enhance the photodynamic antibacterial effect, and show excellent antibacterial effect. According to the antibacterial rate test, the antibacterial rate of the antibacterial hydrogel of the present invention against Staphylococcus aureus is greater than 99%, and the antibacterial rate against Escherichia coli is greater than 95%.

[0033] (2) The polyvinyl alcohol-based antibacterial hydrogel of the present invention has excellent mechanical properties, high tensile strength, good flexibility and elasticity, and can form good adhesion with the skin. It is suitable for wounds in different parts of the body, especially frequently active parts such as elbows, wrists, knees, and ankles.

[0034] (3) The polyvinyl alcohol-based antibacterial hydrogel of the present invention has good biocompatibility and good moisturizing and breathability, which is beneficial to maintaining a sterile environment on the wound surface and accelerating epithelial regeneration. Through the photodynamic antibacterial effect of the AIE photosensitizer, the use of antibiotics and other antibacterial agents is avoided. It has high safety and has the effects of efficient sterilization and promoting wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a photograph of the hydrogel prepared in Example 1;

[0036] Figure 2 This is the test result of elongation at break of antibacterial hydrogel;

[0037] Figure 3 This is a test result diagram of the tensile strength of the antibacterial hydrogel;

[0038] Figure 4 This is a photo of the hydrogel prepared in Example 1 before stretching;

[0039] Figure 5 This is a photograph of the hydrogel prepared in Example 1 when stretched;

[0040] Figure 6This is a photograph of the hydrogel prepared in Example 1 recovering after stretching;

[0041] Figure 7 Photo of the hydrogel fitted to the back of the hand. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0043] The reagents and drugs used in the following examples are polyvinyl alcohol A, CAS No. 9002-89-5, item No. P815725-500g, purchased from Shanghai McLean Biochemical Technology Co., Ltd.; sorbitol, CAS No. 50-70-4, item No. S6169-500g, purchased from Shanghai McLean Biochemical Technology Co., Ltd.; berberine hydrochloride, CAS No. 141433-60-5, item No. B832494-100g, purchased from Shanghai McLean Biochemical Technology Co., Ltd.; glycerol, CAS No. 56-81-5, item No. G810575-2.5L, purchased from Shanghai McLean Biochemical Technology Co., Ltd. Polyvinyl alcohol B, CAS No. 9002-89-5, item No. P105124-500g, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0044] Embodiment 1:

[0045] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 4g glycerol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0046] Figure 1 This is a photo of the hydrogel prepared in this example.

[0047] Embodiment 2:

[0048] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add 17g pure water, put into a borosilicate glass reaction bottle, heat and stir for 3h in a 90℃ water bath, add 6g glycerol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0049] Embodiment 3:

[0050] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add 17g pure water, put into a borosilicate glass reaction bottle, heat and stir for 3h in a 90℃ water bath, add 8g glycerol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0051] Embodiment 4:

[0052] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 4g sorbitol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0053] Embodiment 5:

[0054] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add to 17g pure water, put into a borosilicate glass reaction bottle, heat and stir for 3h in a 90℃ water bath, add 6g sorbitol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0055] Embodiment 6:

[0056] Weigh 0.5g TBP and 2.0g polyvinyl alcohol A, add 17g pure water, put into a borosilicate glass reaction bottle, heat and stir for 3h in a 90℃ water bath, add 6g glycerol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring at 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0057] Embodiment 7:

[0058] Weigh 0.8g ASCP-TPA and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 6g glycerol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0059] Embodiment 8:

[0060] Weigh 1.25g ASCP-TPA and 2.5g polyvinyl alcohol B, add them to 20g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 4g sorbitol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0061] Comparative Example 1:

[0062] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them in a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add a few drops of 1mol / L NaOH solution after uniform dispersion, until the solution pH is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0063] Comparative Example 2:

[0064] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 2g sorbitol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0065] Comparative Example 3:

[0066] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 10g sorbitol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0067] Comparative Example 4:

