Skin repair functional material based on ultra-high molecular weight polyethylene nano-film and application of skin repair functional material

Abstract

The invention discloses a skin repair functional material based on an ultra-high molecular weight polyethylene nano-film and application, and relates to the technical field of biological materials and application. The functional material comprises an ultra-high molecular weight polyethylene nano-film with a three-dimensional porous network structure, and the ultra-high molecular weight polyethylene nano-film is prepared by the following steps: 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 premixing the mixture at 80-200 DEG C; extruding the premix into a film by using extrusion equipment, and then carrying out two-way stretching on the extrudate; extracting the film subjected to two-way stretching; the extracted thin film is dried, and then the dried thin film is subjected to annealing treatment; the skin repair functional material provided by the invention has remarkable advantages in the aspects of mechanical property, air permeability, non-toxicity, biocompatibility, antibacterial property and wound healing, and can meet the requirements of various medical materials and skincare materials.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials and applications, and particularly relates to a skin repair functional material based on an ultra-high molecular weight polyethylene nanofilm. Background Art

[0002] A skin patch is a product that acts on the skin surface through the patch method to achieve treatment or skin care; skin patches usually include therapeutic skin patches such as wound patches, acne patches, pain relief patches, transdermal drug delivery patches, etc., as well as care skin patches such as facial masks and eye patches, and are required to have good mechanical properties, breathability, moisture retention, non-toxicity, and biocompatibility; in addition, for high-end skin repair or care application scenarios, skin patches usually also need to have the efficacy of promoting wound healing and tissue regeneration.

[0003] Ultra-high molecular weight polyethylene (UHMWPE) is a high-performance polymer material with characteristics such as high strength, high modulus, wear resistance, chemical corrosion resistance, and good biocompatibility, and has been widely used in the medical field, such as artificial joints, orthopedic implants, etc.; preparing UHMWPE into nanofibers, the UHMWPE nanofilm formed by the nanofibers has a high specific surface area and high porosity, and is expected to become a high-performance basic material for skin patches; in recent years, studies have shown that UHMWPE is beneficial to cell adsorption and proliferation, and the application of nanomaterials prepared from UHMWPE in the field of wound dressings has attracted wide attention and shown good application prospects; at present, electrospinning technology is a common method for preparing polymer nanofibers and polymer porous nanofilms. This technology stretches polymer solutions or melts into nanofibers through the action of a high-voltage electrostatic field; however, due to its high molecular weight and high crystallinity, it is very difficult to process UHMWPE into a porous nanofilm through electrospinning technology. Therefore, new raw material systems and film-forming processes need to be explored to prepare UHMWPE porous nanofilms with uniform morphology, excellent mechanical properties, and suitable for the application requirements of various skin patches. Summary of the Invention

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

[0005] Raw material premixing: Mix 50-80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05-10 parts of antioxidant, and 0.1-20 parts of polymer behavior regulator, and then perform premixing at 80°C-200°C to obtain a premix;

[0006] Extrusion and stretching: Use an extrusion device to extrude the premix into a film, and then perform biaxial stretching on the extrudate;

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

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

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

[0010] Optionally, in the step of premixing the raw materials, 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.

[0011] Optionally, the antioxidant is at least one of butylated hydroxytoluene, butyl hydroxybenzoic acid, sodium sulfite, tert-butylhydroquinone, propyl gallate, 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, 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, ratio of screw length to diameter 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, 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, edible oil, xylene, tetrachloroethane, methanol, acetone, deionized water, isopropanol, ether, cyclohexane, supercritical carbon dioxide.

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

[0017] Optionally, in the extraction step, the biaxially stretched film is gradually and gradiently extracted successively with n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% aqueous ethanol solution, gasoline, xylene, tetrachloroethane, methanol, acetone, and deionized water.

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

[0019] Optionally, the skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm further includes at least one of an organic hydrophobic material, an organic hydrophilic material, inorganic nanoparticles, natural active ingredients, and synthetic active ingredients loaded on the ultra-high molecular weight polyethylene nanofilm.

