Skin repair functional materials based on ultra-high molecular weight polyethylene nanofilm and their applications

Abstract

The present invention discloses a skin repair functional material based on an ultra-high molecular weight polyethylene nanomembrane and its application, relating to the field of biomaterials and application technology; the functional material comprises an ultra-high molecular weight polyethylene nanomembrane with a three-dimensional porous network structure, and the ultra-high molecular weight polyethylene nanomembrane is prepared by the following steps: 50 to 80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05 to 10 parts of an antioxidant, and 0.1 to 20 parts of a polymer behavior regulator are mixed, and the mixture is premixed at 80° C. to 200° C.; the premix is extruded into a film using an extrusion device, and the extrudate is then biaxially stretched; the biaxially stretched film is extracted; the extracted film is dried, and then the dried film is annealed; the skin repair functional material provided by the present invention has significant advantages in mechanical properties, air permeability, non-toxicity, biocompatibility, antibacterial properties and wound healing, and can meet the needs of various medical materials and beauty and skin care materials.

Description

Technical Field

[0001] The present invention relates to the field of biomaterials and application technologies, and in particular to a skin repair functional material based on ultra-high molecular weight polyethylene nanofilm. Background Art

[0002] A skin dressing is a product that acts on the skin surface through an application to achieve treatment or skin care. Skin dressings typically include therapeutic skin dressings such as wound dressings, acne patches, pain relief patches, transdermal drug delivery patches, as well as nursing skin dressings such as facial masks and eye patches. They are required to have good mechanical properties, breathability, moisturizing properties, non-toxicity, and biocompatibility. In addition, for high-end skin repair or care applications, skin dressings usually also need to have the ability to promote wound healing and tissue regeneration.

[0003] Ultra-high molecular weight polyethylene (UHMWPE) is a high-performance polymer material with high strength, high modulus, wear resistance, chemical corrosion resistance, and good biocompatibility. It is widely used in the medical field, such as artificial joints and orthopedic implants. UHMWPE is prepared into nanofibers. The UHMWPE nanofilm formed by nanofibers has a high specific surface area and high porosity, and is expected to become a high-performance base material for skin dressings. In recent years, studies have shown that UHMWPE is conducive to cell adsorption and proliferation, and nanomaterials prepared with UHMWPE as raw material have been widely used in wounds. Its application in the field of dressings has attracted widespread attention and has shown good application prospects. At present, electrospinning technology is a commonly used method for preparing polymer nanofibers and polymer porous nanomembranes. This technology uses a high-voltage electrostatic field to stretch polymer solutions or melts into nanoscale fibers. However, due to its high molecular weight and high crystallinity, UHMWPE is very difficult to process into porous nanomembranes through electrospinning technology. Therefore, it is necessary to explore new raw material systems and film-forming processes to prepare UHMWPE porous nanomembranes with uniform morphology, excellent mechanical properties and suitable for various skin dressing applications. Summary of the Invention

[0004] The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm provided by the present invention comprises an ultra-high molecular weight polyethylene nanofilm; the ultra-high molecular weight polyethylene nanofilm has a three-dimensional porous network structure and is prepared by the following steps:

[0005] Premixing the raw materials: mixing 50-80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05-10 parts by weight of an antioxidant, and 0.1-20 parts by weight of a polymer behavior regulator, and then premixing at 80° C. to 200° C. to obtain a premix;

[0006] Extrusion and stretching: Extruding the premix into a film using an extrusion device, and then biaxially stretching the extrudate;

[0007] Extraction: Use an extractant to extract the biaxially stretched film;

[0008] Drying and annealing: drying the extracted film, and then annealing the dried film to obtain the ultra-high molecular weight polyethylene nanofilm.

[0009] Optionally, the ultra-high molecular weight polyethylene powder has a molecular weight of 1 to 10 million Daltons, a particle size of 100 to 300 μm, and a density of 0.931 to 0.949 g / cm 3 .

[0010] Optionally, in the step of premixing the raw materials, the ultra-high molecular weight polyethylene powder is 67 parts by weight, the antioxidant is 3 parts by weight, and the polymer behavior regulator is 8 parts by weight.

[0011] Optionally, the antioxidant is at least one of butylated hydroxytoluene, butylated hydroxybenzoic acid, sodium sulfite, tert-butylhydroquinone, propyl gallate, and sodium ascorbate.

[0012] Optionally, the polymer behavior regulator is at least one of polyvinyl alcohol, sodium polyacrylate, calcium stearate, mineral oil, paraffin oil, edible oil, oxidized polyethylene wax, dodecyl mercaptan, mercaptopropionic acid, dicumyl peroxide, decalin, sorbitol derivatives, aluminum benzoate, polyurethane, ethylene-vinyl acetate copolymer, maleic anhydride grafted PE, polyvinyl acetal, and polyethylene glycol formal.

[0013] Optionally, the extrusion equipment is a twin-screw extruder;

[0014] The parameters for extruding the premix into a film using the twin-screw extruder include: screw diameter 30-200 nm, screw length-to-diameter ratio 15-60:1, screw speed 1-200 rpm, feeding section temperature 25-150° C., compression section temperature 100-160° C., metering section temperature 150-250° C., melt temperature 150-250° C., and extrusion pressure 15 MPa.

[0015] Optionally, the extractant is at least one of n-hexane, dichloromethane, ethyl acetate, ethyl acetate / ethanol mixture, ethanol, ethanol aqueous solution, gasoline, cooking oil, xylene, tetrachloroethane, methanol, acetone, deionized water, isopropanol, ether, cyclohexane, and supercritical carbon dioxide.

[0016] Optionally, in the extraction step, multiple extractants are used to perform step-by-step gradient extraction on the biaxially stretched film.

[0017] Optionally, in the extraction step, the biaxially stretched film is subjected to stepwise gradient extraction using n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% ethanol aqueous solution, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water in sequence.

[0018] Optionally, in the drying and annealing steps, the drying temperature is 50-100°C, and the annealing temperature is 50-150°C.

[0019] Optionally, the skin repair functional material based on ultra-high molecular weight polyethylene nanofilm further comprises at least one of an organic hydrophobic material, an organic hydrophilic material, an inorganic nanoparticle, a natural active ingredient, and an artificially synthesized active ingredient loaded on the ultra-high molecular weight polyethylene nanofilm.

[0020] The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm provided by the present invention is suitable for various medical materials or cosmetic skin care materials.

[0021] The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm can be used as a chronic wound patch, a surgical scar-free patch, an acne patch, a medical beauty protective patch or a facial mask.

[0022] Optionally, the thickness of the ultra-high molecular weight polyethylene nanofilm in the ultra-high molecular weight polyethylene nanofilm-based skin repair functional material is 20 nm to 5 μm.

[0023] Optionally, the porosity of the ultra-high molecular weight polyethylene nanomembrane is 25% to 80%.

[0024] Optionally, the pore size of the ultra-high molecular weight polyethylene nanomembrane is 10 nm to 300 nm.

