Biomimetic permeable membrane and preparation method thereof
Patent Information
- Authority / Receiving Office
- HK · HK
- Patent Type
- Patents
- Current Assignee / Owner
- BEIJING RELATEC ENG TECH CO LTD
- Filing Date
- 2026-04-23
- Publication Date
- 2026-07-17
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of wound repair technology, specifically to a biomimetic permeable membrane and its preparation method. Background Technology
[0002] Biomimetic materials mimic the structure and function of organisms in nature, striving to closely resemble human tissue in composition, microstructure, and surface chemistry, thereby achieving higher biocompatibility and functionality. In the field of skin repair, biomimetic materials can provide a microenvironment close to natural skin for wounds, promoting cell migration, proliferation, and regeneration. Furthermore, these biomimetic membranes can be extended to various scenarios such as food preservation, functional packaging, and wastewater treatment. Overall, while existing technologies each have their advantages, they still have significant shortcomings in meeting the synergistic requirements of skin repair for the three key capabilities of "close adhesion, one-way permeability, and active ingredient delivery," and urgently need improvement.
[0003] Existing technology 1: Ordinary gauze dressings. Ordinary gauze has a simple structure, low cost, and is readily available. It can cover the wound and absorb exudate to a certain extent. However, its breathability is insufficient as the moisture level increases. The gauze is easily soaked when used for a long time or when there is a lot of exudate, which leads to a significant decrease in breathability and affects wound metabolism and healing. The gauze cannot effectively lock in water and cannot provide continuous and stable moist conditions for wounds that require a "slightly moist" environment to heal.
[0004] Therefore, while gauze has its value in terms of coverage and absorption, it is systematically inadequate in maintaining the microenvironment required for healing and in blocking microcontamination.
[0005] Existing technology 2: Traditional medical films. Traditional medical films have good barrier properties against liquids and can prevent foreign droplets from entering the wound in the short term. However, most plastic films basically isolate air and moisture, keeping the skin in a closed environment, hindering normal gas / moisture exchange, which can easily lead to the accumulation of metabolic products and induce inflammation.
[0006] Moreover, conventional skin patches do not contain bioactive molecules that promote repair and cannot fundamentally enhance the skin's self-healing ability. Therefore, traditional skin patches lack an ideal compromise between "liquid barrier" and "breathability and moisturizing balance" and cannot simultaneously ensure the stable delivery of active ingredients and the regulation of the local microenvironment.
[0007] This demonstrates that existing solutions have both advantages and limitations—traditional dressings or films typically present a choice between two options: either breathable but lacking in moisture retention and barrier properties, or offering good barrier properties but poor breathability and microenvironment and lacking delivery capabilities. These shortcomings can lead to systemic burdens in clinical use, such as prolonged wound healing periods, increased risk of secondary infection, decreased patient comfort, and the inability to achieve precise local drug delivery.
[0008] Therefore, a novel biomimetic permeable membrane is urgently needed to solve the above problems. By designing a biomimetic layered structure and surface wetting gradient, a tight fit with the skin can be achieved, realizing "inside-out priority" unidirectional moisture permeability to prevent external particles and aerosols from entering while allowing wound metabolic products to be discharged outward. Through a lipid-ion dual continuous nanocapsule carrier system, active ingredients such as peptides, lipids and natural extracts can be gently encapsulated and released in a controlled manner, and the stability of active ingredients can be maintained during construction and sterilization.
[0009] By achieving the above objectives, it is hoped that a biomimetic permeable membrane can be obtained that is superior to existing gauze and traditional films in terms of breathability, moisturizing, one-way permeability, and delivery of active ingredients, thereby reducing the systemic burden caused by the above-mentioned technical limitations and improving wound repair and patient comfort.
[0010] To address these issues, this invention proposes a biomimetic permeable membrane and its preparation method. Summary of the Invention
[0011] To address the shortcomings of existing technologies, this invention provides a biomimetic permeable membrane and its preparation method, thereby resolving the problems mentioned in the background section.
