A topical composite dressing for wound debridement

Abstract

This invention relates to the field of dressing technology and discloses a topical composite dressing for wound debridement. This topical composite dressing is formed by electrospinning using polyvinyl alcohol (PVA) as the base material and functional additives as excipients. The functional additives are diatomaceous earth coated with hyperbranched macromolecular antibacterial agents. The hyperbranched macromolecular antibacterial agents contain numerous ether bonds, which can generate a large number of hydrogen bonds with the hydroxyl groups in the PVA molecular chain. This allows the diatomaceous earth to bond with the PVA molecular chain through hydrogen bond cross-linking, thereby allowing the diatomaceous earth to fully utilize its advantages, improving the mechanical strength of the PVA fiber dressing, and also enhancing the liquid absorption performance of the PVA fibers by utilizing the rich porosity of the diatomaceous earth. Furthermore, the hyperbranched macromolecular antibacterial agent contains a large amount of the broad-spectrum antibacterial agent cinnamaldehyde, which endows the PVA fiber dressing with excellent antibacterial properties, preventing wound infection caused by bacterial growth.

Description

Technical Field

[0001] This invention relates to the field of dressing technology, and more specifically to a topical composite dressing for wound cleaning. Background Technology

[0002] In modern medicine, wound management and treatment are crucial. Effective wound debridement and care not only promote rapid wound healing but also significantly reduce the risk of infection and improve patients' quality of life. Choosing the right dressing is essential during debridement. An ideal wound dressing should possess the following characteristics: It should keep the wound moist, as a moist environment promotes cell migration and wound healing; absorb exudate to keep the wound dry and reduce the risk of infection; not stick to the wound to reduce pain during dressing changes; and have good breathability to reduce the possibility of anaerobic bacterial growth. Furthermore, it should have good antibacterial properties and biocompatibility to further reduce the risk of infection.

[0003] Traditional absorbent cotton gauze and bandages, while inexpensive and convenient, suffer from drawbacks such as easy adhesion to wounds and poor breathability. With advancements in materials science, modern dressings such as hydrocolloid dressings and hydrophilic fiber dressings have emerged. Among these, polyvinyl alcohol (PVA) fiber dressings offer advantages such as complete non-toxicity, good breathability, non-stickiness to wounds, and excellent biocompatibility. They also maintain wound moisture and absorb exudate, meeting most of the needs of wound dressings and thus enjoying widespread application. However, PVA itself lacks antibacterial properties, making it impossible to completely prevent wound infection during use. Therefore, PVA fiber dressings still have limitations in their application.

[0004] In the prior art, polyvinyl alcohol fiber dressings are generally given antibacterial properties by adding inorganic antibacterial agents such as silver. However, these types of inorganic antibacterial agents are heavy metals, and their disposal will inevitably cause environmental pollution. Based on this, the present invention provides a polyvinyl alcohol-based external fiber dressing that 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 topical composite dressing for wound debridement.

[0007] (II) Technical Solution

[0008] A topical composite dressing for wound debridement, comprising the following raw materials measured in weight fractions:

[0009] 45-55 parts of polyvinyl alcohol;

[0010] Functional additives: 2-3.5 parts;

[0011] 120-150 parts deionized water;

[0012] The functional additive is diatomaceous earth coated with hyperbranched macromolecular antibacterial agents.

[0013] As a further aspect of the present invention, the preparation method of the external composite dressing includes the following steps:

[0014] Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 80-100℃, mix evenly, and then ultrasonically treat it at an ultrasonic frequency of 80-100kHz for 1-2 hours to form a uniformly dispersed material.

[0015] The second step is to obtain a topical composite dressing by using monofilament fiber technology to dispersible material. Specifically, dispersible material is added to an electrospinning machine, the injection speed is controlled at 5-15 mL / h, the spinning voltage is 10-20 kV, and the receiving distance is 10-15 cm. Monofilament fibers are formed through electrospinning process, and the topical composite dressing can be obtained.

[0016] As a further aspect of the present invention, the preparation method of the functional additive includes the following steps:

[0017] Step 1: Disperse the pretreated diatomaceous earth ultrasonically in toluene solvent until a uniform dispersion is formed. Then add the surface modifier and p-toluenesulfonic acid to the dispersion. After the addition is complete, stir mechanically until uniform, introduce nitrogen gas, raise the temperature to 90-100℃, keep it at that temperature for 6-8 hours, stop heating, cool down and discharge the material, collect the solid material, and obtain the modified diatomaceous earth body.

