A degradable facial mask cloth and its preparation method

Abstract

The present application provides a degradable facial mask cloth and a preparation method thereof, belonging to the field of facial mask base materials. The method includes: grafting furan groups and maleimide groups into the molecular chain of polyethylene glycol-polylactic acid to obtain a cross-linked polymer; injecting a solution of the cross-linked polymer into silk fibroin gel, adding a photoinitiator and a modified cellulose nanocrystal dispersion liquid, and then performing ultraviolet light irradiation to obtain a composite film; hot-pressing the composite film to obtain a base material; encapsulating sea grape polyphenols and collagen peptides in the inner layer of liposomes, and then encapsulating them in chitosan-poly-N-isopropylacrylamide microcapsules to obtain a core-shell structure microcapsule complex; grafting mercapto groups on the surface of the microcapsule complex, and then loading it into the base material to obtain a facial mask cloth. Through the innovative design of a dynamic covalent bond network, natural-synthetic hybridization enhancement, intelligent dual-responsive microcapsules and an environmentally friendly process, a high-performance, fully degradable and intelligent facial mask cloth material is provided.

Description

Technical Field

[0001] This application relates to the technical field of facial mask base materials, and particularly to a degradable facial mask cloth and a preparation method thereof. Background Art

[0002] A facial mask cloth is a carrier material used in skin care products, mainly for carrying essence and fitting to the skin, and delivering active ingredients (such as moisturizers, antioxidants, peptides, etc.) to the skin surface through physical transmission and slow release effects.

[0003] Currently, most commercially available facial mask cloths are made of non-degradable synthetic polymer materials, which form microplastic pollution after being discarded, with a degradation period exceeding 100 years, seriously damaging the ecological environment. Although existing technologies have tried to replace them with bio-based materials such as polylactic acid or chitosan, there are still significant defects: polylactic acid has high brittleness and is easily torn in the wet state, while chitosan, although degradable, has weak mechanical properties and quickly softens and fails after absorbing moisture. At the same time, the active ingredients in the facial mask cloth are easily oxidized and inactivated during ultraviolet or high-temperature processing, resulting in low utilization rate of the active ingredients in the facial mask cloth. Therefore, how to improve the mechanical properties of the facial mask cloth and the utilization rate of the active ingredients in the facial mask cloth on the basis of improving the degradability of the facial mask cloth is a technical problem that urgently needs to be solved at present. Summary of the Invention

[0004] This application provides a degradable facial mask cloth and a preparation method thereof to solve the following technical problems: how to improve the mechanical properties of the facial mask cloth and the utilization rate of the active ingredients in the facial mask cloth on the basis of improving the degradability of the facial mask cloth.

[0005] In the first aspect, this application provides a preparation method of a degradable facial mask cloth, and the method includes:

[0006] Grafting furan groups and maleimide groups onto the molecular chain of polyethylene glycol-polylactic acid to obtain a cross-linked polymer; the grafting rate of the furan groups ≥ 15%, and the grafting rate of the maleimide groups ≥ 10%;

[0007] Injecting the solution of the cross-linked polymer into silk fibroin gel, adding a photoinitiator and a modified cellulose nanocrystal dispersion liquid, and then performing ultraviolet light irradiation to initiate a photocrosslinking reaction to obtain a composite film; the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate, and its mass is 0.5 - 1% of the total mass of the composite film; the modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, and its mass is 1 - 2% of the total mass of the composite film;

[0008] Performing hot pressing on the composite film to form a reversible covalent bond network to obtain a base material;

[0009] The sea grape polyphenols and collagen peptides are encapsulated in the inner layer of liposomes, and then encapsulated in chitosan-poly(N-isopropylacrylamide) microcapsules to obtain a core-shell structure microcapsule complex; the particle size of the liposomes is 100-150 nm, the particle size of the microcapsule complex is 500-800 nm, and the mass ratio of chitosan to poly(N-isopropylacrylamide) is 3:(6-8);

[0010] Thiol groups are grafted onto the surface of the microcapsule complex, and then it is loaded into the substrate by the vacuum impregnation method to obtain a facial mask cloth.

[0011] Optionally, grafting furan groups and maleimide groups onto the molecular chain of polyethylene glycol-polylactic acid to obtain a crosslinked polymer, including:

[0012] Mix hydroxy-activated polyethylene glycol-polylactic acid, furfuryl alcohol, stannous octoate and dichloromethane to carry out the grafting reaction of furan groups to obtain a furan-grafted polymer;

[0013] Under a nitrogen atmosphere, mix the furan-grafted polymer, maleimide-polyethylene glycol-succinimide ester, triethylamine and dichloromethane to carry out the grafting reaction of maleimide groups, and then carry out purification treatment to obtain the crosslinked polymer.

[0014] Optionally, the mass ratio of the hydroxy-activated polyethylene glycol-polylactic acid, the furfuryl alcohol and the stannous octoate is 100:(20-30):(0.5-1.5);

[0015] The mass ratio of the furan-grafted polymer, the maleimide-polyethylene glycol-succinimide ester and the triethylamine is 100:(30-40):(2-4);

[0016] The heating temperature of the grafting reaction of the furan groups is 75-85 °C, and the reaction time is 24-48 h;

[0017] The temperature of the grafting reaction of the maleimide groups is room temperature, and the reaction time is 6-18 h.

[0018] Optionally, the particle size of the modified cellulose nanocrystals is 100-200 nm;

[0019] The ultraviolet light irradiation includes the following parameters: the ultraviolet light wavelength is 405 nm, the irradiation intensity is 5-10 mW / cm², and the irradiation time is 10-15 min;

[0020] The hot pressing includes the following parameters: temperature 60-70 °C, pressure 0.5-1 MPa, and time 10-15 min.

[0021] Optionally, the method for preparing the silk fibroin gel includes:

[0022] Adding transglutaminase to the silk fibroin solution for cross-linking reaction, and then standing to form a gel to obtain the silk fibroin gel; the mass concentration of silk fibroin in the silk fibroin solution is 6-8%, and the mass of the transglutaminase is 1-3 U / g of the mass of the silk fibroin.

[0023] Optionally, encapsulating the Caulerpa lentillifera polyphenols and collagen peptides in the inner layer of liposomes, and then encapsulating them in chitosan-poly(N-isopropylacrylamide) microcapsules to obtain a core-shell structure microcapsule complex, including:

[0024] Dissolving soybean phospholipid, cholesterol and α-tocopherol in chloroform, and then rotary evaporating to form a film to obtain a lipid film;

[0025] Dissolving the Caulerpa lentillifera polyphenols and collagen peptides in phosphate buffer solution to obtain a hydration solution;

[0026] Adding the hydration solution to the lipid film, and then performing ultrasonic treatment to obtain a liposome suspension;

[0027] Mixing poly(N-isopropylacrylamide) microgel with chitosan solution, then adding the liposome suspension, and performing homogenization treatment to obtain a suspension;

[0028] Dropping sodium tripolyphosphate solution into the suspension for ionic cross-linking, and then performing centrifugation to obtain the microcapsule complex.

