A long-lasting moisturizing soft human-like skin dressing and a method of making the same

Abstract

The present application relates to a long-acting moisturizing soft artificial skin dressing and its preparation method, and belongs to the technical field of artificial skin dressing. The soft artificial skin dressing takes sterilized sheepskin as the base, and the sheepskin base is divided into a wool surface and a dermis surface. The wool surface of the sheepskin base is an air contact surface and is loaded with a moisturizing gel layer. The dermis surface of the sheepskin base is a wound contact surface and is loaded with growth particles. The sterilized sheepskin is used as the base, the air contact surface contacts air and is loaded with a moisturizing gel layer, and the wound contact surface is loaded with growth particles. The layered design makes the moisturizing and healing functions work independently. The dressing is used to fit the human skin and has a soft touch and a good artificial skin experience. The moisturizing gel mainly contains sodium hyaluronate, glycerol and carbomer 940, and is compounded with yellowflower cistanche and opuntia dillenii Haw plant extracts. The formula is reasonable, the gel system has good stability, can long-acting lock water and moisturize, and can relieve the dryness and discomfort of the wound and the surrounding skin.

Description

Technical Field

[0001] This invention belongs to the field of human-like skin dressing technology, specifically relating to a long-lasting moisturizing soft human-like skin dressing and its preparation method. Background Technology

[0002] Dressings are commonly used wound care supplies. Their function is to isolate the wound from the outside world, preventing contamination from dust, bacteria, and other external factors, and providing a good healing environment for the wound. With the continuous advancement of science and technology, there are more and more types of dressings, and their functions are also becoming more and more diverse. Sheepskin has advantages such as being thin, soft, elastic, breathable, able to fit tightly to the wound, and preventing subcutaneous fluid accumulation. It has broad application prospects in the field of dressings.

[0003] However, existing ordinary dressings can only provide basic physical coverage and protection for wounds, lacking active components that promote repair. They cannot actively induce granulation tissue growth or accelerate wound repair, resulting in slow hemostasis, long wound healing cycles, and easy soaking of dressings by exudate. On the other hand, the few ordinary dressings that add repair components have repair materials that have only undergone simple pulverization, resulting in poor biocompatibility and a tendency to trigger immune rejection, which significantly reduces the efficiency of wound repair. Summary of the Invention

[0004] The purpose of this invention is to provide a long-lasting moisturizing soft human skin-like dressing and its preparation method in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions: This invention provides a long-lasting moisturizing soft human skin-like dressing. The soft human skin-like dressing uses sterilized sheepskin as a base. The sheepskin base is divided into a fur side and a dermal side. The fur side of the sheepskin base is the air contact surface and is loaded with a moisturizing gel layer. The dermal side of the sheepskin base is the wound contact surface and is loaded with growth microparticles. The raw materials for preparing the moisturizing gel, by weight, include: 1-5 parts sodium hyaluronate, 3-8 parts glycerin, 2-8 parts plant extracts, 0.5-2 parts carbomer 940, 0.1-0.5 parts triethanolamine, and 75-95 parts deionized water.

[0006] As a further optimization of the present invention, the preparation process of the plant extract is as follows: S1. Take the whole plant of Yellow Flowering Orostachys and Pyrus pyriformis, mix them together and crush them through a 40-60 mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:8-1:12, stir at 60-120 r / min for 30 min, after stirring, sonicate at 25-40 kHz and 200-400 W for 20-30 min, heat to 65℃, reflux extraction at constant temperature for 1 h, filter with 100-200 mesh filter cloth, and collect the filtrate; S3. Centrifuge the filtrate at 4000-6000 r / min for 15-20 min, and then concentrate the supernatant to obtain the plant extract.

[0007] As a further optimization of the present invention, the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4.

[0008] As a further optimization of the present invention, the preparation process of the moisturizing gel is as follows: S1. Mix the plant extract with deionized water, heat to 30-35℃, stir at 60-120r / min for 10-20min to obtain the base solution, and cool to 8-12℃ for later use. S2, mix the base solution and carbomer 940, stir at 160-180 r / min for 30-45 min, add sodium hyaluronate and triethanolamine, continue stirring for 25-40 min, add glycerin, continue stirring for 10-15 min to obtain a moisturizing gel.

