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CN-121971680-A - Dressing for repairing sunken scars and preparation method thereof

CN121971680ACN 121971680 ACN121971680 ACN 121971680ACN-121971680-A

Abstract

The invention belongs to the technical field of medical dressing, and particularly relates to a concave scar repairing dressing and a preparation method thereof. The sunken scar repairing dressing comprises a hydrophilic fiber layer, a hydrophobic barrier layer and a bioactive layer which are sequentially arranged from the side, which is contacted with the wound surface, of the hydrophilic fiber layer, wherein the hydrophobic barrier layer is partially combined with the surface of the hydrophilic fiber layer in a physical embedding mode, the bioactive layer is fixed on the outer side of the hydrophobic barrier layer in a chemical crosslinking mode, and the hydrophilic fiber layer is formed by polyvinyl alcohol/hyaluronic acid composite fibers prepared by electrostatic spinning. The three-layer structure of the dressing simulates the partial functional gradient of skin, covers hydrophilic absorption, barrier protection and active repair, and meets the physiological repair requirement better. The invention realizes interlayer combination through two mechanisms of physical embedding and chemical crosslinking, remarkably improves the integrity and durability of the dressing and avoids layering in use.

Inventors

  • CAO YINGYING

Assignees

  • 青岛悦美信美容科技有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. A sunken scar repairing dressing is characterized by comprising a hydrophilic fiber layer, a hydrophobic barrier layer and a bioactive layer which are sequentially arranged from the side of a contact wound to the outside, wherein the hydrophobic barrier layer is partially combined to the surface of the hydrophilic fiber layer in a physical embedding mode, the bioactive layer is fixed to the outer side of the hydrophobic barrier layer in a chemical crosslinking mode, the hydrophilic fiber layer is formed by a polyvinyl alcohol/hyaluronic acid composite fiber prepared by electrostatic spinning, the average fiber diameter is 100-500 nanometers, the porosity is 80-95%, the hydrophobic barrier layer is a polycaprolactone porous membrane, the average pore diameter is 0.5-5 microns, the bioactive layer is a double slow-release hydrogel loaded with epidermal growth factor and transforming growth factor-beta 3, and the double slow-release hydrogel is formed by Michael addition reaction of genetically engineered modified sulfhydrylated gelatin and four-arm polyethylene glycol acrylate.
  2. 2. The depressed scar repair dressing of claim 1, wherein polyvinyl alcohol and hyaluronic acid in the hydrophilic fiber layer are cross-linked by glutaraldehyde vapor to form a semi-interpenetrating network structure, and the equilibrium swelling ratio is 150% -400%.
  3. 3. The depressed scar repair dressing of claim 1, wherein the polycaprolactone porous membrane of the hydrophobic barrier layer is prepared by a thermally induced phase separation process having an elastic modulus of 10-50 MPa.
  4. 4. The depressed scar repair dressing of claim 1, wherein the bioactive layer has epidermal growth factor loaded on a hydrogel network by ionic bonding and transforming growth factor- β3 loaded by hydrophobic micro-domain entrapment to achieve sequential release of both.
  5. 5. The depressed scar repair dressing of claim 4, wherein the cumulative release rate of epidermal growth factor over 24 hours is up to 60% and the cumulative release rate of transforming growth factor- β3 over 72 hours is up to 70% under physiological pH conditions.
  6. 6. A method of preparing a recessed scar repair dressing according to any one of claims 1 to 5, comprising the steps of: S1, carrying out electrostatic spinning on a polyvinyl alcohol and hyaluronic acid blend solution, collecting to form a fiber felt, and carrying out glutaraldehyde vapor crosslinking to obtain a hydrophilic fiber layer; S2, coating a polycaprolactone solution on the surface of the hydrophilic fiber layer obtained in the step S1, inducing thermal phase separation through temperature gradient, and forming a porous membrane partially embedded into the fiber layer after leaching and drying to form a hydrophobic barrier layer; S3, mixing sulfhydrylation gelatin, four-arm polyethylene glycol acrylic ester, an epidermal growth factor and a transforming growth factor-beta 3 into a precursor solution, coating the precursor solution on the outer side of the composite structure obtained in the step S2, and initiating Michael addition reaction at 37 ℃ to form hydrogel, thus obtaining a bioactive layer and finishing dressing preparation.
  7. 7. The method according to claim 6, wherein in the step S1, the voltage used for the electrostatic spinning is 18-25 kV%, and the mass ratio of the hyaluronic acid in the polyvinyl alcohol and hyaluronic acid blending solution is 1% -5%.
  8. 8. The method according to claim 6, wherein in step S2, the temperature gradient of the thermally induced phase separation is from 60℃to 4℃at a rate of 1-3℃per minute.
  9. 9. The method according to claim 6, wherein in the step S3, the substitution degree of the sulfhydryl gelatin is 30% -70%, the molecular weight of the four-arm polyethylene glycol acrylate is 5000-20000 Da, and the molar ratio of sulfhydryl group to acrylate group is 1:0.8-1:1.2.
  10. 10. The method according to claim 6, wherein the step S3 is followed by a step S4 of slitting the dressing obtained under aseptic conditions and terminal sterilization by electron beam irradiation.

