An antibacterial, antioxidative, self-adhesive multifunctional composite hydrogel dressing and preparation method thereof

Abstract

The invention discloses an antibacterial, anti-oxidant, self-adhesive multifunctional composite hydrogel dressing and a preparation method thereof, and belongs to the field of medical and sanitary materials. The invention prepares a multifunctional composite hydrogel dressing by the following steps: (1) chitosan powder is added to an aqueous solution of glacial acetic acid and completely dissolved, then 2,3-epoxypropyltrimethylammonium chloride is added dropwise, the supernatant is collected by centrifugation, filtered, dialyzed, and freeze-dried to obtain quaternary ammonium chitosan; (2) quaternary ammonium chitosan is dissolved in deionized water to obtain a quaternary ammonium chitosan solution; quercetin is dissolved in anhydrous ethanol to prepare a quercetin solution; dopamine hydrochloride is dissolved in a sodium hydroxide solution; then the three solutions are mixed uniformly in a certain proportion; (3) acrylamide, N,N-methylenebisacrylamide, ammonium persulfate, and N,N,N',N'-tetramethylethylenediamine are added to the above-mentioned mixed solution, ultrasonically degassed after stirring, and loaded into a mold to obtain an antibacterial, anti-oxidant, self-adhesive multifunctional composite hydrogel dressing.

Description

Technical Field

[0001] The invention relates to an antibacterial, antioxidative, self-adhesive multifunctional composite hydrogel dressing and a preparation method thereof, and belongs to the field of medical and sanitary materials. Background Art

[0002] Hydrogel is a three-dimensional network structure polymer that can absorb a large amount of water while maintaining structural integrity. It feels soft and comfortable. Due to the adjustable physical, chemical, and biological properties of hydrogels and their high similarity to biological soft tissue structures, hydrogels have become advanced materials with great application prospects in tissue engineering, drug delivery, and wound healing. Especially in wound healing, hydrogels can absorb excess wound exudate and provide a moist environment for the wound, which is conducive to the migration and rapid growth of epithelial cells, thereby promoting wound healing. It is an excellent wound dressing material.

[0003] Quercetin is a bioflavonoid widely found in fruits and vegetables, and has multiple biological activities, such as anti-oxidation, anti-inflammatory, antibacterial, antiviral, anti-obesity, anti-depression, etc. At present, the application of quercetin in the field of medicine has attracted widespread attention. For example, patent CN111544387A discloses a compound quercetin antibacterial nanoemulsion and its preparation method, adding 24.00% to 40.00% surfactant, 0% to 20% co-surfactant, 3.00% to 23.5% oil, 0.1976% to 0.2056% quercetin, 0.0466% to 0.0486% tannin, 0.7904% to 0.8224% toosendan, and the remainder is distilled water, and the sum of the mass percentages is 100%. The obtained compound quercetin nanoemulsion has good antibacterial effect and good thermodynamic stability. Patent CN109847062A discloses a quercetin metal nano drug and its preparation method and application, wherein quercetin and transition metal elements are coordinated by coordination bonds, and the surface is modified by a high molecular polymer containing carbonyl or hydroxyl groups to form a quercetin metal nano drug, which can inhibit tumor growth and exert a long-term anti-tumor effect, and has good application prospects in the medical field. Patent CN110664838A discloses a preparation method of nano-selenium loaded with quercetin, wherein quercetin and sodium selenite are added to a prepared reaction solution containing a stabilizer, stirred at room temperature for a period of time, and then an appropriate amount of Tween 80 is added, stirring is continued, methanol is removed by rotary evaporation, and finally freeze-dried to obtain nano-selenium loaded with quercetin, providing a preparation method and application of a drug for treating Alzheimer's disease.