[0029] Optionally, the mass ratio of the soybean phospholipid, the cholesterol and the α-tocopherol is (75-85):(15-25):(0.5-1);

[0030] The concentration of the phosphate buffer solution is 0.01 M, and the pH is 6.8-7.2;

[0031] The concentration of the Caulerpa lentillifera polyphenols is 1-5 mg / mL, and the concentration of the collagen peptides is 5-10 mg / mL;

[0032] The mass concentration of chitosan in the chitosan solution is 1-3%, and the solvent is 1% acetic acid solution;

[0033] The particle size of the poly(N-isopropylacrylamide) microgel is 100-200 nm;

[0034] The mass ratio of chitosan in the chitosan solution to the poly(N-isopropylacrylamide) microgel is 3:(6-8);

[0035] The dropping rate of the sodium tripolyphosphate solution is 1 to 2 mL / min, and the final concentration of the sodium tripolyphosphate in the suspension is 0.1 to 0.3%.

[0036] Optionally, the rotary evaporation includes the following parameters: the temperature is 35 to 40 °C, the vacuum degree is -0.08 to -0.1 MPa, the rotation speed is 80 to 100 rpm, and the time is 30 to 60 min;

[0037] The homogenization treatment includes the following parameters: the rotation speed is 10,000 to 15,000 rpm, the time is 5 to 10 min, and the number of cycles is 2 to 3 times;

[0038] The centrifugation includes the following parameters: the centrifugal force is 5,000 to 8,000 × g, the time is 10 to 15 min, and the temperature is 4 to 10 °C.

[0039] Optionally, grafting a mercapto group on the surface of the microcapsule complex, and then loading it into the substrate by vacuum impregnation to obtain a facial mask cloth, including:

[0040] Immerse the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane, adjust the pH to 4.0 to 5.0 to carry out the grafting reaction of the mercapto group to obtain a mercapto-functionalized microcapsule complex; the reaction temperature of the grafting reaction of the mercapto group is 50 to 60 °C, and the reaction time is 4 to 6 h;

[0041] Adopt the vacuum impregnation method to load the mercapto-functionalized microcapsule complex into the substrate to obtain a facial mask cloth.

[0042] In a second aspect, the present application provides a facial mask cloth obtained by the preparation method of the degradable facial mask cloth according to any one of the first aspects, and the facial mask cloth satisfies the following properties:

[0043] The degradation period is 4 to 6 months;

[0044] The dry tensile strength is 20 to 22 MPa;

[0045] The wet tensile strength is 10 to 12 MPa;

[0046] Under the conditions of pH 5.5 and 32 to 37 °C, the cumulative release rate of Caulerpa lentillifera polyphenols within 24 h ≥ 80%, and the cumulative release rate of collagen peptides ≥ 85%;

[0047] Repair at 60 °C for 5 min, and the self-repair efficiency ≥ 95;

[0048] The binding force is 8 to 10 N / cm;

[0049] The biocompatibility ≥ 95%;

[0050] The storage stability ≥ 90%.

[0051] The above technical solution provided by this application has the following advantages compared with the prior art:

[0052] This application provides a preparation method of a degradable facial mask cloth. First, polyethylene glycol-polylactic acid, silk protein substrate and microcapsules are all degradable materials. At the same time, furan and maleimide groups form dynamic covalent bonds through reversible Diels-Alder reaction, and the facial mask material can be rapidly degraded in the natural environment. Secondly, the dynamic bonds formed by furan and maleimide groups can preferentially break and consume energy when stressed, and at the same time, microcracks are repaired by thermal-triggered recombination, significantly improving the tear resistance. In addition, amino-functionalized cellulose nanocrystals are combined with the polymer matrix through hydrogen bonding and mechanical interlocking effects to improve the dry tensile strength. Finally, a core-shell structure microcapsule complex is loaded in the facial mask. Chitosan can dissolve in the weakly acidic environment of the skin to release active ingredients. Poly(N-isopropylacrylamide) microgel shrinks and squeezes the inner core at body temperature to precisely trigger the release of active ingredients. At the same time, thiol groups are grafted on the surface of the microcapsules and covalently bonded to the maleimide groups of the substrate, improving the binding force between the microcapsules and the facial mask substrate. Thus, on the basis of improving the degradability of the facial mask cloth, the mechanical properties of the facial mask cloth and the utilization rate of the active ingredients in the facial mask cloth are improved. Description of the Drawings

[0053] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0054] In order to more clearly illustrate the technical solutions in the embodiments of this application 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, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0055] Figure 1 It is a schematic flow chart of a preparation method of a degradable facial mask cloth provided by an embodiment of this application. Detailed Embodiments

[0056] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0057] Unless otherwise specified, all kinds of raw materials, reagents, instruments and equipment used in this application can be obtained through market purchase or can be prepared by existing methods.

[0058] Figure 1 It is a process schematic diagram of a preparation method of a degradable facial mask cloth provided for the embodiments of this application.

[0059] In a first aspect, as Figure 1 shown, this application provides a preparation method of a degradable facial mask cloth, and the method includes:

[0060] S1. Graft furan groups and maleimide groups in the molecular chain of polyethylene glycol - polylactic acid to obtain a crosslinked polymer; the grafting rate of the furan groups ≥ 15%, and the grafting rate of the maleimide groups ≥ 10%;

[0061] In some embodiments, grafting furan groups and maleimide groups in the molecular chain of polyethylene glycol - polylactic acid to obtain a crosslinked polymer includes:

[0062] Mix hydroxy - activated polyethylene glycol - polylactic acid, furfuryl alcohol, stannous octoate and dichloromethane to carry out the grafting reaction of furan groups to obtain a furan - grafted polymer;

[0063] Under a nitrogen atmosphere, mix the furan - grafted polymer, maleimide - polyethylene glycol - succinimide ester, triethylamine and dichloromethane to carry out the grafting reaction of maleimide groups, and then carry out purification treatment to obtain the crosslinked polymer.

[0064] In some embodiments, the mass ratio of the hydroxy - activated polyethylene glycol - polylactic acid, the furfuryl alcohol and the stannous octoate is 100:(20 - 30):(0.5 - 1.5);

[0065] The mass ratio of the furan - grafted polymer, the maleimide - polyethylene glycol - succinimide ester and the triethylamine is 100:(30 - 40):(2 - 4);

[0066] The heating temperature of the grafting reaction of the furan groups is 75 - 85 °C, and the reaction time is 24 - 48 h;

[0067] The temperature of the grafting reaction of the maleimide groups is room temperature, and the reaction time is 6 - 18 h.

[0068] It should be noted that the synthesis of the dynamic crosslinked polymer in S1 has the following functions:

[0069] (1) Introduce dynamic covalent bonds: Furan groups and maleimide groups form reversible covalent bonds through the Diels - Alder reaction, endowing the material with self - healing ability.

[0070] (2)Furan grafting rate ≥ 15% and maleimide grafting rate ≥ 10%: It can ensure a sufficiently high dynamic bond density to achieve efficient self-healing (healing rate ≥ 90% at 60 °C).

[0071] (3)Enhanced material stability: The cross-linked polymer backbone (PEG-PLA) provides mechanical support, and the dynamic bond network allows local damage to be recombined by thermal triggering, extending the service life.

[0072] (4)Environmental protection and biodegradability: PEG-PLA is a biodegradable material, and its hydrolysis products are lactic acid and polyethylene glycol, which can be completely degraded in the soil in 4 - 6 months, avoiding microplastic pollution.

