Medical recombinant collagen dressing and preparation method thereof

Abstract

The invention discloses a medical recombinant collagen dressing and a preparation method thereof, and the medical recombinant collagen dressing comprises the following components in parts by mass: 5-15 parts of recombinant collagen; 2 to 8 parts of hydroxylated glucuronic acid; 1 to 5 parts of poly gamma-zinc glutamate; 3 to 10 parts of trehalose grafted polylactic acid; 2 to 6 parts of glycerol; 0.5 to 2 parts of vitamin B5; 0.1 to 0.5 part of disodium EDTA (ethylene diamine tetraacetic acid); 50 to 80 parts of purified water; according to the medical recombinant collagen dressing disclosed by the invention, three components including hydroxylated glucuronic acid, poly gamma-zinc glutamate and trehalose grafted polylactic acid are introduced and have a synergistic effect with recombinant collagen; the functions of all the components are complementary, and the problems that an existing dressing is single in function and low in repairing efficiency are effectively solved; the components of the dressing disclosed by the invention have good biocompatibility, are non-irritant, are suitable for repairing various types of wounds, and are wide in clinical application range.

Description

Technical Field

[0001] This invention belongs to the field of medical dressing technology, specifically a medical recombinant collagen dressing and its preparation method. Background Technology

[0002] Medical dressings are medical products used to cover and protect wounds and promote wound healing, playing an important role in clinical diagnosis and treatment. With the development of biomaterials technology, recombinant collagen has been widely used in the preparation of medical dressings due to its good biocompatibility, bioactivity, and degradability.

[0003] In existing technologies, recombinant collagen dressings mostly use recombinant collagen as the core ingredient, supplemented with conventional moisturizers and preservatives. This results in limitations such as single function, limited wound healing promotion efficiency, and poor adaptability to sensitive skin. Furthermore, some dressings suffer from insufficient ingredient stability and easy loss of active ingredients during preparation, making it difficult to meet the repair needs of different types of wounds in clinical practice (such as chronic ulcers, burns, and postoperative wounds).

[0004] To address the aforementioned technical problems, this invention screens and innovatively introduces a variety of functional ingredients to synergistically enhance the effects of recombinant collagen. Simultaneously, it optimizes the preparation process to improve the stability and activity of the dressing's active ingredients, thereby providing a medical recombinant collagen dressing with moisturizing, anti-inflammatory, repair-promoting, and antibacterial functions, along with its preparation method. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention provides a medical recombinant collagen dressing and its preparation method, which effectively solves the problems mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a medical recombinant collagen dressing, comprising the following components in parts by weight: Recombinant collagen: 5-15 parts; Hydroxylated dextranuric acid: 2-8 parts; Poly-γ-glutamic acid zinc: 1-5 parts; Trehalose grafted with polylactic acid: 3-10 parts; Glycerin: 2-6 parts; Vitamin B5: 0.5-2 servings; Disodium EDTA: 0.1-0.5 parts; Purified water: 50-80 parts.

[0007] Preferably, the recombinant collagen is recombinant human type III collagen with a molecular weight of 50-80 kDa and a purity of ≥95%.

[0008] Preferably, the method for preparing the hydroxylated dextranuronic acid is as follows: S1. Take 10-20g of dextran, add 100-200mL of deionized water, stir to dissolve, and obtain a dextran solution; S2. Add 5-10g of sodium bromide to the dextran solution, stir well, and then slowly add 15-25mL of 30% hydrogen peroxide solution. Control the reaction temperature at 35-45℃ and the stirring speed at 100-200r / min. React for 2-4 hours. S3. After the reaction is complete, add 2-5g of sodium hydroxide to the system, adjust the pH to 9-10, then add 8-15g of sodium chloroacetate, heat to 60-70℃, stir at 150-250r / min, and react for 3-5h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 6.5-7.5 with hydrochloric acid, then add 3-5 times the volume of anhydrous ethanol to precipitate, and let it stand for 12-24 hours. S5. Centrifuge to collect the precipitate at a speed of 3000-5000 r / min for 10-20 min. Wash the precipitate 2-3 times with anhydrous ethanol and then dry it in a vacuum drying oven at 40-60℃ for 6-12 h to obtain hydroxylated dextranuric acid.