[0004] However, there are few reports on the use of quercetin loaded into hydrogels for medical dressings. In addition, the current hydrogel medical dressings have weak antibacterial and antioxidant properties, insufficient adhesion to wounds, and the extensive use of antibiotics has increased bacterial resistance, making it more difficult for clinical workers to use drugs. Summary of the invention

[0005] In order to solve the above problems, the present invention modifies chitosan to prepare a soluble quaternary ammonium salt chitosan with strong antibacterial activity, and adds quercetin with multiple biological activities as an antioxidant and dopamine to improve adhesion performance, and combines with synthetic high molecular polymers to prepare an antibacterial, antioxidant, self-adhesive composite multifunctional hydrogel dressing. The combination of natural polymers and high molecular polymers effectively improves the mechanical strength of the hydrogel, the addition of quercetin improves the antioxidant activity of the hydrogel, and the addition of dopamine improves the self-adhesive properties of the hydrogel. The composite multifunctional hydrogel dressing prepared by the present invention has strong water absorption and moisture retention, feels cool and comfortable, provides a moist environment for wounds, has good antibacterial and antioxidant properties, can effectively prevent bacterial invasion, remove free radicals, and promote wound healing.

[0006] The purpose of the present invention is to provide a method for preparing an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing, comprising the following steps:

[0007] (1) adding chitosan powder to an aqueous solution of glacial acetic acid and vigorously stirring until completely dissolved to obtain a chitosan solution; then adding 2,3-epoxypropyltrimethylammonium chloride (GTMAC) dropwise and continuing to vigorously stir, then centrifuging to collect the supernatant, filtering, dialyzing, and finally freeze-drying the supernatant to obtain quaternary ammonium chitosan (QCS);

[0008] (2) dissolving the obtained quaternary ammonium salt chitosan in deionized water to obtain a quaternary ammonium salt chitosan solution; dissolving quercetin (QT) in anhydrous ethanol to prepare quercetin solutions of different concentrations; dissolving dopamine hydrochloride (DA) in a sodium hydroxide solution to obtain a dopamine hydrochloride solution; and uniformly mixing the three solutions in a certain proportion to obtain a mixed solution;

[0009] (3) Add acrylamide (AM) as a monomer, N,N-methylenebisacrylamide as a cross-linking agent, ammonium persulfate as an initiator, and N,N,N',N'-tetramethylethylenediamine as a catalyst to the above mixed solution, mix well, degas by ultrasonic, and put into a mold to obtain an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing, namely dopamine (DA)-quercetin (QT)-quaternary ammonium chitosan (QCS)-polyacrylamide (PAM) hydrogel, recorded as DA-QT-QP hydrogel.

[0010] In one embodiment of the present invention, the concentration of the chitosan solution in step (1) is 3 wt %.

[0011] In one embodiment of the present invention, the concentration of the glacial acetic acid solution in step (1) is 0.5 wt %.

[0012] In one embodiment of the present invention, the chitosan powder in step (1) is added to an aqueous solution of glacial acetic acid and vigorously stirred at a temperature of 50-60°C until it is completely dissolved. The temperature can be specifically 55°C.

[0013] In one embodiment of the present invention, the volume ratio of the 2,3-epoxypropyltrimethylammonium chloride to the glacial acetic acid solution in step (1) is 0.5:100-1:100, preferably 0.8:100.

[0014] In one embodiment of the present invention, the dialysis bag used in the dialysis in step (1) has a specification of MW3500, and the dialysis time is 1-5 days.

[0015] In one embodiment of the present invention, the freeze-drying temperature in step (1) is -60°C.

[0016] In one embodiment of the present invention, the concentration of the quercetin solution in step (2) is 0.01 wt % to 2 wt %, preferably 1 wt %.

[0017] In one embodiment of the present invention, the concentration of the dopamine hydrochloride solution in step (2) is 0.1 wt% to 0.5 wt%, preferably 0.25 wt%.

[0018] In one embodiment of the present invention, the concentration of the quaternary ammonium salt chitosan solution in step (2) is 1 wt% to 3 wt%, preferably 2 wt%.