[0073] S2. Inject the solution of the cross-linked polymer into the silk fibroin gel, add a photoinitiator and a modified cellulose nanocrystal dispersion, and then perform ultraviolet light irradiation to initiate a photocrosslinking reaction to obtain a composite film; the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate, and its mass is 0.5 - 1% of the total mass of the composite film; the modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, and its mass is 1 - 2% of the total mass of the composite film.

[0074] In some embodiments, the particle size of the modified cellulose nanocrystal is 100 - 200 nm, and its mass is 1 - 2% of the total mass of the composite film.

[0075] In some embodiments, the ultraviolet light irradiation includes the following parameters: the ultraviolet light wavelength is 405 nm, the irradiation intensity is 5 - 10 mW / cm², and the irradiation time is 10 - 15 min.

[0076] In some embodiments, the preparation method of the silk fibroin gel includes:[[]]

[0077] Add transglutaminase to the silk fibroin solution to carry out a crosslinking reaction, and then let it stand to form a gel to obtain the silk fibroin gel; the mass concentration of silk fibroin in the silk fibroin solution is 6 - 8%, and the mass of the transglutaminase is 1 - 3 U / g of the mass of the silk fibroin.

[0078] It should be noted that the photocrosslinking and nanocrystal reinforcement of the composite film in S2 have the following effects:[[]]

[0079] (1)Construct an interpenetrating network: The silk fibroin gel can provide natural hydrophilicity and biocompatibility, enhancing the material flexibility and skin adhesion. The photoinitiator (LAP) can generate active free radicals under 405 nm ultraviolet light, triggering the crosslinking of PEG-PLA and silk fibroin to form a stable three-dimensional network.

[0080] (2)Mechanical property enhancement: The amination modification of modified cellulose nanocrystals can enhance the interfacial bonding with polymers and reduce agglomeration. With a particle size of 100 - 200 nm and an addition amount of 1 - 2%, the dry strength and wet tear resistance of the composite film can be improved through hydrogen bonding and mechanical interlocking.

[0081] (3)UV parameter optimization: Controlling the wavelength of ultraviolet light at 405 nm can avoid the damage of short - wave ultraviolet light to active ingredients and ensure the photo - initiation efficiency at the same time. Controlling the irradiation intensity at 5 - 10 mW / cm² and the irradiation time at 10 - 15 min can balance the cross - linking depth and material damage, and prevent embrittlement caused by over - cross - linking.

[0082] S3. Thermally press the composite film to form a reversible covalent bond network and obtain a substrate;

[0083] In some embodiments, the parameters of the thermal pressing include: temperature 60 - 70 °C, pressure 0.5 - 1 MPa, and time 10 - 15 min.

[0084] It should be noted that the formation of a reversible covalent bond network by thermal pressing in S3 has the following functions:

[0085] (1)Activation of the dynamic bond network: Controlling the temperature of thermal pressing at 60 - 70 °C, which is close to the glass transition temperature of PLA, softens the material segments and promotes the dynamic bond recombination of furan and maleimide. Controlling the thermal pressing pressure at 0.5 - 1 MPa can evenly distribute the dynamic bonds, avoid local stress concentration, and form a uniform cross - linked network.

[0086] (2)Improving material toughness: The dynamic bonds preferentially break and consume energy when stressed, preventing crack propagation and maintaining high strength even in the wet state.

[0087] S4. Encapsulate sea grape polyphenols and collagen peptides in the inner layer of liposomes, and then encapsulate them in chitosan - poly(N - isopropylacrylamide) microcapsules to obtain a core - shell structured microcapsule complex; the particle size of the liposomes is 100 - 150 nm, the particle size of the microcapsule complex is 500 - 800 nm, and the mass ratio of chitosan to poly(N - isopropylacrylamide) is 3:(6 - 8);

[0088] In some embodiments, the step of encapsulating sea grape polyphenols and collagen peptides in the inner layer of liposomes and then encapsulating them in chitosan - poly(N - isopropylacrylamide) microcapsules to obtain a core - shell structured microcapsule complex includes:

[0089] S401. Dissolve soybean phospholipid, cholesterol, and α - tocopherol in chloroform, and then evaporate to form a film by rotary evaporation to obtain a lipid film;

[0090] S402. Dissolve sea grape polyphenols and collagen peptides in phosphate - buffered saline to obtain a hydration solution;

[0091] S403. Add the hydration solution to the lipid membrane, and then perform ultrasonic treatment to obtain a liposome suspension;

[0092] S404. Mix poly(N-isopropylacrylamide) microgels with a chitosan solution, then add the liposome suspension, and perform homogenization treatment to obtain a suspension;

[0093] S405. Dropwise add a sodium tripolyphosphate solution to the suspension for ionic crosslinking, and then perform centrifugation to obtain the microcapsule complex.

[0094] In some embodiments, the mass ratio of the soybean phospholipid, the cholesterol, and the α-tocopherol is (75 - 85):(15 - 25):(0.5 - 1);

[0095] The concentration of the phosphate buffer solution is 0.01 M, and the pH is 6.8 - 7.2;

[0096] The concentration of the Caulerpa lentillifera polyphenol is 1 - 5 mg / mL, and the concentration of the collagen peptide is 5 - 10 mg / mL;

[0097] The mass concentration of chitosan in the chitosan solution is 1 - 3%, and the solvent is 1% acetic acid solution;

[0098] The particle size of the poly(N-isopropylacrylamide) microgels is 100 - 200 nm;

[0099] The mass ratio of chitosan in the chitosan solution to the poly(N-isopropylacrylamide) microgels is 3:(6 - 8);

[0100] The dropping rate of the sodium tripolyphosphate solution is 1 - 2 mL / min, and the final concentration of the sodium tripolyphosphate in the suspension is 0.1 - 0.3%.

[0101] In some embodiments, the rotary evaporation includes the following parameters: the temperature is 35 - 40°C, the vacuum degree is -0.08 to -0.1 MPa, the rotation speed is 80 - 100 rpm, and the time is 30 - 60 min;

[0102] The homogenization treatment includes the following parameters: the rotation speed is 10000 - 15000 rpm, the time is 5 - 10 min, and the number of cycles is 2 - 3 times;

[0103] The centrifugation includes the following parameters: the centrifugal force is 5000 - 8000×g, the time is 10 - 15 min, and the temperature is 4 - 10°C.

[0104] It should be noted that the preparation of the core-shell microcapsule complex in S4 has the following functions:

[0105] (1) Active ingredient protection and controlled release: Control the inner layer of the liposome to be 100 - 150 nm, so that the soybean phospholipid / cholesterol membrane protects Caulerpa lentillifera polyphenols (photosensitive to heat) and collagen peptides (hydrolyzable), and the encapsulation efficiency is ≥85%. α-Tocopherol is used as an antioxidant to extend the shelf life of the active ingredient. Control the thickness of the chitosan-PNIPAM shell to be 500 - 800 nm, with chitosan:PNIPAM = 3:(6 - 8). Chitosan can provide pH responsiveness (dissolving at pH 5.5), and PNIPAM can provide temperature responsiveness (shrinking at 32°C), achieving dual-triggered release. The microcapsule structure can be stabilized by ionic crosslinking to avoid burst release.

