Absorbable novel wound dressing and preparation method thereof

Abstract

The invention discloses a novel absorbable wound dressing and a preparation method thereof. The novel absorbable wound dressing is prepared from collagen, acellular extracellular matrix powder and purified water. The novel absorbable wound dressing with activity is prepared by compounding the acellular extracellular matrix powder and the collagen, the acellular extracellular matrix powder contains various growth factors, various growth factors do not need to be additionally added, and compared with a common collagen sponge dressing, the novel absorbable wound dressing has the better effect of promoting wound healing, and the wound healing effect is better. Meanwhile, collagen is directly adopted as a hemostasis carrier of the acellular extracellular matrix powder and is subjected to freeze-drying forming, seepage of the wound surface can be absorbed, the mechanical strength of the acellular extracellular matrix powder can be enhanced, and therefore the wound can be rapidly and effectively bonded, and the hemostasis effect is achieved. The safety is high; and the manufacturing method is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and more particularly, to a novel absorbable wound dressing and a preparation method thereof. Background Art

[0002] After human skin is damaged, it is vulnerable to bacterial and fungal infections, and in severe cases, it may cause various complications and endanger life. Medical wound covering materials can temporarily replace the function of the skin barrier, protect the wound surface and maintain the physiological process of its healing, and are an important and effective means for wound treatment. Early covering materials mainly include gauze, cotton pads, bandages, etc., that is, traditional dressings. Although such materials can provide certain wound surface protection, they lack the ability to promote wound repair, and also have defects such as insufficient moisturization, easy secondary injury during replacement, easy infection, and no positive effect on wound healing. This has also led to the emergence of various novel dressings.

[0003] Collagen, as a natural polymer substance, has a unique triple helix structure, strong physiological activity, can participate in cell proliferation, growth, differentiation and migration, endow tissues such as skin with certain mechanical strength, and has good biocompatibility and biodegradability. Therefore, collagen has a wide range of applications in the fields of medicine and health such as burns, wounds, corneal diseases, health care, beauty, orthopedics, hard tissue repair, wound hemostasis, drug delivery, and sustained release technology.

[0004] The extracellular matrix is recognized as the "soil" for cell growth, including collagen, elastin, proteoglycans and other nutrients. By simulating the natural microenvironment of cells, the extracellular matrix can regulate cell functions, promote the regeneration process of damaged tissues, and play an important role in the tissue reconstruction process. There is no report on the application of extracellular matrix powder in wound repair and traumatic hemostasis. The main problems are as follows: Although the extracellular matrix powder can better guide wound repair, its mechanical strength is low, it is difficult to quickly and effectively bond the wound, and it cannot achieve good hemostasis and wound healing effects. Its adhesion to wet tissues is poor, and it is difficult to be used for massive bleeding or internal organ bleeding.

[0005] In the prior art, a patent document with the application number 202110007144.X discloses a cross-linked composite collagen support and its preparation method, which is prepared by cross-linking porcine acellular dermal extracellular matrix with bovine type I collagen. It has problems such as lack of growth factors and insufficient activity. At the same time, the introduction of cross-linking agents may have potential toxic and side effects on the human body. A patent document with the application number 202011536197.2 discloses a tissue-specific wound dressing and its preparation method and application. It is prepared from extracellular matrix and gel-forming materials. Its extracellular matrix component is in liquid state, requires low-temperature storage, and is mixed with gel-forming materials before use. The dressing has high requirements for storage conditions, and the steps are cumbersome and inconvenient to operate during use. A patent document with the application number 202211553924.5 discloses a freeze-dried absorbable collagen-based medical dressing and its preparation method, which is composed of collagen, glycerol, trehalose, mannitol, pullulan polysaccharide, and purified water. Its composition is complex, multiple excipients are added, and it lacks bioactive factors. Substantially, it is still a pure physical scaffold and still belongs to a passive wound dressing. Summary of the Invention

[0006] To solve at least one of the above technical problems, the present invention provides an absorbable novel wound dressing. For this purpose, the present invention also provides a preparation method of the above absorbable novel wound dressing.

[0007] In the first aspect of the present invention, there is provided an absorbable novel wound dressing, which is composed of collagen, acellular extracellular matrix powder, and the rest is purified water.