[0019] In one embodiment of the present invention, in the mixed solution of step (2), the concentration of dopamine is 0.05 wt% to 0.2 wt%, preferably 1 wt%.

[0020] In one embodiment of the present invention, in the mixed solution of step (2), the mass ratio of quercetin to dopamine hydrochloride is 0.5:1 to 2:1, preferably 1:1.

[0021] In one embodiment of the present invention, in step (2), the volume ratio of the quaternary ammonium chitosan solution, the quercetin solution, and the dopamine hydrochloride solution is 5:1:4.

[0022] In one embodiment of the present invention, in step (3), the amount of acrylamide relative to the mixed solution is 0.2-0.3 g / mL, preferably 0.25 g / mL.

[0023] In one embodiment of the present invention, in step (3), the mass ratio of N,N-methylenebisacryloyl to acrylamide is 0.0001:1 to 0.0002:1, preferably 0.00012:1.

[0024] In one embodiment of the present invention, in step (3), the mass ratio of ammonium persulfate to acrylamide is 0.5:10 to 1.5:10, preferably 1:10.

[0025] In one embodiment of the present invention, in step (3), the volume ratio of N,N,N',N'-tetramethylethylenediamine to the mixed solution is 0.5:1000 to 1:1000, preferably 0.5:1000.

[0026] In one embodiment of the present invention, the stirring condition in step (3) is an ice bath, and after uniform stirring, ultrasonic degassing is performed and the mixture is loaded into a mold.

[0027] In one embodiment of the present invention, the shape of the mold in step (3) includes: cylindrical, thin sheet, and long strip.

[0028] The second objective of the present invention is to prepare an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing using the method of the present invention.

[0029] The third object of the present invention is to use the antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing of the present invention in the field of medical and sanitary materials.

[0030] Beneficial effects:

[0031] (1) The present invention greatly improves the water solubility and antibacterial effect of chitosan by modifying it into quaternary ammonium salt chitosan, effectively inhibits the reproduction of bacteria around the wound, and provides good antibacterial properties for wound dressings.

[0032] (2) The quercetin used in the present invention has multiple biological activities and can effectively improve the antioxidant activity of the hydrogel and remove free radicals on the wound surface, thereby effectively accelerating wound healing.

[0033] (3) The dopamine added in the present invention contains a large number of hydroxyl groups on its surface, which can effectively improve the adhesion performance of the hydrogel and enable the hydrogel dressing to better adhere to the wound surface.

[0034] (4) The preparation method of the present invention is simple, the hydrogel dressing has high water content, good water absorption, good antibacterial and antioxidant properties and adhesion strength, provides a moist environment for the wound, effectively removes free radicals, and promotes wound healing. The composite multifunctional dressing is suitable for wound care in various parts of the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The antibacterial performance test results of the hydrogels of Example 1 and Control Examples 1 to 3 are shown; 0, 1, 2, 3, and 4 in the figure represent the control group, Example 1, Control Example 1, Control Example 2, and Control Example 3, respectively.

[0036] Figure 2 The antioxidant performance test results of the hydrogels of Example 1 and Comparative Examples 1 to 3 are shown.

[0037] Figure 3 The self-adhesion performance test results of the hydrogels of Example 1 and Comparative Examples 1-3 are shown.

[0038] Figure 4 These are pictures of the hydrogel in Example 1 in (a) a bent state, (b) a compressed state, and (c) adhered to the skin. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0040] Antibacterial performance test:

[0041] According to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method", the antibacterial properties of composite hydrogels were tested, and the antibacterial effects of hydrogel samples against Staphylococcus aureus (S. aureus, ATCC6538) and Escherichia coli (E. coli, ATCC8099) were evaluated.