[0012] To achieve the above objectives, the present invention provides the following technical solution:
[0013] Solution preparation:
[0014] Prepare L1 stock solution A, which is an aqueous matrix with a solid content of 8–12 wt% and a pH of 7.0–7.4. The L1 contains gelatin-dopamine, polyvinyl alcohol, glycerophosphate choline and alginate.
[0015] To prepare crosslinking working solution B, mix a 0.05–0.20 wt% sodium tetraborate aqueous solution with... The aqueous solutions were mixed at a mass ratio of 1:1;
[0016] Prepare lipid phase C by melting and mixing the ceramide 3, phytosphoprotein, C16–C18 fatty alcohol and propolis wax at 45–55°C, and add coenzyme Q10;
[0017] Active aqueous phase D was prepared, containing propolis extract, oligopeptide-5, oligopeptide-32, acetyl tetrapeptide-15, dipeptide-4, and Zn ions.
[0018] The outer layer spraying dispersion E is prepared as an aqueous polyurethane-polysiloxane emulsion and a dispersion of silica with slight surface affinity.
[0019] Subsequently, the L1 mother liquor A was used to prepare a wet viscous substrate by electrospinning or blade coating-condensation. The electrospinning parameters were 15–25 kV, 0.6–1.2 mL / h, collection distance 12–18 cm, ambient temperature 22–26°C, and RH 45–60%. The blade coating-condensation conditions were a blade tip of 100–300 μm and a condensation temperature of 4–8°C.
[0020] Atomize and spray crosslinking working solution B onto the surface of the above wet substrate until it is in a non-flowing state and let it stand for 3–8 minutes;
[0021] Nanocapsule construction and polarity reversal: A portion of lipid phase C and active aqueous phase D were sheared and dispersed into a core at a mass ratio of 40:60 to 60:40. Then, chitosan solution was added to form a positively charged outer shell, followed by hyaluronic acid solution to form a negatively charged outer shell. The remaining lipid phase C was then added and stirred until homogeneous to obtain lipid phase C containing nanocapsules.
[0022] The lipid phase C containing nanocapsules prepared in step S3 was infiltrated from the surface of the wet substrate until the surface was slightly wet and glossy under vacuum conditions of 35–40°C and -0.06 to -0.09 MPa. After stopping the infiltration, the subsequent steps were carried out within 2–8 min.
[0023] At 22–28°C and RH 75–85%, with a spray distance of 15–25 cm and a spray volume of 0.8–2.5... The outer layer spray dispersion E is evenly sprayed onto the wet substrate surface and left to stand for 3–7 minutes to complete the synergistic volatilization and curing.
[0024] Subsequently, the product was graded and dried for 2–6 h at 35–45°C and RH 30–50%.
[0025] The material is then sterilized, encapsulated with a low oxygen permeability material, and an oxygen scavenger is inserted.
[0026] The mass ratio of gelatin-dopamine, polyvinyl alcohol, glycerophosphate choline and alginate in the L1 mother liquor A is (3–6):(2–4):(0.2–0.4):(0.3–1).
[0027] In the lipid phase C, the molar ratio of ceramide 3: phytosphingosine: fatty alcohol: propolis wax is 1:(0.3–0.8):(1.2–2.0):(0.2–0.4), and coenzyme Q10 accounts for 0.4–3.0 wt% of the total mass of lipid phase C.
[0028] The chitosan solution was prepared using 0.1 M sodium acetate buffer, with a chitosan solution concentration of 4 mg / mL; the hyaluronic acid solution was also prepared using sodium acetate buffer, with a concentration of 4 mg / mL.
[0029] The proportions of polypeptide active substances in the active aqueous phase D by mass of the "total polypeptide load" are as follows: oligopeptide-5 accounts for 10–50 wt%, oligopeptide-32 accounts for 5–30 wt%, acetyl tetrapeptide-15 accounts for 20–70 wt%, and dipeptide-4 accounts for 1–20 wt%; and the molar ratio of dipeptide-4 to Zn is 1:(0.01–0.2).
[0030] The outer layer spray dispersion E contains 8–15 wt% aqueous resin and 5–15 wt% surface-modified silica.