[0009] Preferably, the preparation method of the polyγ-glutamic acid zinc is as follows: Take 8-15g of polyγ-glutamic acid, add 80-150mL of deionized water, stir to dissolve, and obtain a polyγ-glutamic acid solution. Add 5-10g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 5.5-6.5, control the reaction temperature at 40-50℃, the stirring speed at 120-220r / min, and react for 2-3h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.5. After the reaction is complete, the reaction solution is filtered, the filter residue is washed with deionized water 3-4 times, and then dried in a vacuum drying oven at 50-70℃ for 8-14 hours. After pulverizing, it is passed through an 80-100 mesh sieve to obtain polyγ-glutamic acid zinc.

[0010] Preferably, the preparation method of the trehalose-grafted polylactic acid is as follows: S1. Take 8-16g of trehalose, add 80-160mL of anhydrous ethanol, stir and disperse, then add 0.5-1.5g of catalyst p-toluenesulfonic acid, stir evenly, and heat to 50-60℃, keep warm and stir for 30-60min. S2. Slowly add 12-20 mL of L-lactide to the above system, controlling the dropping rate at 1-2 mL / min. After the addition is complete, raise the temperature to 80-90℃, stir at 200-300 r / min, and react for 5-8 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 3-5 times the volume of n-hexane to precipitate, and let it stand for 12-24 hours. S4. Centrifuge to collect the precipitate at a speed of 4000-6000 r / min for 15-25 min. Wash the precipitate 2-3 times with hexane, then wash it once with anhydrous ethanol. Dry it in a vacuum drying oven at 50-60℃ for 8-12 h to obtain trehalose-grafted polylactic acid.

[0011] A method for preparing a medical recombinant collagen dressing includes the following steps: Step 1, Pretreatment: Heat purified water to 30-40℃, add disodium EDTA, stir at 80-120 r / min for 10-20 min until completely dissolved to obtain the pretreated solution; Step 2: Prepare the moisturizing system: Add glycerin and vitamin B5 to the pretreatment solution, heat to 45-55℃, stir at 120-160 r / min for 20-30 min until the mixture is uniform, and obtain the moisturizing system solution. Step 3: Add innovative ingredients: Add hydroxylated dextranuric acid, polyγ-glutamic acid zinc, and trehalose-grafted polylactic acid to the moisturizing system solution in sequence, control the temperature at 40-50℃, the stirring speed at 180-240r / min, and stir for 30-50min until completely dissolved to obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex solution to 20-30℃, add recombinant collagen, stir at 60-100r / min, and stir slowly for 25-40min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 6.5-7.5. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 20-30 MPa, the homogenization temperature is controlled at 25-35℃, and homogenization is performed 2-3 times, with each homogenization time being 5-10 min, to obtain a homogenized liquid. Step 6, Degassing and Filtration: The homogenized liquid is fed into a vacuum degasser, and the vacuum degree is controlled at -0.06 to -0.09 MPa, the temperature is 20-30℃, and degassing is performed for 15-25 minutes; after degassing, it is filtered through a 0.22μm microporous membrane to obtain the dressing stock solution; Step 7, Forming and Packaging: Inject the dressing concentrate into the pre-sterilized dressing matrix and soak for 30-60 minutes to ensure the concentrate fully saturates the matrix; then seal and package it, and sterilize it by irradiation with an irradiation dose of 25-35 kGy to obtain the finished medical recombinant collagen dressing.

[0012] Preferably, the dressing matrix in step 7 is a sterile degreased nonwoven fabric with a basis weight of 20-30 g / m². 2 The thickness is 0.3-0.5mm.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The medical recombinant collagen dressing of the present invention introduces three components—hydroxylated dextranuric acid, zinc polygamma-glutamate, and trehalose-grafted polylactic acid—which work synergistically with recombinant collagen: hydroxylated dextranuric acid has excellent moisturizing properties and biocompatibility, enhancing the dressing's water-locking ability and providing a moist environment for wound healing; zinc polygamma-glutamate releases zinc ions, exhibiting antibacterial and anti-inflammatory effects, while also promoting fibroblast proliferation and accelerating wound repair; trehalose-grafted polylactic acid combines the moisturizing and stress-resistant properties of trehalose with the biodegradability of polylactic acid, improving the dressing's structural stability, reducing the loss of effective ingredients, and regulating the wound healing microenvironment to further promote tissue repair; the complementary functions of each component effectively solve the problems of existing dressings having single functions and low repair efficiency. 2. The dressing preparation method of the present invention optimizes the process steps and parameters. During the preparation process, the temperature, stirring speed and other conditions are strictly controlled, which can effectively preserve the activity of recombinant collagen and various innovative components. At the same time, through homogenization, degassing and filtration, the uniformity and purity of the dressing stock solution are improved, and the final product has good stability and high biosafety. 3. The dressing components of this invention all have good biocompatibility, are non-irritating, and are suitable for the repair of various types of wounds, with a wide range of clinical applications. Detailed Implementation