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

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

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

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

[0024] Optionally, the pore size of the ultra-high molecular weight polyethylene nanofilm 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] Through improved formulation design, the present invention adopts a combination of ultra-high molecular weight polyethylene powder, antioxidant, and polymer behavior regulator in specific proportions, and combines premixing, extrusion, biaxial stretching process, and extraction process. The prepared ultra-high molecular weight polyethylene nanofilm is formed by nanofibers interweaving to form a three-dimensional porous network structure, which not only has excellent mechanical properties, good biocompatibility, and non-toxicity, but also can obtain the target pore size, porosity, and thickness by regulating process parameters, making the prepared skin repair functional material based on ultra-high molecular weight polyethylene nanofilm suitable for the needs of various skin patches; in addition, the ultra-high molecular weight polyethylene nanofilm adopted in the present invention can also effectively block the penetration of pathogens, aerosols, and polluted liquids. Preclinical experiments show that the prepared ultra-high molecular weight polyethylene nanofilm can effectively promote wound healing and tissue regeneration, and is suitable for clinical wound healing needs such as wound patches. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

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

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

[0031] Figure 3 Surface contact angle test image of the ultra-high molecular weight polyethylene nanofilm prepared in some embodiments of the present invention;

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

[0033] Figure 5 Aerosol barrier test image of the ultra-high molecular weight polyethylene nanofilm prepared in some embodiments of the present invention;

[0034] Figure 6 Wound appearance change images in the preclinical experiment of the ultra-high molecular weight polyethylene nanofilm prepared in some embodiments of the present invention compared with the control group;

[0035] Figure 7 For Figure 6 The curve graph showing the change of the wound healing rate over time in the indicated preclinical experiment;

[0036] Figure 8 For Figure 6 The representative images of wound healing characterized by HE and Masson staining in the preclinical experiments shown;

[0037] Figure 9 For Figure 6 The ToF - SIMS representative images of the chemical composition of the ultra - high molecular weight polyethylene nanofilm from the inside to the outside after a period of time in the preclinical experiments shown. Detailed implementation manners

[0038] To make the object, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to 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 embodiments of the present invention includes an ultra - high molecular weight polyethylene nanofilm; the ultra - high molecular weight polyethylene (UHMWPE) nanofilm can be directly used as a skin repair functional material; or the 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 patch, including but not limited to therapeutic skin patches such as wound patches, acne patches, pain relief patches, transdermal drug delivery patches, etc., and care skin patches such as facial masks and eye patches.

[0040] In the prior art, since UHMWPE exhibits high visco - elasticity in the molten state and has poor melt fluidity, it is easy to form a "material plug" when extruding it into a film using traditional extrusion equipment, resulting in great processing difficulty and low production efficiency.

[0041] The research team where the inventors are located has conducted in-depth research on the preparation of UHMWPE films in previous work: for example, the patent "Nano-porous Ultra-high Molecular Weight Polyethylene Film" with the publication number CN109997247A provides a method for preparing a biaxially oriented nano-porous UHMWPE film. This method reduces the melt viscosity and the entanglement density of polymer chains of UHMWPE during the processing by adding petrolatum to the ultra-high molecular weight polyethylene raw material, improves the fluidity of the material, greatly reduces the processing difficulty of UHMWPE, and the prepared UHMWPE film has a self-supporting structure. Moreover, by adjusting the draw ratio and controlling the annealing temperature, parameters such as the thickness, pore size, and porosity of the UHMWPE film can be adjusted to make it suitable for use as a separator for lithium-ion batteries; the patent "Synthesis Method of Flexible Multifunctional High-porosity Ultra-thin Polyethylene Film" with the publication number CN111491719A prepares an ultra-thin (less than 100 nm) and porous polyethylene film with high mechanical strength through controlling the process of biaxial stretching; the patent with the publication number CN110960995A uses UHMWPE films with specific thickness, pore size, porosity, and tensile strength for seawater desalination.

[0042] However, when the UHMWPE films prepared by existing methods are used in the field of biomaterials such as skin patches, they usually face the following challenges: First, the film properties are uneven. During the preparation of existing UHMWPE films, due to reasons such as differences in raw material ratios, uneven mixing, and improper control of the extrusion process, there are significant differences in physical properties such as the thickness, mechanical strength, porosity, and pore size of the film, which affect the quality and application effect of the final product; Second, the barrier property is insufficient. Existing UHMWPE films are mainly used for ion separators and perform poorly in terms of high gas permeability and blocking the penetration of aerosols and liquids, unable to meet the requirements of high-end medical and beauty skin care applications; Third, the biocompatibility is poor. Many existing polymer film materials are prone to cause adverse reactions when in contact with biological tissues, restricting their applications in the medical field or the beauty skin care field.