[0008] In some embodiments, the mass percentage of collagen is 0.25%-2%; the mass percentage of acellular extracellular matrix powder is 0.1%-1%.

[0009] In some embodiments, the mass percentage of collagen is 0.5%-2%; the mass percentage of acellular extracellular matrix powder is 0.1%-0.5%.

[0010] In some embodiments, the collagen is bovine type I collagen, and the acellular extracellular matrix powder is acellular porcine small intestinal submucosa matrix powder (acellular SIS matrix powder).

[0011] In the second aspect of the present invention, there is provided a preparation method of an absorbable novel wound dressing, including the following steps:

[0012] S1: Take purified water to prepare an organic acid solution, add collagen to the organic acid solution, and stir evenly to obtain a collagen colloidal solution;

[0013] S2: Weigh acellular extracellular matrix powder, add it to the collagen colloidal solution, and stir evenly to obtain the dressing stock solution;

[0014] S3: Pour the stock solution of the dressing into a forming mold, transfer it to a freeze dryer for freeze-drying and forming, demold, package, and obtain the product after sterilization treatment.

[0015] In some embodiments, the mass percentage of collagen is 0.5%-2%; the mass percentage of acellular extracellular matrix powder is 0.1%-0.5%, and the concentration of the organic acid solution is 0.1%.

[0016] In some embodiments, the collagen is bovine type I collagen (commercially available), the acellular extracellular matrix powder is acellular SIS matrix powder, and the organic acid solution is acetic acid solution.

[0017] In some embodiments, in steps S1 and S2, the stirring speed is 100-1000 r / min.

[0018] In some embodiments, in step S3, the freeze-drying process is as follows: maintain at -45°C for 1-3 h, rise from -45°C to -25°C and maintain for 3-6 h, rise from -25°C to -5°C and maintain for 1-3 h, rise from -5°C to 10°C and maintain for 3-5 h, rise from 10°C to 30°C and maintain for 2-4 h.

[0019] In some embodiments, in step S3, the sterilization method is cobalt-60 irradiation sterilization, the irradiation dose is 20-40 KGY, the thickness of the stock solution of the dressing poured into the forming mold is 0.3-1 cm, and the forming mold is a stainless-steel square mold.

[0020] The acellular SIS matrix powder of the present invention is the acellular SIS matrix powder obtained by treating porcine small intestinal submucosa by a conventional method.

[0021] The collagen sponge dressing in the present invention is the collagen sponge dressing obtained by treating bovine type I collagen (commercially available) by a conventional method.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The present invention prepares an active absorbable novel wound dressing by compounding acellular extracellular matrix powder and collagen. The acellular extracellular matrix powder is preferably acellular SIS matrix powder, which itself contains a variety of growth factors and does not require additional addition of various growth factors. Compared with ordinary collagen sponge dressings, it can promote wound healing more quickly; at the same time, directly use collagen as the hemostatic carrier of acellular SIS matrix powder, and freeze-dry and form it. It can not only absorb the exudate of the wound surface, but also enhance the mechanical strength of acellular SIS matrix powder, so as to quickly and effectively bond the wound and achieve the hemostatic effect. The present invention relies on the adhesiveness of collagen, does not require the addition of other cross-linking agents, has a simple composition, high safety and a simple production method. Detailed embodiments

[0024] In order to make the technical means, creative features, achieved purposes and effects of the invention easily understood, the present invention will be further described in combination with specific embodiments. However, the present invention is not limited to the following implemented cases.

[0025] Example 1

[0026] A novel absorbable wound dressing is composed of bovine type I collagen (commercially available) with a mass percentage of 1%, acellular SIS matrix powder with a mass percentage of 0.1%, and the rest is purified water.

[0027] The preparation method of the above-mentioned novel absorbable wound dressing includes the following steps:

[0028] S1: According to the above ratio, first, based on purified water, prepare an acetic acid solution with a concentration of 0.1%. Slowly add bovine type I collagen and fully stir at a stirring speed of 150 r / min to ensure its complete dissolution, and finally obtain a uniform collagen colloidal solution.

[0029] S2: Weigh acellular SIS matrix powder with a mass percentage of 0.1% and add it to the collagen colloidal solution, and stir evenly to obtain the dressing stock solution.

