A functional dressing based on quaternary ammonium salt antibacterial agent and a preparation method thereof

Abstract

The application relates to the technical field of dressings, and discloses a functional dressing based on a quaternary ammonium salt antibacterial agent and a preparation method thereof. The functional dressing is prepared through an electrostatic spinning process by taking polyvinyl alcohol as a base material and taking a macromolecular quaternary ammonium salt antibacterial agent and a reinforcing agent as auxiliary materials. The macromolecular quaternary ammonium salt antibacterial agent can endow the dressing with excellent broad-spectrum antibacterial performance, thereby effectively preventing bacterial infection and other conditions of a wound, and being beneficial to the recovery of the wound. The macromolecular quaternary ammonium salt antibacterial agent has an aerogel structure, and can effectively improve the liquid absorption effect of the dressing, which is very beneficial to keeping the wound dry. The presence of the reinforcing agent can make the medical stone fiber efficiently play the self-reinforcing effect, play a skeleton supporting role, and improve the strength of the dressing fiber. In addition, the medical stone fiber has a far infrared emission function, can produce activated cells, and has the effect of enhancing the cell regeneration capacity, and can accelerate the wound healing.

Description

Technical Field

[0001] This invention relates to the field of dressing technology, specifically to a functional dressing based on quaternary ammonium salt antibacterial agents and its preparation method. Background Technology

[0002] With the continuous advancement of medical technology, dressings, as an important medical auxiliary material, have been widely used in fields such as surgery, dermatology, gynecology, and traumatology. The main function of dressings is to protect wounds, prevent external contamination, and accelerate wound healing. Antibacterial dressings come in many types. Based on material classification, they can be divided into gauze dressings, membrane dressings, and foam dressings, among others. Gauze dressings are relatively breathable and widely used. Based on function, they can be divided into antibacterial dressings, hemostatic dressings, and healing-promoting dressings. Antibacterial dressings, by adding antibacterial components, complement the dressing's properties to prevent wound infection, and are therefore widely used. Among the many antibacterial components, quaternary ammonium salt antibacterial agents, due to their excellent broad-spectrum antibacterial properties, can effectively kill various bacteria, fungi, and viruses, including drug-resistant bacteria, while also exhibiting good stability and safety, making them an important component of antibacterial dressings.

[0003] The invention patent with publication number CN109010897A discloses a method for preparing a medical antibacterial gel dressing. It uses a quaternary ammonium salt cationic etherifying agent to react with starch and apply it to silver nanoparticles as an antibacterial agent for the medical antibacterial gel dressing. However, common small molecule types of quaternary ammonium salt antibacterial agents have serious volatilization and migration phenomena, making it difficult to exist in the dressing substrate for a long time. This may cause the dressing to lose its antibacterial effect during storage, resulting in the inability to exert a good antibacterial effect during use.

[0004] Based on this, the present invention provides a functional dressing based on quaternary ammonium salt antibacterial agents, which has good antibacterial durability and can solve the problems existing in the prior art. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a functional dressing based on quaternary ammonium salt antibacterial agents and its preparation method.

[0007] (II) Technical Solution

[0008] A method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent, wherein the functional dressing is made from raw materials comprising the following parts by weight: 56-62 parts polyvinyl alcohol, 2-3 parts macromolecular quaternary ammonium salt antibacterial agent, 2-5 parts reinforcing agent, and 150-180 parts deionized water;

[0009] The preparation method is as follows:

[0010] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at a temperature of 80-90℃ for 2-4 hours to prepare the precursor liquid.

[0011] Step S2: Inject the precursor liquid into the electrospinning machine and perform electrospinning to obtain the functional dressing.

[0012] As a further aspect of the present invention, the preparation method of the macromolecular quaternary ammonium salt antibacterial agent is as follows:

[0013] Step SS1: Add 1,3-di(dimethylamino)-2-propanol, glycidol and toluene to the reaction vessel, purge with nitrogen for protection, start stirring, and after a homogeneous mixture is formed, gradually raise the temperature to 60-65℃ and stir continuously at this temperature for 2-4 hours. Then remove the solvent by vacuum distillation, collect the product, and obtain the quaternary ammonium salt crosslinking agent.

