Self-assembled liposome instant mask as well as preparation method and application thereof

Abstract

The invention provides a self-assembled liposome instant mask and a preparation method and application thereof, and the preparation method comprises the following steps: 1) preparation of a spinning solution: mixing PVP and PC according to a mass ratio of (1.5-3): 1, adding 0.5-2% of cholesterol to obtain a mixture, dissolving the mixture in absolute ethyl alcohol, and adding skin care active components to obtain the spinning solution; and 2) preparation of the self-assembled liposome instant mask: preparing the spinning solution into nanofibers through an electrostatic spinning technology, carrying out vacuum drying on the nanofibers to obtain the self-assembled liposome instant mask, and preparing the self-assembled liposome instant mask with both environmental protection property and skin care effect on the basis of a molecular template induced self-assembly mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of skin care and cosmetics, in particular to a self-assembled liposome instant mask, a preparation method and application thereof, which can realize rapid release and skin penetration of active skin care ingredients. BACKGROUND

[0002] With the improvement of living standards, consumers' demand for skin care products is upgrading towards high efficiency, safety and environmental protection. Wet masks occupy an important market due to their convenient use experience and instant skin care effect, but have two major defects: first, such products rich in essence liquid need to add preservatives to inhibit the growth of microorganisms, which may cause skin allergy, inflammation and other adverse reactions; second, their packaging is mostly made of plastic or aluminum foil, which will increase the environmental burden. In contrast, dry masks have more prominent environmental advantages because they do not contain essence liquid and thus do not need to add preservatives, and are convenient to use with environmentally friendly packaging. However, the existing dry masks generally have the problems of low dissolution efficiency and poor penetration of active ingredients, which seriously restricts the skin care effect.

[0003] The stratum corneum of the skin acts as a dense cell barrier, which significantly hinders the penetration of exogenous substances (especially water-soluble active ingredients), which makes it difficult for effective ingredients in ordinary cosmetics to penetrate the stratum corneum and reach the deep layer of the skin, thereby limiting their skin care efficacy. As a new type of carrier, liposomes, with their unique bilayer structure, can effectively encapsulate and protect active ingredients, providing a new technical path for crossing the stratum corneum barrier and delivering to the deep layer of the skin. However, the traditional liposome preparation method (such as the film dispersion method) is complex and difficult to combine with the mask carrier, and has problems such as low encapsulation efficiency and poor stability. Although existing research has confirmed that flexible liposomes can enhance the transdermal penetration ability, it has always failed to solve the problem of in-situ construction of liposomes in the mask base material, especially the technical contradiction of maintaining molecular activity during dry storage and quickly triggering self-assembly during use.

[0004] In summary, how to improve skin care performance while considering environmental protection and convenience has become a key problem to be solved in the field of functional mask technology. SUMMARY

[0005] The present application relates to the technical field of skin care and cosmetics, in particular to a self-assembled liposome instant mask, a preparation method and application thereof, which can realize rapid release and skin penetration of active skin care ingredients.

[0006] To achieve the above purpose, the technical solution provides a preparation method of a self-assembled liposome instant mask, comprising the following steps: 1) Preparation of the spinning solution: PVP and PC were mixed in a mass ratio of (1.5-3):1, and 0.5-2% cholesterol was added to obtain a mixture, the mixture was dissolved in anhydrous ethanol, and a skin care active ingredient was added to obtain a spinning solution; 2) Preparation of the self-assembled liposome instant mask: the spinning solution was prepared into nanofibers by electrospinning technology, and the nanofibers were vacuum dried to obtain a self-assembled liposome instant mask.

[0007] The team of the present application has developed a self-assembled liposome technology based on molecular template induction, anchoring soybean lecithin molecules PC in the PVP fiber matrix by electrospinning, using the C=O group of the PVP molecular chain to form a stable complex with the hydrogen bond of the PC phosphate head group, and by precisely controlling the mass ratio of PVP / PC to ensure that the PC molecules are uniformly dispersed in the nanofibers in monomer form, and adding 0.5-2% cholesterol to optimize the molecular fluidity, so that the mask can make the PVP molecular chain swell rapidly when it comes into contact with water, the hydrogen bond is broken, and the PC molecules are released to trigger the self-assembly of the bilayer. This molecular template induction technology uses fiber diameter and three-dimensional network structure as a control means to precisely match the water permeation rate and PC molecule release kinetics, and finally forms a complete liposome that can wrap active ingredients within 1-10 seconds, fundamentally solving the key problems of low in-situ construction efficiency of traditional dry masks and insufficient transdermal delivery of active ingredients.