[0025] Optionally, the elongation at break of the ultra-high molecular weight polyethylene nanofilm is 50-300%.

[0026] The technical solution of the present invention has the following beneficial effects:

[0027] The present invention adopts an improved formula design, adopts a combination of ultra-high molecular weight polyethylene powder, antioxidants and polymer behavior regulators in a specific ratio, and combines premixing, extrusion, biaxial stretching and extraction processes to prepare an ultra-high molecular weight polyethylene nanomembrane with a three-dimensional porous network structure formed by interweaving nanofibers. It not only has excellent mechanical properties and good biocompatibility, and is non-toxic, but also can obtain the target pore size, porosity and thickness by regulating the process parameters, so that the prepared skin repair functional material based on ultra-high molecular weight polyethylene nanomembrane is suitable for various skin application needs; in addition, the ultra-high molecular weight polyethylene nanomembrane used in the present invention can also effectively block the penetration of pathogens, aerosols and contaminated liquids. Preclinical experiments have shown that the prepared ultra-high molecular weight polyethylene nanomembrane can effectively promote wound healing and tissue regeneration, and is suitable for clinical wound healing needs such as wound dressing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 SEM images of ultra-high molecular weight polyethylene nanofilms (20 nm thickness) prepared in some embodiments of the present invention;

[0030] Figure 2 TEM images of ultra-high molecular weight polyethylene nanofilms (20 nm thickness) prepared in some embodiments of the present invention;

[0031] Figure 3 This is a surface contact angle test diagram of ultra-high molecular weight polyethylene nanofilms prepared in some embodiments of the present invention;

[0032] Figure 4 A comparison of the air permeability of ultra-high molecular weight polyethylene nanofilms prepared in some embodiments of the present invention and traditional commercial wound dressings;

[0033] Figure 5 Aerosol barrier test images of ultra-high molecular weight polyethylene nanofilms prepared according to some embodiments of the present invention;

[0034] Figure 6 Images of changes in wound appearance in preclinical experiments conducted on ultra-high molecular weight polyethylene nanofilms prepared in some embodiments of the present invention and a control group;

[0035] Figure 7 for Figure 6 A graph showing the changes in wound healing rate over time in preclinical experiments is shown;

[0036] Figure 8 for Figure 6 The images shown here are of wound healing characterized by HE and Masson staining in preclinical experiments;

[0037] Figure 9 for Figure 6 The ToF-SIMS characterization images of the chemical composition of ultra-high molecular weight polyethylene nanomembranes from the inside out after a period of time in preclinical experiments are shown. DETAILED DESCRIPTION

[0038] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm proposed in the embodiment of the present invention includes ultra-high molecular weight polyethylene nanofilm; ultra-high molecular weight polyethylene (UHMWPE) nanofilm can be directly used as a skin repair functional material; or ultra-high molecular weight polyethylene nanofilm is used as a substrate to load other materials or functional components to form a skin repair functional material; the skin repair functional material is used as a skin dressing, including but not limited to therapeutic skin dressings such as wound dressings, acne patches, analgesic dressings, transdermal drug delivery dressings, as well as care skin dressings such as facial masks and eye patches.

[0040] In the existing technology, since UHMWPE exhibits high viscoelasticity in the molten state and poor melt fluidity, it is easy to form "material plugs" when it is extruded into films using traditional extrusion equipment, which makes processing very difficult and has low production efficiency.

[0041] The inventor's research team has conducted in-depth research on the preparation of UHMWPE films in previous work: for example, the patent "Nanoporous Ultra-High Molecular Weight Polyethylene Film" with publication number CN109997247A provides a method for preparing biaxially oriented nanoporous UHMWPE films. This method reduces the melt viscosity and polymer chain entanglement density of UHMWPE during processing by adding petrolatum to the ultra-high molecular weight polyethylene raw material, thereby improving the fluidity of the material and greatly reducing the processing difficulty of UHMWPE. The prepared UHMWPE film has The self-supporting structure can adjust the thickness, pore size, porosity and other parameters of the UHMWPE film by adjusting the stretching ratio and controlling the annealing temperature, making it suitable for lithium-ion battery separators; the patent with publication number CN111491719A, "Synthesis method of flexible multifunctional high-porosity ultra-thin polyethylene film", uses a controlled biaxial stretching process to prepare an ultra-thin (less than 100nm) porous polyethylene film with high mechanical strength; the patent with publication number CN110960995A uses UHMWPE films with specific thickness, pore size, porosity and tensile strength for seawater desalination.

[0042] However, UHMWPE films prepared by existing methods often face the following challenges when used in biomaterial fields such as skin dressings: First, the film performance is uneven. During the preparation process, existing UHMWPE films often have large differences in physical properties such as film thickness, mechanical strength, porosity, and pore size due to differences in raw material ratios, uneven mixing, and improper extrusion process control, affecting the quality and application effect of the final product; second, insufficient barrier properties. Existing UHMWPE films are mainly used as ion membranes and perform poorly in terms of high air permeability and barrier to aerosol and liquid penetration, and cannot meet the needs of high-end medical and beauty skin care applications; third, poor biocompatibility. Many existing polymer film materials are prone to adverse reactions when in contact with biological tissues, limiting their application in the medical or beauty skin care fields.

[0043] Therefore, based on the previous research of the research team, the skin repair functional material based on ultra-high molecular weight polyethylene nanofilm proposed in the embodiment of the present invention uses ultra-high molecular weight polyethylene nanofilm, which has been improved in raw material components and preparation process to meet the application needs of medical and beauty skin care. The prepared ultra-high molecular weight polyethylene nanofilm has significant advantages in mechanical properties, air permeability, non-toxicity, biocompatibility, antibacterial properties and wound healing.

[0044] Specifically, in an embodiment of the present invention, the ultra-high molecular weight polyethylene nanofilm has a three-dimensional porous network structure formed by interweaving nanofibers, and is prepared by the following steps:

[0045] S1, premixing of raw materials: 50-80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05-10 parts by weight of antioxidant, and 0.1-20 parts by weight of polymer behavior regulator are mixed, and then premixed at 80° C. to 200° C. to obtain a premix.

[0046] The molecular weight of ultra-high molecular weight polyethylene powder is 1~10 million Daltons, the particle size is 100~300μm, and the density is 0.931~0.949g / cm 3 .

[0047] Antioxidants are used to prevent free radical cascade reactions and ensure the stability of polymer materials at high temperatures; antioxidants include but are not limited to one or more of butylated hydroxytoluene, butylated hydroxybenzoic acid, sodium sulfite, tert-butylhydroquinone, propyl gallate, and sodium ascorbate.

[0048] Polymer behavior regulators are used to reduce the melt viscosity of ultra-high molecular weight polyethylene during processing and reduce the entanglement density of polymer chains, so that the premix can be formed into a film through extrusion and stretching processes; polymer behavior regulators include but are not limited to one or more of polyvinyl alcohol, sodium polyacrylate, calcium stearate, mineral oil, paraffin oil, edible oil, oxidized polyethylene wax, dodecyl mercaptan, mercaptopropionic acid, diisopropyl benzene peroxide, decalin, sorbitol derivatives, aluminum benzoate, polyurethane, ethylene-vinyl acetate copolymer, maleic anhydride grafted PE, polyvinyl acetal, and polyethylene glycol formal.