[0014] Step SS2: Mix xanthan gum with a 60-70% ethanol solution and stir until homogeneous. Add an activator and stir at room temperature for 1-2 hours. Then add a quaternary ammonium salt crosslinking agent. After the addition is complete, stir continuously at 50-60℃ for 8-12 hours. Pour the mixture into a mold and let it stand. After the gel is formed, transfer it to a freeze dryer and remove it after 2-4 freeze-thaw cycles to obtain a macromolecular quaternary ammonium salt antibacterial agent.

[0015] As a further aspect of the present invention, in step SS1, the molar ratio of 1,3-bis(dimethylamino)-2-propanol and glycidol is 1:1-2.

[0016] As a further aspect of the present invention, in step SS2, the activator is dicyclohexylcarbodiimide and 4-dimethylaminopyridine in a mass ratio of 1:0.2-0.4.

[0017] As a further aspect of the present invention, in step SS2, the mass ratio of xanthan gum to quaternary ammonium salt crosslinking agent is 1:0.1-0.15.

[0018] As a further aspect of the present invention, the method for preparing the reinforcing agent is as follows:

[0019] Step SSS1: Control the frequency at 80-100kHz, uniformly disperse the maifan stone fiber in dimethyl sulfoxide, then add ethylene glycol diglycidyl ether and catalyst to the formed dispersion. After the addition is complete, raise the temperature to 130-135℃, maintain it for 3-6 hours, cool down, separate the material, and obtain modified maifan stone fiber.

[0020] Step SSS2: Mix the modified maifanite fiber with toluene, disperse it evenly by ultrasonication, add β-polymalic acid and phase transfer catalyst, raise the temperature to 60-70℃, keep it warm and stir for 3-5 hours, and then centrifuge to remove the solid material to obtain the reinforcing agent.

[0021] As a further aspect of the present invention, in step SSS1, the catalyst is stannous chloride.

[0022] As a further aspect of the present invention, in step SSS2, the number-average molecular weight of the β-polymalic acid is 2000.

[0023] As a further aspect of the present invention, in step SSS2, the phase transfer catalyst is at least one of tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, or tetrabutylammonium bromide.

[0024] A functional dressing based on a quaternary ammonium salt antibacterial agent is prepared using the above-described method.

[0025] (iii) Beneficial technical effects

[0026] This invention prepares a functional dressing by mixing a macromolecular quaternary ammonium salt antibacterial agent and a reinforcing agent with a polyvinyl alcohol matrix, followed by electrospinning. The macromolecular quaternary ammonium salt antibacterial agent is prepared by crosslinking xanthan gum with a quaternary ammonium salt crosslinking agent and then freeze-drying. This macromolecular antibacterial agent exhibits aerogel properties. On the one hand, its structure contains a large number of quaternary ammonium salt functional groups, which endow the dressing with excellent broad-spectrum antibacterial properties, thereby effectively preventing bacterial infection of wounds and promoting wound healing. On the other hand, this aerogel structure has abundant pores, and xanthan gum itself has good water absorption, thus effectively improving the dressing's liquid absorption effect. This is very beneficial for keeping wounds dry, thereby improving the dressing's effect on promoting wound healing.

[0027] The reinforcing agent is prepared by modifying the surface of maifan stone fibers with β-polymalic acid. Firstly, the presence of the β-polymalic acid macromolecular chains acts as a transition layer between the maifan stone fibers and the polyvinyl alcohol matrix, enabling better interfacial interaction between the maifan stone fibers and the polyvinyl alcohol matrix. This allows the maifan stone to more effectively exert its reinforcing effect, providing skeletal support and improving the strength of the dressing fibers. Secondly, maifan stone fibers possess far-infrared emitting capabilities, which can activate cells and enhance cell regeneration, thus accelerating wound healing. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 Infrared spectral analysis of quaternary ammonium salt crosslinking agents;

[0030] Figure 2 This is a scanning electron microscope image of a macromolecular quaternary ammonium salt antibacterial agent. Detailed Implementation

[0031] To facilitate understanding of the present invention, a more complete description will be provided below. Preferred embodiments of the invention are given below. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0032] Preparation Example 1

[0033] Preparation of macromolecular quaternary ammonium salt antibacterial agents

[0034] Step SS1: Add 0.6g of 1,3-di(dimethylamino)-2-propanol, 0.6g of glycidol and toluene to the reaction vessel, purge with nitrogen for protection, start stirring, and after a uniform mixture is formed, gradually raise the temperature to 65℃ and stir continuously at this temperature for 3h. Then remove the solvent by vacuum distillation, collect the product, and obtain the quaternary ammonium salt crosslinking agent.