[0008] In addition, the self-assembled liposome instant mask of the present application uses environmentally friendly paper packaging, avoiding the environmental pollution caused by plastic or aluminum foil packaging in wet masks. Through molecular-level self-assembly control technology, the mask substrate is completely dissolved without residue while achieving efficient liposome delivery, eliminating the need for a cleaning step. Compared with traditional wet masks and existing dry masks, the present application innovatively uses electrospun fibers as a molecular template to regulate self-assembly kinetics using their three-dimensional network structure, achieving in-situ generation of water-triggered liposomes, increasing the skin retention of vitamin C by 108% (26.3 vs 12.6 μg / cm²), and achieving a transdermal efficiency 2.3 times that of wet masks (12.9 vs 5.6 μg / cm²).

[0009] In some embodiments, the soluble macromolecule PVP has good water solubility, biocompatibility, and is suitable for use in the skin care field.

[0010] In the embodiments of the present application, PVP and PC are mixed in a mass ratio of (1.5-3):1, and 0.5-2% cholesterol is added, the addition of cholesterol lowers the phase transition temperature of the bilayer of PVP and PC to 37°C, optimizing the fluidity of the PC molecules, and the addition of cholesterol improves the order degree of the bilayer, controlling the transdermal rate to 9.21 μg / cm² in 5 minutes, which is 29.7% higher than that of the free Vc group.

[0011] In some embodiments, the mass ratio of PVP and PC is 2:1.

[0012] In some embodiments, 1% of cholesterol is added.

[0013] In some embodiments, the mass concentration of PVP in the spinning solution is 5-15 wt.%, preferably, the mass concentration of PVP in the spinning solution is 10 wt.%. In the embodiments of the present application, the spinning solution is prepared into nanofibers with a fiber diameter of 100-400 μm by electrospinning technology, the three-dimensional network structure of the nanofibers is used to control the water permeation path, and the good fit and efficient ingredient release of the mask are ensured.

[0014] Preferably, the fiber diameter of the nanofibers is 200-400 nm.

[0015] In some embodiments, the electrospinning conditions are as follows: positive voltage is 13.0 ±1.0 KV, negative voltage is 1-5 KV, spinning speed is 0.5-2.0 mL / h, spinning distance is 10-20 cm, ambient temperature is 20±5.0 ℃, and ambient humidity is 40.0±10.0%.

[0016] Preferably, the negative voltage is controlled to be 3 KV, the spinning speed is 1.00 mL / h, the spinning distance is 15 cm, and the ambient temperature is 25 ℃.

[0017] In some embodiments, a stainless steel injection needle is used as the positive electrode of electrospinning, and a tin foil paper of appropriate size is used as the negative electrode of electrospinning on the drum of the receiving device.

[0018] In some embodiments, the nanofibers are dried in a vacuum drying oven for 4 h. It should be noted that the hydrogen bond complex needs to be maintained stable during the drying process to ensure that the PC molecules are anchored in the fiber matrix of the nanofibers in monomer form.

[0019] In some embodiments, the skin care active ingredient is any one or a combination of vitamin C and PC.

[0020] In some embodiments, the self-assembled liposome instant mask is sealed and stored in a package containing a desiccant.

[0021] In the second aspect, the present application provides a self-assembled liposome instant mask prepared according to the first aspect, wherein the self-assembled liposome instant mask is a nanofiber obtained by electrospinning, the nanofiber comprises a PVP fiber matrix with PC anchored therein, a hydrogen bond complex is formed between the C=O group of PC and the phosphate head group of PC, and the nanofiber contains a skin care active ingredient and cholesterol.

[0022] The self-assembled liposome instant mask is applied in the field of skin care and anti-aging, and is particularly suitable for the field of providing transdermal absorption and sustained release of skin care components. The mask can not only be quickly dissolved during use, has excellent water solubility, provides a good visual effect, and does not need to be removed or washed, thereby being convenient for users to use. In addition, the mask is packaged with environmentally friendly paper, does not need preservatives and plastic packaging, effectively reduces environmental pollution, and meets the needs of the market for environmentally friendly packaging.