[0009] As a further optimization of the present invention, the preparation process of the grown microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse with deionized water 3-5 times, drain and set aside. S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:10-1:15 for 10-15 minutes; after removal, rinse 2-3 times with sterile PBS buffer. S3. Compound decellularization treatment: Immerse the fish skin in a 0.1% Triton X-100 PBS aqueous solution (pH=7.2-7.4) at a material-to-liquid ratio of 1:10-1:15 and treat with constant temperature shaking at 37℃ for 6-9 hours to remove lipids and cell membrane structures. Rinse continuously with deionized water until no foam residue remains on the surface. Then immerse the fish skin in a 1% SDS aqueous solution and treat with shaking at room temperature for 3-6 hours. After treatment, rinse with deionized water 5-7 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:10-1:15 and incubate at 37℃ for 2-3 hours to degrade residual nucleic acids; after removal, rinse 3-5 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 4-6 hours, and then vacuum freeze-dried. The freeze-drying vacuum degree is 5-10Pa and the freeze-drying time is 24-48 hours. The final moisture content is controlled at 3-5% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 25-30 kGy gamma irradiation to obtain growth microparticles.

[0010] As a further optimization of the present invention, the frozen fish skin is made from a mixture of tilapia skin and cod skin; the weight ratio of the tilapia skin to the cod skin is 1:0.3.

[0011] As a further optimization of the present invention, the sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, and the subcutaneous fat is shaved off to obtain a skin piece with a thickness of 0.5-0.8 mm. The skin piece is washed with deionized water 3-5 times, and then immersed in a 0.1-0.2% benzalkonium bromide disinfectant solution for 10-30 minutes. Finally, it is rinsed with sterile saline until no disinfectant residue remains, thus obtaining the sheepskin base material.

[0012] This invention also provides a method for preparing a long-lasting moisturizing soft human skin-like dressing, comprising the following steps: S1. Place the sheepskin base material in a Class 100,000 clean operating table, lay sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline to keep it flat, control the ambient temperature at 20-25℃ and the relative humidity at 40%-60%, and let it air dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel, 0.5-1.0 mm thick, and allow it to gel naturally in a sterile environment at 18-24℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.1-0.5 mg / cm². Use a sterile pressure plate to apply light pressure of 5-10 kPa and let it stand for 20 minutes in a sterile environment at 18-24℃ to fix it, thus obtaining a soft human skin-like dressing.

[0013] The beneficial effects of the present invention are as follows: The dressing of the present invention uses sterilized sheepskin as a base, the air contact surface is in contact with air and loaded with a moisturizing gel layer, and the wound contact surface is loaded with growth microparticles. The layered design allows the moisturizing and healing functions to perform their respective functions. It fits the human skin well, has a soft touch, and provides a good human skin-like experience. The moisturizing gel is mainly composed of sodium hyaluronate, glycerin, and carbomer 940, combined with plant extracts of Orostachys pubescens and Pyracantha fortuneana. The formula is well-matched and the gel system has good stability, which can lock in moisture for a long time and relieve dryness and discomfort of wounds and surrounding skin. Plant extracts synergistically impart additional soothing and protective effects to the dressing; the wound contact surface is loaded with growth microparticles made from a compound of tilapia and cod skin, which, after processing, have good biocompatibility, can effectively guide tissue regeneration, accelerate granulation tissue growth, significantly shorten hemostasis time, and improve wound healing rate and integrity. Detailed Implementation

[0014] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0015] Unless otherwise specified, all methods used in this invention are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products.