[0018] Step 2: Add the diatomaceous earth modifier to N,N-dimethylformamide and sonicate for 20-40 minutes. Then, add an epoxy chain extender and a phase transfer catalyst to the resulting dispersion. After the addition is complete, purge with nitrogen for protection and raise the temperature to 60-70°C. Stir for 1-3 hours, then add the reactive biological antibacterial agent to the dispersion. After the addition is complete, continue to raise the temperature to 80-90°C and maintain the temperature for 8-16 hours. Then, stop heating, cool down, and discharge the material to obtain the functional additive.

[0019] As a further aspect of the present invention, in step one, the pretreatment method for the diatomaceous earth specifically includes:

[0020] Immerse diatomaceous earth in a 1-3 mol / L nitric acid solution and stir until homogeneous. Then raise the temperature to 70-80℃ and keep stirring for 4-8 hours. Separate the solid material, wash it with water until neutral, and then place it in a sintering furnace. Purge with nitrogen gas and control the heating rate at 3-5℃ / min. Raise the temperature to 400-450℃ and calcine for 1-3 hours. Remove the material and allow it to cool naturally.

[0021] As a further aspect of the present invention, in step one, the surface modifier is any one of maleic anhydride, succinic anhydride, or glutaric anhydride.

[0022] As a further aspect of the present invention, in step two, the epoxy chain extender is pentaerythritol glycidyl ether or trimethylolpropane triglycidyl ether.

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

[0024] In the above technical solution, firstly, impurities in the pores of diatomaceous earth are removed by acid leaching and high-temperature calcination, and the silanol groups on its surface are fully exposed. Then, by using p-toluenesulfonic acid as a catalyst, an anhydride surface modifier is catalyzed to undergo esterification condensation with the silanol groups of diatomaceous earth, thereby modifying the surface of diatomaceous earth with active carboxyl substituents to obtain a modified diatomaceous earth body.

[0025] An epoxide containing multiple epoxy substituents in its structure is used as a chain extender. Under the action of a phase transfer catalyst, it first undergoes ring-opening esterification with the substituted carboxyl groups modified by diatomaceous earth to form an intermediate. Then, a reactive biological antibacterial agent is added. Under the action of a phase transfer catalyst, the epoxy substituents in the epoxy chain extender and the carboxyl substituents in the reactive biological antibacterial agent can undergo continuous ring-opening esterification, thereby coating the diatomaceous earth surface with a hyperbranched macromolecular antibacterial agent to obtain a functional additive.

[0026] As a further aspect of the present invention, the specific preparation method of the reactive biological antibacterial agent in step two is as follows:

[0027] Add glutamic acid, cinnamaldehyde, and ethanol solution to a reaction vessel, start stirring, and after a homogeneous reaction solution is formed, raise the temperature to 50-55℃ and stir at a constant temperature for 6-12 hours under nitrogen protection. Then remove the nitrogen, remove the solvent by rotary evaporation, and purify the product by Soxhlet extraction to obtain the reactive biological antibacterial agent.

[0028] As a further embodiment of the present invention, the molar ratio of glutamic acid to cinnamaldehyde is 1:1.

[0029] As a further aspect of the present invention, the volume fraction of the ethanol solution is 60-70%.

[0030] In the above technical solution, glutamic acid and cinnamaldehyde are used as reactants. By utilizing the principle that the active amino and aldehyde groups in their structures can undergo Schiff base reaction, a reactive biological antibacterial agent containing two equivalent active carboxyl substituents in its structure is prepared.