[0030] S3: Pour the dressing stock solution into a stainless-steel square mold. The thickness of the dressing stock solution poured into the mold is 0.6 cm, and then transfer it to a freeze dryer for freeze-drying and forming. Specifically: maintain at -45°C for 2 h, rise from -45°C to -25°C and maintain for 5 h, rise from -25°C to -5°C and maintain for 2 h, rise from -5°C to 10°C and maintain for 4 h, rise from 10°C to 30°C and maintain for 3 h, demold, package, and perform sterilization treatment by cobalt-60 irradiation with an irradiation dose of 25 KGY to obtain the product.

[0031] Example 2

[0032] The acellular SIS matrix powder in the present invention is prepared by the following method:

[0033] 1) Pretreatment: Take porcine jejunum, remove the mucosal layer, serosal layer and muscular layer to obtain porcine small intestinal submucosa (SIS).

[0034] 2) Inactivation: Take porcine small intestinal submucosa, and use a mixed aqueous solution of peracetic acid with a concentration of 0.3% - 3% and ethanol with a concentration of 10% - 30%. Under ultrasonic conditions, treat at room temperature for 60 - 180 min for inactivation.

[0035] 3) Decellularization: The inactivated SIS was placed in a 5% sodium chloride hypertonic solution and treated under ultrasonic conditions for 30-90 minutes, then washed with PBS solution three times; a mixed aqueous solution containing 0.02%-0.1% trypsin and 0.01%-0.05% EDTA was used for ultrasonic treatment for 30-90 minutes, and a 10mM-40mM NaOH aqueous solution was used for ultrasonic treatment for 10-60 minutes; then, the SIS was washed with water under ultrasonic conditions until it became neutral;

[0036] 4) Freeze-drying: fix the decellularized SIS sheet on a mold and freeze-dry;

[0037] 5) Crushing: the freeze-dried SIS tablets are frozen with liquid nitrogen and then crushed;

[0038] 6) Sieving: Use a 30-mesh (pore size 550 μm) stainless steel sieve for sieving. The powder passing through the sieve is the desired SIS decellularized matrix powder.

[0039] Example 3

[0040] Collagen sponge is prepared by:

[0041] 1) Based on purified water, prepare a 0.1% acetic acid solution, slowly add bovine type I collagen (commercially available), the collagen mass percentage is 1%, stir at a stirring speed of 150 r / min to ensure that it is completely dissolved, and finally obtain a uniform collagen gel solution;

[0042] 2) Pour the collagen solution into a stainless steel square mold with a thickness of 0.6 cm, transfer it into a freeze dryer and freeze-dry it to form, specifically: keep it at -45°C for 2 hours, increase the temperature from -45°C to -25°C for 5 hours, increase the temperature from -25°C to -5°C for 2 hours, increase the temperature from -5°C to 10°C for 4 hours, increase the temperature from 10°C to 30°C for 3 hours, demold, package, and sterilize it by cobalt 60 irradiation with an irradiation dose of 25KGY to obtain the product.

[0043] Example 4

[0044] In order to verify the content of key active factors and cell growth factors in the present invention to prove that the technical solution has the technical effect of promoting wound healing, we used a commercial ELISA kit (commercially available) to determine the content of key active factors and cell growth factors in the decellularized SIS matrix powder. All operation steps strictly followed the instructions of the kit. The test results are summarized in Table 1.

[0045] Table 1

[0046]

[0047] The data in Table 1 show that the acellular SIS matrix powder is rich in active factors and cell growth factors. These components can significantly promote cell proliferation and differentiation, thereby accelerating the vascularization process and having a significant promoting effect on wound repair.