[0016] Example 1: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 40-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:8, stir at 60 r / min for 30 min, after stirring, sonicate at an ultrasonic frequency of 25 kHz and ultrasonic power of 200 W for 20 min, heat to 65℃, reflux extract at constant temperature for 1 h, filter with 100 mesh filter cloth and collect the filtrate. S3, centrifuge the filtrate at 4000 r / min for 15 min, and take the supernatant and concentrate it to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 2 parts of plant extract with 75 parts of deionized water, heat to 30°C, stir at 60 r / min for 10 min to obtain a base solution, and cool to ℃ for later use. S2, mix the base solution with 0.5 parts of carbomer 940, stir at 160 r / min for 30 min, add 1 part of sodium hyaluronate and 0.1 parts of triethanolamine, continue stirring for 25 min, add 3 parts of glycerin, continue stirring for 10 min to obtain a moisturizing gel; The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse it 3 times with deionized water, drain and set aside (the frozen fish skin is a mixture of tilapia skin and cod skin; the weight ratio of tilapia skin to cod skin is 1:0.3). S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:10 for 10 minutes; after removal, rinse twice with sterile PBS buffer. S3. Composite decellularization treatment: Immerse the fish skin in a 0.1% Triton X-100 PBS aqueous solution (pH=7.2) at a material-to-liquid ratio of 1:10 and treat with constant temperature shaking at 37℃ for 6 hours to remove lipids and cell membrane structures. Rinse continuously with deionized water until no foam residue remains on the surface. Then immerse the fish skin in a 1% SDS aqueous solution and treat with shaking at room temperature for 3 hours. After treatment, rinse with deionized water 5 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:10 and incubate at 37°C for 2 hours to degrade residual nucleic acids; after removal, rinse 3 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 4 hours, and then vacuum freeze-dried at a vacuum degree of 5Pa and a freeze-drying time of 24 hours, with the final moisture content controlled at 3% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 25kGy gamma irradiation to obtain growth microparticles. The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.5 mm is obtained. The skin piece is washed 3 times with deionized water, and then immersed in 0.1% benzalkonium bromide disinfectant solution for 10 minutes. Then it is rinsed with sterile saline until there is no disinfectant residue, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, lay sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline to keep it flat, control the ambient temperature at 20℃ and relative humidity at 40%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.5mm, and allow it to gel naturally in a sterile environment at 18℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.1 mg / cm². Use a sterile pressure plate to apply light pressure at 5 kPa and let it stand for 20 minutes at 18°C ​​under sterile conditions to fix it, thus obtaining a soft human skin-like dressing.

[0017] Example 2: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 50-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:10, stir at 90 r / min for 30 min, after stirring, sonicate at 35 kHz and 300 W for 25 min, heat to 65 ℃, reflux extract at constant temperature for 1 h, filter with 150 mesh filter cloth and collect the filtrate. S3, the filtrate was centrifuged at 5000 r / min for 17 min, and the supernatant was concentrated to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 6 parts of plant extract with 80 parts of deionized water, heat to 32°C, stir at 100r / min for 15min to obtain a base solution, and cool to 10°C for later use. S2, mix the base solution with 1 part of carbomer 940, stir at 170 r / min for 40 min, add 3 parts of sodium hyaluronate and 0.3 parts of triethanolamine, continue stirring for 35 min, add 6 parts of glycerin, continue stirring for 12 min to obtain a moisturizing gel; The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse it 4 times with deionized water, drain and set aside (the frozen fish skin is a mixture of tilapia skin and cod skin; the weight ratio of tilapia skin to cod skin is 1:0.3). S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:12 for 12 minutes; after removal, rinse twice with sterile PBS buffer. S3. Composite decellularization treatment: The fish skin was immersed in a 0.1% Triton X-100 PBS aqueous solution (pH=7.3) at a material-to-liquid ratio of 1:12 and treated at 37°C with shaking for 7 hours to remove lipids and cell membrane structures. The fish skin was then rinsed with deionized water until no foam residue remained on the surface. The fish skin was then immersed in a 1% SDS aqueous solution and treated at room temperature with shaking for 4 hours. After the treatment was completed, the fish skin was rinsed with deionized water 6 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:12 and incubate at 37℃ for 2.5 h to degrade residual nucleic acids; after removal, rinse 4 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 5 hours, and then vacuum freeze-dried at a vacuum degree of 8Pa and a freeze-drying time of 32 hours, with the final moisture content controlled at 4% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 27kGy gamma irradiation to obtain growth microparticles. The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.7mm is obtained. The skin piece is washed 4 times with deionized water, and then immersed in 0.1% benzalkonium bromide disinfectant solution for 20 minutes. Then it is rinsed with sterile saline until there is no disinfectant residue, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, with sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline solution, keep it flat, control the ambient temperature at 22℃ and relative humidity at 50%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.8mm, and allow it to gel naturally in a sterile environment at 21℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.4 mg / cm². Use a sterile pressure plate to apply light pressure at 8 kPa and let it stand for 20 minutes in a sterile environment at 20°C to fix it, thus obtaining a soft human skin-like dressing.