[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 embodiments of the present invention has made improvements in raw material components and preparation processes for the application requirements of medical and beauty skin care for the ultra-high molecular weight polyethylene nanofilm used, so that the prepared ultra-high molecular weight polyethylene nanofilm has significant advantages in mechanical properties, gas permeability, non-toxicity, biocompatibility, antibacterial properties, and wound healing.

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

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

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

[0047] The antioxidant is used to prevent free radical cascade reactions and ensure the stability of the polymer material at high temperatures; the antioxidant includes but is not limited to one or more of butylated hydroxytoluene, butyl hydroxybenzoic acid, sodium sulfite, tert-butylhydroquinone, propyl gallate, sodium ascorbate.

[0048] The polymer behavior regulator is used to reduce the melt viscosity of ultra-high molecular weight polyethylene during the processing and reduce the entanglement density of polymer chains, enabling the premix to form a film through extrusion and stretching processes; the polymer behavior regulator includes but is 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, dicumyl peroxide, decalin, sorbitol derivatives, aluminum benzoate, polyurethane, ethylene-vinyl acetate copolymer, maleic anhydride grafted PE, polyvinyl acetal, 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: Use extrusion equipment to extrude the premix into a film, and then perform biaxial stretching on the extrudate to make the film reach the predetermined thickness and physical properties.

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

[0052] The specific parameters for using a twin-screw extruder to extrude the premix into a film are: 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, extrusion pressure 15 MPa.

[0053] In the embodiments of the present invention, the gel film extruded by the extrusion device can be stretched by a biaxial stretching device or can be stretched by a uniaxial stretching device in two perpendicular directions; the stretched film 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 within the range of 20 nm to 5 μm, the pore size can be adjusted within the range of 10 nm to 300 nm, and the porosity can be adjusted within the range of 25% to 80%.

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

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

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

[0058] In the embodiments of the present invention, the extraction method can adopt multiple extraction agents for stepwise gradient extraction to fully remove potential allergens and other impurities, so that the finally prepared ultra-high molecular weight polyethylene nanofilm has no toxicity and good biocompatibility.

[0059] In some preferred embodiments, the film after biaxial stretching can be successively extracted stepwise with n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% aqueous ethanol solution, gasoline, xylene, tetrachloroethane, methanol, acetone, deionized water.

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

[0061] Among them, the drying temperature can be selected as 50 to 100 °C to fully remove the residual solvent, and the annealing temperature can be selected as 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 embodiments of the present invention can be characterized by SEM (scanning electron microscope) and TEM (transmission electron microscope), such as Figure 1 andFigure 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 a combination of ultra-high molecular weight polyethylene powder, antioxidants and polymer behavior regulators in a specific ratio through improved formula design, and combines premixing, extrusion, biaxial stretching and extraction processes, so that the prepared ultra-high molecular weight polyethylene nanofilm is formed by interweaving nanofibers to form a three-dimensional porous network structure. The prepared ultra-high molecular weight polyethylene nanofilm not only has excellent mechanical properties (flexibility, tensile strength and peel strength, etc.) and good biocompatibility and non-toxicity, but also can obtain the target pore size, porosity and thickness by regulating the process parameters, so that the prepared ultra-high molecular weight polyethylene nanofilm is 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 dressings.

[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 designs 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 in nature and do not constitute any form of limitation to the protection scope 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 that the components were uniform, 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 and 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) Bidirectional 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 extracted stepwise with 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 residual solvent, and then annealed at 50°C.

[0082] (7) Film roll:

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

[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 butyl 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 antioxidant, and 20 parts by weight of polymer behavior regulator were weighed and fully mixed in a dry environment to ensure that the components were uniform, 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: feeding section is 150℃, compression section is 160℃, metering section is 250℃, melt temperature is 250℃; extrusion pressure is 15MPa.

[0094] (4) Bidirectional 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 extracted stepwise with 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 ultra-high molecular weight polyethylene nanofilm is wound and formed.

[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 antioxidant, and 10 parts by weight of polymer behavior regulator were weighed and fully mixed in a dry environment to ensure that the components were uniform, thereby obtaining a mixture.

[0107] (2) Premix:

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

[0109] (3) Extrusion:

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

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

[0112] (4) Biaxial stretching:

[0113] The extrudate is biaxially stretched through a biaxial film stretcher to achieve a predetermined film thickness and mechanical properties.