[0023] Regarding the use method of the self-assembled liposome instant mask, when the self-assembled liposome instant mask needs to be used, the base film of the self-assembled liposome instant mask is torn and the self-assembled liposome instant mask is attached to the face, and a small amount of water is sprayed on the face. Because when the self-assembled liposome instant mask is contacted with water, the PVP molecular chains of the PVP fiber matrix swell to break the hydrogen bonds of the hydrogen bond complex, the PC is released to realize directional self-assembly to form a monolayer liposome encapsulating the skin care active component, and the skin care active component released by the monolayer liposome quickly penetrates and is absorbed by the skin, so that the user does not need to wash the face after attaching the mask, thereby avoiding the cumbersome step of removing the mask.

[0024] In some embodiments, the self-assembled liposome instant mask can be quickly and completely dissolved by contacting water through handheld spraying, nanofogging instrument, manual water spraying, etc., and simultaneously spontaneously self-assembles to form a monolayer liposome loaded with a skin care active component. The dissolution process of the self-assembled liposome instant mask is rapid and is completed within 1 to 10 seconds. The mask dissolves simultaneously with the spontaneous self-assembly of the liposome. The liposome carrying the skin care active component penetrates into the deep layer of the skin to achieve effective skin care effect.

[0025] In some embodiments, the particle size of the monolayer liposome is between 50 nm and 600 nm, which ensures that the monolayer liposome can effectively penetrate the skin barrier.

[0026] Preferably, the particle size of the monolayer liposome is 362±28 nm.

[0027] In some embodiments, the nanofiber guides the directional penetration of water, so that the PC can form a monolayer liposome within 1.8±0.3 s, which is 6000 times faster than the traditional liposome (3~5h) self-assembly method.

[0028] In some embodiments, the encapsulation efficiency of the monolayer liposome encapsulating the skin care active component is 82.3±1.9%, which is increased by 86.6% compared with the group without adding cholesterol (44.1±5.6%) and the standard deviation is reduced by 67%.

[0029] In some embodiments, the retention amount of the skin care active component in the monolayer liposome accounts for 63.2%, achieving deep targeted delivery.

[0030] Compared with the prior art, the technical scheme has the following characteristics and beneficial effects: The self-assembled liposome instant mask of the present application innovatively converts the electrospinning process into a molecular template tool, realizes the integration of liposome self-assembly and transdermal delivery on demand through key technologies such as hydrogen bond regulation and phase transition control, and this new mechanism of "storage-triggering-release" not only breaks through the technical bottleneck of the stability of active ingredients in traditional masks and transdermal absorption, but also, through the process control method of molecular self-assembly, ensures environmental safety, and makes the transdermal efficiency of active ingredients reach 2.3 times that of wet masks, providing a quantifiable and controllable technical platform for the development of functional skin care products, and showing great application value in the field of precise skin care.

[0031] The self-assembled liposome instant mask of the present application realizes directional self-assembly mechanism induced by molecular template, and shows breakthrough effect in applications such as antioxidant and anti-aging. The self-assembly three-stage kinetics revealed by high-speed microscopic photography makes the skin care active components form a gradient concentration distribution in the stratum corneum, and the transdermal absorption efficiency is greatly improved compared with conventional liposomes. The technical advantages are as follows: 1) create a molecular template induced self-assembly mechanism, realize in-situ construction of liposomes on demand through controllable dissociation of PVP-PC hydrogen bond complex; 2) develop a synergistic control method of fiber structure-water penetration-molecular release, shorten the self-assembly process from several hours to 1.8±0.3 seconds; 3) innovatively introduce cholesterol as a phase change regulator, reduce the phase transition temperature of the bilayer to 37℃, improve the fluidity of PC molecules, and the encapsulation efficiency of liposomes reaches 82.3±1.9%, and the standard deviation is reduced by 67% (from ±5.6% to ±1.9%); 4) establish a three-dimensional parameter control model of PVP / PC ratio, fiber diameter and cholesterol concentration, so that the transdermal efficiency is 2.3 times (12.9 vs 5.6 μg / cm²) that of wet masks, and the skin retention amount is increased by 108% (26.3 vs 12.6 μg / cm²). BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the macroscopic morphology observation of the instant mask in Example 1, wherein (a) PVP / PC digital photo; (b) VP / PC / Vc 0.025g digital photo; (c) PVP / PC / Vc 0.050g digital photo; (d) PVP / PC optical microscope; (e) PVP / PC / Vc 0.025g optical microscope; (f) PVP / PC / Vc 0.050g optical microscope.

[0033] Figure 2are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image 0.025g are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image 0.050 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image

[0034] Figure 3 are the mechanical properties of the instant mask in Example One, (a) stress-strain curve; (b) Young's modulus; (c) elongation at break.

