Waterproof and breathable wound protecting dressing with antibacterial, hemostatic and healing promoting functions and preparation method of waterproof and breathable wound protecting dressing

Abstract

The invention discloses a waterproof breathable wound-protecting dressing with antibacterial, hemostatic and healing-promoting functions and a preparation method of the waterproof breathable wound-protecting dressing. The dressing is prepared from the following raw materials: 2%-5% of polyvinyl butyral, 0.4%-0.8% of polyvinylpyrrolidone, 0.2%-0.5% of glycerol and ethanol. After the product is sprayed to the skin surface, a thin film can be rapidly formed, the waterproof effect is achieved, and meanwhile good air permeability is achieved. The product has good hemostatic, antibacterial and healing-promoting effects, and has good prevention and treatment effects on difficult-to-heal wounds (such as scalded and infected wounds).

Description

Technical Field

[0001] The invention belongs to the technical field of medical dressings, and particularly relates to a waterproof and breathable wound dressing with antibacterial, hemostatic and healing effects and a preparation method thereof. Background Art

[0002] In today's medical field, wound care is an important link. There are many types of wounds, including surgical wounds, trauma, diabetic foot, etc., and wound healing is crucial to the patient's quality of life and clinical treatment. There are many types of wound dressings, including gauze, tape, various types of bandages and liquid dressings. Among them, liquid dressings, as a new type of wound treatment material, have played an important role in providing a protective barrier for wounds and promoting healing, and have received widespread attention in recent years. However, the existing liquid dressings still have deficiencies in some key properties. For example, most products have problems such as non-persistent antibacterial effects, limited hemostatic effects, slow wound healing (especially for some difficult-to-heal wounds), and poor adaptability. In addition, although some existing dressings can achieve good healing effects, their complex ingredients, high content, and high raw material prices lead to high production costs, which limit their promotion in the market. Therefore, it is necessary to develop a new type of liquid dressing to solve the above problems and meet the market demand and high standards for wound care in modern medicine. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a waterproof and breathable wound dressing with antibacterial, hemostatic and healing effects and a preparation method thereof.

[0004] The technical solution of the present invention is as follows:

[0005] A waterproof and breathable wound dressing comprises the following raw materials by mass percentage: 2% to 5% polyvinyl butyral, 0.4% to 0.8% polyvinyl pyrrolidone, 0.2% to 0.5% glycerol and ethanol.

[0006] Polyvinyl butyral is a product of condensation of polyvinyl alcohol and butyraldehyde under acid catalysis. Polyvinyl pyrrolidone is a high molecular compound generated by polymerization of ethylene and pyrrolidone. It has the same pyrrole ring as polypyrrole and belongs to a N-containing compound with a pyrrole type structure. The present invention intends to improve the performance of the dressing by cross-linking polyvinyl butyral and polyvinyl pyrrolidone. The composition and preparation method of the blend of polyvinyl butyral and polyvinyl pyrrolidone are optimized, thereby effectively improving the antibacterial and healing effects of the product. Glycerin has a moisturizing effect and improves the moisturizing and healing ability of the product.

[0007] Furthermore, the waterproof and breathable wound dressing comprises, by weight percentage, 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol and ethanol.

[0008] Furthermore, the number average molecular weight of the polyvinyl alcohol pyrrolidone is 10000 to 40000. In the following examples, polyvinyl alcohol pyrrolidone with a number average molecular weight of 10000 is selected.

[0009] Furthermore, the waterproof and breathable wound dressing comprises, by mass percentage, 2% to 5% polyvinyl butyral, 0.4% to 0.8% polyvinyl pyrrolidone, 0.2% to 0.5% glycerol, 0.2% to 0.5% tannic acid and ethanol.

[0010] Furthermore, the waterproof and breathable wound dressing comprises, by mass percentage, 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and ethanol.

[0011] On the other hand, the present invention also provides a method for preparing the waterproof and breathable wound dressing, comprising the following steps:

[0012] (1) Take polyvinyl butyral and polyvinyl pyrrolidone, dissolve them in ethanol, and stir them evenly;

[0013] (2) standing at -25 to -5°C for 8 to 10 hours, and then quickly standing at 22 to 25°C for 4 to 6 hours, and performing a temperature change cycle at least 3 times; the temperature change cycle allows the polyvinyl butyral and polyvinyl pyrrolidone to form intermolecular and intramolecular hydrogen bonds, thereby generating physical crosslinks;

[0014] (3) Add glycerol and mix well.