[0049] In some preferred embodiments, by weight, the ultra-high molecular weight polyethylene powder is 67 parts, the antioxidant is 3 parts, and the polymer behavior regulator is 8 parts; this raw material ratio has good processing performance, and the prepared ultra-high molecular weight polyethylene nanofilm exhibits excellent mechanical properties.

[0050] S2, extrusion and stretching: The premix is extruded into a film using an extrusion device, and then the extrudate is biaxially stretched to achieve the desired thickness and physical properties of the film.

[0051] Among them, the extrusion equipment can be a twin-screw extruder.

[0052] The specific parameters for extruding the premix into a film using a twin-screw extruder are: screw diameter 30~200nm, screw length to diameter ratio 15~60:1, screw speed 1~200rpm, feeding section temperature 25~150℃, compression section temperature 100~160℃, metering section temperature 150~250℃, melt temperature 150~250℃, and extrusion pressure 15MPa.

[0053] In the embodiment of the present invention, the gel film extruded by the extrusion device can be stretched by a biaxial stretching device or stretched in two perpendicular directions by a uniaxial stretching device; the film after stretching has biaxial orientation, thereby improving the mechanical properties of the film.

[0054] By controlling the stretching ratio of biaxial stretching, the thickness of the prepared ultra-high molecular weight polyethylene nanofilm can be adjusted in the range of 20nm~5μm, the pore size can be adjusted in the range of 10nm~300nm, and the porosity can be adjusted in the range of 25%~80%.

[0055] In some preferred embodiments, the pore size of the prepared ultra-high molecular weight polyethylene nanomembrane is in the range of 20 to 50 nm, which can effectively block the penetration of most pathogens and larger liquid / solid particles.

[0056] S3, Extraction: Extract the biaxially oriented film to remove potential allergens and other impurities; other impurities usually include some unreacted monomers or low molecular weight substances.

[0057] The extractant includes but is not limited to one or more of n-hexane, dichloromethane, ethyl acetate, ethyl acetate / ethanol mixture, ethanol, ethanol aqueous solution), gasoline, edible oil, xylene, tetrachloroethane, methanol, acetone, deionized water, isopropanol, ether, cyclohexane, and supercritical carbon dioxide.

[0058] In the embodiment of the present invention, the extraction method can adopt a plurality of extractants for step-by-step gradient extraction to fully remove potential allergens and other impurities, so that the finally prepared ultra-high molecular weight polyethylene nanofilm has non-toxicity and good biocompatibility.

[0059] In some preferred embodiments, the biaxially stretched film can be subjected to stepwise gradient extraction using n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% ethanol aqueous solution, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water in sequence.

[0060] S4, drying and annealing: drying the extracted film, and then annealing the dried film to obtain an ultra-high molecular weight polyethylene nanofilm.

[0061] The drying temperature can be selected from 50 to 100°C to fully remove the residual solvent, and the annealing temperature can be selected from 50 to 150°C to improve the stability and mechanical properties of the film.

[0062] The microstructure of the ultra-high molecular weight polyethylene nanofilm prepared in the embodiment of the present invention can be characterized by SEM (scanning electron microscopy) and TEM (transmission electron microscopy), as shown in FIG. Figure 1 and Figure 2 As shown, it can be clearly seen that the ultra-high molecular weight polyethylene nanomembrane has a three-dimensional porous network structure.

[0063] The embodiment of the present invention adopts an improved formula design, adopts a combination of ultra-high molecular weight polyethylene powder, antioxidants and polymer behavior regulators in a specific ratio, and combines premixing, extrusion, biaxial stretching and extraction processes to prepare an ultra-high molecular weight polyethylene nanomembrane with a three-dimensional porous network structure formed by interweaving nanofibers. The prepared ultra-high molecular weight polyethylene nanomembrane not only has excellent mechanical properties (flexibility, tensile strength and peel strength, etc.) and good biocompatibility and is non-toxic, but also can obtain the target pore size, porosity and thickness by regulating the process parameters, making the prepared ultra-high molecular weight polyethylene nanomembrane suitable for various skin application needs.

[0064] In addition, the ultra-high molecular weight polyethylene nanomembrane used in the skin repair functional material based on ultra-high molecular weight polyethylene nanomembrane of the present invention can also effectively block the penetration of pathogens, aerosols and contaminated liquids. Preclinical experiments have shown that the prepared ultra-high molecular weight polyethylene nanomembrane can effectively promote wound healing and tissue regeneration, and is suitable for clinical wound healing needs such as wound dressing.

[0065] Based on the preparation method proposed in the above embodiment, in order to more clearly illustrate the implementation mode, research process and beneficial effects of the technical solution of the present invention, the present invention designed the following experimental group and control group; wherein, the experimental group includes several specific embodiments, and the control group includes several comparative examples; it can be understood that the experimental group and the control group are only exemplary and do not constitute any form of limitation to the scope of protection of the present invention.

[0066] Example 1

[0067] The ultra-high molecular weight polyethylene nanofilm provided in this embodiment is prepared by the following steps:

[0068] (1) Raw material preparation:

[0069] The ultra-high molecular weight polyethylene powder used has a molecular weight of 1 million Dalton, a particle size of 100 μm, and a density of 0.931 g / cm 3 ; The antioxidant is butylated hydroxytoluene and the polymer regulator is polyvinyl alcohol.

[0070] 50 parts by weight of ultra-high molecular weight polyethylene powder, 0.05 parts by weight of an antioxidant, and 0.1 parts by weight of a polymer behavior regulator were weighed and fully mixed in a dry environment to ensure uniformity of the components, thereby obtaining a mixture.

[0071] (2) Premix:

[0072] The mixture was premixed at 80°C.

[0073] (3) Extrusion:

[0074] The premix was extruded using a twin-screw extruder to form a preliminary nanofilm morphology.

[0075] Among them, the screw diameter is 30mm, the screw length to diameter ratio is 15:1, the screw speed is 1.0rpm; the heating zone temperature: the feeding section is 25℃, the compression section is 100℃, the metering section is 150℃, the melt temperature is 150℃; the extrusion pressure is 15MPa.

[0076] (4) Biaxial stretching:

[0077] The extrudate is passed through a biaxial film stretching machine for biaxial stretching to achieve the desired film thickness and mechanical properties.

[0078] (5) Extraction:

[0079] The biaxially stretched film was subjected to stepwise gradient extraction using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

[0080] (6) Drying and annealing:

[0081] The extracted nanofilm was dried at 50°C to remove the residual solvent, and then annealed at 50°C.

[0082] (7) Film roll:

[0083] The final formed ultra-high molecular weight polyethylene nanofilm is wound into shape.