[0106] (2) Stability and targeting: Homogenization treatment can ensure the uniform dispersion of liposomes, and centrifugation can remove unencapsulated components to improve the drug loading efficiency.

[0107] S5. Graft thiol groups on the surface of the microcapsule complex, and then use the vacuum impregnation method to load it into the substrate to obtain a facial mask cloth.

[0108] In some embodiments, grafting thiol groups on the surface of the microcapsule complex and then using the vacuum impregnation method to load it into the substrate to obtain a facial mask cloth includes:

[0109] Immerse the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane, and adjust the pH to 4.0 - 5.0 to carry out the grafting reaction of thiol groups to obtain a thiolated microcapsule complex; the reaction temperature of the grafting reaction of thiol groups is 50 - 60°C, and the reaction time is 4 - 6 h;

[0110] Use the vacuum impregnation method to load the thiolated microcapsule complex into the substrate to obtain a facial mask cloth.

[0111] It should be noted that the thiol grafting and vacuum impregnation loading in S5 have the following functions:

[0112] (1) Surface functionalization to enhance binding force: Thiol grafting can covalently bind to the maleimide groups in the substrate through click reaction, thereby improving the binding force of the microcapsule complex. Vacuum impregnation can drive the microcapsules to penetrate into the pores of the substrate under negative pressure.

[0113] (2) Uniform distribution and long-term stability: After vacuum release, the pressure difference makes the microcapsules tightly embed in the substrate. Freeze-drying or low-temperature drying retains the active ingredients, and the storage stability is ≥12 months.

[0114] In the second aspect, the present application provides a facial mask cloth obtained by the preparation method of the degradable facial mask cloth described in any one of the first aspects, and the facial mask cloth satisfies the following properties:

[0115] The degradation period is 4 to 6 months;

[0116] The dry tensile strength is 20 to 22 MPa;

[0117] The wet tensile strength is 10 to 12 MPa;

[0118] Under the conditions of pH 5.5 and 32 to 37 °C, the cumulative release rate of Caulerpa lentillifera polyphenols is ≥80% within 24 h, and the cumulative release rate of collagen peptide is ≥85%;

[0119] Repaired at 60 °C for 5 min, the self-healing efficiency is ≥95;

[0120] The binding force is 8 to 10 N / cm;

[0121] The biocompatibility is ≥95%;

[0122] The storage stability is ≥90%.

[0123] In summary, a degradable facial mask fabric and its preparation method provided by this application have the following advantages:

[0124] I. Dynamic covalent bond network and self-healing performance

[0125] (1) Dual-group synergistic dynamic crosslinking:

[0126] Furan-maleimide Diels-Alder reaction: Introduce a PEG-PLA polymer grafted with furan and maleimide dual groups into the degradable facial mask fabric to form a reversible covalent bond network, achieving a microcrack repair rate of ≥90% at 60 °C.

[0127] (2) High grafting rate and controllable degradation: Through the optimization of hydroxyl activation and esterification reaction processes, ensure the balance of dynamic bond density and degradation rate (complete degradation in 4 to 6 months). At the same time, the degradation products are lactic acid and polyethylene glycol, without microplastic residues, far exceeding traditional polyacrylate facial mask materials.

[0128] II. Natural-synthetic hybrid structure

[0129] (1) Silk fibroin and PEG-PLA interpenetrating network (IPN): Utilize the natural β-sheet structure of silk fibroin to improve the flexibility of the composite film (dry tensile strength ≥15 MPa, wet ≥8 MPa), overcoming the brittleness problem of pure PLA materials.

[0130] (2) Innovation in photocrosslinking process: Use a 405 nm visible light initiator (LAP) to replace traditional ultraviolet light (254 nm), reducing the damage to active ingredients while ensuring uniform crosslinking depth.

[0131] (3)Nanocrystal reinforcement and interface optimization: Amino-functionalized cellulose nanocrystals (CNC) enhance the PLA / silk fibroin interface through hydrogen bonding and mechanical interlocking, thereby improving the wet tear resistance.

[0132] III. Core-shell microcapsule intelligent release system

[0133] (1)Dual-responsive controlled release mechanism: Chitosan (dissolved at pH 5.5) can match the weakly acidic environment on the skin surface and release Caulerpa lentillifera polyphenols (antioxidant). PNIPAM (shrinks at 32°C) triggers the release of collagen peptides at body temperature, and the cumulative release rate within 24 hours is ≥85%.

[0134] (2)Structural parameter optimization: The lipid inner core protects sensitive components, and the microcapsule outer shell ensures slow-release stability, thereby achieving an encapsulation efficiency of ≥85%.

[0135] IV. Interface bonding process

[0136] (1)Thiol-maleimide click chemistry: Thiol groups are introduced onto the surface of the microcapsules by MPTMS treatment and covalently bonded to the maleimide on the substrate.

[0137] (2)Fully degradable material system: The substrate (PEG-PLA) and the microcapsules (chitosan-PNIPAM) are both biodegradable materials, and the degradation period is 4 - 6 months, meeting the requirements of EU REACH and China's "Plastic Limit Order".

[0138] It can be seen that through the innovative design of a dynamic covalent bond network, natural-synthetic hybridization enhancement, intelligent dual-responsive microcapsules, and an environmentally friendly process, this application systematically solves the core problems of traditional facial mask fabrics such as non-degradability, poor wet mechanical properties, low utilization rate of active ingredients, and process toxicity residues, and provides a high-performance, fully degradable, and intelligent next-generation skincare material solution.

[0139] The following further elaborates on this application in combination with specific examples. It should be understood that these examples are only used to illustrate this application and not to limit the scope of this application. The experimental methods without specific conditions noted in the following examples are generally determined according to industry standards. If there are no corresponding industry standards, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0140] Example 1

[0141] This example provides a method for preparing a degradable facial mask fabric, and the method includes the following steps:

[0142] S11. Mix hydroxylated poly(ethylene glycol)-poly(lactic acid) (from Ruixi Biotechnology, purity 95%), furfuryl alcohol, stannous octoate, and dichloromethane to carry out the grafting reaction of furan groups to obtain a furan-grafted polymer. Then, under a nitrogen atmosphere, mix the furan-grafted polymer, maleimide-poly(ethylene glycol)-succinimidyl ester (product model: Macklin, M864396), triethylamine, and dichloromethane to carry out the grafting reaction of maleimide groups, and then carry out purification treatment to obtain the crosslinked polymer;

[0143] Among them, the grafting rate of the furan group is 15%, and the grafting rate of the maleimide group is 10%;

[0144] The mass ratio of the hydroxylated poly(ethylene glycol)-poly(lactic acid), the furfuryl alcohol, and the stannous octoate is 100:25:1;

[0145] The mass ratio of the furan-grafted polymer, the maleimide-poly(ethylene glycol)-succinimidyl ester, and the triethylamine is 100:35:3;

[0146] The heating temperature of the grafting reaction of the furan group is 80 °C, and the reaction time is 36 h;

[0147] The temperature of the grafting reaction of the maleimide group is room temperature, and the reaction time is 12 h;