[0035] Figure 1 This is the infrared spectrum of the quaternary ammonium salt crosslinking agent, where 3322 cm⁻¹... -1 The absorption peak appearing at 2800–3000 cm⁻¹ is a characteristic absorption peak of hydroxyl groups. -1 The absorption peak appearing at 1416 cm⁻¹ is a characteristic hydrocarbon absorption peak of methyl and ethyl groups. -1 The absorption peak appearing at 900–1000 cm⁻¹ is a characteristic absorption peak of CN in the quaternary ammonium salt functional group. -1 No obvious characteristic absorption peaks of epoxy groups were found at the location;

[0036] Step SS2: Mix 2.4g xanthan gum with a 70% ethanol solution and stir until homogeneous. Then add 0.5g dicyclohexylcarbodiimide and 0.2g 4-dimethylaminopyridine. Stir and activate at room temperature for 2 hours. Then add 0.3g quaternary ammonium salt crosslinking agent. After the addition is complete, stir continuously at 55℃ for 9 hours. Then pour it into a mold and let it stand. After gelation, transfer it to a freeze dryer and remove it after 3 freeze-thaw cycles to obtain a macromolecular quaternary ammonium salt antibacterial agent.

[0037] Figure 2 The image shows a scanning electron microscope image of a macromolecular quaternary ammonium salt antibacterial agent. It is observed that the agent has a distinct porous structure with uniform distribution and size, exhibiting aerogel properties. This allows it to absorb exudate from wounds, creating a relatively dry environment that helps prevent bacterial growth.

[0038] Analysis shows that the principle of the above technical solution is as follows: Under high temperature conditions, the tertiary amine group in the 1,3-di(dimethylamino)-2-propanol structure can undergo a quaternization ring-opening reaction with the epoxy group in the glycidyl structure to form a bisquaternary ammonium salt intermediate containing multiple hydroxyl substituents, i.e., a quaternary ammonium salt crosslinking agent. Since its structure contains multiple hydroxyl substituents, it can continuously undergo esterification condensation with the carboxyl substituents in the xanthan gum structure under the action of an activator, thereby obtaining a xanthan gum crosslinked modified body. Then, through a freeze-drying process, a macromolecular quaternary ammonium salt antibacterial agent is prepared.

[0039] Preparation Example 2

[0040] Preparation of reinforcing agents:

[0041] Step SSS1: Control the frequency at 100kHz, uniformly disperse 2.5g of maifan stone fiber in dimethyl sulfoxide, then add 1.5g of ethylene glycol diglycidyl ether and 0.01g of stannous chloride to the formed dispersion. After the addition is complete, raise the temperature to 130℃, maintain it for 4h, cool down, separate the material, and obtain modified maifan stone fiber.

[0042] The epoxy value of the modified maifan stone fiber was tested using the hydrochloric acid-acetone method. The specific test method refers to the standard GB / T 1677-2008. The test results show that the epoxy value of the modified maifan stone fiber is 0.515 mmol / g, indicating that there are epoxy groups on the surface of the modified maifan stone fiber.

[0043] Step SSS2: Mix 1.6g of modified maifan stone fiber with toluene, and after ultrasonic dispersion, add 5g of β-polymalic acid with a number average molecular weight of 2000 and 0.2g of tetrabutylammonium bromide. After the addition is complete, raise the temperature to 70℃, keep it warm and stir for 4 hours, and then centrifuge to remove the solid material to obtain the reinforcing agent.