[0084] Example 2

[0085] The ultra-high molecular weight polyethylene nanofilm provided in this embodiment is prepared by the following steps:

[0086] (1) Raw material preparation:

[0087] The ultra-high molecular weight polyethylene powder used has a molecular weight of 10 million Daltons, a particle size of 300 μm, and a density of 0.949 g / cm 3 ; The antioxidant is butylated hydroxybenzoic acid and the polymer regulator is sodium polyacrylate.

[0088] 80 parts by weight of ultra-high molecular weight polyethylene powder, 10 parts by weight of an antioxidant, and 20 parts by weight of a polymer behavior regulator were weighed and fully mixed in a dry environment to ensure uniformity of the components, thereby obtaining a mixture.

[0089] (2) Premix:

[0090] The mixture was premixed at 200°C.

[0091] (3) Extrusion:

[0092] The premix was extruded using a twin-screw extruder to form a preliminary nanofilm morphology.

[0093] Among them, the screw diameter is 200mm, the screw length to diameter ratio is 60:1, the screw speed is 200rpm; the heating zone temperature: the feeding section is 150℃, the compression section is 160℃, the metering section is 250℃, the melt temperature is 250℃; the extrusion pressure is 15MPa.

[0094] (4) Biaxial stretching:

[0095] The extrudate is passed through a biaxial film stretching machine for biaxial stretching to achieve the desired film thickness and mechanical properties.

[0096] (5) Extraction:

[0097] The biaxially stretched film was subjected to stepwise gradient extraction using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

[0098] (6) Drying and annealing:

[0099] The extracted nanofilm was dried at 100°C to remove the residual solvent and then annealed at 150°C.

[0100] (7) Film roll:

[0101] The final formed ultra-high molecular weight polyethylene nanofilm is wound into shape.

[0102] Example 3

[0103] The ultra-high molecular weight polyethylene nanofilm provided in this embodiment is prepared by the following steps:

[0104] (1) Raw material preparation:

[0105] The ultra-high molecular weight polyethylene powder used has a molecular weight of 3 million Daltons, a particle size of 250 μm, and a density of 0.931 g / cm 3 ; The antioxidant is sodium sulfite and the polymer regulator is polyurethane.

[0106] 60 parts by weight of ultra-high molecular weight polyethylene powder, 2 parts by weight of an antioxidant, and 10 parts by weight of a polymer behavior regulator were weighed and fully mixed in a dry environment to ensure uniformity of the components, thereby obtaining a mixture.

[0107] (2) Premix:

[0108] The mixture was premixed at 115°C.

[0109] (3) Extrusion:

[0110] The premix was extruded using a twin-screw extruder to form a preliminary nanofilm morphology.

[0111] Among them, the screw diameter is 60mm, the screw length to diameter ratio is 50:1, the screw speed is 40rpm; the heating zone temperature: the feeding section is 50℃, the compression section is 140℃, the metering section is 180℃, the melt temperature is 220℃; the extrusion pressure is 15MPa.

[0112] (4) Biaxial stretching:

[0113] The extrudate is passed through a biaxial film stretching machine for biaxial stretching to achieve the desired film thickness and mechanical properties.

[0114] (5) Extraction:

[0115] The biaxially stretched film was subjected to stepwise gradient extraction using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

[0116] (6) Drying and annealing:

[0117] The extracted nanofilm was dried at 65°C to remove residual solvent and then annealed at 130°C.

[0118] (7) Film roll:

[0119] The final formed ultra-high molecular weight polyethylene nanofilm is wound into shape.

[0120] Example 4

[0121] The ultra-high molecular weight polyethylene nanofilm provided in this embodiment is prepared by the following steps:

[0122] (1) Raw material preparation:

[0123] The ultra-high molecular weight polyethylene powder used has a molecular weight of 8 million Daltons, a particle size of 125 μm, and a density of 0.949 g / cm 3 ; The antioxidant is butylated hydroxytoluene and the polymer regulator is polyvinyl alcohol.

[0124] 75 parts by weight of ultra-high molecular weight polyethylene powder, 5 parts by weight of an antioxidant, and 6 parts by weight of a polymer behavior regulator were weighed and fully mixed in a dry environment to ensure uniformity of the components, thereby obtaining a mixture.

[0125] (2) Premix:

[0126] The mixture was premixed at 180°C.

[0127] (3) Extrusion:

[0128] The premix was extruded using a twin-screw extruder to form a preliminary nanofilm morphology.

[0129] Among them, the screw diameter is 180mm, the screw length to diameter ratio is 20:1, the screw speed is 30rpm; the heating zone temperature: the feeding section is 130℃, the compression section is 120℃, the metering section is 220℃, the melt temperature is 180℃; the extrusion pressure is 15MPa.

[0130] (4) Biaxial stretching:

[0131] The extrudate is passed through a biaxial film stretching machine for biaxial stretching to achieve the desired film thickness and mechanical properties.

[0132] (5) Extraction:

[0133] The biaxially stretched film was subjected to stepwise gradient extraction using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

[0134] (6) Drying and annealing:

[0135] The extracted nanofilm was dried at 85°C to remove residual solvent and then annealed at 75°C.

[0136] (7) Roll film:

[0137] The final formed ultra-high molecular weight polyethylene nanofilm is wound into shape.

[0138] Example 5

[0139] The ultra-high molecular weight polyethylene nanofilm provided in this embodiment is prepared by the following steps:

[0140] (1) Raw material preparation:

[0141] The ultra-high molecular weight polyethylene powder used has a molecular weight of 5 million Daltons, a particle size of 200 μm, and a density of 0.931 g / cm 3 ; The antioxidant is sodium sulfite and the polymer regulator is polyvinyl acetal.

[0142] 67 parts by weight of ultra-high molecular weight polyethylene powder, 3 parts by weight of an antioxidant, and 8 parts by weight of a polymer behavior regulator were weighed and fully mixed in a dry environment to ensure uniformity of the components, thereby obtaining a mixture.

[0143] (2) Premix:

[0144] The mixture was premixed at 155°C.

[0145] (3) Extrusion:

[0146] The premix was extruded using a twin-screw extruder to form a preliminary nanofilm morphology.

[0147] Among them, the screw diameter is 100mm, the screw length to diameter ratio is 45:1, the screw speed is 120rpm; the heating zone temperature: the feeding section is 130℃, the compression section is 140℃, the metering section is 200℃, the melt temperature is 200℃; the extrusion pressure is 15MPa.

[0148] (4) Biaxial stretching:

[0149] The extrudate is passed through a biaxial film stretching machine for biaxial stretching to achieve the desired film thickness and mechanical properties.

[0150] (5) Extraction:

[0151] The biaxially stretched film was subjected to stepwise gradient extraction using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

[0152] (6) Drying and annealing:

[0153] The extracted nanofilm was dried at 75°C to remove the residual solvent and then annealed at 100°C.

[0154] (7) Film roll:

[0155] The final formed ultra-high molecular weight polyethylene nanofilm is wound into shape.

[0156] Example 6

[0157] The difference between this embodiment and embodiment 5 is that the extraction operation in step (5) is not performed, and the remaining steps are the same as those in embodiment 5.