[0114] (5) Extraction:

[0115] The biaxially stretched film is successively 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 is dried at 65 °C to remove residual solvents, and then annealed at 130 °C.

[0118] (7) Film winding:

[0119] The finally 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 example is prepared by the following steps:

[0122] (1) Raw material preparation:

[0123] The selected ultra-high molecular weight polyethylene powder 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] Weigh 75 parts by weight of ultra-high molecular weight polyethylene powder, 5 parts of antioxidant, and 6 parts of polymer behavior regulator, and mix them thoroughly in a dry environment to ensure uniform components and obtain a mixture.

[0125] (2)Premixing:

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

[0127] (3)Extrusion:

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

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

[0130] (4)Biaxial stretching:

[0131] The extrudate is biaxially stretched through a biaxial film stretcher to reach the predetermined film thickness and mechanical properties.

[0132] (5)Extraction:

[0133] The biaxially stretched film is successively subjected to stepwise gradient extraction with 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 is dried at 85 °C to remove residual solvents, and then annealed at 75 °C.

[0136] (7)Film winding:

[0137] The finally 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 example is prepared by the following steps:

[0140] (1)Raw material preparation:

[0141] The selected ultra-high molecular weight polyethylene powder 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] Weigh 67 parts by weight of ultra-high molecular weight polyethylene powder, 3 parts of antioxidant, and 8 parts of polymer behavior regulator, and mix them thoroughly in a dry environment to ensure uniform components, obtaining a mixture.

[0143] (2)Premixing:

[0144] Premix the mixture at 155 °C.

[0145] (3)Extrusion:

[0146] Use a twin-screw extruder to extrude the premix to form a preliminary nanofilm morphology.

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

[0148] (4)Biaxial stretching:

[0149] Stretch the extrudate through a biaxial film stretcher to achieve the predetermined film thickness and mechanical properties.

[0150] (5)Extraction:

[0151] Successively perform stepwise gradient extraction on the biaxially stretched film with 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] Dry the extracted nanofilm at 75 °C to remove residual solvents, and then perform annealing at 100 °C.

[0154] (7)Film winding:

[0155] Wind the finally formed ultra-high molecular weight polyethylene nanofilm into a roll.

[0156] Example 6

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

[0158] Example 7

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

[0160] Example 8

[0161] The difference between this example and Example 5 lies in step (5): Gradient extraction is carried out step by step using 100% n-hexane, 100% dichloromethane, 100% ethyl acetate, 50% / 50% ethyl acetate / ethanol, 100% ethanol, 50% ethanol, and deionized water; the remaining steps are the same as those in Example 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] It is found from the experimental results that Comparative Examples 2-4 cannot form films; Films with a thickness of 100 μm are prepared using Examples 1-8 and Comparative Example 1 respectively, and tensile tests, peel strength tests, and sensitization tests are carried out on the films.

[0171] Among them, for the tensile test, a material testing machine is used, and the tensile test of the sample is carried out according to the ASTM D638 standard; during the test, the maximum tensile strength and elongation at break of the sample are recorded.

[0172] For the peel strength test, the sample is adhered to a suitable simulated skin material (such as a polyurethane film, fresh skin of an in vitro model animal), ensuring that the contact area between different samples and the substrate is the same; a peel tester is used, and the peel strength test is carried out according to the ASTM D903 standard, the peel force is recorded, and the peel strength is calculated.

[0173] The sensitization test includes the volunteer skin sensitization test and the cytotoxicity test. Specifically, the material is attached to the volunteer's skin, and after 1, 3, 6, 9, and 12 hours, the skin is checked for redness, rash, itching, or other discomfort. For the cytotoxicity test, the L929 and NIH-3T3 cell lines are used as models, and the CCCK-8 method is used as the detection means. A cell survival rate of more than 95% is used as the criterion 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 show that the tensile strength of the samples prepared in each example of the experimental group reaches 500 MPa to 1000 MPa, and the elongation at break reaches 50% - 300%. This indicates that the ultra-high molecular weight polyethylene nanofilm prepared in 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 show that the peel strength of the samples prepared in each example of the experimental group reaches 4.7 - 5.0 N / 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 forces, maintain good adhesion, and ensure that it does not fall off the skin during exercise or daily activities.

[0177] The results of the sensitization test show that the ultra-high molecular weight polyethylene nanofilm prepared using the gradient extraction solvent system in Examples 1 - 5 and Example 8 has good biocompatibility and non-toxicity, and meets the non-sensitization standard in both the volunteer skin sensitization test and the cytotoxicity test.