[0035] Figure 4 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image

[0036] Figure 5 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image

[0037] Figure 6 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image 0.025g are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image c0.050g are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image

[0038] Figure 7 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image

[0039] Figure 8 are the micro-morphology observation of the instant mask in Example One, (a) PVP / PC SEM image; (b) PVP / PC / Vc SEM image DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0041] Example One: Preparation of the mask 1) Spinning solution preparation: polyvinylpyrrolidone (PVP) and soy lecithin (PC) were mixed according to a mass ratio of 2:1, 1.0% cholesterol (0.1 g) was added as a phase change regulator, and the mixture was dissolved in 10 mL of anhydrous ethanol to prepare a spinning solution with a PVP mass concentration of 10 wt.%, followed by the addition of 0 g, 0.025 g, and 0.05 g of vitamin C (Vc) in sequence. C After stirring uniformly, the spinning solution was obtained.

[0042] 2) Preparation of the mask: 18-gauge stainless steel injection needle (inner diameter 0.86 mm) as the anode, tin foil paper of appropriate size covered on the roller at the receiving device as the receiving carrier connected to the cathode, spinning conditions: positive voltage (13.0 ± 1.0) KV, negative voltage 3.0 KV, spinning speed 1.0 mL / h, spinning distance 15.0 cm, ambient temperature (10.0 ± 5.0) °C, ambient humidity (40.0 ± 10.0) %.

[0043] 3) Preservation of the mask: the mask prepared in step 2) was dried in a vacuum drying oven for 4.0 h and stored in a sealed bag with a desiccant.

[0044] Control group 1: preparation of the mask without cholesterol 1) Spinning solution preparation: polyvinylpyrrolidone (PVP) and soy lecithin (PC) were mixed in a mass ratio of 2:1, dissolved in 10 mL of anhydrous ethanol to prepare a spinning solution with a PVP mass concentration of 10 wt.%, then 0.05 g of vitamin C (VC) was added and stirred uniformly to obtain the spinning solution.

[0045] 2) Preparation of the mask: 18-gauge stainless steel injection needle (inner diameter 0.86 mm) as the anode, tin foil paper of appropriate size covered on the roller at the receiving device as the receiving carrier connected to the cathode, spinning conditions: positive voltage (13.0 ± 2.0) KV, negative voltage 3.0 KV, spinning speed 1.0 mL / h, spinning distance 15.0 cm, ambient temperature (20.0 ± 5.0) °C, ambient humidity (40.0 ± 10.0) %.

[0046] 3) Preservation of the mask: the mask prepared in step 2) was dried in a vacuum drying oven for 4.0 h and stored in a sealed bag with a desiccant.

[0047] Control group 2: preparation of the free Vc mask 1) Spinning solution preparation: polyvinylpyrrolidone (PVP) was dissolved in 10 mL of anhydrous ethanol to prepare a spinning solution with a PVP mass concentration of 10 wt.%, then 0.05 g of vitamin C (VC) was added and stirred uniformly to obtain the spinning solution.

[0048] 2) Preparation of the mask: using a 18-gauge stainless steel needle (inner diameter 0.86 mm) as the positive electrode, and a tin foil paper of appropriate size on the roller of the receiving device as the receiving carrier connected to the negative electrode, the spinning conditions are as follows: positive voltage (13.0 ± 1.0) KV, negative voltage 3.0 KV, spinning speed 1.0 mL / h, spinning distance 15.0 cm, ambient temperature (20.0 ± 5.0) °C, and ambient humidity (40.0 ± 10.0) %.

[0049] 3) Preservation of the mask: the mask prepared in step 2) is dried in a vacuum drying oven for 4.0 h, and then stored in a sealed bag with a drying agent.

[0050] Example Two: Performance characterization of the mask (1) Test 1: Morphology observation The different component nanofiber membranes are taken out, and samples of about 1.0 cm x 1.0 cm are cut. The nanofiber membranes are carefully torn (to avoid affecting their apparent morphology), laid flat on a cleaned glass slide, and gently pressed flat with forceps. The samples are placed on the stage of an optical microscope, the converter is adjusted, and the appropriate magnification is selected for observation and photography of the samples. Another sample of about 1.0 cm x 1.0 cm is cut, the nanofiber membrane is carefully torn (to avoid affecting its apparent morphology), and fixed on the conductive glue. The other side of the conductive glue is fixed to the observation table, and the gold spraying time is 60 s. The gold-sprayed sample is observed by scanning electron microscopy, and the appropriate magnification is selected to observe the structure and diameter of the nanofiber. The average diameter and diameter distribution are measured and analyzed by Image J software.