[0148] S21. Add transglutaminase (CAS No. 80146-85-6, enzyme activity 120) to a silk fibroin solution (commercial model SFS-1) to carry out a crosslinking reaction, and then let it stand to form a gel to obtain a silk fibroin gel. Then, inject the solution of the crosslinked polymer into the silk fibroin gel, add a photoinitiator and a modified cellulose nanocrystal dispersion, and then carry out ultraviolet irradiation to initiate a photocrosslinking reaction to obtain a composite film;

[0149] Among them, the mass concentration of silk fibroin in the silk fibroin solution is 7%, and the mass of the transglutaminase is 2 U / g of the mass of silk fibroin;

[0150] The photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate, and its mass is 0.8% of the total mass of the composite film;

[0151] The modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, with a particle size of 100-150 nm, and its mass is 1.5% of the total mass of the composite film;

[0152] The preparation method of the amino-modified cellulose nanocrystals is as follows: Mix the cellulose nanocrystal suspension with EDC and NHS at a mass ratio of 1:0.2:0.1, adjust the pH to 5.0, stir at room temperature for 2 h, then add ethylenediamine (mass ratio with cellulose nanocrystals is 1:1), adjust the pH to 9.0, react in a water bath at 60 °C for 6 h, and carry out purification and drying to obtain the amino-modified cellulose nanocrystals;

[0153] The ultraviolet light irradiation includes the following parameters: the wavelength of the ultraviolet light is 405 nm, the irradiation intensity is 8 mW / cm², and the irradiation time is 12 min;

[0154] S31. Thermally press the composite film to form a reversible covalent bond network to obtain a substrate;

[0155] Among them, the thermal pressing includes the following parameters: temperature 65 °C, pressure 0.7 MPa, and time 12 min;

[0156] S41. Dissolve soy lecithin (CAS No.: 8002-43-5), cholesterol (CAS No.: 57-88-5), and α-tocopherol (CAS No.: 59-02-9) in chloroform, and then spin-evaporate to form a film to obtain a lipid film; dissolve Caulerpa lentillifera polyphenols (CAS No. 84929-27-1‌‌) and collagen peptides (CAS No. 2239-67-0‌‌) in phosphate buffer to obtain a hydration solution; add the hydration solution to the lipid film, and then perform ultrasonic treatment to obtain a liquid suspension; mix poly-N-isopropylacrylamide microgel (product model PNIPAM-40,000‌) with chitosan (CAS No. 9012-76-4‌) solution, then add the liposome suspension, and perform homogenization treatment to obtain a suspension. Dropwise add sodium tripolyphosphate solution to the suspension for ionic cross-linking, and then centrifuge to obtain the microcapsule complex;

[0157] Among them, the particle size of the liposome is 100-120 nm, the particle size of the microcapsule complex is 500-600 nm, and the mass ratio of chitosan to poly-N-isopropylacrylamide is 3:7;

[0158] The mass ratio of the soy lecithin, the cholesterol, and the α-tocopherol is 80:20:0.7;

[0159] The concentration of the phosphate buffer is 0.01 M and the pH is 7.0;

[0160] The concentration of the Caulerpa lentillifera polyphenols is 3 mg / mL, and the concentration of the collagen peptides is 8 mg / mL;

[0161] The mass concentration of chitosan in the chitosan solution is 2%, and the solvent is 1% acetic acid solution;

[0162] The particle size of the poly(N-isopropylacrylamide) microgel is 100 to 150 nm;

[0163] The mass ratio of chitosan in the chitosan solution to the poly(N-isopropylacrylamide) microgel is 3:7;

[0164] The dropping rate of the sodium tripolyphosphate solution is 1 to 2 mL / min, and the final concentration of sodium tripolyphosphate in the suspension is 0.2%;

[0165] The rotary evaporation includes the following parameters: temperature is 35 to 40 °C, vacuum degree is -0.08 to -0.1 MPa, rotation speed is 90 rpm, and time is 40 min;

[0166] The homogenization treatment includes the following parameters: rotation speed is 12000 rpm, time is 8 min, and the number of cycles is 3 times;

[0167] The centrifugation includes the following parameters: centrifugal force is 6000×g, time is 12 min, and temperature is 7 °C.

[0168] S51. Immerse the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane (CAS No. 4420-74-0), adjust the pH to 4.0 to 5.0 to carry out the grafting reaction of sulfhydryl groups to obtain a sulfhydryl-functionalized microcapsule complex; use the vacuum impregnation method to load the sulfhydryl-functionalized microcapsule complex onto the substrate to obtain a facial mask cloth.

[0169] Among them, the reaction temperature of the grafting reaction of sulfhydryl groups is 55 °C, and the reaction time is 5 h.

[0170] Example 2

[0171] This example provides a preparation method of a degradable facial mask cloth, and the method includes the following steps:

[0172] S11. Mix hydroxylated polyethylene glycol-polylactic acid (source: Ruixi Biotech, purity: 95%), furfuryl alcohol, stannous octoate, and dichloromethane to carry out the grafting reaction of furan groups to obtain a furan-grafted polymer; then, under a nitrogen atmosphere, mix the furan-grafted polymer, maleimide-polyethylene glycol-succinimide ester (product model: Macklin, M864396), triethylamine, and dichloromethane to carry out the grafting reaction of maleimide groups, and then carry out purification treatment to obtain the cross-linked polymer;

[0173] Among them, the grafting rate of furan groups is 16%, and the grafting rate of maleimide groups is 12%;

[0174] The mass ratio of the hydroxyl-activated polyethylene glycol-polylactic acid, the furfuryl alcohol, and the stannous octoate is 100:20:0.5;

[0175] The mass ratio of the furan-grafted polymer, the maleimide-polyethylene glycol-succinimide ester, and the triethylamine is 100:30:2;

[0176] The heating temperature for the grafting reaction of the furan group is 75 °C, and the reaction time is 48 h;

[0177] The temperature for the grafting reaction of the maleimide group is room temperature, and the reaction time is 6 h;

[0178] S21. Add transglutaminase (CAS No. 80146-85-6, enzyme activity 120) to the silk fibroin solution (commercial model SFS-1) for crosslinking reaction, and then let it stand to form a gel to obtain a silk fibroin gel; then inject the solution of the crosslinked polymer into the silk fibroin gel, add a photoinitiator and a modified cellulose nanocrystal dispersion, and then perform ultraviolet irradiation to initiate a photocrosslinking reaction to obtain a composite film;

[0179] Among them, the mass concentration of silk fibroin in the silk fibroin solution is 6%, and the mass of the transglutaminase is 1 U / g of the mass of silk fibroin;

[0180] The photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate, and its mass is 0.5% of the total mass of the composite film;

[0181] The modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, with a particle size of 100-150 nm, and its mass is 1% of the total mass of the composite film;

[0182] The preparation method of the amino-modified cellulose nanocrystal is as follows: Mix the cellulose nanocrystal suspension with EDC and NHS at a mass ratio of 1:0.2:0.1, adjust the pH to 5.0, stir at room temperature for 2 h, then add ethylenediamine (mass ratio to cellulose nanocrystals 1:1), adjust the pH to 9.0, react in a water bath at 60 °C for 6 h, and perform purification and drying to obtain the amino-modified cellulose nanocrystal;

[0183] The ultraviolet irradiation includes the following parameters: ultraviolet light wavelength is 405 nm, irradiation intensity is 5 mW / cm², and irradiation time is 15 min;