Description

Dressing for repairing sunken scars and preparation method thereof Technical Field The invention belongs to the technical field of medical dressing, and particularly relates to a concave scar repairing dressing and a preparation method thereof. Background Depressed scars are a common type of scar formed by the repair and replacement of newly-generated fibrous connective tissue after defects in the dermis and subcutaneous tissue of the skin. Traditional repairing methods such as silica gel patches, compression therapy and the like mainly act on the surface of scars, and have limited effects on filling and structural regeneration of deep tissue defects. In recent years, dressings based on the principle of tissue engineering have become a research hotspot. In the prior art, some dressings attempt to promote wound repair by loading growth factors (e.g., epidermal growth factor, EGF). However, it is often difficult to regulate complex scar repair processes throughout the course of a single growth factor, and the growth factor is prone to inactivation, release too rapidly, and effective concentrations are difficult to maintain at the focal site. In addition, the layers of most composite dressings are simply stacked, the interface binding force is weak, interlayer separation easily occurs in use, and the functional integrity and the use experience are affected. In addition, the mechanical properties of the dressing, if not matched to the surrounding tissue, may interfere with the normal repair process. Thus, there is an urgent need for a recessed scar repair dressing that mimics normal skin structure and functional gradients and has layers that are firmly bonded. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a concave scar repairing dressing and a preparation method thereof. In order to achieve the purpose of the invention, the technical scheme adopted by the invention comprises the following steps: According to a first aspect of the embodiment of the invention, a sunken scar repairing dressing is provided, which comprises a hydrophilic fiber layer, a hydrophobic barrier layer and a bioactive layer which are sequentially arranged from the side of a wound surface to the outside, wherein the hydrophobic barrier layer is partially combined with the surface of the hydrophilic fiber layer in a physical embedding way, the bioactive layer is fixed on the outer side of the hydrophobic barrier layer in a chemical crosslinking way, the hydrophilic fiber layer is formed by a polyvinyl alcohol/hyaluronic acid composite fiber prepared by electrostatic spinning, the average fiber diameter is 100-500 nanometers, the porosity is 80-95%, the hydrophobic barrier layer is a polycaprolactone porous membrane, the average pore diameter is 0.5-5 microns, the bioactive layer is a double slow-release hydrogel loaded with an epidermal growth factor and a transforming growth factor-beta 3, and the double slow-release hydrogel is formed by a Michael addition reaction of genetically modified sulfhydrylated gelatin and four-arm polyethylene glycol acrylate. Further, polyvinyl alcohol and hyaluronic acid in the hydrophilic fiber layer are crosslinked through glutaraldehyde vapor to form a semi-interpenetrating network structure, and the equilibrium swelling ratio is 150% -400%. Furthermore, the polycaprolactone porous membrane of the hydrophobic barrier layer is prepared by adopting a thermally induced phase separation method, and the elastic modulus is 10-50 MPa. Furthermore, the epidermal growth factor in the bioactive layer is loaded on the hydrogel network through ionic bonding, and the transforming growth factor-beta 3 is loaded through hydrophobic micro-region embedding, so that the sequential release of the epidermal growth factor and the transforming growth factor-beta 3 is realized. Furthermore, under the physiological pH environment, the cumulative release rate of the epidermal growth factor in 24 hours is more than 60%, and the cumulative release rate of the transforming growth factor-beta 3 in 72 hours is more than 70%. According to a second aspect of embodiments of the present invention, there is provided a method of preparing a recessed scar repair dressing comprising the steps of: S1, carrying out electrostatic spinning on a polyvinyl alcohol and hyaluronic acid blend solution, collecting to form a fiber felt, and carrying out glutaraldehyde vapor crosslinking to obtain a hydrophilic fiber layer; S2, coating a polycaprolactone solution on the surface of the hydrophilic fiber layer obtained in the step S1, inducing thermal phase separation through temperature gradient, and forming a porous membrane partially embedded into the fiber layer after leaching and drying to form a hydrophobic barrier layer; S3, mixing sulfhydrylation gelatin, four-arm polyethylene glycol acrylic ester, an epidermal growth factor and a transforming growth factor-beta 3 into a precursor solution, coating the p