[0158] Example 7

[0159] The difference between this embodiment and embodiment 5 is that in step (5), 100% n-hexane, 100% dichloromethane, 100% ethyl acetate and deionized water are used for stepwise gradient extraction; the remaining steps are the same as those in embodiment 5.

[0160] Example 8

[0161] The difference between this embodiment and embodiment 5 is that in step (5), 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, and deionized water are used for stepwise gradient extraction; the remaining steps are the same as those in embodiment 5.

[0162] Comparative Example 1

[0163] The difference between this comparative example and Example 5 is that the antioxidant is removed from the raw materials; the remaining steps are carried out with reference to Example 5.

[0164] Comparative Example 2

[0165] The difference between this comparative example and Example 5 is that the polymer behavior regulator is removed from the raw materials; the remaining steps are carried out with reference to Example 5.

[0166] Comparative Example 3

[0167] The difference between this comparative example and Example 5 is that the antioxidant and the polymer behavior regulator are removed from the raw materials; the remaining steps are carried out with reference to Example 5.

[0168] Comparative Example 4

[0169] The difference between this comparative example and Example 5 is that low-density polyethylene (LDPE) is used instead of ultra-high molecular weight polyethylene; the remaining steps are carried out with reference to Example 5.

[0170] The experimental results show that comparative examples 2-4 cannot form films; films with a thickness of 100 μm were prepared using Examples 1-8 and comparative example 1, respectively, and the films were subjected to tensile tests, peel strength tests, and sensitization tests.

[0171] Among them, the tensile test uses a material testing machine to perform tensile tests on samples in accordance with ASTM D638 standards; during the test, the maximum tensile strength and elongation at break of the sample are recorded.

[0172] During the peel strength test, the sample is attached to a suitable simulated skin material (e.g., polyurethane film, fresh skin from a model animal) to ensure that the contact area between different samples and the substrate is consistent. Use a peel tester to perform the peel strength test according to ASTM D903, record the peel force, and calculate the peel strength.

[0173] Sensitization tests include volunteer skin sensitization tests and cytotoxicity tests. Specifically, the material is attached to the volunteer's skin, and the skin is checked for redness, swelling, rash, itching or other discomfort after 1, 3, 6, 9, and 12 hours. The cytotoxicity test uses L929 and NIH-3T3 cell lines as models, and the CCCK-8 method as the detection method, with a cell survival rate of more than 95% as the judgment standard for non-sensitization.

[0174] The test results of the tensile test, peel strength test, and sensitization test are shown in Table 1.

[0175] The results of the tensile test showed that the tensile strength of the samples prepared in each embodiment of the experimental group reached 500MPa~1000MPa, and the elongation at break reached 50%-300%, which indicates that the ultra-high molecular weight polyethylene nanofilm prepared by the experimental group has excellent rigidity and strength, can effectively resist external stress, and is suitable for high-load application scenarios.

[0176] The results of the peel strength test showed that the peel strength of the samples prepared in each embodiment of the experimental group reached 4.7~5.0N / m, indicating that the ultra-high molecular weight polyethylene nanofilm prepared in the experimental group can be in close contact with the skin through van der Waals force, maintaining good fit, and ensuring that it will not fall off from the skin during exercise or daily activities.

[0177] The results of the sensitization test showed that the ultra-high molecular weight polyethylene nanofilms prepared by the gradient extraction solvent system adopted in Examples 1-5 and Example 8 had good biocompatibility and non-toxicity, and met the non-sensitization standards in the volunteer skin sensitization test and cytotoxicity test.

[0178] Among them, the tensile strength of the nanofilm prepared in Example 5 reaches 900 MPa, the elongation at break reaches 160%, the peel strength reaches 5.0 N / m, and it is non-allergenic, meeting the requirements of high-performance skin dressings for mechanical strength and biocompatibility.

[0179] Table 1 Tensile test, peel test and sensitization test results of different samples

[0180]

[0181] In Table 1, NA means that film formation was not possible and thus testing could not be performed.

[0182] The test results of the control group showed that the antioxidant was removed in Comparative Example 1, and the strength and flexibility of the membrane were significantly reduced; this phenomenon was mainly caused by the following reasons: the oxidation stability was reduced. Without the protection of the antioxidant, the membrane material was more susceptible to oxidation reactions, resulting in a decrease in the physical and chemical properties of the material; oxidation can cause the material to become brittle, reduce strength and shorten its service life; the oxidation reaction can cause the polymer chain to break, thereby affecting the Young's modulus and tensile strength of the material.

[0183] Comparative Example 2 removed the polymer behavior regulator, and Comparative Example 3 removed both the antioxidant and the polymer behavior regulator. The results showed that in the absence of a polymer behavior regulator, the fluidity of the UHMWPE material during processing would decrease significantly, resulting in difficulty in molding and inability to form a film; Comparative Example 4 showed that using low-density polyethylene to replace the ultra-high molecular weight polyethylene in the experimental group also made film formation difficult.

[0184] It can be seen from this that the embodiments of the present invention adopt a specific combination of ultra-high molecular weight polyethylene powder, antioxidants and polymer behavior regulators, combined with optimized premixing, extrusion, biaxial stretching and extraction processes, so that the prepared ultra-high molecular weight polyethylene nanofilm has excellent mechanical strength, peel strength, non-toxicity and biocompatibility; among them, the ultra-high molecular weight polyethylene nanofilm prepared in Example 5 has a tensile strength of 900 MPa, an elongation at break of 160%, and a peel strength of 5.0 N / m. Ultra-high molecular weight polyethylene nanofilms of this strength can be used as skin dressings in the application environment of various medical materials or beauty and skin care materials. It remains stable and is not easy to tear or damage; and the ultra-high molecular weight polyethylene nanofilm prepared in Example 5 has non-toxicity and excellent biocompatibility, and is suitable for high-standard medical dressings, medical protective materials and other needs.

[0185] In addition, in the preparation process of the ultra-high molecular weight polyethylene nanofilms in Examples 1-5, the UHMWPE material exhibited good processing properties. Therefore, the ultra-high molecular weight polyethylene films prepared in the examples of the present invention are suitable for large-scale production and have industrial value.

[0186] Based on Example 5, which has the best comprehensive performance in the above experimental group, the present invention further conducted additional tests on the ultra-high molecular weight polyethylene film prepared in Example 5 to explore its performance as a wound dressing. The relevant test results are as follows: Figure 1-9 shown.

[0187] Among them, the preclinical experiment of wound dressing used two ultra-high molecular weight polyethylene nanofilms of different thicknesses as experimental groups, namely GPNano-H (solid thickness of about 820nm) and GPNano-L (solid thickness of about 85nm).