[0048] Example 5

[0049] To verify the technical effects of the present invention, the following experiments were conducted:

[0050] (1) Hemostatic performance test: Nine rats with a body weight of 180 g ± 20 were used as test subjects and divided into 3 groups, namely the experimental group, control group A, and control group B. In the experimental group, the absorbable novel wound dressing in Example 1 was used; in control group A, the acellular SIS matrix powder in Example 2 was used as the wound dressing; in control group B, the collagen sponge in Example 3 was used as the wound dressing. There were 3 rats in each group. The rats were anesthetized by intraperitoneal injection of 2% sodium pentobarbital at a dose of 45 mg / Kg body weight, fixed, the hair on the back with an area of 2 cm * 2 cm was shaved and disinfected, and a wound with a perimeter of 1 cm and a depth of 2 mm was made with a disinfected blade at the hair-removed area. The dressings prepared above were used to apply to the wounds of the three groups of rats. The dressing sizes of Example 1 and Example 3 were both 2 cm * 2 cm, and the dressing in Example 2 had the same mass as that in Example 1. The hemostasis time was recorded.

[0051] (2) Wound surface healing test: The rats in each group after the operation in (1) were re-dressed with the corresponding wound dressings of the same size and bandaged with sterile gauze, raised normally, and the wound surface healing condition was observed every day. The wound surface healing time was recorded. The test results are shown in Table 2.

[0052] Table 2

[0053]

[0054] The data in Table 2 show that the hemostasis time of the absorbable novel wound dressing of the present invention is only within 3.7 minutes, and the wound healing time does not exceed 6 days. Its effect is significantly better than that of the acellular SIS matrix powder group and the collagen sponge group. Thus, it can be seen that using the acellular SIS matrix powder alone as a dressing and using the collagen sponge alone as a dressing have relatively low effects on wound healing. The technical solution provided by the present invention combines the two, and their effects are mutually additive. The acellular SIS matrix powder makes up for the lack of growth factors in collagen, and collagen makes up for the low mechanical strength of acellular materials.

[0055] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in this technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art shall fall within the protection scope determined by the claims.

Claims

1. A novel absorbable wound dressing, characterized in that: It is composed of collagen, decellularized extracellular matrix powder and purified water.

2. The novel absorbable wound dressing according to claim 1, characterized in that: The mass percentage of the collagen is 0.25%-2%; the mass percentage of the decellularized extracellular matrix powder is 0.1%-1%.

3. The novel absorbable wound dressing according to claim 2, characterized in that: The mass percentage of the collagen is 0.5%-2%; the mass percentage of the decellularized extracellular matrix powder is 0.1%-0.5%.

4. The novel absorbable wound dressing according to claim 1, characterized in that: The collagen is bovine type I collagen, and the decellularized extracellular matrix powder is decellularized porcine small intestinal submucosal matrix powder.

5. The method for preparing a novel absorbable wound dressing according to claim 1, characterized in that: The steps include: S1: preparing an organic acid solution with the purified water, adding the collagen to the organic acid solution, and stirring evenly to obtain a collagen gel solution; S2: Weigh the decellularized extracellular matrix powder, add it to the collagen gel solution, and stir evenly to obtain a dressing stock solution; S3: pouring the dressing stock solution into a molding mold, transferring the dressing into a freeze dryer for freeze drying, demoulding, packaging, and sterilizing to obtain the product.

6. The method for preparing a novel absorbable wound dressing according to claim 5, characterized in that: The mass percentage of the collagen is 0.5%-2%; the mass percentage of the decellularized extracellular matrix powder is 0.1%-0.5%, and the concentration of the organic acid solution is 0.1%.

7. The method for preparing a novel absorbable wound dressing according to claim 6, characterized in that: The collagen is bovine type I collagen, the decellularized extracellular matrix powder is decellularized porcine small intestinal submucosal matrix powder, and the organic acid solution is acetic acid solution.

8. The method for preparing a novel absorbable wound dressing according to claim 5, characterized in that: In steps S1 and S2, the stirring speed is 100-1000 r / min.

9. The method for preparing a novel absorbable wound dressing according to claim 5, characterized in that: In step S3, the freeze-drying process is: keep at -45°C for 1-3 hours, increase from -45°C to -25°C for 3-6 hours, increase from -25°C to -5°C for 1-3 hours, increase from -5°C to 10°C for 3-5 hours, and increase from 10°C to 30°C for 2-4 hours.

10. The method for preparing a novel absorbable wound dressing according to claim 5, characterized in that: In step S3, the sterilization method is cobalt 60 irradiation sterilization, the irradiation dose is 20-40KGY, the thickness of the dressing stock solution poured into the forming mold is 0.3-1 cm, and the forming mold is a stainless steel square mold.

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