[0044] The epoxy value of the reinforcing agent was tested and found to be 0.107 mmol / g. Based on this, the principle of the above technical solution can be deduced as follows: First, stannous chloride is used as a catalyst to catalyze the ring-opening of the hydroxyl groups of the maifan stone fiber with the epoxy groups at one end of the ethylene glycol diglycidyl ether structure, thereby modifying the epoxy groups onto the surface of the maifan stone fiber. Then, under the action of the phase-transfer catalyst tetrabutylammonium bromide, the carboxyl groups in the β-polymalic acid structure can further undergo ring-opening esterification with the epoxy groups of the modified maifan stone fiber, thereby modifying the β-polymalic acid onto the surface of the maifan stone fiber. Example 1

[0045] A functional dressing based on a quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 56 parts polyvinyl alcohol, 2 parts macromolecular quaternary ammonium salt antibacterial agent, 2 parts reinforcing agent, and 150 parts deionized water.

[0046] The preparation method of the functional dressing is as follows:

[0047] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at 80°C for 2 hours to prepare the precursor liquid.

[0048] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing.

[0049] The preparation method of the macromolecular quaternary ammonium salt antibacterial agent is given in Preparation Example 1; the preparation method of the reinforcing agent is given in Preparation Example 2. The same applies below. Example 2

[0050] A functional dressing based on a quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 60 parts polyvinyl alcohol, 2.5 parts macromolecular quaternary ammonium salt antibacterial agent, 4 parts reinforcing agent, and 160 parts deionized water;

[0051] The preparation method of the functional dressing is as follows:

[0052] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at 90°C for 3 hours to prepare the precursor liquid.

[0053] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing. Example 3

[0054] A functional dressing based on quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 62 parts polyvinyl alcohol, 3 parts macromolecular quaternary ammonium salt antibacterial agent, 5 parts reinforcing agent, and 180 parts deionized water.

[0055] The preparation method of the functional dressing is as follows:

[0056] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at a temperature of 90°C for 4 hours to prepare the precursor liquid.

[0057] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing.

[0058] Comparative Example 1

[0059] A functional dressing based on quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 60 parts polyvinyl alcohol, 2.5 parts macromolecular quaternary ammonium salt antibacterial agent, 4 parts maifan stone fiber, and 160 parts deionized water.

[0060] The preparation method of the functional dressing is as follows:

[0061] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at 90°C for 3 hours to prepare the precursor liquid.

[0062] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing.

[0063] Comparative Example 2

[0064] A functional dressing based on a quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 60 parts polyvinyl alcohol, 2.5 parts macromolecular quaternary ammonium salt antibacterial agent, and 160 parts deionized water;

[0065] The preparation method of the functional dressing is as follows:

[0066] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at 90°C for 3 hours to prepare the precursor liquid.

[0067] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing.

[0068] Comparative Example 3

[0069] A functional dressing based on a quaternary ammonium salt antibacterial agent is made from the following raw materials in parts by weight: 60 parts polyvinyl alcohol, 2.5 parts dialcyldimethylammonium chloride, 4 parts reinforcing agent, and 160 parts deionized water;

[0070] The preparation method of the functional dressing is as follows:

[0071] Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at 90°C for 3 hours to prepare the precursor liquid.

[0072] Step S2: Inject the precursor liquid into the electrospinning machine, control the injection speed to be 5 mm / h, the voltage to be 15 kV, and the receiving distance to be 10 cm, and carry out the electrospinning process. Arrange the formed yarn in a temperature environment of 100℃ for heat treatment for 30 min to obtain the functional dressing.

[0073] Test case

[0074] The functional dressings in the embodiments and comparative examples of this invention were subjected to various performance tests, and the results are recorded in Table 1:

[0075] Table 1 - Performance Test Results

[0076] ;

[0077] Note: The antibacterial rate test method refers to GB / T 20944.3-2008, with Staphylococcus aureus selected as the test strain, and the test time is 2 months after the functional dressings in the examples and comparative examples are placed at room temperature.

[0078] The tensile strength was tested using a YG004 electronic single-fiber tensile tester, with the tensile speed set at 20 mm / min.