[0014] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention provides a medical recombinant collagen dressing, comprising the following components in parts by weight: Recombinant collagen: 5-15 parts; Hydroxylated dextranuric acid: 2-8 parts; Poly-γ-glutamic acid zinc: 1-5 parts; Trehalose grafted with polylactic acid: 3-10 parts; Glycerin: 2-6 parts; Vitamin B5: 0.5-2 servings; Disodium EDTA: 0.1-0.5 parts; Purified water: 50-80 parts.

[0016] The recombinant collagen in this embodiment is recombinant human type III collagen with a molecular weight of 50-80 kDa and a purity of ≥95%.

[0017] The preparation method of hydroxylated dextranuronic acid in this embodiment is as follows: S1. Take 10-20g of dextran, add 100-200mL of deionized water, stir to dissolve, and obtain a dextran solution; S2. Add 5-10g of sodium bromide to the dextran solution, stir well, and then slowly add 15-25mL of 30% hydrogen peroxide solution. Control the reaction temperature at 35-45℃ and the stirring speed at 100-200r / min. React for 2-4 hours. S3. After the reaction is complete, add 2-5g of sodium hydroxide to the system, adjust the pH to 9-10, then add 8-15g of sodium chloroacetate, heat to 60-70℃, stir at 150-250r / min, and react for 3-5h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 6.5-7.5 with hydrochloric acid, then add 3-5 times the volume of anhydrous ethanol to precipitate, and let it stand for 12-24 hours. S5. Centrifuge to collect the precipitate at a speed of 3000-5000 r / min for 10-20 min. Wash the precipitate 2-3 times with anhydrous ethanol and then dry it in a vacuum drying oven at 40-60℃ for 6-12 h to obtain hydroxylated dextranuric acid.

[0018] The preparation method of poly-γ-glutamic acid zinc in this embodiment is as follows: Take 8-15g of polyγ-glutamic acid, add 80-150mL of deionized water, stir to dissolve, and obtain a polyγ-glutamic acid solution. Add 5-10g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 5.5-6.5, control the reaction temperature at 40-50℃, the stirring speed at 120-220r / min, and react for 2-3h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.5. After the reaction is complete, the reaction solution is filtered, the filter residue is washed with deionized water 3-4 times, and then dried in a vacuum drying oven at 50-70℃ for 8-14 hours. After pulverizing, it is passed through an 80-100 mesh sieve to obtain polyγ-glutamic acid zinc.

[0019] The preparation method of trehalose-grafted polylactic acid in this embodiment is as follows: S1. Take 8-16g of trehalose, add 80-160mL of anhydrous ethanol, stir and disperse, then add 0.5-1.5g of catalyst p-toluenesulfonic acid, stir evenly, and heat to 50-60℃, keep warm and stir for 30-60min. S2. Slowly add 12-20 mL of L-lactide to the above system, controlling the dropping rate at 1-2 mL / min. After the addition is complete, raise the temperature to 80-90℃, stir at 200-300 r / min, and react for 5-8 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 3-5 times the volume of n-hexane to precipitate, and let it stand for 12-24 hours. S4. Centrifuge to collect the precipitate at a speed of 4000-6000 r / min for 15-25 min. Wash the precipitate 2-3 times with hexane, then wash it once with anhydrous ethanol. Dry it in a vacuum drying oven at 50-60℃ for 8-12 h to obtain trehalose-grafted polylactic acid.

[0020] A method for preparing a medical recombinant collagen dressing includes the following steps: Step 1, Pretreatment: Heat purified water to 30-40℃, add disodium EDTA, stir at 80-120 r / min for 10-20 min until completely dissolved to obtain the pretreated solution; Step 2: Prepare the moisturizing system: Add glycerin and vitamin B5 to the pretreatment solution, heat to 45-55℃, stir at 120-160 r / min for 20-30 min until the mixture is uniform, and obtain the moisturizing system solution. Step 3: Add innovative ingredients: Add hydroxylated dextranuric acid, polyγ-glutamic acid zinc, and trehalose-grafted polylactic acid to the moisturizing system solution in sequence, control the temperature at 40-50℃, the stirring speed at 180-240r / min, and stir for 30-50min until completely dissolved to obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex solution to 20-30℃, add recombinant collagen, stir at 60-100r / min, and stir slowly for 25-40min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 6.5-7.5. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 20-30 MPa, the homogenization temperature is controlled at 25-35℃, and homogenization is performed 2-3 times, with each homogenization time being 5-10 min, to obtain a homogenized liquid. Step 6, Degassing and Filtration: The homogenized liquid is fed into a vacuum degasser, and the vacuum degree is controlled at -0.06 to -0.09 MPa, the temperature is 20-30℃, and degassing is performed for 15-25 minutes; after degassing, it is filtered through a 0.22μm microporous membrane to obtain the dressing stock solution; Step 7, Forming and Packaging: Inject the dressing concentrate into the pre-sterilized dressing matrix and soak for 30-60 minutes to ensure the concentrate fully saturates the matrix; then seal and package it, and sterilize it by irradiation with an irradiation dose of 25-35 kGy to obtain the finished medical recombinant collagen dressing.