[0015] Furthermore, the preparation method comprises the following steps:

[0016] (1) Take polyvinyl butyral and polyvinyl pyrrolidone, dissolve them in ethanol, and stir them evenly;

[0017] (2) Place at -25 to -20°C for 8 to 10 hours, then quickly place at 22 to 25°C for 4 to 6 hours, repeating this process at least three times;

[0018] (3) Add glycerol and mix well.

[0019] Furthermore, the preparation method comprises the following steps:

[0020] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0021] (2) Place at -25 to -5°C for 8 to 10 hours, then quickly place at 25°C for 4 to 6 hours, repeating this process at least three times;

[0022] (3) Add glycerol and mix well.

[0023] Furthermore, the preparation method comprises the following steps:

[0024] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0025] (2) Place at -25 to -20°C for 8 to 10 hours, then quickly place at 22 to 25°C for 4 to 6 hours, repeating this process at least three times;

[0026] (3) Add glycerol and mix well.

[0027] Beneficial effects of the present invention:

[0028] The product of the present invention has simple ingredients, and the amount of added functional ingredients is lower than that of the prior art, which is beneficial to controlling production costs.

[0029] The product of the present invention can quickly form a thin film after being sprayed on the skin surface, which has a waterproof effect and good air permeability. The product has good hemostatic, antibacterial and healing effects, is conducive to the healing of wounds, and has a good preventive and therapeutic effect on difficult-to-heal wounds (such as burns and wounds after infection).

[0030] The present invention further improves the preparation method of the dressing, and through the cyclic temperature change treatment, polyvinyl butyral, polyvinyl pyrrolidone and tannic acid form a certain physical crosslinking. In addition, the present invention uses ethanol as a solvent, and the presence of ethanol hinders the strong hydrogen bond crosslinking of polyvinyl butyral, polyvinyl pyrrolidone and tannic acid, avoids the gel-like precipitation produced in the co-dissolution process, and maintains a stable intermediate state between the components. When the dressing is sprayed onto the wound surface, after the ethanol gradually evaporates, polyvinyl butyral, polyvinyl pyrrolidone, and tannic acid are further cross-linked to form a semi-interpenetrating polymer network, complete the phase transition, and quickly form a film on the wound surface, providing a good healing environment for the wound surface, and no additional antibacterial and antibacterial components are required to inhibit the growth and reproduction of harmful microorganisms, promote the growth of fibroblasts and angiogenesis, thereby accelerating wound healing. DETAILED DESCRIPTION

[0031] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0032] Embodiment 1:

[0033] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing-promoting. The dressing is made of 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol and the balance anhydrous ethanol in terms of mass percentage concentration.

[0034] Preparation of dressing:

[0035] (1) Take polyvinyl butyral and polyvinyl pyrrolidone, dissolve them in ethanol, and stir them evenly;

[0036] (2) Place at -25 to -20°C for 10 h, then quickly place at 22 to 25°C for 6 h, and repeat this temperature change cycle 3 times;

[0037] (3) Add glycerol and mix well.

[0038] Embodiment 2:

[0039] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing-promoting. The dressing is made of 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol and the balance of anhydrous ethanol in terms of mass concentration.

[0040] Preparation method of dressing: Mix all raw materials evenly.

[0041] Example 3

[0042] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing. The dressing is made of 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and the balance anhydrous ethanol in terms of mass concentration.

[0043] The preparation method of the dressing comprises the following steps:

[0044] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0045] (2) Place at -25 to -20°C for 10 h, then quickly place at 22 to 25°C for 6 h, and repeat this temperature change cycle 3 times;

[0046] (3) Add glycerol and mix well.

[0047] Example 4

[0048] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing. Its raw materials are: 5% polyvinyl butyral, 0.4% polyvinyl pyrrolidone, 0.2% glycerol, 0.2% tannic acid and the balance anhydrous ethanol in terms of mass concentration.

[0049] The preparation method of the dressing comprises the following steps:

[0050] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0051] (2) Place at -25 to -20°C for 10 h, then quickly place at 22 to 25°C for 6 h, and repeat this temperature change cycle 3 times;

[0052] (3) Add glycerol and mix well.

[0053] Example 5

[0054] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing. Its raw materials are as follows by mass concentration: 2% polyvinyl butyral, 0.8% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and the balance anhydrous ethanol.

[0055] The preparation method of the dressing comprises the following steps:

[0056] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0057] (2) Place at -25 to -20°C for 10 h, then quickly place at 22 to 25°C for 6 h, and repeat this temperature change cycle 3 times;

[0058] (3) Add glycerol and mix well.