[0068] Weigh 0.025g berberine hydrochloride and 2.0g polyvinyl alcohol A, add them to 17g pure water, put them into a borosilicate glass reaction bottle, heat and stir them in a 90℃ water bath for 3h, add 4g propylene glycol to the reaction bottle after uniform dispersion, add a few drops of 1mol / L NaOH solution until the pH of the solution is 8.0, keep heating and stirring in a 90℃ water bath for 2h, stop heating after the reaction system presents a uniform sol state. Take out the sol and pour it into the mold. The colloid thickness is about 4mm. After cooling, cover the mold, put it in a -20℃ refrigerator and freeze it for 12h, take out the mold and thaw it at room temperature, repeat freezing and thawing twice, and then place it at room temperature for 24h to form a hydrogel.

[0069] Comparative Example 5:

[0070] Weigh 0.5g of the structure AIE molecules and 2.0g polyvinyl alcohol A were added to 17g of pure water and placed in a borosilicate glass reaction bottle. They were heated and stirred for 3h in a 90℃ water bath. After uniform dispersion, 6g of glycerol was added to the reaction bottle. Several drops of 1mol / L NaOH solution were added until the pH of the solution reached 8.0. The 90℃ water bath was heated and stirred for 2h. After the reaction system showed a uniform sol state, heating was stopped. The sol was taken out and poured into a mold. The colloid thickness was about 4mm. After cooling, the mold was covered and placed in a -20℃ refrigerator for 12h. The mold was taken out and thawed at room temperature. After repeated freezing and thawing for 2 times, it was placed at room temperature for 24h to form a hydrogel.

[0071] The antibacterial hydrogels prepared in Examples 1-8 and Comparative Examples 1-5 were tested for performance as follows:

[0072] 1. Mechanical properties test

[0073] The antibacterial hydrogel was prepared according to the national standard GB / T 1040-1992 plastic tensile properties test method, and its elongation at break and tensile strength were measured using a universal testing machine. The tensile rate was 500 mm / min, the measuring temperature was 20° C., and the measuring humidity was 71%.

[0074] Figure 4 This is a photo of the hydrogel prepared in Example 1 before stretching; Figure 5 This is a photograph of the hydrogel prepared in Example 1 when stretched; Figure 6 This is a photograph of the recovery of the hydrogel prepared in Example 1 after stretching; the hydrogel can be quickly restored to the state before stretching after being released after being stretched to a certain length. It can be seen that the hydrogel of the present invention has good flexibility and elasticity. Figure 7 This is a photo of the hydrogel attached to the back of the hand. It can be observed that the hydrogel of the present invention can form good adhesion with the skin and is not easy to fall off.

[0075] The test results of the elongation at break and tensile strength of the antibacterial hydrogels of the embodiments and comparative examples are as follows: Figure 2 and Figure 3 As shown, the data are summarized in Table 1. From the comparison between the embodiments and the comparative examples, it can be seen that the PVA hydrogel of the present application has excellent mechanical properties (tensile strength>520kPa, elongation at break>225%); the PVA hydrogels in comparative examples 1 and 2 without adding a modifier or with too little modifier added have relatively low elongation at break and tensile strength, poor mechanical properties, and cannot meet the use requirements of antibacterial dressings; the amount of modifier used in comparative example 3 is too much, although good elongation at break and tensile strength can be obtained, it is found through antibacterial tests that adding excessive modifiers leads to poor antibacterial properties; comparative example 4 uses propylene glycol as a modifier, the elongation at break of the hydrogel is low, and through antibacterial tests, it is found that its antibacterial properties are poor.