[0021] In step 7 of this embodiment, the dressing matrix is ​​a sterile degreased nonwoven fabric with a basis weight of 20-30 g / m². 2 The thickness is 0.3-0.5mm. Example 1

[0022] A medical recombinant collagen dressing, by weight, comprises the following components: Recombinant human type III collagen (molecular weight 60kDa, purity ≥95%): 10 parts; Hydroxylated dextranuric acid: 5 parts; Poly-γ-glutamic acid zinc: 3 parts; Trehalose-grafted polylactic acid: 6 parts; Glycerin: 4 parts; Vitamin B5: 1.2 servings; Disodium EDTA: 0.3 parts; Purified water: 65 parts.

[0023] Preparation of hydroxylated dextranuronic acid: S1. Take 15g of dextran, add 150mL of deionized water, stir to dissolve, and obtain a dextran solution. S2. Add 7g of sodium bromide to the dextran solution, stir well, and then slowly add 20mL of 30% hydrogen peroxide solution. Control the reaction temperature at 40℃ and the stirring speed at 150r / min. React for 3h. S3. After the reaction is complete, add 3.5g of sodium hydroxide to the system to adjust the pH to 9.5, then add 12g of sodium chloroacetate, heat to 65℃, stir at 200r / min, and react for 4h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 7.0 with hydrochloric acid, then add 4 times the volume of anhydrous ethanol to precipitate, and let stand for 18 hours. S5. Centrifuge to collect the precipitate at a speed of 4000 r / min for 15 min. Wash the precipitate three times with anhydrous ethanol and then dry it in a vacuum drying oven at 50℃ for 9 h to obtain hydroxylated dextranuric acid.

[0024] Preparation of poly-γ-glutamic acid zinc: S1. Take 12g of polyγ-glutamic acid, add 120mL of deionized water, stir to dissolve, and obtain polyγ-glutamic acid solution. S2. Add 8g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 6.0, control the reaction temperature at 45℃, the stirring speed at 180r / min, and react for 2.5h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.5. S4. After the reaction is complete, the reaction solution is filtered, the filter residue is washed with deionized water 4 times, and then dried in a vacuum drying oven at 60℃ for 11 hours. After pulverizing, it is passed through a 90-mesh sieve to obtain polyγ-glutamic acid zinc.

[0025] Preparation of trehalose-grafted polylactic acid: S1. Take 12g of trehalose, add 120mL of anhydrous ethanol, stir and disperse, then add 1.0g of catalyst p-toluenesulfonic acid, stir evenly, and heat to 55℃, keep warm and stir for 45min. S2. Slowly add 16 mL of L-lactide to the above system, controlling the dropping rate at 1.5 mL / min. After the dropping is completed, raise the temperature to 85 °C, stir at 250 r / min, and react for 6.5 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 4 times the volume of n-hexane to precipitate, and let it stand for 18 hours. S4. Centrifuge to collect the precipitate at a speed of 5000 r / min for 20 min. Wash the precipitate three times with hexane and once with anhydrous ethanol. Dry it in a vacuum drying oven at 55℃ for 10 h to obtain trehalose-grafted polylactic acid.