[0079] The test method for water absorption ratio is as follows: Take a sample with a size of 5cm×5cm, weigh it and record the weight as W1. Then immerse the sample in water and take it out after 4 hours. When no more water droplets drip from its surface, weigh it again and record the weight as W2. Calculate the water absorption ratio of the sample. The calculation formula is (W2-W1) / W1.

[0080] Analysis shows that the functional dressing in the embodiments of the present invention has good antibacterial properties, mechanical properties and water absorption properties, and its overall performance is excellent.

[0081] Replacing the reinforcing agent with unmodified maifanite fibers resulted in a decrease in mechanical properties because the interfacial properties could not be resolved. Complete removal of the reinforcing agent further diminished the advantages of the maifanite fibers, leading to a further decrease in mechanical properties and a slight reduction in antibacterial properties. This indicates that the addition of maifanite fibers has a synergistic effect on improving the antibacterial properties of the dressing.

[0082] When macromolecular quaternary ammonium salt antibacterial agents are replaced with conventional small-molecule quaternary ammonium salt antibacterial agents, it can be found that they migrate and volatilize during long-term storage, resulting in a significant reduction in the antibacterial properties of the dressing.

[0083] Based on the preferred embodiments of the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent, characterized in that, The functional dressing is made from the following raw materials in parts by weight: 56-62 parts polyvinyl alcohol, 2-3 parts macromolecular quaternary ammonium salt antibacterial agent, 2-5 parts reinforcing agent, and 150-180 parts deionized water. The preparation method is as follows: Step S1: After weighing each raw material according to the weight proportions, put them into the mixing tank and mechanically stir and mix them at a temperature of 80-90℃ for 2-4 hours to prepare the precursor liquid. Step S2: Inject the precursor liquid into the electrospinning machine and perform electrospinning to obtain the functional dressing. The preparation method of the macromolecular quaternary ammonium salt antibacterial agent is as follows: Step SS1: Add 1,3-di(dimethylamino)-2-propanol, glycidol and toluene to the reaction vessel, purge with nitrogen for protection, start stirring, and after a homogeneous mixture is formed, gradually raise the temperature to 60-65℃ and stir continuously at this temperature for 2-4 hours. Then remove the solvent by vacuum distillation, collect the product, and obtain the quaternary ammonium salt crosslinking agent. Step SS2: Mix xanthan gum with a 60-70% ethanol solution and stir until homogeneous. Add an activator and stir at room temperature for 1-2 hours. Then add a quaternary ammonium salt crosslinking agent. After the addition is complete, stir continuously at 50-60℃ for 8-12 hours. Pour the mixture into a mold and let it stand. After the gel is formed, transfer it to a freeze dryer and remove it after 2-4 freeze-thaw cycles to obtain a macromolecular quaternary ammonium salt antibacterial agent. The reinforcing agent was prepared by modifying maifan stone fibers sequentially with ethylene glycol diglycidyl ether and β-polymalic acid. The preparation method of the reinforcing agent is as follows: Step SSS1: Using dimethyl sulfoxide as a medium, and under the action of a catalyst, ethylene glycol diglycidyl ether is used to modify the surface of maifan stone fibers to obtain modified maifan stone fibers. Step SSS2: Using toluene as a medium and β-polymalic acid as a modifier, the modified maifanite fiber is modified under the action of a phase transfer catalyst to obtain a reinforcing agent.

2. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SS1, the molar ratio of 1,3-bis(dimethylamino)-2-propanol and glycidol is 1:1-2.

3. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SS2, the activator is dicyclohexylcarbodiimide and 4-dimethylaminopyridine in a mass ratio of 1:0.2-0.

4.

4. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SS2, the mass ratio of xanthan gum to quaternary ammonium salt crosslinking agent is 1:0.1-0.

15.

5. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SSS1, the catalyst is stannous chloride.

6. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SSS2, the number-average molecular weight of the β-polymalic acid is 2000.

7. The method for preparing a functional dressing based on a quaternary ammonium salt antibacterial agent according to claim 1, characterized in that, In step SSS2, the phase transfer catalyst is at least one of tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, or tetrabutylammonium bromide.

8. A functional dressing based on a quaternary ammonium salt antibacterial agent, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

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