[0178] Among them, the nanofilm prepared in Example 5 has a tensile strength of 900 MPa, an elongation at break of 160%, a peel strength of 5.0 N / m, and is non-sensitizing, meeting the requirements of high-performance skin patches 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 indicates that film formation could not be achieved, so the test could not be carried out.

[0182] The test results of the control group showed that in Comparative Example 1, the antioxidant was removed, and the strength and flexibility of the film were significantly reduced. This phenomenon was mainly caused by the following reasons: the oxidation stability decreased. Without the protection of the antioxidant, the film material was more vulnerable to oxidation reactions, resulting in a decline in the physical and chemical properties of the material. Oxidation would cause embrittlement of the material, a decrease in strength, and a shortening of the service life. The oxidation reaction would lead to the breakage of polymer chains, thereby affecting the Young's modulus and tensile strength of the material.

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

[0184] It can be seen from this that in the embodiments of the present invention, by using a specific combination of ultra-high molecular weight polyethylene powder, antioxidant, and high-molecular behavior regulator, combined with optimized premixing, extrusion, biaxial stretching, and extraction processes, the prepared ultra-high molecular weight polyethylene nanofilm has superior mechanical strength, peel strength, non-toxicity, and biocompatibility. Among them, the tensile strength of the ultra-high molecular weight polyethylene nanofilm prepared in Example 5 reached 900 MPa, the elongation at break reached 160%, and the peel strength reached 5.0 N / m. Such a strong ultra-high molecular weight polyethylene nanofilm can be used as a skin patch and can remain stable in the application environments of various medical materials or beauty and skin care materials, and is not easily torn or damaged. Moreover, the ultra-high molecular weight polyethylene nanofilm prepared in Example 5 has non-toxicity and superior biocompatibility, and is suitable for the requirements of high-standard medical dressings, medical protective materials, etc.

[0185] In addition, during the preparation process of the ultra-high molecular weight polyethylene nanofilm in Examples 1-5, the UHMWPE material showed good processing performance. Therefore, the ultra-high molecular weight polyethylene thin film prepared in the embodiments of the present invention is suitable for large-scale production and has industrialization value.

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

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

[0188] Figure 1SEM image of ultra-high molecular weight polyethylene nanofilm sample (20 nm thickness). Figure 2 TEM image of ultra-high molecular weight polyethylene nanofilm sample (20 nm 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 the irritation to skin tissue; The SEM image and TEM image also reveal that the ultra-high molecular weight polyethylene nanofilm has a microporous structure, with a pore size of about 20-50 nm, and the porosity can be adjusted between 25% and 80%. This not only helps to improve the breathability of the film and allows water vapor to pass through, but also can effectively block the penetration of most pathogens and large liquid / solid particles.

[0189] Figure 3 Drop surface contact angle test image of 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 the penetration of liquids.

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

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

[0192] Combined Figures 1-5 Based on the test results, the ultra-high molecular weight polyethylene nanofilm prepared in the embodiments of the present invention has good barrier properties against pathogens, aerosols and liquids, and also has extremely excellent breathability; The excellent breathability can effectively discharge moisture and prevent the wound environment from being too humid. These characteristics are crucial for preventing wound infection and promoting healing.

[0193] Furthermore, preclinical experiments on wound healing were conducted on ultra-high molecular weight polyethylene nanofilm samples GPNano-H and GPNano-L. A control group without using a wound dressing and a control group using the traditional commercial dressing "Tegaderm" were set up, and the healing conditions of the wounds were observed on the 0th day, 5th day, 9th day, and 14th day respectively. The experimental results are as Figure 6 and Figure 7 shown, Figure 6 which is a diagram of the wound appearance changes, Figure 7 and this is a curve graph showing the change of the wound healing rate over time.

[0194] From Figure 6 and Figure 7 it can be seen that the healing speed of the wounds using the ultra-high molecular weight polyethylene nanofilm provided in the embodiments of the present invention as a wound dressing is significantly improved compared with the control groups within 14 days; among them, the wounds using the GPNano-H sample were completely healed in 14 days. In subsequent observations, the wound healing time was shortened by nearly 50% compared with the control group. This experimental result shows that the ultra-high molecular weight polyethylene nanofilm can effectively accelerate the wound healing speed; in addition, there was no obvious scabbing during the wound healing process in the GPNano-H group, and there was almost no obvious scar after the wound healed. There was only slight scabbing and scarring in the GPNano-L group, which indicates 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 experiment on wound healing, HE (hematoxylin-eosin staining) and Masson staining techniques were used to evaluate the wound healing conditions. The experimental results are as 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 the wound healing process.

