Scar prevention dressing shielding wound tension and preparation method thereof

Abstract

The application discloses an anti-scar dressing for shielding wound tension, which comprises the following components in parts by weight: 2-5 parts of sodium carboxymethyl cellulose, 2-5 parts of modified hydroxypropyl methyl cellulose, 20-50 parts of acrylic acid and 0.5-5 parts of ammonium persulfate; the above raw materials are dissolved and uniformly mixed by using a mixed solvent of sodium hydroxide aqueous solution and dimethyl sulfoxide to prepare a hydrogel dressing which can shrink in response to body temperature and adhere to skin. The hydrogel dressing patch has skin tissue adhesion, can be firmly adhered to the surface of skin and will not leave residues or damage the integrity of skin when separated from the skin; the hydrogel dressing has body temperature response and shrinkage, and still has skin adhesion during shrinkage; the hydrogel dressing shrinks in response to body temperature and adheres to the edges of a wound to gather the wound edges to the central area of a wound bed, thereby reducing stress concentration around the wound edges and balancing the wound tension.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biological medicine and biomaterial technology, and particularly relates to an anti-scar dressing for shielding wound tension and a preparation method thereof. BACKGROUND

[0002] From the perspective of molecular analysis, skin scar can be understood as a fibrosis disease caused by incomplete repair of skin damage. In clinical research, it is found that the disease usually occurs more easily in positions where the skin is highly tensioned and rigid, such as joints, chest, upper back and shoulders. Complications such as protruding skin surface, irregular shape, redness and bleeding, pain and itching of the scar not only affect the appearance, but also cause limb contracture and lead to limb dysfunction, and even cause skin cancer and endanger life. Therefore, the stress field in the wound bed is considered to be a key factor affecting the pathological fibrosis of skin tissue, i.e., leading to the formation of skin scar. If measures are taken to balance the tension in the wound bed, the stimulation to the skin keratinocytes and the over-activation of fibroblasts can be reduced. This will avoid the deformation of the surface structure and dermis structure of the skin tissue caused by the large deposition of collagen, thereby achieving the purpose of reducing skin scar.

[0003] At present, the common means for preventing and treating scars in the clinic mainly include injection of drugs, surgery, radiation, laser and physical rehabilitation. However, invasive treatment methods often cause secondary damage to the body and increase the pain of patients. In comparison, non-invasive physical therapy may be more easily accepted by patients, such as common compression garments, elastic sleeves and scar dressings. Silicone gel scar patches mainly play a role in reducing skin scar by occlusion of the patch to enhance the hydration of keratinocytes. However, there is no dressing in the existing wound care standards that promotes scar-free healing of wounds by balancing the tension in the wound. SUMMARY

[0004] 1. Technical problem to be solved

[0005] The purpose of the present application is to solve the problem that there is no dressing in the existing wound care standards that promotes scar-free healing of wounds by balancing the tension in the wound, and to propose an anti-scar dressing for shielding wound tension and a preparation method thereof.

[0006] 2. Technical solution

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0008] An anti-scar dressing for shielding wound tension comprises the following components by weight parts: 2-5 parts of sodium carboxymethyl cellulose, 2-5 parts of modified hydroxypropyl methyl cellulose, 20-50 parts of acrylic acid and 0.5-5 parts of ammonium persulfate.

[0009] Preferably, it comprises the following components by weight parts: sodium carboxymethyl cellulose 2 parts, modified hydroxypropyl methyl cellulose 3 parts, acrylic acid 30 parts, ammonium persulfate 1 part.

[0010] Preferably, it comprises the following components by weight parts: sodium carboxymethyl cellulose 2 parts, modified hydroxypropyl methyl cellulose 5 parts, acrylic acid 20 parts, ammonium persulfate 5 parts.

[0011] Preferably, it comprises the following components by weight parts: sodium carboxymethyl cellulose 5 parts, modified hydroxypropyl methyl cellulose 2 parts, acrylic acid 50 parts, ammonium persulfate 0.5 parts.