[0018] Example 3: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 60-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:12, stir at 120r / min for 30min, after stirring, sonicate at 40kHz ultrasonic frequency and 400W ultrasonic power for 30min, heat to 65℃, reflux extraction at constant temperature for 1h, filter with 200 mesh filter cloth, and collect the filtrate. S3, centrifuge the filtrate at 6000 r / min for 20 min, and take the supernatant and concentrate it to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 8 parts of plant extract with 95 parts of deionized water, heat to 35°C, stir at 120r / min for 20min to obtain a base solution, and cool to 12°C for later use. S2, mix the base solution with 2 parts of carbomer 940, stir at 180 r / min for 45 min, add 5 parts of sodium hyaluronate and 0.5 parts of triethanolamine, continue stirring for 40 min, add 8 parts of glycerin, continue stirring for 15 min to obtain a moisturizing gel; The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse it 5 times with deionized water, drain and set aside (the frozen fish skin is a mixture of tilapia skin and cod skin; the weight ratio of tilapia skin to cod skin is 1:0.3). S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:15 for 15 minutes; after removal, rinse 3 times with sterile PBS buffer. S3. Composite decellularization treatment: The fish skin was immersed in a 0.1% Triton X-100 PBS aqueous solution (pH=7.4) at a material-to-liquid ratio of 1:15 and treated at 37°C with shaking for 9 hours to remove lipids and cell membrane structures. The fish skin was then continuously rinsed with deionized water until no foam residue remained on the surface. The fish skin was then immersed in a 1% SDS aqueous solution and treated at room temperature with shaking for 6 hours. After the treatment was completed, the fish skin was rinsed with deionized water 7 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:15 and incubate at 37°C for 3 hours to degrade residual nucleic acids; after removal, rinse 5 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 6 hours, and then vacuum freeze-dried at a vacuum degree of 10Pa and a freeze-drying time of 48 hours, with the final moisture content controlled at 5% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 30kGy γ-irradiation to obtain growth microparticles. The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.8mm is obtained. The skin piece is washed 5 times with deionized water, and then immersed in a 0.2% benzalkonium bromide disinfectant solution for 30 minutes. Finally, it is rinsed with sterile saline until no disinfectant residue is left, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, with sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline solution, keep it flat, control the ambient temperature at 25℃ and relative humidity at 60%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 1.0 mm, and allow it to gel naturally in a sterile environment at 24℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.5 mg / cm². Use a sterile pressure plate to apply light pressure at 10 kPa and let it stand for 20 minutes in a sterile environment at 24°C to fix it, thus obtaining a soft human skin-like dressing.