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

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

[0199] The results of Masson staining showed that the deposition of collagen fibers in the wound area using the ultra-high molecular weight polyethylene nanofilm increased significantly and was arranged more orderly. This indicates that the ultra-high molecular weight polyethylene nanofilm not only promoted cell proliferation but also promoted the synthesis and deposition of collagen, contributing to the structural reconstruction of the wound. Compared with the control group, the wound using the ultra-high molecular weight polyethylene nanofilm formed less scar in terms of collagen deposition, indicating that the ultra-high molecular weight polyethylene nanofilm can promote scarless healing.

[0200] Furthermore, the chemical composition of the ultra-high molecular weight polyethylene nanofilm applied to the wound from the inside out after a period of time was analyzed by ToF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometer), and the test results are as Figure 9 shown.

[0201] It can be Figure 9 seen that during the wound healing process, electrolytes (Cl - , PO3 - ) and chemical substances (CNO - ) related to wound exudates penetrated into the ultra-high molecular weight polyethylene nanofilm. The wound exudates combined with the porous film and gradually accumulated mineral crystals, which could form an epidermis-like structure. This further improved the barrier effect of the ultra-high molecular weight polyethylene nanofilm against pathogens, aerosols, and liquids, and further enhanced the adhesion of the ultra-high molecular weight polyethylene nanofilm to the wound site, contributing to scarless healing.

[0202] Based on the above experimental results, it can be known that the ultra-high molecular weight polyethylene nanofilm provided in the embodiments of the present invention used as a wound dressing can accelerate cell proliferation and collagen deposition, not only effectively shortening the wound healing time but also achieving a scarless healing effect.

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

[0204] As can be seen from the above examples and experimental results, the embodiments of the present invention use ultra-high molecular weight polyethylene thin films as skin patches; the ultra-high molecular weight polyethylene nanofilm prepared by a 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 gas permeability; hydrophobicity; excellent aerosol barrier ability and high antibacterial property; high biocompatibility; non-toxicity; and through the verification of preclinical wound healing experiments, using the ultra-high molecular weight polyethylene nanofilm prepared by the embodiments of the present invention as a wound patch can not only accelerate wound healing but also effectively reduce scar formation.

[0205] Therefore, through the optimized material formula and improved production process, the ultra-high molecular weight polyethylene nanofilm prepared in the embodiments of the present invention as a wound patch has great application potential 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 embodiments of the present invention is not only suitable for wound patches but also widely applicable to various skin patches. In fact, it is a very promising skin repair functional material with broad application prospects in the fields of medical materials and beauty skin care materials.

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

[0208] Application Example 1: Chronic wound patch.

[0209] Chronic wound dressings are dressings specifically used for chronic wound care, applicable to the care of chronic wounds such as pressure ulcers, venous ulcers, diabetic foot ulcers, radiation ulcers, and difficult-to-heal postoperative wounds. They need to have good breathability, moisture retention, adhesiveness, low allergenicity, and the ability to absorb exudate.

[0210] For the application of chronic wound dressings, the draw ratio of ultra-high molecular weight polyethylene nanofilm during the preparation process can be selected from 100 to 400, the thickness of the finished chronic wound dressing is controlled within the range of 1 to 8 μm, and the porosity is within the range of 30% to 80%.

[0211] For the application of chronic wound dressings, ultra-high molecular weight polyethylene nanofilm can be further loaded with exudate-absorbing materials (such as sodium carboxymethylcellulose, alginate, polyurethane, etc., for absorbing wound exudate), photothermal materials (such as gold nanorods / wires, polyaniline, carbon nanomaterials, etc., for generating heat under the irradiation of light with specific wavelengths such as near-infrared light to promote wound healing), anti-inflammatory materials (such as chitosan, silver nanoparticles, anti-inflammatory drugs, etc., for preventing wound infection, reducing wound inflammation, and playing roles such as anti-inflammation and pain relief), or healing-promoting components (such as epidermal growth factor, fibroblast growth factor, collagen, hyaluronic acid, etc., for promoting tissue regeneration and reducing scar formation) to achieve comprehensive wound care effects.