[0026] Preparation of medical recombinant collagen dressings: Step 1, Pretreatment: Heat 65 parts of purified water to 35°C, add 0.3 parts of disodium EDTA, stir at 100 r / min for 15 min until completely dissolved, to obtain the pretreated solution; Step 2: Preparation of moisturizing system: Add 4 parts glycerin and 1.2 parts vitamin B5 to the pretreatment solution, heat to 50℃, stir at 140 r / min for 25 min until evenly mixed to obtain the moisturizing system solution; Step 3: Add innovative ingredients: Add 5 parts of hydroxylated dextranuric acid, 3 parts of polyγ-glutamic acid zinc, and 6 parts of trehalose-grafted polylactic acid to the moisturizing system solution in sequence, control the temperature at 45℃, the stirring speed at 220r / min, and stir for 40min until completely dissolved to obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex system solution to 25°C, add 10 parts of recombinant human type III collagen, stir at 80 r / min, and stir slowly for 35 min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 7.0. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 25 MPa and the homogenization temperature at 30℃. Homogenize 3 times, and the homogenization time is 8 min each time to obtain a homogenized liquid. Step 6, Degassing and Filtration: The homogenized liquid is fed into a vacuum degasser, and the vacuum degree is controlled at -0.08MPa and the temperature at 25℃ for 20 minutes. After degassing, it is filtered through a 0.22μm microporous membrane to obtain the dressing stock solution. Step 7, Forming and Packaging: Inject the dressing solution into pre-sterilized sterile degreased nonwoven fabric (25g / m²). 2 The solution is soaked in a solution (0.4 mm thick) for 45 minutes to fully saturate the matrix; then it is sealed and packaged, and sterilized by irradiation with an irradiation dose of 30 kGy to obtain the finished medical recombinant collagen dressing. Example 2

[0027] A medical recombinant collagen dressing, by weight, comprises the following components: Recombinant human type III collagen (molecular weight 50kDa, purity ≥95%): 5 portions; Hydroxylated dextranuric acid: 2 parts; Poly-γ-glutamic acid zinc: 1 part; Trehalose-grafted polylactic acid: 3 parts; Glycerin: 2 parts; Vitamin B5: 0.5 parts; Disodium EDTA: 0.1 parts; Purified water: 50 parts.

[0028] Preparation of hydroxylated dextranuronic acid: S1. Take 10g of dextran, add 100mL of deionized water, stir to dissolve, and obtain a dextran solution. S2. Add 5g of sodium bromide to the dextran solution, stir well, and then slowly add 15mL of 30% hydrogen peroxide solution. Control the reaction temperature at 35℃ and the stirring speed at 100r / min. React for 2h. S3. After the reaction is complete, add 2g of sodium hydroxide to the system to adjust the pH to 9, then add 8g of sodium chloroacetate, heat to 60℃, stir at 150r / min, and react for 3h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 6.5 with hydrochloric acid, then add 3 times the volume of anhydrous ethanol to precipitate, and let stand for 12 hours. S5. Centrifuge to collect the precipitate at a speed of 3000 r / min for 10 min. Wash the precipitate twice with anhydrous ethanol and then dry it in a vacuum drying oven at 40℃ for 6 h to obtain hydroxylated dextranuric acid.

[0029] Preparation of poly-γ-glutamic acid zinc: S1. Take 8g of polyγ-glutamic acid, add 80mL of deionized water, stir to dissolve, and obtain polyγ-glutamic acid solution. S2. Add 5g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 5.5, control the reaction temperature at 40℃, the stirring speed at 120r / min, and react for 2h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.5. S4. After the reaction is complete, the reaction solution is filtered, the filter residue is washed three times with deionized water, and then dried in a vacuum drying oven at 50°C for 8 hours. After pulverizing, it is passed through an 80-mesh sieve to obtain polyγ-glutamic acid zinc.

[0030] Preparation of trehalose-grafted polylactic acid: S1. Take 8g of trehalose, add 80mL of anhydrous ethanol, stir and disperse, then add 0.5g of catalyst p-toluenesulfonic acid, stir evenly, heat to 50℃, keep warm and stir for 30min; S2. Slowly add 12 mL of L-lactide to the above system, controlling the dropping rate to 1 mL / min. After the addition is complete, raise the temperature to 80 °C, stir at 200 r / min, and react for 5 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 3 times the volume of n-hexane to precipitate, and let it stand for 12 hours. S4. Centrifuge to collect the precipitate at a speed of 4000 r / min for 15 min. Wash the precipitate twice with hexane and once with anhydrous ethanol. Dry it in a vacuum drying oven at 50℃ for 8 h to obtain trehalose-grafted polylactic acid.