[0012] The present application also proposes an anti-scar dressing for shielding wound tension and a preparation method thereof, comprising the following steps:

[0013] Step 1: a certain amount of hydroxypropyl methyl cellulose is dissolved in a sodium hydroxide solution with a concentration of 1M, then 2mol of bromine propylene is added, stirred for 24 hours at room temperature, neutralized with a hydrochloric acid solution, and finally purified by dialysis and freeze-dried to obtain modified hydroxypropyl methyl cellulose for standby use;

[0014] Step 2: the weight parts of acrylic acid are added to a mixed solvent of sodium hydroxide aqueous solution and dimethyl sulfoxide, mixed uniformly, then the weight parts of modified hydroxypropyl methyl cellulose and sodium carboxymethyl cellulose are added, followed by the weight parts of ammonium persulfate, and the mixed solution is shaken and dispersed, then poured into a mold and placed in an oven at 60 degrees Celsius for 10-30 minutes to form a gel;

[0015] Step 3: after the gel is taken off from the mold, it is soaked in physiological saline to replace the dimethyl sulfoxide solvent in the gel;

[0016] Step 4: sterilization treatment is required before use.

[0017] Preferably, the parts of sodium carboxymethyl cellulose and modified hydroxypropyl methyl cellulose in step 2 need to be prepared into an aqueous solution of equivalent amount, and the acrylic acid mixed solvent is added in the form of an aqueous solution; and the dimethyl sulfoxide solvent needs to be added to the acrylic acid solution before adding the sodium carboxymethyl cellulose and modified hydroxypropyl methyl cellulose solution.

[0018] Preferably, the gel prepared in step 3 needs to be soaked in physiological saline for about 24 hours, and the physiological saline needs to be replaced every 6 hours to accelerate the replacement of dimethyl sulfoxide solvent molecules.

[0019] Preferably, the disinfection treatment method in step 4 is: first soaked in 75% alcohol solution for 10 minutes, then washed with deionized water for 3-5 times, and finally sterilized by ultraviolet light for 4 hours.

[0020] 3. Beneficial effects

[0021] Compared with the prior art, the present application has the advantages of:

[0022] (1) In the present application, the hydrogel dressing patch has skin tissue adhesion performance, which can firmly adhere to the skin surface and will not leave residues and damage the integrity of the skin when separated from the skin.

[0023] (2) In the present application, the hydrogel dressing has body temperature response shrinkage performance, which still has skin adhesion performance while shrinking. The hydrogel dressing shrinks in response to body temperature and adheres to the wound edge to gather it to the center area of the wound bed, thereby reducing the stress concentration around the wound edge and balancing the wound tension.

[0024] (3) In the present application, the dressing is used to repair full-thickness skin injury animal models. After 6 weeks of treatment, it is found that the experimental group treated with the dressing has a significant effect of reducing skin scar compared with the control group.

[0025] (4) In the present application, the force generated by the shrinkage of the dressing intervenes in the healing process of the wound, and the histopathological analysis and histological chemical analysis show that the dressing inhibits the activation of fibroblasts and mechanical transduction to some extent, which is of great significance for preventing the formation of scar tissue. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A dressing response temperature shrinkage performance curve of an anti-scar dressing for shielding wound tension is provided for the present application;

[0027] Figure 2 A dressing and pig skin tissue model lap joint shear tensile experiment curve of an anti-scar dressing for shielding wound tension is provided for the present application;

[0028] Figure 3 A tensile strength control diagram of normal rat skin, control group and experimental group rat skin tissue is provided for the present application;

[0029] Figure 4 A comparison diagram of wound scar size of control group and experimental group rat back skin in animal experiments is provided for the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application.

[0031] Embodiment 1

[0032] A scar prevention dressing shielding wound tension comprises the following components by weight parts: sodium carboxymethyl cellulose 2-5 parts, modified hydroxypropyl methyl cellulose 2-5 parts, acrylic acid 20-50 parts, ammonium persulfate 0.5-5 parts.