[0031] (III) Beneficial Technical Effects

[0032] This invention utilizes diatomaceous earth coated with a hyperbranched macromolecular antibacterial agent as a functional additive. Firstly, the hyperbranched macromolecular antibacterial agent is formed by ring-opening esterification polymerization of an epoxy chain extender and a reactive biological antibacterial agent. Therefore, its structure contains numerous ether bonds, which can generate a large number of hydrogen bonds with the hydroxyl groups in the polyvinyl alcohol (PVA) molecular chain. This effectively solves the interface problem between diatomaceous earth and PVA, promoting the bonding of diatomaceous earth with the PVA molecular chain through hydrogen bond cross-linking. On the one hand, this allows diatomaceous earth to fully leverage its advantages, improving the mechanical strength of PVA fiber dressings; on the other hand, it utilizes the rich porous structure of diatomaceous earth to enhance the liquid absorption performance of PVA fibers. Secondly, the hyperbranched macromolecular antibacterial agent structure contains a large amount of the broad-spectrum biological antibacterial agent cinnamaldehyde, which imparts excellent antibacterial properties to PVA fiber dressings, preventing wound infections caused by bacterial growth.

[0033] This invention uses monofilament fiber technology to prepare fibers with nanoscale diameters. These fibers have high specific surface area and porosity, which can effectively extract and adhere to silt and debris on the wound surface, while also rapidly absorbing wound exudate, creating a clean and dry environment for the wound. Attached Figure Description

[0034] 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.

[0035] Figure 1 This is an infrared analysis test image of a reactive biological antibacterial agent. Detailed Implementation

[0036] 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.

[0037] Example 1

[0038] A topical composite dressing for wound debridement, comprising the following raw materials measured in weight fractions:

[0039] 45 parts of polyvinyl alcohol;

[0040] 2 portions of functional additives;

[0041] 120 parts deionized water;

[0042] The preparation method of the external composite dressing includes the following steps:

[0043] Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 80℃, mix evenly, and then ultrasonically treat at an ultrasonic frequency of 80kHz for 2 hours to form a uniformly dispersed material.

[0044] The second step is to add the dispersed material into an electrospinning machine, control the injection speed to be 5 mL / h, the spinning voltage to be 10 kV, and the receiving distance to be 10 cm. Through the electrospinning process, the external composite dressing can be obtained.

[0045] The preparation method of the functional additives includes the following steps:

[0046] Step 1: Immerse 5g of diatomaceous earth in 200mL of 2mol / L nitric acid solution and stir until homogeneous. Then raise the temperature to 80℃ and keep stirring for 6 hours. Separate the solid material, wash it with water until neutral, and then place it in a sintering furnace. Pour nitrogen gas into the furnace and control the heating rate to 5℃ / min. Raise the temperature to 450℃ and calcine for 2 hours. Remove the calcined material and let it cool naturally to obtain pretreated diatomaceous earth.

[0047] Step 2: Disperse 1.8g of pretreated diatomaceous earth ultrasonically in toluene solvent until a uniform dispersion is formed. Then add 2.5g of succinic anhydride and 0.1g of p-toluenesulfonic acid to the dispersion. After the addition is complete, stir mechanically until uniform, introduce nitrogen gas, raise the temperature to 95℃, keep it at that temperature for 8 hours, stop heating, cool down and discharge the material, collect the solid material, and obtain the modified diatomaceous earth body.

[0048] Step 3: Add 1.5g of diatomaceous earth modifier to N,N-dimethylformamide and sonicate for 30 minutes. Then, add 4g of trimethylolpropane triglycidyl ether and 0.1g of tetrabutylammonium bromide to the resulting dispersion. After the addition is complete, purge with nitrogen for protection and raise the temperature to 65℃. Stir for 2 hours, then add 2.2g of reactive biological antibacterial agent to the dispersion. After the addition is complete, continue to raise the temperature to 90℃ and maintain the temperature for 12 hours. Then, stop heating, cool down and discharge the material to obtain the functional additive.

[0049] 0.2g of functional additive was taken as a titration test sample and a soap back titration test was performed. The test results showed that the ester content of the sample was 0.817mmol / g. It can be inferred that the ester group was formed by the ring-opening esterification polymerization of trimethylolpropane triglycidyl ether and reactive biological antibacterial agent on the surface of diatomaceous earth.

[0050] The specific preparation method of the reactive biological antibacterial agent is as follows:

[0051] Add 0.5g of glutamic acid, 0.45g of cinnamaldehyde and a 70% ethanol solution to a reaction vessel, start stirring, and after a homogeneous reaction solution is formed, raise the temperature to 50℃ and stir at a constant temperature for 9 hours under nitrogen protection. Then remove the nitrogen, remove the solvent by rotary evaporation, and purify the product by Soxhlet extraction to obtain the reactive biological antibacterial agent.