[0031] Preparation of medical recombinant collagen dressings: Step 1, Pretreatment: Heat 50 parts of purified water to 30°C, add 0.1 parts of disodium EDTA, stir at 80 r / min for 10 min until completely dissolved, to obtain the pretreated solution; Step 2: Preparation of moisturizing system: Add 2 parts glycerin and 0.5 parts vitamin B5 to the pretreatment solution, heat to 45℃, stir at 120 r / min for 20 min until evenly mixed to obtain the moisturizing system solution; Step 3: Add innovative ingredients: Add 2 parts of hydroxylated dextranuric acid, 1 part of polyγ-glutamic acid zinc, and 3 parts of trehalose-grafted polylactic acid to the moisturizing system solution in sequence, control the temperature at 40℃, stir at 180r / min, stir for 30min until completely dissolved, and obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex system solution to 20°C, add 5 parts of recombinant human type III collagen, stir at 60 r / min, and stir slowly for 25 min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 6.5. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 20MPa and the homogenization temperature at 25℃. The homogenization is performed twice, and the homogenization time is 5min each time to obtain a homogenized liquid. Step 6, Degassing and Filtration: The homogenized liquid is fed into a vacuum degasser, and the vacuum degree is controlled at -0.06MPa and the temperature at 20℃ for 15 minutes. After degassing, it is filtered through a 0.22μm microporous membrane to obtain the dressing stock solution. Step 7, Forming and Packaging: Inject the dressing solution into pre-sterilized sterile degreased nonwoven fabric (20g / m²). 2 The solution is soaked in a solution (0.3 mm thick) for 30 minutes to fully saturate the matrix; then it is sealed and packaged, and sterilized by irradiation with an irradiation dose of 25 kGy to obtain the finished medical recombinant collagen dressing. Example 3

[0032] A medical recombinant collagen dressing, by weight, comprises the following components: Recombinant human type III collagen (molecular weight 80kDa, purity ≥95%): 15 portions; Hydroxylated dextranuric acid: 8 parts; Poly-γ-glutamic acid zinc: 5 parts; Trehalose-grafted polylactic acid: 10 parts; Glycerin: 6 parts; Vitamin B5: 2 servings; Disodium EDTA: 0.5 parts; Purified water: 80 parts.

[0033] Preparation of hydroxylated dextranuronic acid: S1. Take 20g of dextran, add 200mL of deionized water, stir to dissolve, and obtain a dextran solution; S2. Add 10g of sodium bromide to the dextran solution, stir well, and then slowly add 25mL of 30% hydrogen peroxide solution. Control the reaction temperature at 45℃, the stirring speed at 200r / min, and react for 4h. S3. After the reaction is complete, add 5g of sodium hydroxide to the system, adjust the pH to 10, then add 15g of sodium chloroacetate, heat to 70℃, stir at 250r / min, and react for 5h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 7.5 with hydrochloric acid, then add 5 times the volume of anhydrous ethanol to precipitate, and let stand for 24 hours. S5. Centrifuge to collect the precipitate at a speed of 5000 r / min for 20 min. Wash the precipitate three times with anhydrous ethanol and then dry it in a vacuum drying oven at 60℃ for 12 h to obtain hydroxylated dextranuric acid.

[0034] Preparation of poly-γ-glutamic acid zinc: S1. Take 15g of polyγ-glutamic acid, add 150mL of deionized water, stir to dissolve, and obtain polyγ-glutamic acid solution. S2. Add 10g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 6.5, control the reaction temperature at 50℃, the stirring speed at 220r / min, and react for 3h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.5. S4. After the reaction is complete, the reaction solution is filtered, the filter residue is washed with deionized water 4 times, and then dried in a vacuum drying oven at 70℃ for 14 hours. After pulverizing, it is passed through a 100-mesh sieve to obtain polyγ-glutamic acid zinc.

[0035] Preparation of trehalose-grafted polylactic acid: S1. Take 16g of trehalose, add 160mL of anhydrous ethanol, stir and disperse, then add 1.5g of catalyst p-toluenesulfonic acid, stir evenly, and heat to 60℃, keep warm and stir for 60min. S2. Slowly add 20 mL of L-lactide to the above system, controlling the dropping rate at 2 mL / min. After the addition is complete, raise the temperature to 90 °C, stir at 300 r / min, and react for 8 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 5 times the volume of n-hexane to precipitate, and let it stand for 24 hours. S4. Centrifuge to collect the precipitate at a speed of 6000 r / min for 25 min. Wash the precipitate three times with hexane and once with anhydrous ethanol. Dry it in a vacuum drying oven at 60℃ for 12 h to obtain trehalose-grafted polylactic acid.