[0051] The nanofiber membrane prepared in Example 1 is shown in Figure 1 , wherein (a) is a PVP / PC digital photograph, (b) is a PVP / PC / Vc digital photograph, (c) is a PVP / PC / Vc digital photograph, (d) is a PVP / PC optical microscope photograph, (e) is a PVP / PC / Vc optical microscope photograph, and (f) is a PVP / PC / Vc optical microscope photograph. 0.025g 0.050g 0.025g 0.050g The surface of the nanofiber membrane is smooth and flat, and can be completely peeled off on the tin paper. The fiber membrane is soft and can be folded at will, but there are a small amount of droplets at the edges. Analysis shows that the spinning conditions are greatly affected by temperature and humidity, and therefore the ambient humidity is preferably less than 40%.

[0052] Further observation under an optical microscope shows that the nanofiber membranes of different components all have complete fiber structures, and the diameter distribution is relatively uniform overall. The above results show that the V C ​​​The liposome nanofiber mask has the basic conditions required for a mask substrate. The SEM of the fiber membrane of different components is shown in Figure 2 (a) PVP / PC SEM image; (b) PVP / PC / Vc 0.025g SEM image; (c) PVP / PC / Vc 0.050 g SEM image; (d) fiber diameter distribution image, it can be seen that the nanofiber fiber structure of different V C content is complete, and there is no liquid bead residue on the fiber, and the nanofiber diameter distribution of different V C content is relatively uniform, mainly concentrated in 100-400 nm, and the addition of V C makes the fiber diameter decrease to a certain extent, and still within the required range of nanofiber diameter.

[0053] (2) Test 2: Mechanical property test About 4.0 cm x 1.0 cm samples were cut according to the fiber direction, and 3 samples of each fiber membrane were cut for detection. Adjust the position of the clamp and clamp the two ends of the sample, so that the sample is in the middle of the clamp, and the fiber remains flat and vertical. Avoid directly touching the fiber membrane with your hand during the operation, and be careful during the process of clamping with tweezers. Test conditions: tensile speed 50.0 mm / min, load size 10.0 N. After the sample tensile test, the data is arranged to draw the mechanical curve and analyze the mechanical properties. Figure 3 The mechanical properties of the nanofiber membrane of different components are shown in Figure 3 (a) stress-strain curve from which it can be seen that the nanofiber membrane has weak resistance to deformation, and there is no plastic deformation zone after breaking, and the addition of V C slightly increases the maximum deformation, and the Young's modulus and breaking elongation of the nanofiber mask of different components have no obvious difference, wherein the Young's modulus is about 80 KPa, and the breaking elongation is between 30% and 40%, which indicates that the addition of functional component VC has no obvious effect on the stretchability and toughness of the nanofiber mask.

[0054] Example Three: Method of using the mask and functional test (1) Test 1: Mask dissolving and liposome self-assembly process The dissolution of the nanofiber membrane and the self-assembly process of the VC liposome were observed by optical microscope. The nanofiber membrane was cut into a sample of 1.0 cm x 1.0 cm, laid on a clean glass slide, and covered with a glass slide and gently pressed with tweezers until flat. Take an appropriate amount of distilled water and drop it several times on one side of the glass slide, so that the distilled water slowly infiltrates along the edge of the cover glass and dissolves the nanofiber mask. The complete dissolution process was recorded by optical microscope, and the self-assembly of the liposome was observed. C The liposome self-assembly process is shown in Figure 4Wherein, (a) is the fiber before adding water; (b) is the process of self-assembly of the fiber to form liposomes; (c) is the liposome formed by self-assembly of the fiber, and (d) is the liposome after the fiber is completely dissolved. Figure 4 As shown in (1) of the figure, the fiber begins to dissolve along the edge in contact with distilled water. This dissolution occurs in the instant that the nanofiber mask contacts water molecules, but some of the fiber remains in a fibrous form because it has not contacted water (as shown in (b) of the figure). The PVP white powder dissolves into a white transparent form when it contacts water, so it is not visible in the lens. In the partially dissolved solution, white dots can be clearly seen, Figure 4 As shown in (c) of the figure, the fiber is completely dissolved after a few minutes, and a large number of white dots, i.e., V C The self-assembly process is completed in 1.8±0.3 seconds, which is 6000 times faster than the traditional film dispersion method (3-5 hours).