[0052] Figure 1 This is the infrared analysis result of the reactive bio-antibacterial agent, 3078 cm⁻¹. -1 and 3051cm -1 The absorption peak appearing at 3025 cm⁻¹ is the hydrocarbon absorption peak of the benzene ring skeleton in cinnamaldehyde. -1 The absorption peak appearing at 1719 cm⁻¹ is the hydrocarbon absorption peak of the unsaturated carbon-carbon double bond in cinnamaldehyde. -1 The absorption peak appearing at 1581 cm⁻¹ is a characteristic absorption peak of C=O with an active substituted carboxyl group. -1 The absorption peak appearing at this point is a characteristic absorption peak of Schiff base C=N.

[0053] Example 2

[0054] A topical composite dressing for wound debridement, comprising the following raw materials measured in weight fractions:

[0055] 50 parts of polyvinyl alcohol;

[0056] 3 parts functional additives;

[0057] 130 parts of deionized water;

[0058] The preparation method of the external composite dressing includes the following steps:

[0059] Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 90℃, mix evenly, and then ultrasonically treat it at an ultrasonic frequency of 100kHz for 1 hour to form a uniformly dispersed material.

[0060] The second step is to add the dispersed material into an electrospinning machine, control the injection speed to be 10 mL / h, the spinning voltage to be 15 kV, and the receiving distance to be 12 cm. Through the electrospinning process, the external composite dressing can be obtained.

[0061] The preparation method of the functional additives is described in Example 1.

[0062] Example 3

[0063] A topical composite dressing for wound debridement, comprising the following raw materials measured in weight fractions:

[0064] 55 parts of polyvinyl alcohol;

[0065] 3.5 parts of functional additives;

[0066] 150 parts of deionized water;

[0067] The preparation method of the external composite dressing includes the following steps:

[0068] Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 100℃, mix evenly, and then ultrasonically treat at an ultrasonic frequency of 100kHz for 2 hours to form a uniformly dispersed material.

[0069] The second step is to add the dispersed material into an electrospinning machine, control the injection speed to be 15 mL / h, the spinning voltage to be 20 kV, and the receiving distance to be 15 cm. Through the electrospinning process, the external composite dressing can be obtained.

[0070] The preparation method of the functional additives is described in Example 1.

[0071] Comparative Example 1

[0072] A topical composite dressing for wound debridement, comprising the following raw materials measured in weight fractions:

[0073] 50 parts of polyvinyl alcohol;

[0074] 3 parts diatomaceous earth;

[0075] 130 parts of deionized water;

[0076] The preparation method of the external composite dressing includes the following steps:

[0077] Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 90℃, mix evenly, and then ultrasonically treat it at an ultrasonic frequency of 100kHz for 1 hour to form a uniformly dispersed material.

[0078] The second step is to add the dispersed material into an electrospinning machine, control the injection speed to be 10 mL / h, the spinning voltage to be 15 kV, and the receiving distance to be 12 cm. Through the electrospinning process, the external composite dressing can be obtained.

[0079] Test case

[0080] According to standard GB / T 20944.3-2008, the antibacterial properties of the dressings in the examples and comparative examples were tested, and the test strain was Escherichia coli;

[0081] Prepare a test sample of the dressing with a length of 4cm and a height of 4cm, weigh it and record it as t, then immerse it completely in water. After it is fully swollen, take it out, wipe the surface moisture dry, weigh it and record it as T. Calculate the water absorption ratio of the dressing and evaluate the liquid absorption performance of the dressing. The calculation formula is (Tt) / t.

[0082] The mechanical properties of the dressing were tested using a YM-06E electronic single-fiber tensile strength tester. The tensile rate was set to 50 mm / min. The test results are recorded in Table 1.

[0083] Table 1 - Test Results

[0084] Antibacterial rate / % Water absorption ratio / g Fracture strength / cN / tex Example 1 99.1 151.1 4.8 Example 2 99.4 152.0 5.1 Example 3 99.2 151.8 5.0 Comparative Example 1 60.6 148.5 3.9

[0085] Analysis of the test results shows that the fiber dressing made by adding unmodified diatomaceous earth as an additive has significantly poor antibacterial properties. Moreover, due to the interfacial incompatibility between diatomaceous earth and polyvinyl alcohol, some of the diatomaceous earth detached, resulting in a decrease in the absorbency of the fiber dressing. Furthermore, due to the interfacial incompatibility, the reinforcing effect of diatomaceous earth could not be effectively utilized, thus the mechanical properties of the dressing were also poor.