[0188] Figure 1This is the SEM image of the ultra-high molecular weight polyethylene nanofilm sample (20nm thickness). Figure 2 This is a TEM image of an ultra-high molecular weight polyethylene nanomembrane sample (20nm thickness); the SEM image and TEM image show that there are no obvious particles or defects on the surface of the film, and the overall surface is relatively smooth and uniform, which is beneficial to improving the biocompatibility of the film and reducing irritation to skin tissue; the SEM image and TEM image also reveal that the ultra-high molecular weight polyethylene nanomembrane has a tiny pore structure with a pore size of approximately 20~50nm and a porosity that can be adjusted between 25% and 80%, which not only helps to improve the air permeability of the membrane, allowing water vapor to pass through, but also can effectively block the penetration of most pathogens and larger liquid / solid particles.

[0189] Figure 3 This is an image of the contact angle test of the droplet surface of the ultra-high molecular weight polyethylene nanofilm sample. The contact angle of the water droplet on the sample surface reaches 130°, indicating that the ultra-high molecular weight polyethylene nanofilm has good hydrophobic properties and can effectively block liquid penetration.

[0190] Figure 4 This is a comparison chart of the air permeability test results of ultra-high molecular weight polyethylene nanofilm samples GPNano-H and GPNano-L and the commercial transparent dressing "Tegaderm". The air permeability test results show that the air permeability flux of GPNano-L reaches 5.6×10 6 L / m 2 / 24h, the air permeability of GPNano-H reached 7×10 5 L / m 2 / 24h, while the traditional commercial dressing "Tegaderm" has a permeability flux of only 2.74 L / m 2 / 24h, the air permeability of the ultra-high molecular weight polyethylene nanofilm sample was about 250,000 to 2 million times higher than that of "Tegaderm".

[0191] Figure 5 This is an aerosol barrier test diagram of an ultra-high molecular weight polyethylene nanofilm sample. Its three-dimensional porous network structure can effectively block aerosol particles within the range of 75±25nm.

[0192] Combine Figure 1-5 The test results show that the ultra-high molecular weight polyethylene nanofilm prepared in the embodiment of the present invention has excellent barrier properties against pathogens, aerosols and liquids, and also has extremely excellent air permeability; the excellent air permeability can effectively discharge moisture and prevent the wound environment from being too humid. These properties are crucial for preventing wound infection and promoting healing.

[0193] Furthermore, the ultra-high molecular weight polyethylene nanofilm samples GPNano-H and GPNano-L were used in preclinical experiments on wound healing. A control group without wound dressing and a control group using the traditional commercial dressing "Tegaderm" were set up to observe the healing of the wounds on the 0th, 5th, 9th and 14th days respectively. The experimental results are as follows Figure 6 and Figure 7 As shown, Figure 6 This is a diagram showing changes in wound appearance. Figure 7 The figure shows the changes of wound healing rate over time.

[0194] Depend on Figure 6 and Figure 7 It can be seen that the wounds using the ultra-high molecular weight polyethylene nanofilm provided by the embodiment of the present invention as wound dressing have a significantly improved healing rate within 14 days compared with the control group; among them, the wounds using the GPNano-H sample have been completely healed in 14 days, and in subsequent observations, the wound healing time was shortened by nearly 50% compared with the control group. The experimental results show that the ultra-high molecular weight polyethylene nanofilm can effectively accelerate the healing rate of wounds; in addition, no obvious scab was observed during the wound healing process of the GPNano-H group, and there was almost no obvious scar after the wound healed. The GPNano-L group also had only slight scab and scar, which shows that during the wound healing process, the ultra-high molecular weight polyethylene nanofilm can effectively reduce the formation of scars; in addition, during the experiment, no obvious inflammatory reaction or other adverse reactions were observed in the GPNano-H group and the GPNano-L group, indicating that the ultra-high molecular weight polyethylene nanofilm has good biocompatibility and is suitable for clinical wound healing.

[0195] Furthermore, in the above preclinical experiments on wound healing, HE (hematoxylin-eosin staining) and Masson staining techniques were used to evaluate the wound healing. The experimental results are as follows: Figure 8 shown.

[0196] Among them, HE staining is a commonly used histological staining method that can clearly show the structure of tissues and the distribution of cells. In this experiment, HE staining was used to observe the formation of new tissues during wound healing.

[0197] Masson staining is mainly used to observe the distribution of collagen fibers and can provide information about collagen deposition during wound healing.

[0198] Depend on Figure 8It can be seen that the number of cells in the wound area using ultra-high molecular weight polyethylene nanofilm increased significantly, indicating active cell proliferation. This phenomenon shows that ultra-high molecular weight polyethylene nanofilm can effectively promote cell migration and proliferation, thereby accelerating wound healing. It was also observed that the tissue structure after wound healing was relatively complete and the cells were arranged regularly, which indicates that the quality of the new tissue is high. The restoration of this structure is crucial for the functional recovery of skin tissue and can ensure that the skin has normal physiological functions after wound healing.

[0199] Masson staining results showed that the deposition of collagen fibers in the wound area using ultra-high molecular weight polyethylene nanofilm increased significantly and was arranged in a more orderly manner, indicating that ultra-high molecular weight polyethylene nanofilm not only promoted cell proliferation, but also promoted the synthesis and deposition of collagen, which contributed to the structural reconstruction of the wound; compared with the control group, the wounds using ultra-high molecular weight polyethylene nanofilm formed fewer scars in terms of collagen deposition, indicating that ultra-high molecular weight polyethylene nanofilm can promote scarless healing.

[0200] Furthermore, ToF-SIMS (time-of-flight secondary ion mass spectrometry) was used to analyze the chemical composition of the ultra-high molecular weight polyethylene nanofilm applied to the wound from the inside out after a period of time. The test results are as follows: Figure 9 shown.

[0201] Depend on Figure 9 It is known that during the wound healing process, the electrolytes related to wound exudate (Cl - PO3 - ) and chemicals (CNO - ) penetrates into the ultra-high molecular weight polyethylene nanomembrane, and the wound exudate combines with the porous membrane to gradually accumulate mineral crystals to form an epidermal-like structure. This further improves the ultra-high molecular weight polyethylene nanomembrane's barrier effect against pathogens, aerosols, and liquids, and further enhances the fit between the ultra-high molecular weight polyethylene nanomembrane and the wound site, contributing to scar-free healing.

[0202] Based on the above experimental results, it can be seen that the ultra-high molecular weight polyethylene nanofilm provided by the embodiment of the present invention can be used as a wound dressing to accelerate cell proliferation and collagen deposition, which can not only effectively shorten the wound healing time but also achieve a scar-free healing effect.

[0203] The effect of promoting wound healing and tissue regeneration is mainly attributed to the following mechanisms: 1. Good biocompatibility: The good compatibility of ultra-high molecular weight polyethylene nanofilm with the tissue around the wound reduces the inflammatory response, promotes the smooth growth of cells and tissue regeneration; 2. Suitable microenvironment: The high air permeability and humidity regulation ability of ultra-high molecular weight polyethylene nanofilm provide a suitable healing environment for the wound, which helps cells maintain good activity and functionality; 3. Effective antibacterial performance: Ultra-high molecular weight polyethylene nanofilm has a three-dimensional porous network structure, which can effectively block the penetration of most pathogens and large-particle aerosols and droplets. Its own hydrophobicity can further block the penetration of liquids and reduce the risk of wound infection. On the wound surface, the nanofilm combines with skin metabolic components and gradually accumulates mineral crystals to form a protective layer, further improving the blocking effect. Therefore, its ability to block pathogens, aerosols and liquids reduces the risk of wound infection, thereby creating safe conditions for wound healing.