[0042] Antioxidant performance test:

[0043] The antioxidant activity of the hydrogel was detected by testing the scavenging ability of the hydrogel sample on 1,1-diphenyl-2-picrylhydrazide (DPPH) free radicals. The DPPH reagent was dissolved in anhydrous ethanol to prepare a 100mM test solution, and the sample was immersed in anhydrous ethanol to prepare a sample extract. Then, the DPPH test solution and the sample extract were mixed in equal volumes and incubated in the dark for 1h. The absorbance of the sample at 517nm was measured, and the scavenging ability of DPPH was calculated according to the formula:

[0044]

[0045] In the formula, A b is the absorbance value of the DPPH test solution, A s It is the absorbance value of DPPH test solution and sample extract. Adhesion test:

[0046] The adhesion test of the hydrogel was performed by adhering the hydrogel to two pieces of fresh pig skin and placing them on a single-column universal electronic testing machine for tensile testing. The tensile speed was 10 mm / min, and each group of samples was tested 5 times.

[0047] Experimental materials used in the examples:

[0048] Chitosan (CS, deacetylation degree of 80-95%, viscosity of 50-800 mPa·s), dopamine hydrochloride (DA), glycidyltrimethylammonium chloride (GTMAC), anhydrous ethanol, glacial acetic acid, sodium hydroxide, acrylamide, ammonium persulfate, N,N′-methylenebisacrylamide, N,N,N′,N′-tetramethylethylenediamine were purchased from Sinopharm Chemical Reagent Co., Ltd., and quercetin (QT) was purchased from MacLean Reagent Co., Ltd.

[0049] Example 1

[0050] A method for preparing an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing comprises the following steps:

[0051] (1) 3 g of chitosan powder was added to 100 mL of 0.5 wt% glacial acetic acid aqueous solution and stirred vigorously until completely dissolved. Then, 0.8 mL of 2,3-epoxypropyltrimethylammonium chloride was added dropwise and continued to be stirred vigorously. The undissolved chitosan was removed by centrifugation, and the supernatant was filtered through a Buchner funnel. Finally, it was dialyzed in deionized water (dialysis bag specification was MW3500), and the dialyzate was freeze-dried (-60°C) to obtain quaternary ammonium salt chitosan.

[0052] (2) Dissolve 0.1 g of quaternary ammonium salt chitosan in 5 mL of deionized water to obtain a 2 wt% quaternary ammonium salt chitosan solution; dissolve 0.1 g of quercetin in 10 mL of anhydrous ethanol to prepare a quercetin solution with a concentration of 1 wt%; dissolve 0.01 g of dopamine hydrochloride in 4 mL of sodium hydroxide solution to prepare a dopamine hydrochloride solution with a concentration of 0.25 wt%; mix the obtained quaternary ammonium salt chitosan solution, quercetin solution, and dopamine hydrochloride solution in a volume ratio of 5:1:4, and stir evenly to obtain a mixed solution (wherein the concentration of DA in the mixed solution is 0.1% and the concentration of QT is 0.1%).

[0053] (3) 2.5 g acrylamide (AM) as a monomer, 0.0003 g N,N-methylenebisacrylamide as a cross-linking agent, 0.25 g ammonium persulfate as an initiator, and 5 μL N,N,N',N'-tetramethylethylenediamine as a catalyst were added to the above 10 mL mixed solution, stirred evenly, and then ultrasonically degassed and loaded into a cylindrical mold to obtain an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing, named 0.1DA-0.1QT-QP hydrogel.

[0054] Comparative Example 1

[0055] The weight of quercetin in step (2) of Example 1 was changed to 0.025 g, and other conditions remained unchanged to obtain 0.1DA-0.025QT-QP hydrogel.

[0056] Comparative Example 2

[0057] The weight of quercetin in step (2) of Example 1 was changed to 0.050 g, while other conditions remained unchanged, to obtain 0.10DA-0.050QT-QP hydrogel.

[0058] Comparative Example 3

[0059] The weight of quercetin in step (2) of Example 1 was changed to 0.075 g, while other conditions remained unchanged, to obtain 0.10DA-0.075QT-QP hydrogel.