[0184] S31. Thermally press the composite film to form a reversible covalent bond network to obtain a substrate;

[0185] Among them, the thermal pressing includes the following parameters: temperature 60 °C, pressure 0.5 MPa, time 15 min;

[0186] S41. Dissolve soy lecithin (CAS No.: 8002-43-5), cholesterol (CAS No.: 57-88-5) and α-tocopherol (CAS No.: 59-02-9) in chloroform, and then rotary evaporate to form a film to obtain a lipid film; dissolve Caulerpa lentillifera polyphenols (CAS No. 84929-27-1‌‌) and collagen peptide (CAS No. 2239-67-0‌‌) in phosphate buffer solution to obtain a hydration solution; add the hydration solution to the lipid film, and then perform ultrasonic treatment to obtain a liquid suspension; mix poly-N-isopropylacrylamide microgel (product model PNIPAM-40,000‌) with chitosan (CAS No. 9012-76-4‌) solution, then add the liposome suspension, and perform homogenization treatment to obtain a suspension. Dropwise add sodium tripolyphosphate solution to the suspension for ionic crosslinking, and then perform centrifugation to obtain the microcapsule complex;

[0187] Among them, the particle size of the liposome is 100 - 120 nm, the particle size of the microcapsule complex is 600 - 800 nm, and the mass ratio of chitosan to poly-N-isopropylacrylamide is 3:6;

[0188] The mass ratio of the soy lecithin, the cholesterol and the α-tocopherol is 75:15:0.5;

[0189] The concentration of the phosphate buffer solution is 0.01 M and the pH is 7;

[0190] The concentration of the Caulerpa lentillifera polyphenols is 1 mg / mL, and the concentration of the collagen peptide is 5 mg / mL;

[0191] The mass concentration of chitosan in the chitosan solution is 1%, and the solvent is 1% acetic acid solution;

[0192] The particle size of the poly-N-isopropylacrylamide microgel is 100 - 120 nm;

[0193] The mass ratio of chitosan in the chitosan solution to the poly-N-isopropylacrylamide microgel is 3:6;

[0194] The dropping rate of the sodium tripolyphosphate solution is 1 mL / min, and the final concentration of the sodium tripolyphosphate in the suspension is 0.1%;

[0195] The rotary evaporation includes the following parameters: temperature is 35°C, vacuum degree is -0.08 to -0.1 MPa, rotation speed is 80 rpm, and time is 60 min;

[0196] The homogenization treatment includes the following parameters: rotation speed is 10,000 rpm, time is 5 min, and the number of cycles is 3 times;

[0197] The centrifugation includes the following parameters: the centrifugal force is 5000×g, the time is 15 min, and the temperature is 4°C.

[0198] S51. Immerse the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane (CAS No. 4420-74-0), adjust the pH to 4.0 - 5.0 to carry out the grafting reaction of the mercapto group, and obtain the mercapto-functionalized microcapsule complex; use the vacuum impregnation method to load the mercapto-functionalized microcapsule complex into the substrate to obtain the mask fabric.

[0199] Among them, the reaction temperature of the grafting reaction of the mercapto group is 50°C, and the reaction time is 6 h.

[0200] Example 3

[0201] This example provides a preparation method of a degradable mask fabric, and the method includes the following steps:

[0202] S11. Mix hydroxy-activated polyethylene glycol-poly(lactic acid) (source: Ruixi Biotechnology, purity: 95%), furfuryl alcohol, stannous octoate, and dichloromethane to carry out the grafting reaction of the furan group to obtain the furan-grafted polymer; then, under a nitrogen atmosphere, mix the furan-grafted polymer, maleimide-polyethylene glycol-succinimidyl ester (product model: Macklin, M864396), triethylamine, and dichloromethane to carry out the grafting reaction of the maleimide group, and then carry out purification treatment to obtain the cross-linked polymer;

[0203] Among them, the grafting rate of the furan group is 15%, and the grafting rate of the maleimide group is 10%;

[0204] The mass ratio of the hydroxy-activated polyethylene glycol-poly(lactic acid), the furfuryl alcohol, and the stannous octoate is 100:30:1.5;

[0205] The mass ratio of the furan-grafted polymer, the maleimide-polyethylene glycol-succinimidyl ester, and the triethylamine is 100:40:4;

[0206] The heating temperature of the grafting reaction of the furan group is 85°C, and the reaction time is 24 h;

[0207] The temperature of the grafting reaction of the maleimide group is room temperature, and the reaction time is 18 h;

[0208] S21. Add transglutaminase (CAS No. 80146-85-6, enzyme activity 120) to the silk fibroin solution (commercial model SFS-1) to carry out a cross-linking reaction, then let it stand to form a gel to obtain a silk fibroin gel; then inject the solution of the cross-linked polymer into the silk fibroin gel, add a photoinitiator and a modified cellulose nanocrystal dispersion, and then carry out ultraviolet light irradiation to initiate a photo-cross-linking reaction to obtain a composite film;

[0209] Among them, the mass concentration of silk fibroin in the silk fibroin solution is 8%, and the mass of the transglutaminase is 3 U / g of the mass of silk fibroin;

[0210] The photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphonate, and its mass is 1% of the total mass of the composite film;

[0211] The modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, with a particle size of 150-200 nm, and its mass is 2% of the total mass of the composite film;

[0212] The preparation method of the amino-modified cellulose nanocrystal is as follows: Mix the cellulose nanocrystal suspension with EDC and NHS at a mass ratio of 1:0.2:0.1, adjust the pH to 5.0, stir at room temperature for 2 h, then add ethylenediamine (mass ratio to cellulose nanocrystals 1:1), adjust the pH to 9.0, react in a water bath at 60 °C for 6 h, and carry out purification and drying to obtain the amino-modified cellulose nanocrystal;

[0213] The ultraviolet light irradiation includes the following parameters: ultraviolet light wavelength is 405 nm, irradiation intensity is 10 mW / cm², and irradiation time is 10 min;

[0214] S31. Thermally press the composite film to form a reversible covalent bond network to obtain a substrate;

[0215] Among them, the thermal pressing includes the following parameters: temperature 70 °C, pressure 1 MPa, time 10 min;

[0216] S41. Dissolve soybean phospholipid (CAS No.: 8002-43-5), cholesterol (CAS No.: 57-88-5) and α-tocopherol (CAS No.: 59-02-9) in chloroform, and then evaporate to form a film by rotary evaporation to obtain a lipid film; dissolve sea grape polyphenols (CAS No.: 84929-27-1‌‌) and collagen peptides (CAS No.: 2239-67-0‌‌) in phosphate buffer solution to obtain a hydration solution; add the hydration solution to the lipid film, and then perform ultrasonic treatment to obtain a liquid suspension; mix poly N-isopropylacrylamide microgel (product model: PNIPAM-40,000‌) with chitosan (CAS No.: 9012-76-4‌) solution, then add the liposome suspension, and perform homogenization treatment to obtain a suspension. Dropwise add sodium tripolyphosphate solution to the suspension for ionic crosslinking, and then centrifuge to obtain the microcapsule complex;

[0217] Among them, the particle size of the liposome is 120 - 150 nm, the particle size of the microcapsule complex is 600 - 700 nm, and the mass ratio of chitosan to poly N-isopropylacrylamide is 3:8;