[0204] It can be seen from the above embodiments and experimental results that the embodiments of the present invention use ultra-high molecular weight polyethylene film as a skin dressing; the ultra-high molecular weight polyethylene nanofilm prepared by special material formula and process has a three-dimensional porous network structure and has the following advantages: controllable thickness; adjustable pore size and porosity; excellent mechanical strength and peel strength; low surface roughness; high air permeability; hydrophobicity; excellent aerosol barrier ability and high antibacterial property; high biocompatibility; non-toxicity; and verified by preclinical wound healing experiments, the use of the ultra-high molecular weight polyethylene nanofilm prepared by the embodiments of the present invention as a wound dressing can not only accelerate wound healing, but also effectively reduce scar formation.

[0205] Therefore, the ultra-high molecular weight polyethylene nanofilm prepared by the embodiment of the present invention through optimized material formula and improved production process has great application potential as a wound dressing, and provides a new solution for clinical wound healing management.

[0206] Based on the above advantages, the ultra-high molecular weight polyethylene nanofilm prepared in the embodiment of the present invention is not only suitable for wound dressing, but also widely applicable to various skin dressings. It is actually a very promising skin repair functional material and has broad application prospects in the fields of medical materials and beauty and skin care materials.

[0207] Therefore, the present invention also proposes the following types of skin patch applications to fully illustrate the market potential of the technical solution of the present invention and its strong technical support for high-performance medical and beauty skin care materials.

[0208] Application example 1: chronic wound patch.

[0209] Chronic wound patch is a dressing specially used for chronic wound care. It is suitable for the care of chronic wounds such as pressure ulcers, venous ulcers, diabetic foot ulcers, radiation ulcers, and difficult-to-heal wounds after surgery. It needs to have good breathability, moisturizing, adhesion, hypoallergenicity and exudate absorption ability.

[0210] For the application of chronic wound patches, the stretching ratio of ultra-high molecular weight polyethylene nanofilm can be selected to be 100~400 during the preparation process. The thickness of the finished chronic wound patch is controlled in the range of 1~8μm, and the porosity is in the range of 30%~80%.

[0211] For the application of chronic wound patches, ultra-high molecular weight polyethylene nanofilm can be further loaded with exudate absorption materials (such as sodium carboxymethyl cellulose, alginate, polyurethane, etc., used to absorb wound exudate), photothermal materials (such as gold nanorods / wires, polyaniline, carbon nanomaterials, etc., used to generate heat under irradiation of specific wavelengths of light such as near-infrared light to promote wound healing), anti-inflammatory materials (such as chitosan, silver nanoparticles, anti-inflammatory drugs, etc., used to prevent wound infection, reduce wound inflammation, and exert anti-inflammatory and analgesic effects) or healing-promoting ingredients (such as epidermal growth factor, fibroblast growth factor, collagen, hyaluronic acid, etc., used to promote tissue regeneration and reduce scar formation) to achieve comprehensive wound care effects.

[0212] Application example 2: surgical scar-free patch.

[0213] The surgical scarless patch is a medical product used for fresh wounds after surgery. It is suitable for wound care after various surgeries such as general surgery, plastic surgery, endoscopic / minimally invasive surgery incisions, etc. It is also suitable for the care of traumatic skin wounds after debridement and suture. It needs to have a certain elasticity and tension to avoid excessive pulling of the wound, and needs to have waterproof and breathable properties, antibacterial properties, good adhesion properties and the function of reducing scars.

[0214] For the application of scarless surgical patches, the stretching ratio of the ultra-high molecular weight polyethylene nanofilm can be selected to be 100~400 during the preparation process. The thickness of the finished product of the scarless surgical patch is controlled in the range of 1~8μm, and the porosity is in the range of 30%~80%.

[0215] For the application of surgical scarless patches, the ultra-high molecular weight polyethylene nanofilm can be further loaded with exudate absorption materials or healing-promoting ingredients, etc. The exudate absorption materials include but are not limited to sodium carboxymethyl cellulose, alginate, polyurethane, etc., and the healing-promoting ingredients include but are not limited to epidermal growth factor, fibroblast growth factor, collagen, hyaluronic acid, etc.

[0216] Application example 3: acne patch.

[0217] Acne patches are used as an auxiliary treatment for acne. They reduce the environment for bacterial growth by absorbing secretions and oil on the surface of acne. They need to meet requirements such as good fluid adsorption capacity, non-toxicity, non-irritation, non-sensitization, and good skin adhesion.

[0218] For the application of acne patches, the stretching ratio of ultra-high molecular weight polyethylene nanofilm can be selected from 30 to 200 during the preparation process. The thickness of the finished acne patch is controlled in the range of 5 to 10 μm, and the porosity is in the range of 30% to 80%. The ultra-high molecular weight polyethylene nanofilm has a multi-layer pore structure, with the surface layer blocking bacteria, the middle layer absorbing secretions, and the bottom layer being breathable and moisturizing, which can realize the integrated management of "bacteria blocking-cleaning-repairing" of acne wounds.

[0219] In acne patches, ultra-high molecular weight polyethylene nanofilm is used as a base material to load anti-acne ingredients to exert antibacterial, anti-inflammatory, oil-control and other therapeutic effects, such as antibacterial and anti-inflammatory drug ingredients such as benzoyl peroxide and metronidazole, salicylic acid oil-control ingredients, etc., or load absorption ingredients such as cellulose, hydrogel freeze-dried body, etc.

[0220] Application example 4: medical beauty protective patch.

[0221] Medical beauty protective patches are used in medical beauty projects or skin repair process care, and need to meet the requirements of protecting wounds, promoting healing and reducing inflammatory responses.

[0222] For the application of medical beauty protective patches, the stretching ratio of ultra-high molecular weight polyethylene nanofilm can be selected from 30 to 200 during the preparation process. The thickness of the finished medical beauty protective patch is controlled in the range of 3 to 10 μm, and the porosity is in the range of 30% to 80%. The nanomembrane can achieve a bacterial filtration efficiency of > 99.5% through physical barrier (pore size < 50 nm), and can fit tightly to the skin without adhesive, avoiding the risk of allergies caused by traditional adhesive patches. At the same time, the high breathability can maintain the balance of the wound microenvironment and accelerate the healing process.

[0223] In medical beauty protective patches, ultra-high molecular weight polyethylene nanofilms can be loaded with nanoparticles (such as nanosilver, nanozinc oxide, etc.) or other anti-infection materials (such as chitosan, quaternary ammonium compounds, and plant extracts such as plant essential oils, etc.), and can also be loaded with polylactic acid-glycolic acid copolymer (PLGA for short, which is hydrophobic and degradable and can be further loaded with inorganic nanoparticles and active ingredients) and other coatings or surface modification materials with specific functions to increase the functionality of medical beauty protective patches.