[0060] The multifunctional composite hydrogel dressings obtained in Example 1 and Comparative Examples 1 to 3 were tested for their antibacterial properties. Figure 1 As shown. It was observed that except for the control group (without addition), there were no live colonies in the other groups. The experimental results show that the hydrogels of Example 1 and Control Examples 1 to 3 have good antibacterial effects on Staphylococcus aureus and Escherichia coli.

[0061] The multifunctional composite hydrogel dressings obtained in Example 1 and Comparative Examples 1 to 3 were tested for their antioxidant properties. Figure 2 It can be observed that compared with control examples 1 to 3, the DPPH scavenging rate of Example 1 is the highest, which can reach about 60%. As the quercetin content increases, the antioxidant performance gradually improves, indicating that quercetin has excellent antioxidant capacity.

[0062] The multifunctional composite hydrogel dressings obtained in Example 1 and Comparative Examples 1 to 3 were subjected to an adhesion test. The test results are as follows: Figure 3 As shown. Figure 3 It can be seen that the adhesion strength of Example 1 is the highest, and the adhesion strength of Control Examples 1 to 3 gradually weakens as the quercetin content decreases. The adhesion strength of Control Example 3 is equivalent to that of Example 1, but the elongation of Control Example 3 is smaller, so the adhesion performance of Example 1 is the best. By comparing Control Examples 1 to 3 with Example 1, it is found that the increase in the content of quercetin is beneficial to improving the adhesion strength of the hydrogel, mainly because the molecular structure of quercetin contains a large number of structures such as hydroxyl groups and phenolic hydroxyl groups.

[0063] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing, characterized in that: The following steps are involved: (1) adding chitosan powder to an aqueous glacial acetic acid solution and vigorously stirring until completely dissolved to obtain a chitosan solution; then adding 2,3-epoxypropyltrimethylammonium chloride dropwise and continuing to vigorously stir, then centrifuging to collect the supernatant, filtering and dialyzing the supernatant, and finally freeze-drying to obtain quaternary ammonium salt chitosan; the concentration of the chitosan solution is 3wt%; the concentration of the aqueous glacial acetic acid solution is 0.5wt%; the volume ratio of 2,3-epoxypropyltrimethylammonium chloride to the aqueous glacial acetic acid solution is 0.8:100; (2) dissolving the obtained quaternary ammonium salt chitosan in deionized water to obtain a quaternary ammonium salt chitosan solution; dissolving quercetin in anhydrous ethanol to prepare a quercetin solution; dissolving dopamine hydrochloride in a sodium hydroxide solution to obtain a dopamine hydrochloride solution; mixing the three solutions in a certain proportion to obtain a mixed solution; the concentration of the quercetin solution is 1wt%; the concentration of the dopamine hydrochloride solution is 0.25wt%; the concentration of the quaternary ammonium salt chitosan solution is 2wt%; the volume ratio of the quaternary ammonium salt chitosan solution, the quercetin solution, and the dopamine hydrochloride solution is 5:1:4; (3) Add acrylamide as a monomer, N,N-methylenebisacrylamide as a cross-linking agent, ammonium persulfate as an initiator, and N,N,N',N'-tetramethylethylenediamine as a catalyst to the above-mentioned mixed solution, mix well, degas by ultrasonication, and put into a mold to obtain an antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing, namely dopamine-quercetin-quaternary ammonium salt chitosan-polyacrylamide hydrogel, recorded as DA-QT-QP hydrogel; the amount of acrylamide relative to the mixed solution is 0.25 g / mL; the mass ratio of N,N-methylenebisacrylamide to acrylamide is 0.00012:1; the mass ratio of ammonium persulfate to acrylamide is 1:10; the volume ratio of N,N,N',N'-tetramethylethylenediamine to the mixed solution is 0.5:1000.

2. An antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing prepared by the method of claim 1.

3. Use of the antibacterial, antioxidant, self-adhesive multifunctional composite hydrogel dressing according to claim 2 in the field of preparing medical and sanitary materials.

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