[0212] Application Example 2: Surgical scarless dressing.

[0213] Surgical scarless dressings are medical supplies for fresh postoperative wounds, applicable to the wound care after various surgeries such as general surgery, plastic surgery, endoscopic / minimally invasive surgery incisions, etc., and also applicable to the care of traumatic skin wounds after debridement and suture. They need to have a certain elasticity and tension to avoid excessive stretching of the wound, and also need to have waterproof and breathable properties, antibacterial properties, good fitting properties, and the function of fading scars.

[0214] For the application of surgical scarless dressings, the draw ratio of ultra-high molecular weight polyethylene nanofilm during the preparation process can be selected from 100 to 400, the thickness of the finished surgical scarless dressing is controlled within the range of 1 to 8 μm, and the porosity is within the range of 30% to 80%.

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

[0216] Application Example 3: Acne patch.

[0217] The acne patch is used for the adjuvant treatment of acne. By adsorbing the secretions and oils on the surface of acne, it reduces the environment for bacteria to breed and needs to meet requirements such as good exudate adsorption capacity, non-toxic, non-irritating, non-sensitizing, and good skin adhesion.

[0218] For the application of the acne patch, the draw ratio of the ultra-high molecular weight polyethylene nanofilm during the preparation process can be selected from 30 to 200. The thickness of the finished acne patch is controlled within the range of 5 to 10 μm, and the porosity is within the range of 30% to 80%. The ultra-high molecular weight polyethylene nanofilm has a multi-layer pore structure, with a bacteria-blocking surface layer, a secretion-adsorbing middle layer, and a breathable and moisturizing bottom layer, which can achieve the integrated management of "bacteria-blocking - cleaning - repair" of the acne wound surface.

[0219] In the acne patch, the ultra-high molecular weight polyethylene nanofilm is used as the base material and can be loaded with anti-acne components to exert treatment effects such as antibacterial, anti-inflammatory, and oil control, such as antibacterial and anti-inflammatory drug components like benzoyl peroxide and metronidazole, and oil-control components like salicylic acid, or loaded with absorption and infiltration components, such as cellulose and hydrogel lyophilized bodies.

[0220] Application Example 4: Medical aesthetic protection patch.

[0221] The medical aesthetic protection patch is applied to the care during medical aesthetic projects or skin repair processes and needs to meet requirements such as protecting the wound surface, promoting healing, and reducing the inflammatory response.

[0222] For the application of the medical aesthetic protection patch, the draw ratio of the ultra-high molecular weight polyethylene nanofilm during the preparation process can be selected from 30 to 200. The thickness of the finished medical aesthetic protection patch is controlled within the range of 3 to 10 μm, and the porosity is within the range of 30% to 80%. The nanofilm can achieve a bacteria filtration efficiency of >99.5% through physical barrier (pore size <50 nm), and can closely adhere to the skin without adhesives, avoiding the allergic risk 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 the medical aesthetic protection patch, the ultra-high molecular weight polyethylene nanofilm can be loaded with nanoparticles (such as silver nanoparticles, zinc oxide nanoparticles, etc.) or other anti-infection materials (such as chitosan, quaternary ammonium salt compounds, and plant extracts such as plant essential oils), or can be loaded with coating or surface modification materials with specific functions such as poly(lactic-co-glycolic acid) (abbreviation: PLGA, which has hydrophobicity and degradability and can further load inorganic nanoparticles and active ingredients) to increase the functionality of the medical aesthetic protection patch.

[0224] Application Example 5: Facial mask.

[0225] The facial mask is used for daily facial care and needs to meet requirements such as good adhesion, soft texture, good breathability, and the ability to effectively load skin care ingredients.

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

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

[0228] For the relevant parameters and types of loadings of the above applications, please refer to Table 2.

[0229] Table 2 Ultra-high molecular weight polyethylene nanofilm and its loadings used for 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 embodiments of the present invention can be used as a skin patch, and various different functions can be achieved 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 carried by the ultra-high molecular weight polyethylene nanofilm include organic hydrophobic materials, organic hydrophilic materials, inorganic nanoparticles, natural or synthetic active ingredients, etc.