[0019] Comparative Example 1: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 50-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:10, stir at 90 r / min for 30 min, after stirring, sonicate at 35 kHz and 300 W for 25 min, heat to 65 ℃, reflux extract at constant temperature for 1 h, filter with 150 mesh filter cloth and collect the filtrate. S3, the filtrate was centrifuged at 5000 r / min for 17 min, and the supernatant was concentrated to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 6 parts of plant extract with 80 parts of deionized water, heat to 32°C, stir at 100r / min for 15min to obtain a base solution, and cool to 10°C for later use. S2, mix the base solution with 1 part of carbomer 940, stir at 170 r / min for 40 min, add 3 parts of sodium hyaluronate and 0.3 parts of triethanolamine, continue stirring for 35 min, add 6 parts of glycerin, continue stirring for 12 min to obtain a moisturizing gel; The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim it neatly, rinse it 4 times with deionized water, and drain it for later use (frozen fish skin is tilapia skin). S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:12 for 12 minutes; after removal, rinse twice with sterile PBS buffer. S3. Composite decellularization treatment: The fish skin was immersed in a 0.1% Triton X-100 PBS aqueous solution (pH=7.3) at a material-to-liquid ratio of 1:12 and treated at 37°C with shaking for 7 hours to remove lipids and cell membrane structures. The fish skin was then rinsed with deionized water until no foam residue remained on the surface. The fish skin was then immersed in a 1% SDS aqueous solution and treated at room temperature with shaking for 4 hours. After the treatment was completed, the fish skin was rinsed with deionized water 6 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:12 and incubate at 37℃ for 2.5 h to degrade residual nucleic acids; after removal, rinse 4 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 5 hours, and then vacuum freeze-dried at a vacuum degree of 8Pa and a freeze-drying time of 32 hours, with the final moisture content controlled at 4% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 27kGy gamma irradiation to obtain growth microparticles. The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.7mm is obtained. The skin piece is washed 4 times with deionized water, and then immersed in 0.1% benzalkonium bromide disinfectant solution for 20 minutes. Then it is rinsed with sterile saline until there is no disinfectant residue, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, with sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline solution, keep it flat, control the ambient temperature at 22℃ and relative humidity at 50%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.8mm, and allow it to gel naturally in a sterile environment at 21℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.4 mg / cm². Use a sterile pressure plate to apply light pressure at 8 kPa and let it stand for 20 minutes in a sterile environment at 20°C to fix it, thus obtaining a soft human skin-like dressing.

[0020] Comparative Example 2: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 50-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:10, stir at 90 r / min for 30 min, after stirring, sonicate at 35 kHz and 300 W for 25 min, heat to 65 ℃, reflux extract at constant temperature for 1 h, filter with 150 mesh filter cloth and collect the filtrate. S3, the filtrate was centrifuged at 5000 r / min for 17 min, and the supernatant was concentrated to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 6 parts of plant extract with 80 parts of deionized water, heat to 32°C, stir at 100r / min for 15min to obtain a base solution, and cool to 10°C for later use. S2, mix the base solution with 1 part of carbomer 940, stir at 170 r / min for 40 min, add 3 parts of sodium hyaluronate and 0.3 parts of triethanolamine, continue stirring for 35 min, add 6 parts of glycerin, continue stirring for 12 min to obtain a moisturizing gel; The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse it 4 times with deionized water, and drain it for later use (frozen fish skin is cod skin). S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:12 for 12 minutes; after removal, rinse twice with sterile PBS buffer. S3. Composite decellularization treatment: The fish skin was immersed in a 0.1% Triton X-100 PBS aqueous solution (pH=7.3) at a material-to-liquid ratio of 1:12 and treated at 37°C with shaking for 7 hours to remove lipids and cell membrane structures. The fish skin was then rinsed with deionized water until no foam residue remained on the surface. The fish skin was then immersed in a 1% SDS aqueous solution and treated at room temperature with shaking for 4 hours. After the treatment was completed, the fish skin was rinsed with deionized water 6 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:12 and incubate at 37℃ for 2.5 h to degrade residual nucleic acids; after removal, rinse 4 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 5 hours, and then vacuum freeze-dried at a vacuum degree of 8Pa and a freeze-drying time of 32 hours, with the final moisture content controlled at 4% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 27kGy gamma irradiation to obtain growth microparticles. The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.7mm is obtained. The skin piece is washed 4 times with deionized water, and then immersed in 0.1% benzalkonium bromide disinfectant solution for 20 minutes. Then it is rinsed with sterile saline until there is no disinfectant residue, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, with sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline solution, keep it flat, control the ambient temperature at 22℃ and relative humidity at 50%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.8mm, and allow it to gel naturally in a sterile environment at 21℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.4 mg / cm². Use a sterile pressure plate to apply light pressure at 8 kPa and let it stand for 20 minutes in a sterile environment at 20°C to fix it, thus obtaining a soft human skin-like dressing.