[0218] The mass ratio of the soybean phospholipid, the cholesterol and the α-tocopherol is 85:25:1;

[0219] The concentration of the phosphate buffer solution is 0.01 M and the pH is 7;

[0220] The concentration of the sea grape polyphenols is 5 mg / mL, and the concentration of the collagen peptides is 10 mg / mL;

[0221] The mass concentration of chitosan in the chitosan solution is 3%, and the solvent is 1% acetic acid solution;

[0222] The particle size of the poly N-isopropylacrylamide microgel is 150 - 200 nm;

[0223] The mass ratio of chitosan in the chitosan solution to the poly N-isopropylacrylamide microgel is 3:8;

[0224] The dropping rate of the sodium tripolyphosphate solution is 2 mL / min, and the final concentration of sodium tripolyphosphate in the suspension is 0.3%;

[0225] The rotary evaporation includes the following parameters: temperature is 40°C, vacuum degree is -0.08 to -0.1 MPa, rotation speed is 100 rpm, and time is 30 min;

[0226] The homogenization treatment includes the following parameters: rotation speed is 15000 rpm, time is 5 min, and the number of cycles is 2 times;

[0227] The centrifugation includes the following parameters: the centrifugal force is 8000×g, the time is 10 min, and the temperature is 4°C.

[0228] S51. Immerse the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane (CAS No. 4420-74-0), adjust the pH to 4.0 - 5.0 to carry out the grafting reaction of sulfhydryl groups, and obtain a sulfhydryl-functionalized microcapsule complex; use the vacuum impregnation method to load the sulfhydryl-functionalized microcapsule complex into the substrate to obtain a facial mask cloth.

[0229] Among them, the reaction temperature of the grafting reaction of sulfhydryl groups is 60°C, and the reaction time is 4 h.

[0230] Comparative Example 1

[0231] On the basis of what is disclosed in Example 1, this comparative example is modified as follows:

[0232] In step S11, only furan groups are grafted onto the molecular chain of the hydroxyl-activated polyethylene glycol - polylactic acid.

[0233] Comparative Example 2

[0234] On the basis of what is disclosed in Example 1, this comparative example is modified as follows:

[0235] In step S11, only maleimide groups are grafted onto the molecular chain of the hydroxyl-activated polyethylene glycol - polylactic acid.

[0236] Comparative Example 3

[0237] On the basis of what is disclosed in Example 1, this comparative example is modified as follows:

[0238] In step S11, no furan groups and maleimide groups are grafted onto the molecular chain of the hydroxyl-activated polyethylene glycol - polylactic acid.

[0239] Comparative Example 4

[0240] In step S21, the modified cellulose nanocrystal dispersion is not added.

[0241] Comparative Example 5

[0242] On the basis of what is disclosed in Example 1, this comparative example is modified as follows:

[0243] In step S41, the sea grape polyphenols and collagen peptides are not encapsulated with liposomes and microcapsules.

[0244] Comparative Example 6

[0245] On the basis of what is disclosed in Example 1, this comparative example is modified as follows:

[0246] In step S41, the Caulerpa lentillifera polyphenols and collagen peptides are directly encapsulated in the chitosan-poly(N-isopropylacrylamide) microcapsules without liposome coating.

[0247] Comparative Example 7

[0248] On the basis of what is disclosed in Example 1, the following modifications are made in this comparative example:

[0249] In step S51, without grafting the surface thiol groups of the microcapsule complex, the microcapsule complex is directly loaded into the substrate to obtain a mask fabric.

[0250] The properties of the mask fabrics of Examples 1 to 3 and Comparative Examples 1 to 7 were measured, and the results are shown in Table 1. The property measurement methods are as follows:

[0251] Degradation period: Soil burial test (ISO 20200), measure the time when the weight loss rate of the sample is ≥ 90%.

[0252] Dry / wet tensile strength: Universal material testing machine (ASTM D638), tensile rate 5 mm / min, and the wet samples are tested after soaking for 24 hours.

[0253] Release rate of active ingredients: In vitro dissolution test (USP 42), pH 5.5 phosphate buffer solution, constant temperature water bath at 32°C, and HPLC (for Caulerpa lentillifera polyphenols) and BCA method (for collagen peptides) are used to measure the cumulative release amount.

[0254] Self-healing efficiency: SEM is used to observe the morphology before and after the repair of microcracks (width ≤ 50 μm), and the tensile strength recovery rate = (strength after repair / original strength) × 100%.

[0255] Binding force (peel strength): 90° peel test (ASTM D1876), and the peel force at the interface between the substrate and the microcapsules is tested.

[0256] Biocompatibility: Human fibroblasts (HaCaT) are cultured for 48 hours, and the CCK-8 method is used to measure the survival rate (ISO 10993-5).

[0257] Storage stability: Accelerated test at 40°C / 75% humidity for 3 months, and HPLC / BCA method is used to measure the retention rate of active ingredients.

[0258] Table 1 Properties of the mask fabrics of Examples 1 to 3 and Comparative Examples 1 to 7

[0259]

[0260] As can be seen from Table 1, Examples 1 to 3 are significantly superior to the Comparative Examples in terms of indicators such as degradability, mechanical properties, and active ingredient utilization rate through the design of a dual-dynamic bond network, nanocrystal enhancement, and core-shell microcapsules. The degradation period of the mask fabrics in Examples 1 to 3 is 4 to 6 months, the dry tensile strength is 20 to 22 MPa, the wet tensile strength is 10 to 12 MPa, and under the conditions of pH 5.5 and 32 to 37 °C, the cumulative release rate of Caulerpa lentillifera polyphenols within 24 hours is ≥80%, the cumulative release rate of collagen peptides is ≥85%, after repairing at 60 °C for 5 minutes, the self-repair efficiency is ≥95, the binding force is 8 to 10 N / cm, the biocompatibility is ≥95%, and the storage stability is ≥90%.

[0261] Comparative Example 1 only grafted furan groups and lacked maleimide groups, unable to form a dynamic covalent bond network, resulting in a low self-repair efficiency.

[0262] Comparative Example 2 only grafted maleimide groups, with insufficient dynamic bond density, resulting in a low self-repair efficiency, and the release of the active ingredient decreased due to the weak binding force of the microcapsules.

[0263] Comparative Example 3 did not graft dynamic groups, the material had high brittleness and no self-repair ability, and the active ingredient degraded rapidly without the protection of microcapsules.

[0264] Comparative Example 4 did not add modified cellulose nanocrystals (CNC), resulting in weak interfacial binding force and a decrease in wet tensile strength.

[0265] Comparative Example 5 did not coat liposomes, the active ingredient was directly exposed, the burst release rate was high, and the storage stability was poor.

[0266] Comparative Example 6 did not coat the liposome core, and collagen peptides were prone to leakage, resulting in a decrease in stability.

[0267] Comparative Example 7 did not graft mercapto groups, the microcapsules and the substrate were only physically adsorbed, the binding force was low, and they were prone to falling off during use.

[0268] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the description of the range from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0269] In addition, in the description of the specification of this application, the terms "comprise", "include" and the like mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, both A and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural.