[0059] Example 6

[0060] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing. The dressing is made of 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and the balance anhydrous ethanol in terms of mass concentration.

[0061] The preparation method of the dressing comprises the following steps:

[0062] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0063] (2) Place at -25 to -20°C for 8 hours, then quickly place at 22 to 25°C for 4 hours, and repeat this temperature change cycle 3 times;

[0064] (3) Add glycerol and mix well.

[0065] Example 7

[0066] The waterproof and breathable wound dressing has the functions of antibacterial, hemostatic and healing. The dressing is made of 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and the balance anhydrous ethanol in terms of mass concentration.

[0067] The preparation method of the dressing comprises the following steps:

[0068] (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly;

[0069] (2) Place at -10 to -5°C for 8 hours, then quickly place at 22 to 25°C for 4 hours, and repeat this temperature change cycle three times;

[0070] (3) Add glycerol and mix well.

[0071] Comparative Example 1:

[0072] Polyvinyl butyral 12%, glycerol 1.2%, polyvinyl pyrrolidone 1% and the balance anhydrous ethanol.

[0073] Experimental Example 1: Antibacterial and healing-promoting experiments

[0074] SD rats were randomly divided into a control group and an experimental group, with 10 rats in each group. The rats were anesthetized with 2% sodium pentobarbital solution, and the backs were depilated. The rats were disinfected with 70% ethanol by volume. Then, two circular deep second-degree wounds with a diameter of 2.5 cm were permed along the spine with an electric perm device at a temperature of 80°C and an action time of 8 seconds, with a 2-cm interval between the wounds. A methicillin-resistant Staphylococcus aureus liquid (10 4 CFU / mL), and then 300uL of bacterial solution was added to the wound surface to model the wound contamination. No debridement was performed. The wound surface of the experimental group was sprayed with 0.6-0.8ml dressing for 1min and then bandaged with clean medical gauze. The control group 1 was sprayed with anhydrous ethanol and bandaged with clean medical gauze. The control group 2 was sprayed with 0.5wt% tannic acid ethanol solution. Raised in a single cage. The rats were killed after 3 days, the wound was observed, and the wound healing rate was measured and calculated. Wound healing rate (%) = (original wound area - unhealed wound area) / original wound area × 100%. Unhealed wound tissue was taken for quantitative bacterial culture, and the amount of tissue bacteria under the same culture conditions was compared. The experimental results are shown in Table 1.

[0075] Table 1

[0076] Wound healing rate (%) Bacterial load in tissue (cfu / g) Experimental Group 1 - Example 1 47.2±3.1％ <![CDATA[(4.2~4.5)×10 4 ]]> Experimental Group 2 - Example 2 34.5±4.7％ <![CDATA[(8.6~9.0)×10 4 ]]> Experimental Group 3 - Example 3 92.3±1.6％ <![CDATA[(1.2~1.3)×10 2 ]]> Experimental Group 4 - Example 4 77.4±3.3％ <![CDATA[(5.6~6.0)×10 3 ]]> Experimental Group 5 - Example 5 72.6±2.1％ <![CDATA[(4.1~4.5)×10 3 ]]> Experimental Group 6 - Example 6 77.9±0.9％ <![CDATA[(4.0~4.6)×10 3 ]]> Experimental Group 7-Example 7 88.8±1.7％ <![CDATA[(1.5~1.8)×10 2 ]]> Experimental Group 8-Comparative Example 1 33.5±1.8％ <![CDATA[(2.4~2.9)×10 5 ]]> Control group 1 5.8±0.3％ <![CDATA[(6.7~6.9)×10 6 ]]> Control group 2 12.5±0.7％ <![CDATA[(5.5~5.9)×10 6 ]]>

[0077] Compared with Example 2, Example 1 has a higher wound healing rate and a lower tissue bacterial content (p < 0.05), and has a better healing effect on the wound of the second-degree burn infection model. The reason may be that polyvinyl butyral and polyvinyl pyrrolidone form intermolecular and intramolecular hydrogen bonds through temperature cycling, resulting in physical crosslinking. When the dressing is sprayed onto the wound surface, as the ethanol evaporates, the dressing quickly forms a film on the wound, providing a good antibacterial environment and healing environment for the wound. By comparing the control group 2, experimental group 1 and experimental group 3, it can be seen that the composite crosslinking of polyvinyl butyral, polyvinyl pyrrolidone and tannic acid can significantly improve the healing effect of the wound infected with methicillin-resistant Staphylococcus aureus and reduce the tissue bacterial content. Compared with Examples 4 and 5, Example 3 is the optimal ratio.