[0033] In the present application, a method for preparing a scar prevention dressing shielding wound tension comprises the following steps:

[0034] Step 1: a certain amount of hydroxypropyl methyl cellulose is dissolved in a 1M sodium hydroxide solution, then 2 mol of bromine propylene is added, stirred at room temperature for 24 hours, neutralized with a hydrochloric acid solution, and finally purified by dialysis, freeze-dried to obtain modified hydroxypropyl methyl cellulose for standby;

[0035] Step 2: the weight parts of acrylic acid are added to a mixed solvent of sodium hydroxide aqueous solution and dimethyl sulfoxide, mixed uniformly, then the weight parts of modified hydroxypropyl methyl cellulose and sodium carboxymethyl cellulose are added, followed by the addition of the weight parts of ammonium persulfate, and the mixed solution is shaken and dispersed, then poured into a mold and placed in an oven at 60 degrees Celsius for 10-30 minutes to form a gel, the parts of sodium carboxymethyl cellulose and modified hydroxypropyl methyl cellulose need to be prepared into an equivalent aqueous solution, and the acrylic acid mixed solvent is added in the form of an aqueous solution; and the dimethyl sulfoxide solvent needs to be added to the acrylic acid solution before adding the sodium carboxymethyl cellulose and modified hydroxypropyl methyl cellulose solution;

[0036] Step 3: after the gel is taken off from the template, it is soaked in physiological saline to replace the dimethyl sulfoxide solvent in the gel, and the gel preparation is successful, which needs to be soaked in physiological saline for about 24 hours, and the physiological saline needs to be replaced every 6 hours to accelerate the replacement of dimethyl sulfoxide molecules;

[0037] Step 4: before use, it needs to be sterilized, the sterilization method is: first soaked in an alcohol solution with a concentration of 75% for 10 minutes, then washed with deionized water for 3-5 times, finally sterilized and killed by ultraviolet light for 4 hours and standby.

[0038] In the present application, the hydrogel dressing patch has skin tissue adhesion performance, which can firmly adhere to the skin surface and will not leave residues and damage the integrity of the skin when separated from the skin.

[0039] In this embodiment, the hydrogel dressing has a body temperature responsive shrinkable property, and still has a skin adherable property while shrinking. The hydrogel dressing shrinks in response to body temperature and adheres to the wound edge to gather it to the central area of the wound bed, thereby reducing the stress concentration around the wound edge and balancing the wound tension.

[0040] In this embodiment, the dressing is used to repair full-thickness skin injury in an animal model. After 6 weeks of treatment, it is found that the experimental group treated with the dressing has a significant effect of reducing skin scar compared with the control group.

[0041] In this embodiment, the force generated by the shrinkage of the dressing intervenes in the healing process of the wound. Histopathological analysis and tissue immunochemical analysis show that the dressing inhibits the activation of fibroblasts and mechanical transduction to some extent, which is of great significance in preventing the formation of scar tissue.

[0042] Embodiment 2:

[0043] It has the implementation content of the above-mentioned embodiments, wherein for the specific implementation of the above-mentioned embodiments, please refer to the above description, and the embodiment herein will not be repeated in detail; and in the embodiment of the present application, the difference from the above-mentioned embodiments is that:

[0044] An anti-scar dressing for shielding wound tension, comprising the following components by weight: 3 parts of modified hydroxypropyl methylcellulose, 30 parts of acrylic acid, and 1 part of ammonium persulfate.

[0045] The method for preparing the wound tension shielding dressing using the above-mentioned raw materials comprises the following steps:

[0046] Step 1: Dissolve 4 g of hydroxypropyl methylcellulose in 200 mL of 1M sodium hydroxide solution, then add 2 mol of bromine propylene, stir at room temperature for 24 hours, neutralize with 1M hydrochloric acid solution, purify by dialysis, and freeze-dry to obtain modified hydroxypropyl methylcellulose for standby.

[0047] Step 2: Add the weight parts of acrylic acid to a mixed solvent of aqueous sodium hydroxide and dimethyl sulfoxide, then dissolve the modified hydroxypropyl methylcellulose in the aqueous solution, and add the weight parts of modified hydroxypropyl methylcellulose solution to the above acrylic acid solution. Next, mix it evenly and add the weight parts of ammonium persulfate. After the ammonium persulfate is completely dissolved and dispersed by oscillation, pour the mixture into a mold, and place it in a 60°C oven for 20 minutes.