[0021] Comparative Example 3: The preparation process of the plant extract is as follows: S1. Take the whole plant of *Orostachys pubescens* and *Opuntia ficus-indica* (the weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* is 0.3:0.4), mix them, and then crush them through a 50-mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:10, stir at 90 r / min for 30 min, after stirring, sonicate at 35 kHz and 300 W for 25 min, heat to 65 ℃, reflux extract at constant temperature for 1 h, filter with 150 mesh filter cloth and collect the filtrate. S3, the filtrate was centrifuged at 5000 r / min for 17 min, and the supernatant was concentrated to obtain the plant extract; The preparation process of the moisturizing gel is as follows: S1. Mix 6 parts of plant extract with 80 parts of deionized water, heat to 32°C, stir at 100r / min for 15min to obtain a base solution, and cool to 10°C for later use. S2, mix the base solution with 1 part of carbomer 940, stir at 170 r / min for 40 min, add 3 parts of sodium hyaluronate and 0.3 parts of triethanolamine, continue stirring for 35 min, add 6 parts of glycerin, continue stirring for 12 min to obtain a moisturizing gel; The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, the subcutaneous fat is removed, and a skin piece with a thickness of 0.7mm is obtained. The skin piece is washed 4 times with deionized water, and then immersed in 0.1% benzalkonium bromide disinfectant solution for 20 minutes. Then it is rinsed with sterile saline until there is no disinfectant residue, and the sheepskin base material is obtained. Preparation process of soft human skin-like dressings: S1. Place the sheepskin base material in a Class 100,000 clean operating table, with sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline solution, keep it flat, control the ambient temperature at 22℃ and relative humidity at 50%, and let it dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.8mm, and allow it to gel naturally in a sterile environment at 21℃ for 30 minutes to form a uniform moisturizing gel layer, resulting in a soft, human-skin-like dressing.

[0022] Performance testing The sheepskin dressings prepared in Examples 1-3 and Comparative Examples 1-3 were used as samples. 2 ml of Staphylococcus aureus and Escherichia coli bacterial suspensions at a concentration of 10⁻⁵ CFU / ml were added dropwise to the sterilized sample surfaces and incubated at 37°C for 12 h. Then, 40 μL of the cultured bacterial suspension was evenly spread onto a solid culture medium and incubated at 37°C for 36 h. The number of colonies on the culture medium was counted, and a blank experiment was performed. The antibacterial rate was calculated using the formula W = (P - P₁) / P × 100%, where W is the antibacterial rate and P is the number of colonies counted in the blank experiment. The number of colonies on the culture medium was recorded; P1 is the number of colonies on the culture medium counted in the sample experiment; the sheepskin dressings prepared in Examples 1-3 and Comparative Examples 1-3 were made into samples with a size of 8cm×12cm, the initial weight of the samples was recorded, and then the samples were soaked in water for 20min. After soaking, the samples were hung up and when no more liquid dripped, the samples were weighed again. The water absorption ratio of the samples was calculated using the following formula: D=(m1-m) / m, where D is the water absorption ratio, m is the initial weight of the sample, and m1 is the weight of the sample after soaking and hanging. The test results are shown in Table 1.

[0023] Table 1

[0024] As can be seen from Table 1, Examples 1-3 showed the best antibacterial effect: the antibacterial rate against Staphylococcus aureus was 99.1-99.3%, and the antibacterial rate against Escherichia coli was 98.3-98.6%, with the overall values ​​being higher than all comparative examples.

[0025] The antibacterial ability of Comparative Examples 1-3 decreased sequentially: the antibacterial rate against Staphylococcus aureus decreased from 99.0% to 98.2%, and the antibacterial rate against Escherichia coli decreased from 98.1% to 97.8%, with the antibacterial effect gradually weakening as the group increased; The water absorption ratio range of the example groups was 85.8-87.5 g / g, with Example 2 showing the best water absorption performance.