[0036] Preparation of medical recombinant collagen dressings: Step 1, Pretreatment: Heat 80 parts of purified water to 40℃, add 0.5 parts of disodium EDTA, stir at 120r / min for 20min until completely dissolved to obtain the pretreated solution; Step 2: Preparation of moisturizing system: Add 6 parts glycerin and 2 parts vitamin B5 to the pretreatment solution, heat to 55℃, stir at 160 r / min for 30 min until evenly mixed to obtain the moisturizing system solution; Step 3: Add innovative ingredients: Add 8 parts of hydroxylated dextranuric acid, 5 parts of polyγ-glutamic acid zinc, and 10 parts of trehalose-grafted polylactic acid to the moisturizing system solution in sequence. Control the temperature at 50℃, the stirring speed at 240r / min, and stir for 50min until completely dissolved to obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex system solution to 30°C, add 15 parts of recombinant human type III collagen, stir at 100 r / min, and stir slowly for 40 min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 7.5. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 30 MPa and the homogenization temperature at 35℃. Homogenize 3 times, and the homogenization time is 10 min each time to obtain a homogenized liquid. Step 6, Degassing and Filtration: The homogenized liquid is fed into a vacuum degasser, and the vacuum degree is controlled at -0.09MPa and the temperature at 30℃ for 25 minutes. After degassing, it is filtered through a 0.22μm microporous membrane to obtain the dressing stock solution. Step 7, Forming and Packaging: Inject the dressing solution into pre-sterilized sterile degreased nonwoven fabric (30g / m²). 2 The solution is soaked in a solution (0.5 mm thick) for 60 minutes to fully saturate the matrix; then it is sealed and packaged, and sterilized by irradiation with an irradiation dose of 35 kGy to obtain the finished medical recombinant collagen dressing.

[0037] Performance testing The performance of the medical recombinant collagen dressings prepared in Examples 1-3 was tested, and the results are as follows: 1. Moisturizing performance: Using the gravimetric method, after the dressing was placed at 37℃ and 43% relative humidity for 24 hours, the moisturizing rate was ≥85%, which is significantly higher than that of conventional recombinant collagen dressings (moisturizing rate 60-70%). 2. Antibacterial properties: Tested according to GB 15979-2002 standard, the inhibition rate against Staphylococcus aureus and Escherichia coli is ≥99%, demonstrating excellent antibacterial effect; 3. Cytotoxicity: Using the MTT assay, the relative cell proliferation rate was ≥100%, the cytotoxicity grade was 0, and there was no cytotoxicity. 4. Wound healing effect: In a rat back wound model, the wound healing time of rats using the dressing of this invention was shortened by 30-40% compared with that of rats using conventional dressings, and the wound surface after healing was smooth and the scar area was small.

[0038] The above test results show that the medical recombinant collagen dressing of the present invention has excellent moisturizing, antibacterial and biocompatibility properties, can significantly promote wound healing and meet the needs of clinical application.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A medical recombinant collagen dressing, characterized in that, The ingredients include the following parts by weight: Recombinant collagen: 5-15 parts; Hydroxylated dextranuric acid: 2-8 parts; Poly-γ-glutamic acid zinc: 1-5 parts; Trehalose grafted with polylactic acid: 3-10 parts; Glycerin: 2-6 parts; Vitamin B5: 0.5-2 servings; Disodium EDTA: 0.1-0.5 parts; Purified water: 50-80 parts.

2. The medical recombinant collagen dressing according to claim 1, characterized in that, The recombinant collagen is recombinant human type III collagen with a molecular weight of 50-80 kDa and a purity of ≥95%.

3. The medical recombinant collagen dressing according to claim 1, characterized in that, The preparation method of the hydroxylated dextranuronic acid is as follows: S1. Take 10-20g of dextran, add 100-200mL of deionized water, stir to dissolve, and obtain a dextran solution; S2. Add 5-10g of sodium bromide to the dextran solution, stir well, and then slowly add 15-25mL of 30% hydrogen peroxide solution. Control the reaction temperature at 35-45℃ and the stirring speed at 100-200r / min. React for 2-4 hours. S3. After the reaction is complete, add 2-5g of sodium hydroxide to the system, adjust the pH to 9-10, then add 8-15g of sodium chloroacetate, heat to 60-70℃, stir at 150-250r / min, and react for 3-5h. S4. After the reaction is complete, cool the reaction solution to room temperature, adjust the pH to 6.5-7.5 with hydrochloric acid, then add 3-5 times the volume of anhydrous ethanol to precipitate, and let it stand for 12-24 hours. S5. Centrifuge to collect the precipitate at a speed of 3000-5000 r / min for 10-20 min. Wash the precipitate 2-3 times with anhydrous ethanol and then dry it in a vacuum drying oven at 40-60℃ for 6-12 h to obtain hydroxylated dextranuric acid.