[0048] Step 3: After the gel is taken out of the mold, it is soaked in physiological saline for 24 hours, and the physiological saline is replaced every 6 hours to replace the dimethyl sulfoxide solvent in the gel.

[0049] Step 4: The method of sterilization treatment is as follows: first, soak in 75% alcohol solution for 10 minutes, then rinse with deionized water for 3-5 times, and finally sterilize with ultraviolet light for 4 hours before use.

[0050] Example 3

[0051] It has the implementation content of the above-mentioned examples, wherein for the specific implementation of the above-mentioned examples, refer to the above description, and the examples herein are not repeated in detail; and in the examples of the present application, the difference from the above-mentioned examples is that:

[0052] A wound tension shielding hydrogel dressing, comprising the following components by weight parts: sodium carboxymethyl cellulose 2 parts, modified hydroxypropyl methyl cellulose 5 parts, acrylic acid 20 parts, ammonium persulfate 5 parts

[0053] Example 4

[0054] It has the implementation content of the above-mentioned examples, wherein for the specific implementation of the above-mentioned examples, refer to the above description, and the examples herein are not repeated in detail; and in the examples of the present application, the difference from the above-mentioned examples is that:

[0055] A wound tension shielding hydrogel dressing, comprising the following components by weight parts: sodium carboxymethyl cellulose 5 parts, modified hydroxypropyl methyl cellulose 2 parts, acrylic acid 50 parts, ammonium persulfate 0.5 parts

[0056] Example 5

[0057] It has the implementation content of the above-mentioned examples, wherein for the specific implementation of the above-mentioned examples, refer to the above description, and the examples herein are not repeated in detail; and in the examples of the present application, the difference from the above-mentioned examples is that:

[0058] A wound tension shielding hydrogel dressing, comprising the following components by weight parts: sodium carboxymethyl cellulose 2 parts, acrylic acid 30 parts, ammonium persulfate 2 parts.

[0059] To study the performance and efficacy of a dressing made in Example 1, the following experiments were conducted:

[0060] 1. Evaluate the performance of the dressing in terms of temperature response shrinkable and skin tissue adherable

[0061] Firstly, the mold was used to prepare the gel dressing into a cylindrical gel block with a diameter of 15 mm and a thickness of 3 mm, which was placed in a glass culture dish, and then the glass culture dish was placed in a 37℃ water bath to simulate the temperature of human skin. And at different time points, the digital camera was used to take pictures to record the bottom area of the hydrogel block. ImageJ image processing software was used to calculate the bottom area of the hydrogel block at different time points. According to the formula: gel shrinkage rate = [(A0-A1) / A0]x100%, the gel shrinkage rate at different time points was calculated (the bottom areas of the gel at different time points were recorded as A0, A1, A2, A3……respectively), and the results are shown in Figure 1 The adhesion performance of the hydrogel was quantitatively analyzed by lap shear test using a pig skin model to measure the adhesion force of the hydrogel on the skin surface. The lap area between the pig skin and the hydrogel was pre-set to 100mm 2 , and the test rate of the sample was pre-set to 10mm / min, and the results are shown in Figure 2 .

[0062] 2. Dressing repair of full-thickness skin injury animal model experiment

[0063] Firstly, two circular full-thickness skin excision wounds with a diameter of 10 mm were made on the back skin of the rats, and the distance between the two wounds was greater than 20 mm. After the animal model was successfully constructed, the experimental group was treated with hydrogel dressing, and the control group was not treated. At the 6th week, the colorimeter and the universal mechanical tester were used to test the color of the skin and the strength of the new skin tissue, and the results are shown in Figure 3 . At the 6th week, the scar situation at the wound site was recorded by taking pictures, and the results are shown in Figure 4 .