[0078] Experimental Example 2: Hemostasis Experiment

[0079] New Zealand white rabbits were selected and anesthetized with 2% sodium pentobarbital solution. The test site was routinely depilated and the skin was disinfected with a volume fraction of 75% ethanol solution. A circular wound with a diameter of 1.5 cm was cut symmetrically on both sides of the spine of each rabbit, deep to the full layer of the skin, and then the larger blood vessels in the subcutaneous tissue layer were avoided and cut to the fascia layer. Ensure that all wounds ooze blood. The wounds on both sides were symmetrically treated with dressings (sprayed 0.6-0.8 ml) + sterile gauze (wipe the oozing blood) and sterile gauze (wipe the oozing blood), respectively, and observed once every 30 seconds until the bleeding stopped. The mass of the gauze before and after hemostasis was accurately weighed to calculate the amount of bleeding. Bleeding volume (mL) = [mass of gauze wiping blood after hemostasis-mass of dry gauze before hemostasis] / blood density. The experimental results are shown in Table 2.

[0080] Table 2

[0081] Amount of bleeding (mL) Experimental Group 1 - Example 3 0.11±0.02 Experimental Group 2-Comparative Example 1 0.18±0.03 Sterile gauze set 0.23±0.06

[0082] The results showed that the amount of bleeding in the experimental group was lower than that in the sterile gauze group (P < 0.05), indicating that the dressing in the experimental group was significantly better than the sterile gauze in hemostasis. The hemostasis effect of the dressing in experimental group 1 was significantly better than that in experimental group 2 (P < 0.05).

[0083] The above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.

Claims

1. A waterproof and breathable wound dressing, characterized in that: Calculated by mass percentage, the raw materials include: 2% to 5% polyvinyl butyral, 0.4% to 0.8% polyvinyl pyrrolidone, 0.2% to 0.5% glycerol and ethanol.

2. The waterproof and breathable wound dressing according to claim 1, characterized in that: The raw materials include, by mass percentage, 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol and ethanol.

3. The waterproof and breathable wound dressing according to claim 1, characterized in that: The number average relative molecular mass of the polyvinyl alcohol pyrrolidone is 10000-40000.

4. The waterproof and breathable wound dressing according to claim 1, characterized in that: The raw materials are as follows, by mass percentage: 2% to 5% polyvinyl butyral, 0.4% to 0.8% polyvinyl pyrrolidone, 0.2% to 0.5% glycerol, 0.2% to 0.5% tannic acid and ethanol.

5. The waterproof and breathable wound dressing according to claim 1, characterized in that: The raw materials are: 3.5% polyvinyl butyral, 0.5% polyvinyl pyrrolidone, 0.5% glycerol, 0.5% tannic acid and ethanol in terms of mass percentage.

6. The method for preparing the waterproof and breathable wound dressing according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Take polyvinyl butyral and polyvinyl pyrrolidone, dissolve them in ethanol, and stir them evenly; (2) Place at -25 to -5°C for 8 to 10 hours, then quickly place at 25°C for 4 to 6 hours, repeating this process at least three times; (3) Add glycerol and mix well.

7. The preparation method according to claim 6, characterized in that: The following steps are involved: (1) Take polyvinyl butyral and polyvinyl pyrrolidone, dissolve them in ethanol, and stir them evenly; (2) Place at -25 to -20°C for 8 to 10 hours, then quickly place at 25°C for 4 to 6 hours, repeating this process at least three times; (3) Add glycerol and mix well.

8. The preparation method according to claims 4 to 5, characterized in that: The following steps are involved: (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly; (2) Place at -25 to -5°C for 8 to 10 hours, then quickly place at 22 to 25°C for 4 to 6 hours, repeating this process at least three times; (3) Add glycerol and mix well.

9. The preparation method according to claim 8, characterized in that: The following steps are involved: (1) dissolving polyvinyl butyral, polyvinyl pyrrolidone and tannic acid in ethanol and stirring evenly; (2) Place at -25 to -20°C for 8 to 10 hours, then quickly place at 22 to 25°C for 4 to 6 hours, repeating this process at least three times; (3) Add glycerol and mix well.

10. Use of the dressing according to any one of claims 1 to 5 or the preparation method according to any one of claims 6 to 9 in preparing a product having antibacterial, hemostatic and healing effects.