[0076] Table 1

[0077]

[0078]

[0079] 2. Hydrogel antibacterial rate test

[0080] Staphylococcus aureus and Escherichia coli were used as test bacteria. The 24-hour fresh slant culture of the test bacteria was washed with PBS and diluted to about 10 5 CFU / mL~10 6CFU / mL, make a bacterial suspension for later use. Use sterile scissors to cut the test sample and control sample into 20mm×30mm samples under sterile conditions for later use. Add 0.1mL of bacterial suspension during the test. The control sample needs to be irradiated with ultraviolet light for 30 minutes before infection. Take a sterile plate, use sterile tweezers to take 2 test samples, do not overlap, place in a 20℃±1℃ water bath for 5 minutes, add 0.1mL of test bacterial suspension to each sample, and place in a 10mw / cm 2 Irradiate at the right intensity for 20 minutes, and start timing. The test bacteria are in contact with the sample for 16 hours, and the infected sample is clamped and added to a 5.0mL PBS test tube and mixed. Oscillate and elute, and take 1.0mL of sample solution respectively. The number of surviving bacteria is determined by the live bacteria culture counting method. Two plates are inoculated with each tube of sample solution. The test was repeated 3 times, and the antibacterial rate was calculated. The test results of the hydrogel antibacterial rate are shown in Table 2. The hydrogels of Examples 1-8 have excellent antibacterial effects (the antibacterial rates against Escherichia coli are all above 95%, and the antibacterial rates against Staphylococcus aureus are all above 99%). The amount of modifier added in Example 2 / 3 is too little or too much, which will affect the antibacterial effect of the hydrogel. The antibacterial rate of the hydrogel prepared in the example using berberine, ASCP-TPA and TBP is greater than that of the structure The antibacterial rate of the hydrogel prepared by AIE molecules.

[0081] Table 2

[0082] serial number Escherichia coli Staphylococcus aureus Example 1 98.55％ 99.99％ Example 2 96.80％ 99.99％ Example 3 96.46％ 99.99％ Example 4 96.50％ 99.99％ Example 5 95.63％ 99.99％ Example 6 98.24％ 99.99％ Example 7 96.49％ 99.75％ Example 8 97.85％ 99.99％ Comparative Example 1 90.18％ 92.40％ Comparative Example 2 92.12％ 96.26％ Comparative Example 3 91.87％ 97.60％ Comparative Example 4 92.47％ 96.58％ Comparative Example 5 12.04％ 25.70％

[0083] 3. Hydrogel antibacterial ring test

[0084] Escherichia coli was used as the test bacteria. A 24-hour fresh slant culture of the test bacteria was washed with PBS and diluted to 5.0×10 5 CFU / mL~5.0×10 6 CFU / mL for later use. The hydrogel antibacterial sheet was directly made into a 5mm diameter and 4mm thick disc, with 4 discs in a group. Preparation of negative control samples: Take a sample of the same material without antibacterial ingredients and make a disc of the same size as the test group. Use a sterile cotton swab to dip a 5.0×10 5 CFU / mL~5.0×10 6Apply CFU / mL test bacterial suspension evenly on the surface of a suitable culture medium plate for 3 times. Each time you apply it, the plate should be rotated 60°, and finally the cotton swab should be applied around the edge of the plate. Cover the plate and let it dry at room temperature for 5 minutes. For each test, place one infected plate, 4 test samples and 1 negative control sample on each plate, for a total of 5 samples. Use sterile tweezers to take the sample and stick it on the surface of the plate. The negative control sample should be placed in the center of the plate, and the test sample should be placed around the edges. After placing them, use sterile tweezers to gently press the sample to make it close to the surface of the plate. The centers of each sample should be more than 25 mm apart, and more than 15 mm away from the edge of the plate. Cover the plate and place it at 10mw / cm 2 After irradiation for 20 minutes at a high intensity of light, place it at 36℃±1℃ for 16h~18h, observe the results, and repeat the test 3 times. Use a vernier caliper to measure the diameter of the antibacterial ring (including the patch) and record it. When measuring the antibacterial ring, a uniform and completely sterile antibacterial ring should be selected, and its diameter should be measured based on the outer edge of the antibacterial ring. The negative control sample should not produce an antibacterial ring. The test sample with an antibacterial ring diameter of >7mm is judged to have an antibacterial effect; the antibacterial ring diameter of ≤7mm is judged to have no antibacterial effect. The test is repeated 3 times. The test results are shown in Table 3. The antibacterial ring diameters of Examples 1-8 are all greater than 7mm and have an antibacterial effect. The antibacterial ring diameter of Comparative Example 5 is less than 7mm and has no antibacterial effect. It indicates that adding 0.5g of structure The hydrogel prepared in Comparative Example 5 using the AIE molecules has no antibacterial effect.