[0233] Among them, the organic hydrophobic materials include, but are not limited to, poly(lactic-co-glycolic acid) (PLGA), polyvinylidene fluoride (PVDF), polystyrene (PS), poly(lactic acid) (PLA), etc. The organic hydrophobic materials can be loaded onto the ultra-high molecular weight polyethylene nanofilm by means of negative pressure filtration, spin coating, 3D in-situ printing, sacrificial material printing method, electrospinning, etc.

[0234] The 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 nanofilm can be 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 methods such as spin coating, in-situ printing, sacrificial material printing, or freeze drying.

[0235] The 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, and the loading can be achieved by means of evaporation coating, magnetron sputtering, in-situ growth, etc.

[0236] The ultra-high molecular weight polyethylene nanofilm can also be filled with natural active ingredients (such as hyaluronic acid, collagen, various plant extracts, etc.) or synthetic 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 specific functions of the product without affecting the interfacial 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A skin repair functional material based on a ultra-high molecular weight polyethylene nanofilm, characterized in that, It includes an ultra-high molecular weight polyethylene nanofilm; the ultra-high molecular weight polyethylene nanofilm has a three-dimensional porous network structure and is prepared through the following steps: Raw material premixing: Mix 50 - 80 parts by weight of ultra-high molecular weight polyethylene powder, 0.05 - 10 parts of antioxidant, and 0.1 - 20 parts of polymer behavior regulator, and then conduct premixing at 80°C - 200°C to obtain a premix; Extrusion and stretching: Use extrusion equipment to extrude the premix into a film, and then conduct biaxial stretching on the extrudate; Extraction: Use an extractant to extract the biaxially stretched film; Drying and annealing: Dry the extracted film, and then conduct annealing treatment on the dried film to obtain the ultra-high molecular weight polyethylene nanofilm.

2. The skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm according to claim 1, wherein The molecular weight of the ultra-high molecular weight polyethylene powder is 1 to 10 million Daltons, the particle size is 100 to 300 μm, and the density is 0.931 to 0.949 g / cm 3 .

3. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, wherein In the step of raw material premixing, 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.

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

5. The skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that, 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, polyethylene glycol formal.

6. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, characterized in that, The extrusion equipment is a twin-screw extruder; The parameters for using the twin-screw extruder to extrude the premix into a film include: screw diameter 30 - 200 nm, ratio of screw length to diameter 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, extrusion pressure 15 MPa.

7. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, wherein, The extractant is at least one of n-hexane, dichloromethane, ethyl acetate, ethyl acetate / ethanol mixture, ethanol, aqueous ethanol solution, gasoline, edible oil, xylene, tetrachloroethane, methanol, acetone, deionized water, isopropanol, ether, cyclohexane, supercritical carbon dioxide.

8. The skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm according to claim 7, wherein In the extraction step, multiple extractants are used to conduct stepwise gradient extraction on the biaxially stretched film.

9. The skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm according to claim 7, characterized in that In the extraction step, n-hexane, dichloromethane, ethyl acetate, 50% / 50% ethyl acetate / ethanol, ethanol, 50% aqueous ethanol solution, gasoline, xylene, tetrachloroethane, methanol, acetone, deionized water are successively used to conduct stepwise gradient extraction on the biaxially stretched film.

10. 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 step, the drying temperature is 50 - 100°C, and the annealing temperature is 50 - 150°C.

11. The skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to claim 1, wherein It also includes at least one of an organic hydrophobic material, an organic hydrophilic material, inorganic nanoparticles, natural active ingredients, and synthetic active ingredients loaded on the ultra-high molecular weight polyethylene nanofilm.

12. Application of the skin repair functional material based on ultra-high molecular weight polyethylene nanofilm according to any one of claims 1 - 11 in medical materials or beauty and skincare materials.

13. The application according to claim 12, characterized in that, The skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm is applied to chronic wound patches, surgical scarless patches, acne patches, medical aesthetic protection patches or facial masks.

14. The application according to claim 12 or 13, characterized in that, The thickness of the ultra-high molecular weight polyethylene nanofilm in the skin repair functional material based on the ultra-high molecular weight polyethylene nanofilm is 20 nm to 5 μm.

15. The application according to claim 14, wherein The porosity of the ultra-high molecular weight polyethylene nanofilm is 25% to 80%.

16. The application according to claim 15, wherein The pore size of the ultra-high molecular weight polyethylene nanofilm is 10 nm to 300 nm.

17. The application according to claim 14, characterized in that, The elongation at break of the ultra-high molecular weight polyethylene nanofilm is 50 - 300%.

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