[0064] 3. Effect of dressing treatment on scar formation of skin

[0065] The tissue was immersed in 10% formalin for one week for fixation, dehydrated in ethanol (70%, 90%, 95% and 100%), removed in xylene and embedded in paraffin, and 4-6μm thick sections were made with a rotary microtome, stained with hematoxylin and eosin (H&E) to observe the tissue repair; in addition, further analysis of collagen deposition and distribution and proportion of type I and type III collagen was carried out by Masson and Sirius red staining. The skin wound is stimulated by mechanical force, which activates the inflammatory pathway by adhering to the cytoplasmic kinase (FAK) through connecting the mechanical stress from the extracellular matrix to the cytoplasm, thereby promoting the transmission of cell signals. Fibroblasts are recruited to the wound through inflammatory signals, at which time the fibroblast-derived fibrosis-promoting cytokine (TGF-β1) promotes the proliferation of fibroblasts, exacerbating fibrosis and collagen deposition.

[0066] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A scar-resistant dressing that shields wound tension, characterized in that, It includes the following components by weight: 2-5 parts sodium carboxymethyl cellulose, 2-5 parts carbon-carbon double bond modified hydroxypropyl methyl cellulose, 20-50 parts acrylic acid, and 0.5-5 parts ammonium persulfate; The preparation method of the anti-scar dressing includes the following steps: Step 1: Dissolve a certain amount of hydroxypropyl methylcellulose in a 1M sodium hydroxide solution, then add 2 mol of bromopropene, stir at room temperature for 24 hours, neutralize with hydrochloric acid solution, and finally purify by dialysis and freeze-dry to obtain carbon-carbon double bond modified hydroxypropyl methylcellulose for later use. Step 2: Add the acrylic acid of the specified weight to a mixture of sodium hydroxide aqueous solution and dimethyl sulfoxide solvent and mix evenly. Then add the carbon-carbon double bond modified hydroxypropyl methylcellulose and sodium carboxymethyl cellulose of the specified weight. Then add the ammonium persulfate of the specified weight, and after shaking and dispersing the mixture, pour it into a mold and place it in an oven at 60 degrees Celsius to react for 10-30 minutes to form a gel. Step 3: After removing the gel from the template, soak it in physiological saline to displace the dimethyl sulfoxide solvent in the gel; Step 4: Disinfection is required before use; In step 2, the amounts of sodium carboxymethyl cellulose and carbon-carbon double-bond modified hydroxypropyl methylcellulose need to be prepared into equivalent aqueous solutions and added to the acrylic acid mixed solvent in the form of aqueous solutions. Furthermore, the sodium carboxymethyl cellulose and carbon-carbon double-bond modified hydroxypropyl methylcellulose solution needs to be added to the acrylic acid solution after dimethyl sulfoxide solvent has been added. In step 3, after successful gel preparation, the soaking time with physiological saline is approximately 24 hours, and the physiological saline needs to be replaced every 6 hours to accelerate the replacement of dimethyl sulfoxide solvent molecules. In step 4, the disinfection method is as follows: first soak in a 75% alcohol solution for 10 minutes, then rinse with deionized water 3-5 times, and finally disinfect with ultraviolet light for 4 hours before use.

2. The anti-scarring dressing for shielding wound tension according to claim 1, characterized in that, It includes the following components by weight: 2 parts sodium carboxymethyl cellulose, 3 parts carbon-carbon double bond modified hydroxypropyl methyl cellulose, 30 parts acrylic acid, and 1 part ammonium persulfate.

3. The anti-scarring dressing for shielding wound tension according to claim 1, characterized in that, It includes the following components by weight: 2 parts sodium carboxymethyl cellulose, 5 parts carbon-carbon double bond modified hydroxypropyl methyl cellulose, 20 parts acrylic acid, and 5 parts ammonium persulfate.

4. The anti-scarring dressing for shielding wound tension according to claim 1, characterized in that, It includes the following components by weight: 5 parts sodium carboxymethyl cellulose, 2 parts carbon-carbon double bond modified hydroxypropyl methyl cellulose, 50 parts acrylic acid, and 0.5 parts ammonium persulfate.

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