[0224] Application example 5: facial mask.

[0225] Facial masks are used for daily facial care and need to meet requirements such as good adhesion, soft texture, good breathability, and the ability to effectively carry skin care ingredients.

[0226] For facial mask applications, the stretching ratio of ultra-high molecular weight polyethylene nanofilm can be selected to be 25~250 during the preparation process. The thickness of the finished facial mask is controlled in the range of 5~20μm, and the porosity is in the range of 20%~50%.

[0227] Ultra-high molecular weight polyethylene nanofilm can be loaded with moisturizing ingredients such as hyaluronic acid, glycerin, natural moisturizing factors, or other functional ingredients such as niacinamide, tranexamic acid, vitamin C, collagen, retinol, peptides, etc. It can also be filled with adsorption materials such as kaolin, activated carbon, and bentonite.

[0228] The relevant parameters and load types of the above applications are shown in Table 2.

[0229] Table 2 Ultra-high molecular weight polyethylene nanofilms and their loadings used in different skin patches

[0230]

[0231] Through the above application examples, those skilled in the art can understand that the ultra-high molecular weight polyethylene nanofilm prepared in the embodiment of the present invention can be used as a skin dressing and can achieve various functions by loading different substances, which greatly expands its application in the fields of medical materials and beauty and skin care materials.

[0232] Specifically, the materials and components that can be loaded by the ultra-high molecular weight polyethylene nanofilm include organic hydrophobic materials, organic hydrophilic materials, inorganic nanoparticles, natural or artificially synthesized active ingredients, etc.

[0233] Among them, organic hydrophobic materials include but are not limited to polylactic acid-glycolic acid copolymer (PLGA), polyvinylidene fluoride (PVDF), polystyrene (PS), polylactic acid (PLA), etc. Organic hydrophobic materials can be loaded on ultra-high molecular weight polyethylene nanomembranes by negative pressure filtration, spin coating, 3D in situ printing, sacrificial material printing, electrospinning, etc.

[0234] Organic hydrophilic materials include but are not limited to hyaluronic acid, chitosan, collagen, polyethylene glycol (PEG), polyacrylic acid (PAA), sodium alginate, etc. For the loading of organic hydrophilic materials, the surface of the ultra-high molecular weight polyethylene nanomembrane can be first modified in the short term by plasma cleaning, or modified in the long term with polydopamine. After modification, the loading of organic hydrophilic materials can be achieved by spin coating, in situ printing, sacrificial material printing or freeze-drying.

[0235] Inorganic nanoparticles include but are not limited to inorganic metal nanoparticles (such as gold, silver, etc.), metal oxide nanoparticles (such as zinc oxide, titanium dioxide, etc.), carbon nanomaterials (carbon nanotubes, nanospheres, nanowires, etc.) or other nanoparticles with specific functions, which can be loaded through evaporation, magnetron sputtering, in situ growth, etc.

[0236] Ultra-high molecular weight polyethylene nanofilms can also be filled with natural active ingredients (such as hyaluronic acid, collagen, various plant extracts, etc.) or artificially synthesized active ingredients (such as salicylic acid, ceramide, various vitamins, etc.), or the active ingredients can be modified on organic hydrophobic materials, organic hydrophilic materials or inorganic nanoparticles to achieve the specific functions of the product without affecting the interface bonding.

[0237] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A skin repair functional material based on ultra-high molecular weight polyethylene nanofilm, characterized in that: The invention comprises an ultra-high molecular weight polyethylene nanomembrane having a three-dimensional porous network structure; the ultra-high molecular weight polyethylene nanomembrane has a thickness of 20 nm to 5 μm, a porosity of 25% to 80%, an elongation at break of 50-300%, a tensile strength of 500 to 1000 MPa, a peel strength of 4.7 to 5.0 N / m, and a pore size of the three-dimensional porous network structure of 20 nm to 50 nm; the ultra-high molecular weight polyethylene nanomembrane is prepared by the following steps: Premixing the raw materials: 50-80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05-10 parts of an antioxidant, and 0.1-20 parts of a polymer behavior regulator are mixed, and then premixed at 80° C. to 200° C. to obtain a premix; the ultra-high molecular weight polyethylene powder has a molecular weight of 1-10 million Daltons; and the polymer behavior regulator is at least one of polyvinyl alcohol, sodium polyacrylate, calcium stearate, mineral oil, edible oil, oxidized polyethylene wax, dodecyl mercaptan, mercaptopropionic acid, dicumyl peroxide, decalin, a sorbitol derivative, aluminum benzoate, polyurethane, ethylene-vinyl acetate copolymer, maleic anhydride grafted PE, polyvinyl acetal, and polyethylene glycol formal; Extrusion and stretching: Extruding the premix into a film using an extrusion device, and then biaxially stretching the extrudate; wherein the extrusion device is a twin-screw extruder; parameters for extruding the premix into a film using the twin-screw extruder include: screw diameter 30-200 nm, screw length-to-diameter ratio 15-60:1, screw speed 1-200 rpm, feeding section temperature 25-150° C., compression section temperature 100-160° C., metering section temperature 150-250° C., melt temperature 150-250° C., and extrusion pressure 15 MPa; Extraction: extracting the biaxially stretched film with an extractant; the extraction steps are sequentially using n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% ethanol aqueous solution, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water to perform step-by-step gradient extraction on the biaxially stretched film, or sequentially using n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% ethanol aqueous solution, and deionized water to perform step-by-step gradient extraction on the biaxially stretched film; Drying and annealing: drying the extracted film, and then annealing the dried film to obtain the ultra-high molecular weight polyethylene nanofilm.

2. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: The particle size of the ultra-high molecular weight polyethylene powder is 100-300 μm, and the density is 0.931-0.949 g / cm 3 .

3. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: In the step of premixing the raw materials, the ultra-high molecular weight polyethylene powder is 67 parts by weight, the antioxidant is 3 parts by weight, and the polymer behavior regulator is 8 parts by weight.

4. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: The antioxidant is at least one of butylated hydroxytoluene, butylated hydroxybenzoic acid, sodium sulfite, tert-butylhydroquinone, propyl gallate, and sodium ascorbate.

5. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: The polymer behavior regulator is paraffin oil.

6. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: In the drying and annealing steps, the drying temperature is 50-100° C., and the annealing temperature is 50-150° C.

7. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that: It also includes at least one of an organic hydrophobic material, an organic hydrophilic material, an inorganic nanoparticle, a natural active ingredient, and an artificially synthesized active ingredient supported on the ultra-high molecular weight polyethylene nanofilm.

8. Use of the skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to any one of claims 1 to 7 in the preparation of medical materials or cosmetic and skin care materials.

9. The use according to claim 8, characterized in that The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm is used to prepare chronic wound patches, surgical scar-free patches, acne patches, medical beauty protective patches or facial masks.

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