[0026] The water absorption rate of the comparative groups ranged from 83.1 to 84.2 g / g, with an overall low water absorption rate. Furthermore, the water absorption rate of comparative groups 1-3 continued to decrease.

[0027] (II) Fifty mice weighing 50±3g were randomly divided into five groups of ten each. Anesthesia was administered, the back fur of the mice was shaved, and a 1.5cm×1.5cm wound was made. 0.3mL of Staphylococcus aureus solution with a concentration of 10⁶ CFU / mL was dripped into the wound for infection. The infected wounds were covered with sheepskin dressings prepared in Examples 1-3 and Comparative Examples 1-3 of this invention. Hemostasis time was recorded, and the average value was taken. The wound healing rate of the mice was observed on days 2, 4, 8, and 16. The wound healing rate was calculated using the following formula: A = (T-T1) / T×100%, where A is the wound healing rate, T is the original wound area, and T1 is the unhealed wound area. The control group used commercially available ordinary dressings to cover the wounds. The test results are shown in Table 2.

[0028] Table 2

[0029] As can be seen from Table 2, on day 2: the healing rate of the example group was 24.2-25.4%, while that of the comparative group was only 15.3-16.4%, indicating that the example group had a stronger initial wound repair ability.

[0030] Day 4: The gap widened further. The healing rate of the example group was 45.9-49.1%, while that of the control group was only 30-31.2%, showing a significant difference in wound repair rate.

[0031] Day 8: The healing rate of the example group reached 82.2-85.5%, and the wound was basically healed; the rate of the comparative group was 64.1-67.5%, and the repair progress was much slower.

[0032] Day 16: The healing rate in the example group was 98.4-99.7%, and the wound was almost completely healed; the highest in the comparative group was only 80.2%, with obvious wound residue and no good healing. The hemostasis time in the example group was 11-14 seconds, indicating a fast hemostasis speed; among them, Example 2 had the shortest hemostasis time of 11 seconds and the best hemostasis effect. The hemostasis time in the comparative group was 21-25 seconds, and the hemostasis efficiency was significantly weaker. The overall time was nearly twice that of the example group.

[0033] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A long-lasting, moisturizing, soft, human-skin-like dressing, characterized in that, The soft, human-skin-like dressing uses sterilized sheepskin as a base, which is divided into a fur side and a dermal side. The fur side of the sheepskin base is the air contact surface and is loaded with a moisturizing gel layer. The dermal side of the sheepskin base is the wound contact surface and is loaded with growth microparticles. The raw materials for preparing the moisturizing gel, by weight, include: 1-5 parts sodium hyaluronate, 3-8 parts glycerin, 2-8 parts plant extracts, 0.5-2 parts carbomer 940, 0.1-0.5 parts triethanolamine, and 75-95 parts deionized water.

2. The long-lasting moisturizing soft human skin-like dressing according to claim 1, characterized in that, The preparation process of the plant extract is as follows: S1. Take the whole plant of Yellow Flowering Orostachys and Pyrus pyriformis, mix them together and crush them through a 40-60 mesh sieve for later use. S2, put it into the extraction tank, add 70% ethanol aqueous solution at a material-liquid mass ratio of 1:8-1:12, stir at 60-120 r / min for 30 min, after stirring, sonicate at 25-40 kHz and 200-400 W for 20-30 min, heat to 65℃, reflux extraction at constant temperature for 1 h, filter with 100-200 mesh filter cloth, and collect the filtrate; S3. Centrifuge the filtrate at 4000-6000 r / min for 15-20 min, and then concentrate the supernatant to obtain the plant extract.

3. The long-lasting moisturizing soft human skin-like dressing according to claim 2, characterized in that, The weight ratio of the whole plant of *Orostachys pubescens* to *Opuntia ficus-indica* was 0.3:0.

4.

4. The long-lasting moisturizing soft human skin-like dressing according to claim 3, characterized in that, The preparation process of the moisturizing gel is as follows: S1. Mix the plant extract with deionized water, heat to 30-35℃, stir at 60-120r / min for 10-20min to obtain the base solution, and cool to 8-12℃ for later use. S2, mix the base solution and carbomer 940, stir at 160-180 r / min for 30-45 min, add sodium hyaluronate and triethanolamine, continue stirring for 25-40 min, add glycerin, continue stirring for 10-15 min to obtain a moisturizing gel.