[0270] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A preparation method of a degradable facial mask cloth, characterized in that, The method includes: Grafting furan groups and maleimide groups onto the molecular chains of polyethylene glycol-polylactic acid to obtain a cross-linked polymer; the grafting rate of the furan groups is ≥15%, and the grafting rate of the maleimide groups is ≥10%; Injecting the solution of the cross-linked polymer into silk fibroin gel, adding a photoinitiator and a modified cellulose nanocrystal dispersion, and then performing ultraviolet irradiation to initiate a photocrosslinking reaction to obtain a composite film; the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphinate, and its mass is 0.5-1% of the total mass of the composite film; the modified cellulose nanocrystal is an amino-modified cellulose nanocrystal, and its mass is 1-2% of the total mass of the composite film; Thermally pressing the composite film to form a reversible covalent bond network to obtain a substrate; Encapsulating Caulerpa lentillifera polyphenols and collagen peptides in the inner layer of liposomes, and then encapsulating them in chitosan-poly(N-isopropylacrylamide) microcapsules to obtain a core-shell structure microcapsule complex; the particle size of the liposomes is 100-150 nm, the particle size of the microcapsule complex is 500-800 nm, and the mass ratio of chitosan to poly(N-isopropylacrylamide) is 3:(6-8); Grafting mercapto groups onto the surface of the microcapsule complex, and then loading it into the substrate by vacuum impregnation to obtain a facial mask cloth; wherein, The grafting of furan groups and maleimide groups onto the molecular chains of polyethylene glycol-polylactic acid to obtain a cross-linked polymer includes: Mixing hydroxyl-activated polyethylene glycol-polylactic acid, furfuryl alcohol, stannous octoate and dichloromethane to carry out the grafting reaction of furan groups to obtain a furan-grafted polymer; Under a nitrogen atmosphere, mixing the furan-grafted polymer, maleimide-polyethylene glycol-succinimide ester, triethylamine and dichloromethane to carry out the grafting reaction of maleimide groups, and then performing purification treatment to obtain the cross-linked polymer; The grafting of mercapto groups onto the surface of the microcapsule complex and then loading it into the substrate by vacuum impregnation to obtain a facial mask cloth includes: Immersing the microcapsule complex in an ethanol solution containing 3-mercaptopropyltrimethoxysilane, adjusting the pH to 4.0-5.0 to carry out the grafting reaction of mercapto groups to obtain a mercapto-functionalized microcapsule complex; the reaction temperature of the grafting reaction of mercapto groups is 50-60 °C, and the reaction time is 4-6 h; Using vacuum impregnation to load the mercapto-functionalized microcapsule complex into the substrate to obtain a facial mask cloth.

2. The preparation method of the degradable facial mask cloth according to claim 1, wherein, The mass ratio of the hydroxyl-activated polyethylene glycol-polylactic acid, the furfuryl alcohol and the stannous octoate is 100:(20-30):(0.5-1.5); The mass ratio of the furan-grafted polymer, the maleimide-polyethylene glycol-succinimide ester and the triethylamine is 100:(30-40):(2-4); The heating temperature of the grafting reaction of furan groups is 75-85 °C, and the reaction time is 24-48 h; The temperature of the grafting reaction of maleimide groups is room temperature, and the reaction time is 6-18 h.

3. The preparation method of the degradable facial mask cloth according to claim 1, characterized in that, The particle size of the modified cellulose nanocrystal is 100-200 nm; The ultraviolet light irradiation includes the following parameters: the wavelength of the ultraviolet light is 405 nm, the irradiation intensity is 5 - 10 mW / cm², and the irradiation time is 10 - 15 min; The hot pressing includes the following parameters: the temperature is 60 - 70 °C, the pressure is 0.5 - 1 MPa, and the time is 10 - 15 min.

4. The preparation method of the degradable facial mask cloth according to claim 1, wherein, The preparation method of the silk fibroin gel includes: Adding transglutaminase to the silk fibroin solution to carry out a crosslinking reaction, and then standing to form a gel to obtain the silk fibroin gel; the mass concentration of the silk fibroin in the silk fibroin solution is 6 - 8%, and the mass of the transglutaminase is 1 - 3 U / g of the silk fibroin mass.

5. The preparation method of the degradable facial mask cloth according to claim 1, characterized in that, Encapsulating the Caulerpa lentillifera polyphenols and collagen peptides in the inner layer of liposomes, and then encapsulating them in chitosan-poly(N-isopropylacrylamide) microcapsules to obtain a core-shell structure microcapsule complex, including: Dissolving soy lecithin, cholesterol, and α-tocopherol in chloroform, and then rotary evaporating to form a film to obtain a lipid film; Dissolving the Caulerpa lentillifera polyphenols and collagen peptides in a phosphate buffer solution to obtain a hydration solution; Adding the hydration solution to the lipid film, and then performing ultrasonic treatment to obtain a liposome suspension; Mixing the poly(N-isopropylacrylamide) microgel with the chitosan solution, then adding the liposome suspension, and performing homogenization treatment to obtain a suspension; Dropping a sodium tripolyphosphate solution into the suspension to carry out ionic crosslinking, and then centrifuging to obtain the microcapsule complex.

6. The preparation method of the degradable facial mask cloth according to claim 5, wherein, The mass ratio of the soy lecithin, the cholesterol, and the α-tocopherol is (75 - 85):(15 - 25):(0.5 - 1); The concentration of the phosphate buffer solution is 0.01 M, and the pH is 6.8 - 7.2; The concentration of the Caulerpa lentillifera polyphenols is 1 - 5 mg / mL, and the concentration of the collagen peptides is 5 - 10 mg / mL; The mass concentration of chitosan in the chitosan solution is 1 - 3%, and the solvent is 1% acetic acid solution; The particle size of the poly(N-isopropylacrylamide) microgel is 100 - 200 nm; The mass ratio of the chitosan in the chitosan solution to the poly(N-isopropylacrylamide) microgel is 3:(6 - 8); The dropping rate of the sodium tripolyphosphate solution is 1 - 2 mL / min, and the final concentration of the sodium tripolyphosphate in the suspension is 0.1 - 0.3%; 7. The preparation method of the degradable facial mask cloth according to claim 5, wherein, The rotary evaporation includes the following parameters: the temperature is 35 - 40 °C, the vacuum degree is -0.08 to -0.1 MPa, the rotation speed is 80 - 100 rpm, and the time is 30 - 60 min; The homogenization treatment includes the following parameters: the rotation speed is 10000 - 15000 rpm, the time is 5 - 10 min, and the number of cycles is 2 - 3 times; The centrifugation includes the following parameters: the centrifugal force is 5000 - 8000×g, the time is 10 - 15 min, and the temperature is 4 - 10 °C.

8. A facial mask cloth obtained by the preparation method of the degradable facial mask cloth described in any one of claims 1 to 7, characterized in that, The mask cloth meets the following performance: The degradation period is 4 - 6 months; The dry tensile strength is 20 - 22 MPa; The wet tensile strength is 10 - 12 MPa; Under the conditions of pH 5.5 and 32 - 37 °C, the cumulative release rate of Caulerpa lentillifera polyphenols is ≥80% within 24 h, and the cumulative release rate of collagen peptides is ≥85%; Repair for 5 min at 60 °C, and the self - repair efficiency is ≥95; The binding force is 8 - 10 N / cm; The biocompatibility is ≥95%; The storage stability is ≥90%.

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