[0085] Table 3

[0086]

[0087] In summary, the test results of the antibacterial hydrogel show that the antibacterial rate of Examples 1-8 is higher than that of Comparative Examples 1-5. Examples 1-8 of the present invention form a three-dimensional network structure by adding sorbitol and / or glycerol to the polyvinyl alcohol hydrogel system, and after modification with sorbitol and / or glycerol, the AIE photosensitizer molecules can be wrapped inside the structure to limit the intramolecular motion of the AIE photosensitizer, thereby showing enhanced fluorescence and the ability to continuously generate ROS, effectively enhancing the photodynamic antibacterial effect, and showing excellent antibacterial effect. The three-dimensional network structure of Comparative Examples 1-4 is not ideally formed, and the wrapping effect on the AIE molecules is poor. It cannot well limit the intramolecular motion of the AIE molecules, the photodynamic antibacterial effect is poor, and therefore the antibacterial effect is poor. Comparative Example 5 replaces the AIE molecules with As a result, the antibacterial effect becomes poorer.

[0088] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the polyvinyl alcohol-based antibacterial hydrogel with aggregation-induced luminescence properties, antibacterial dressing, preparation method and application thereof, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An antibacterial hydrogel, characterized in that: The antibacterial hydrogel is composed of 1.25-2.5 parts of polyvinyl alcohol, 4-8 parts of a modifier, 0.0125-1.25 parts of an AIE photosensitizer and 17-20 parts of water, by weight. The modifier is at least one of sorbitol and glycerol, and the AIE photosensitizer is at least one of berberine, TBP and ASCP-TPA; The structural formula of berberine is: ； TBP structure: ； ASCP-TPA structure: 。 2. The antibacterial hydrogel according to claim 1, characterized in that: The alcoholysis degree of the polyvinyl alcohol is 85%-100%.

3. The antibacterial hydrogel according to claim 2, characterized in that: The alcoholysis degree of the polyvinyl alcohol is 95%-100%.

4. The antibacterial hydrogel according to claim 1, characterized in that: The viscosity of the polyvinyl alcohol is 18-35 mPa·S.

5. The antibacterial hydrogel according to claim 4, characterized in that: The viscosity of the polyvinyl alcohol is 20-31 mPa·S.

6. The method for preparing the antibacterial hydrogel according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: The AIE photosensitizer and polyvinyl alcohol are added to water, heated and stirred, and after being evenly dispersed, a modifier is added, the pH of the solution is adjusted, and stirring is continued until the reaction system presents a uniform sol state, heating is stopped, and then a cycle of freezing and thawing is performed to obtain the antibacterial hydrogel.

7. The preparation method according to claim 6, characterized in that: The heating and stirring is carried out in a water bath at 90° C.-95° C. for 3 h-4 h.

8. The preparation method according to claim 6, characterized in that: The solution pH is adjusted to a pH of 6.5-8.

9. The preparation method according to claim 6, characterized in that: The continued stirring is to maintain the temperature at 90° C.-95° C. for 2-3.5 hours.

10. The preparation method according to claim 6, characterized in that: The freeze-thaw cycle is as follows: freezing at -80°C to -20°C for 10-16 hours, then thawing, repeating the freezing and thawing process 2-4 times, and then placing the mixture at room temperature for 12-24 hours.

11. An antibacterial dressing, characterized in that: The antibacterial dressing comprises the antibacterial hydrogel according to any one of claims 1 to 5.

12. Use of the antibacterial hydrogel according to any one of claims 1 to 5 or the antibacterial dressing according to claim 11 in the preparation of medical materials.

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