5. The long-lasting moisturizing soft human skin-like dressing according to claim 1, characterized in that, The preparation process of the growth microparticles is as follows: S1. Raw material pretreatment: Thaw the frozen fish skin, remove scales, skin mucus, subcutaneous fat and residual fish meat, trim and clean it, rinse with deionized water 3-5 times, drain and set aside. S2. Degreasing and disinfection: Immerse the pre-treated fish skin in 75% ethanol solution at a material-to-liquid mass ratio of 1:10-1:15 for 10-15 minutes; after removal, rinse 2-3 times with sterile PBS buffer. S3. Compound decellularization treatment: Immerse the fish skin in a 0.1% Triton X-100 PBS aqueous solution (pH=7.2-7.4) at a material-to-liquid ratio of 1:10-1:15 and treat with constant temperature shaking at 37℃ for 6-9 hours to remove lipids and cell membrane structures. Rinse continuously with deionized water until no foam residue remains on the surface. Then immerse the fish skin in a 1% SDS aqueous solution and treat with shaking at room temperature for 3-6 hours. After treatment, rinse with deionized water 5-7 times. S4. Nucleic acid removal: Immerse the decellularized fish skin in Tris-HCl buffer solution with a concentration of 0.05 mol / L and pH=7.5 at a material-to-liquid ratio of 1:10-1:15 and incubate at 37℃ for 2-3 hours to degrade residual nucleic acids; after removal, rinse 3-5 times with sterile PBS buffer. S5. Drying and shaping: The treated fish skin is laid flat and pre-frozen at -20℃ for 4-6 hours, and then vacuum freeze-dried. The freeze-drying vacuum degree is 5-10Pa and the freeze-drying time is 24-48 hours. The final moisture content is controlled at 3-5% to obtain the basic skin material. S6. Sterilization and Packaging: The base leather material is aseptically crushed, passed through a 600-mesh sieve, and sterilized by 25-30 kGy gamma irradiation to obtain growth microparticles.

6. The long-lasting moisturizing soft human skin-like dressing according to claim 5, characterized in that, The frozen fish skin is made from a mixture of tilapia skin and cod skin; the weight ratio of tilapia skin to cod skin is 1:0.

3.

7. The long-lasting moisturizing soft human skin-like dressing according to claim 1, characterized in that, The sheepskin base material processing process is as follows: using the skin of an adult sheep as raw material, the wool on the surface of the sheepskin is removed, and the subcutaneous fat is shaved off to obtain a skin piece with a thickness of 0.5-0.8mm. The skin piece is washed with deionized water 3-5 times, and then immersed in a 0.1-0.2% benzalkonium bromide disinfectant solution for 10-30 minutes. Finally, it is rinsed with sterile saline until no disinfectant residue remains, thus obtaining the sheepskin base material.

8. A method for preparing a long-lasting moisturizing soft human skin-like dressing according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Place the sheepskin base material in a Class 100,000 clean operating table, lay sterile gauze at the bottom, and flatten it with sterile tweezers to ensure that the leather piece is wrinkle-free and undamaged; wipe the surface with sterile saline to keep it flat, control the ambient temperature at 20-25℃ and the relative humidity at 40%-60%, and let it air dry until there is no visible water on the surface. S2, with the air-contact side facing up, spread the moisturizing gel to a thickness of 0.5-1.0 mm, and allow it to gel naturally in a sterile environment at 18-24℃ for 30 minutes to form a uniform moisturizing gel layer. S3. Turn the sheepskin coated with moisturizing gel over so that the wound contact surface is facing up. Spread the growth microparticles evenly on the wound surface with a drug loading of 0.1-0.5 mg / cm². Use a sterile pressure plate to apply light pressure of 5-10 kPa and let it stand for 20 minutes in a sterile environment at 18-24℃ to fix it, thus obtaining a soft human skin-like dressing.

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