[0055] The "dissolution" process of the composite fiber in water is essentially a PC hydration and liposome formation process. The electrospun nanofiber acts as a template, and the interaction between the different components in the fiber and water plays a fundamental role in the bottom-up molecular self-assembly process. Figure 5 A self-assembly process mechanism consistent with the experimental data is given. This can be summarized as follows: (1) The composite fiber contacts water molecules, and the hydrogen bond between the C=O group of PVP and the water molecules produces a strong interaction, causing the water molecules to release the PC molecules anchored on the PVP chain, and at the same time the PC molecules are hydrated, at which time the fiber swells and the PC molecules are fully hydrated and have fluidity. (2) The PVP fiber matrix further absorbs water, swells, and gradually detangles, and due to the hydrophobic repulsion of the solvent, the hydrated PC molecules are aggregated in the swollen nanofiber framework, and the water molecules act to connect the adjacent PC unit head groups. (3) The hydrated PC molecules co-assemble into vesicles containing water molecules, and the water molecules contain fully dissolved VC molecules. When the fiber completely collapses and the PVP molecules detangle and dissolve, the PC molecules are released into the dissolution medium. Due to the high moisture absorption and hydrophilicity of the polymer PVP, and the small fiber diameter, the nanofiber has a three-dimensional continuous network structure, and the bottom-up assembly process is completely spontaneous.

[0056] (2) Test 2: Liposome performance test 1) Morphology observation Accurately weigh 0.03 g of different components of nanofiber membrane into 3 5.0 mL sample bottles, then pour 3.0 mL of double distilled water, ultrasonic oscillation for 10 minutes, get light yellow liposome suspension, centrifugation at 25 ℃ and 5000 r / min for 10 minutes, take the supernatant to remove the liposome to facilitate observation. Because the density of liposome is larger, take 10.0 μL of supernatant, add 490.0 μL of double distilled water for dilution, number for standby. Cover the glass slide on the cleaned glass slide, use dropper to suck the liposome suspension, drop a drop on one side of the cover glass, and let it cover the whole cover glass. If there is air bubble, use forceps to knock it out gently. After the liposome suspension stops flowing, observe it through the optical microscope with appropriate magnification. The prepared V C Liposomes are observed under optical microscope Figure 6 , wherein (a) is the liposome prepared by fiber PVP / PC; (b) is the liposome prepared by fiber PVP / PC / Vc 0.025g , (c) is the liposome prepared by fiber PVP / PC / V c0.050g , and (d) is the liposome prepared by fiber PVP / PC / V C It can be seen that the particle sizes of the liposomes with different V

[0057] 2) Particle size test Weigh 3.0 g of different components of nanofiber membrane into 3 5.0 mL sample bottles, then pour 3.0 mL of double distilled water, control its concentration within the test range, ultrasonic oscillation for 10 minutes, get a relatively thick light yellow liposome suspension for standby. According to the instrument prompt, drop appropriate amount of liposome suspension for particle size measurement and analysis, get the average particle size and polydispersity index of liposome.

[0058] In this experiment, the particle size of liposome was analyzed by nanoparticle size analyzer. The average particle size of liposome containing cholesterol decreased by 21% (361 nm vs 458 nm), and the standard deviation of particle size distribution decreased from ± 85 nm to ± 42 nm. The particle size of Vc-containing liposome was mainly concentrated in 350~600 nm. The average particle size of liposome with different Vc content (0 g, 0.025 g and 0.05 g) was 361 nm, 497 nm and 562 nm respectively. With the increase of V C content, the particle size of liposome gradually increased, and the polydispersity index (PDI) of the three was less than 0.3, which was consistent with the microscope observation result. It showed that under this preparation process condition, liposome with small particle size and spherical shape could be obtained.

[0059] 3) Encapsulation efficiency test Prepare 10 µg / mL V C The solution was subjected to full-wavelength ultraviolet scanning using a full-wavelength scanning multi-function reader, and the V was determined by the spectrum. C The maximum absorption wavelength in double-distilled water. Measure and plot V at the maximum absorption wavelength. C The standard curve is used to derive the fitting equation.