[0086] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A topical composite dressing for wound debridement, characterized in that, It is made from the following raw materials, measured in weight fractions: 45-55 parts of polyvinyl alcohol; Functional additives: 2-3.5 parts; 120-150 parts deionized water; The functional additive is diatomaceous earth coated with hyperbranched macromolecular antibacterial agents, and the preparation method of the functional additive includes the following steps: Step 1: Disperse the pretreated diatomaceous earth ultrasonically in toluene solvent until a uniform dispersion is formed. Then add the surface modifier and p-toluenesulfonic acid to the dispersion. After the addition is complete, stir mechanically until uniform, introduce nitrogen gas, raise the temperature to 90-100℃, keep it at that temperature for 6-8 hours, stop heating, cool down and discharge the material, collect the solid material, and obtain the modified diatomaceous earth body. Step 2: Add the diatomaceous earth modifier to N,N-dimethylformamide and sonicate for 20-40 minutes. Then add an epoxy chain extender and a phase transfer catalyst to the resulting dispersion. After the addition is complete, purge with nitrogen for protection and raise the temperature to 60-70°C. Stir for 1-3 hours, then add the reactive biological antibacterial agent to the dispersion. After the addition is complete, continue to raise the temperature to 80-90°C and keep it at that temperature for 8-16 hours. Then stop heating, cool down and discharge the material to obtain the functional additive. The surface modifier is any one of maleic anhydride, succinic anhydride, or glutaric anhydride; The specific preparation method of the reactive biological antibacterial agent is as follows: Add glutamic acid, cinnamaldehyde, and ethanol solution to a reaction vessel, start stirring, and after a homogeneous reaction solution is formed, raise the temperature to 50-55℃ and stir at a constant temperature for 6-12 hours under nitrogen protection. Then remove the nitrogen, remove the solvent by rotary evaporation, and purify the product by Soxhlet extraction to obtain the reactive biological antibacterial agent.

2. The topical composite dressing for wound debridement according to claim 1, characterized in that, The preparation method of the external composite dressing includes the following steps: Step 1: Add each raw material to the high-speed mixer according to the weight proportions, control the mixing temperature to 80-100℃, mix evenly, and then ultrasonically treat it at an ultrasonic frequency of 80-100kHz for 1-2 hours to form a uniformly dispersed material. The second step is to add the dispersion material into the electrospinning machine, control the injection speed to be 5-15 mL / h, the spinning voltage to be 10-20 kV, and the receiving distance to be 10-15 cm. Through the electrospinning process, the external composite dressing can be obtained.

3. The topical composite dressing for wound debridement according to claim 1, characterized in that, In step one, the pretreatment method for diatomaceous earth is specifically as follows: Immerse diatomaceous earth in a 1-3 mol / L nitric acid solution and stir until homogeneous. Then raise the temperature to 70-80℃ and keep stirring for 4-8 hours. Separate the solid material, wash it with water until neutral, and then place it in a sintering furnace. Purge with nitrogen gas and control the heating rate at 3-5℃ / min. Raise the temperature to 400-450℃ and calcine for 1-3 hours. Remove the material and allow it to cool naturally.

4. The topical composite dressing for wound debridement according to claim 1, characterized in that, In step two, the epoxy chain extender is pentaerythritol tetraglycidyl ether or trimethylolpropane triglycidyl ether.

5. A topical composite dressing for wound debridement according to claim 1, characterized in that, In step one, the phase transfer catalyst is any one of tetramethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium chloride, tetramethylammonium bromide, or tetrabutylammonium hydrogen sulfate.

6. The topical composite dressing for wound debridement according to claim 1, characterized in that, The molar ratio of glutamic acid to cinnamaldehyde is 1:

1.

7. A topical composite dressing for wound debridement according to claim 1, characterized in that, The volume fraction of the ethanol solution is 60-70%.

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