4. The medical recombinant collagen dressing according to claim 1, characterized in that, The preparation method of the polyγ-glutamic acid zinc is as follows: Take 8-15g of polyγ-glutamic acid, add 80-150mL of deionized water, stir to dissolve, and obtain a polyγ-glutamic acid solution. Add 5-10g of zinc oxide to the polyγ-glutamic acid solution, adjust the pH of the system to 5.5-6.5, control the reaction temperature at 40-50℃, the stirring speed at 120-220r / min, and react for 2-3h. S3. During the reaction, continuously monitor the pH of the system. If the pH is lower than 5.5, slowly add 10% sodium hydroxide solution to adjust it to 5.5-6.

5. After the reaction is complete, the reaction solution is filtered, the filter residue is washed with deionized water 3-4 times, and then dried in a vacuum drying oven at 50-70℃ for 8-14 hours. After pulverizing, it is passed through an 80-100 mesh sieve to obtain polyγ-glutamic acid zinc.

5. A medical recombinant collagen dressing according to claim 1, characterized in that, The preparation method of the trehalose-grafted polylactic acid is as follows: S1. Take 8-16g of trehalose, add 80-160mL of anhydrous ethanol, stir and disperse, then add 0.5-1.5g of catalyst p-toluenesulfonic acid, stir evenly, and heat to 50-60℃, keep warm and stir for 30-60min. S2. Slowly add 12-20 mL of L-lactide to the above system, controlling the dropping rate at 1-2 mL / min. After the addition is complete, raise the temperature to 80-90℃, stir at 200-300 r / min, and react for 5-8 h. S3. After the reaction is complete, cool the reaction solution to room temperature, add 3-5 times the volume of n-hexane to precipitate, and let it stand for 12-24 hours. S4. Centrifuge to collect the precipitate at a speed of 4000-6000 r / min for 15-25 min. Wash the precipitate 2-3 times with hexane, then wash it once with anhydrous ethanol. Dry it in a vacuum drying oven at 50-60℃ for 8-12 h to obtain trehalose-grafted polylactic acid.

6. A method for preparing a medical recombinant collagen dressing, characterized in that, Includes the following steps: Step 1, Pretreatment: Heat purified water to 30-40℃, add disodium EDTA, stir at 80-120 r / min for 10-20 min until completely dissolved to obtain the pretreated solution; Step 2: Prepare the moisturizing system: Add glycerin and vitamin B5 to the pretreatment solution, heat to 45-55℃, stir at 120-160 r / min for 20-30 min until the mixture is uniform, and obtain the moisturizing system solution. Step 3: Add innovative ingredients: Add hydroxylated dextranuric acid, polyγ-glutamic acid zinc, and trehalose-grafted polylactic acid to the moisturizing system solution in sequence, control the temperature at 40-50℃, the stirring speed at 180-240r / min, and stir for 30-50min until completely dissolved to obtain the composite system solution. Step 4: Add recombinant collagen: Cool the complex solution to 20-30℃, add recombinant collagen, stir at 60-100r / min, and stir slowly for 25-40min until completely dissolved. During this period, continuously monitor the pH of the system to ensure that the pH is maintained at 6.5-7.

5. Step 5, Homogenization: The above solution is sent to a high-pressure homogenizer, and the homogenization pressure is controlled at 20-30 MPa, the homogenization temperature is controlled at 25-35℃, and homogenization is performed 2-3 times, with each homogenization time being 5-10 min, to obtain a homogenized liquid. Step 6, Degassing and Filtration: Send the homogenized liquid into a vacuum degasser, control the vacuum degree to -0.06 to -0.09 MPa, the temperature to 20-30℃, and degas for 15-25 minutes; After degassing, the solution was filtered through a 0.22μm microporous membrane to obtain the dressing stock solution; Step 7, Forming and Packaging: Inject the dressing concentrate into the pre-sterilized dressing matrix and soak for 30-60 minutes to ensure the concentrate fully saturates the matrix; then seal and package it, and sterilize it by irradiation with an irradiation dose of 25-35 kGy to obtain the finished medical recombinant collagen dressing.

7. The method for preparing a medical recombinant collagen dressing according to claim 6, characterized in that, The dressing matrix mentioned in step 7 is a sterile degreased nonwoven fabric with a basis weight of 20-30 g / m². 2 The thickness is 0.3-0.5mm.