[0060] Weigh 1.0 g of nanofiber membranes with different components and place them in three 5.0 mL sample bottles. Then, pour in 3.0 mL of double-distilled water, controlling the concentration within the test range. After sonication for 10 minutes, a pale yellow liposome suspension is obtained, which is labeled as the stock solution. Take 1.0 mL of the stock solution and centrifuge twice at room temperature, setting the speed to 8000 r / min, with each centrifugation lasting 20 minutes. Take the supernatant and dilute it to 10.0 mL, while adding 2.0 mL of methanol and shaking well to demulsify the liposomes. Label this as the free drug assay solution. Take another 1.0 mL of the stock solution and dilute it to 10.0 mL, while adding 2.0 mL of methanol and shaking well to demulsify the liposomes. Label this as the total drug assay solution. The encapsulation efficiency is calculated using the following formula: Encapsulation efficiency = (1-W) 游 / W 总 )×100% (Formula 1) The encapsulation efficiency of different liposome components was determined by ultracentrifugation using the above method. The encapsulation efficiency of the optimized group (PVP / PC=2:1+1% cholesterol) reached 82.3±1.9%, which was 86.6% higher than that of the group without added cholesterol (44.1±5.6%).

[0061] (3) Liposome bioavailability determination 1) Transdermal performance test Transdermal drug delivery experiments were conducted using a transdermal drug delivery system. The experimental conditions were set at a water bath temperature of 37 °C with magnetic stirring. Cryopreserved nude mouse skin was used, and the cut skin was fixed in a Franz diffusion apparatus with a diffusion area of ​​2.5 cm² and a receiving cell volume of 15 mL. The stratum corneum faced the delivery chamber, and the dermis faced the receiving cell. The cumulative release time was set at 30 minutes, with 2.0 mL samples taken every 5 minutes, and an equal volume of PBS buffer added to the receiving cell. The collected samples were placed in brown volumetric flasks, and the vitamin C concentration was determined using ultraviolet spectrophotometry.

[0062] like Figure 7 As shown in the comparative test using the Franz diffusion device, the optimized group (PVP / PC = 2:1 + 1% cholesterol) achieved a cumulative transdermal dose of 9.21 μg / cm² at 5 minutes, which was 29.7% higher than the cholesterol-free group (7.10 μg / cm²) and significantly higher than the free vitamin C content. C(6.35 μg / cm2). This difference is due to the molecular template-induced self-assembly mechanism: the rapid water absorption and swelling of PVP fibers (fiber diameter 215 ± 38 nm) shorten the hydrogen bond breaking time, and the released PC molecules quickly complete the bilayer closure with the assistance of cholesterol, forming monolayer liposomes with a particle size of 362 ± 28 nm (PDI = 0.18) (accounting for 92%), and the total transdermal amount of the optimized group is 12.1 μg / cm2at 20 minutes, which is 18.6% higher than that of the liposome without cholesterol (10.2 μg / cm2), and is 1.53 times that of the free Vc wet mask (7.9 μg / cm2). The release curve slope analysis shows that the release rate of the optimized group is 1.84 μg / (cm2·min) in 0-5 minutes, which is 1.29 times that of the group without cholesterol (1.42 μg / (cm2·min)), which confirms the role of cholesterol in improving the fluidity of PC molecules.

[0063] 2) Skin retention amount determination After the transdermal experiment, the rat skin was removed, the residual drug on the surface was washed off, the transdermal skin was taken out, crushed, 1 mL of methanol was added, vortexed, 12 000 r·min -1 centrifuged for 10 min, the residue was re-extracted with 0.5 mL of methanol once, the supernatants were combined, and the volume was made to 2 mL, and the Vc content was determined.

[0064] As shown in Figure 8 , the Vc skin retention amount of the optimized group (PVP / PC = 2:1 + 1% cholesterol) is 26.3 μg / cm2, which is 43% higher than that of the group without cholesterol (18.4 μg / cm2), and is 2.1 times that of the free V C (12.6 μg / cm2). This significant difference is due to the synergistic effect of the molecular template: the nanoscale pore structure (diameter 215 ± 38 nm) and three-dimensional network of PVP fibers accelerate water penetration (rate 0.38 mm / s), allowing PC molecules to quickly complete hydrogen bond dissociation. The added cholesterol improves the fluidity of PC molecules by lowering the bilayer phase transition temperature, promoting the structural fusion of liposomes with the stratum corneum lipids, thereby enhancing the retention capacity of liposomes in the epidermis, indicating that cholesterol achieves deep targeted delivery of active ingredients by stabilizing the bilayer structure.

[0065] Through the above examples, the present application innovatively constructs a synergistic control system of PVP / PC ratio (2:1), cholesterol addition amount (1%), and fiber diameter (215 ± 38 nm), which realizes precise regulation of the liposome self-assembly process.

[0066] The experimental data show that the system shortens the self-assembly time of liposomes from 3-5 hours of the traditional method to 1.8±0.3 seconds, improves the efficiency by 6000 times; the encapsulation rate reaches 82.3±1.9%, which is improved by 86.6% compared with the non-optimized group, and the standard deviation is reduced by 67%; the formed liposome particle size is uniform (361±28 nm), and the single-layer structure proportion is as high as 92%, which is improved by 40% compared with the conventional method. It is particularly worth noting that the addition of cholesterol makes the order degree of the lipid bilayer of the liposome increase by 37% (I 2880 / I 2850 The ratio increases from 1.02 to 1.40), the transdermal rate increases by 29.7% (the cumulative amount at 5 minutes reaches 9.21 μg / cm²), and the skin retention amount increases by 43% (26.3 μg / cm²). These breakthrough results are derived from the self-assembly mechanism induced by the molecular template: the nanoscale pore structure and three-dimensional network of PVP fibers provide an ideal channel for water penetration, and the phase change regulation of cholesterol significantly improves the fluidity of PC molecules, and both of them realize the ultrafast (1.8±0.3 seconds) precise conversion from fiber dissolution to liposome formation, providing a reliable technical platform for the engineering production of functional skin care products.

[0067] The present application is not limited to the above-mentioned best mode, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any changes in shape or structure, any technical solution with the same or similar technical solution as the present application falls within the protection scope of the present application.

Claims

1. A method of preparing a self-assembling liposome fast dissolving mask, characterized by, The method comprises the following steps: 1) Preparation of the spinning solution: PVP and PC are mixed in a mass ratio of (1.5-3):1, 0.5-2% cholesterol is added to obtain a mixture, the mixture is dissolved in anhydrous ethanol, and a skin care active component is added to obtain the spinning solution; 2) Preparation of the self-assembled liposome instant mask: the spinning solution is prepared into nanofibers by electrospinning technology, and the nanofibers are vacuum dried to obtain the self-assembled liposome instant mask.

2. The method of claim 1, wherein the self-assembling liposome rapidly dissolving mask is prepared by the steps of: The mass concentration of PVP in the spinning solution is 5-15 wt.%.

3. The method for preparing a self-assembled liposome instant facial mask according to claim 1, characterized in that, The mass ratio of PVP to PC is 2:1, and 1% cholesterol is added.

4. The method for preparing a self-assembled liposome instant facial mask according to claim 1, characterized in that, The spinning solution is prepared into nanofibers with a fiber diameter of 100-400 μm by electrospinning technology.

5. The method for preparing a self-assembled liposome instant facial mask according to claim 1, characterized in that, The skin care active component is any one or a combination of vitamin C and PC.

6. A self-assembling liposome fast dissolving mask characterized in that, The self-assembled liposome instant mask is prepared according to the preparation method of the self-assembled liposome instant mask in any one of claims 1 to 5, and the self-assembled liposome instant mask is the nanofibers obtained by electrospinning, wherein the nanofibers comprise a PVP fiber matrix with PC anchored, and the C=O group of PC and the phosphate head group of PC form a hydrogen bond complex, and the nanofibers contain a skin care active component and cholesterol.

7. The self-assembling liposome rapid dissolve facial mask of claim 5, wherein, When the self-assembled liposome instant mask is exposed to water, the PVP molecular chains of the PVP fiber matrix swell to break the hydrogen bonds of the hydrogen bond complex, and PC is released to realize directional self-assembly to form a monolayer liposome that encapsulates the skin care active component.

8. The self-assembling liposome rapid dissolve facial mask of claim 7, wherein, The particle size of the monolayer liposome is between 50 nm and 600 nm.

9. The self-assembling liposome rapid dissolve facial mask of claim 7, wherein, The retention amount of the skin care active component in the monolayer liposome accounts for 63.2%, the encapsulation rate of the skin care active component in the monolayer liposome is 82.3±1.9%, and the retention amount of the skin care active component in the monolayer liposome accounts for 63.2%.

10. The self-assembling liposome rapid dissolve facial mask of claim 7, wherein, When the self-assembled liposome instant mask is needed, the base film of the self-assembled liposome instant mask is torn open, the self-assembled liposome instant mask is applied to the face, and a small amount of moisture is sprayed on the face.

Images