[0031] The sterilization process involves ethylene oxide and electron beam sterilization.
[0032] The permeable membrane can be used for skin repair, wound care, and protection of sensitive skin.
[0033] This invention provides a biomimetic permeable membrane and its preparation method. It has the following beneficial effects:
[0034] 1. By constructing a layered structure of a wet adhesive base biomimetic layer and a permeable lipid phase, a tight fit with the skin surface is achieved and microscopic gaps are reduced, thus playing a barrier role in physically blocking the invasion of external particles and moisture aerosols.
[0035] 2. By forming a wetting gradient with an inner hydrophilic and an outer hydrophobic layer and using a lipid-ion bicontinuous nanocapsule system, anisotropic moisture permeability with an inner-outer priority is obtained, which can maintain the micro-moist environment of the wound while preventing the reverse entry of external droplets.
[0036] 3. By encapsulating peptides, lipid-soluble components, and natural extracts in mild nanocapsules and limiting the application and sterilization process window, the active ingredients remain stable and released in a controlled manner after application and sterilization, thus ensuring local delivery efficiency and product sterilizability compatibility. Attached Figure Description
[0037] Figure 1 This is a schematic diagram of the structure of the sample of the present invention. Detailed Implementation
[0038] To enable those skilled in the art to understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.
[0039] The present invention will now be described in detail with reference to the accompanying drawings:
[0040] Example 1 (refer to) Figure 1 This embodiment provides a biomimetic permeable membrane and its preparation method. The specific implementation method is as follows:
[0041] I. Formula 1
[0042] 1. Preparation of L1 mother liquor A: 30 g gelatin-dopamine (Gel-DA), 20 g PVA, 5 g sodium alginate, 495 g deionized water, and 1.65 g glycerophosphate choline (GPC).
[0043] Deionized water was heated to 40–50°C, and gelatin-dopamine (Gel-DA) was added and fully dissolved under magnetic stirring. PVA was added in portions while continuing stirring, allowing it to completely dissolve at 40–50°C to obtain a homogeneous solution. Sodium alginate was then added and stirring continued until completely dissolved and uniformly dispersed. Finally, the solution was cooled to room temperature, the pH was adjusted to 7.0–7.4, glycerophosphate choline (GPC) was added, and the mixture was stirred thoroughly. The solution was filtered through a 0.45 μm filter to obtain L1 mother liquor A.
[0044] 2. Preparation of crosslinking solution B: Prepare a 0.1 wt% sodium tetraborate aqueous solution and a 0.1 wt% calcium chloride aqueous solution. When using, mix them in a 1:1 mass ratio and spray using a dual-path atomizer.
[0045] 3. Preparation of L2 lipid phase C: ceramide 35 g, phytosphingosine 1.5 g, cetyl alcohol (C16–C18) 10 g, propolis wax 1.0 g, coenzyme Q10 0.2 g.
[0046] In a thermostatic stirrer, heat ceramide 3, phytosphoprotein, cetyl alcohol, and propolis wax to 45–55°C and stir slowly until homogeneous and melted. Then add coenzyme Q10 in a small amount and mix well, maintaining the temperature at 45–50°C for later use. Avoid overheating to protect Q10.
[0047] 4. Preparation of active aqueous phase D: 0.6 g propolis extract, 40 mg oligopeptide-5 (bFGF), 30 mg oligopeptide-32, 60 mg acetyl tetrapeptide-15, and 10 mg dipeptide-4 were mixed with 20 ppm of [a specific solution / concentration]. , buffer pH 7.0, total water content 0 g.
[0048] Add propolis extract to PBS buffer and stir to dissolve. Under conditions of ≤25°C and protected from light, add oligopeptide-5, oligopeptide-32, acetyl tetrapeptide-15, and dipeptide-4 sequentially, and then mix. To the target concentration of 20 ppm, stir until completely dispersed. Filter through a 0.22 μm filter for later use.
[0049] 5. Prepare L3 dispersion E, based on a total wet weight of 100 g: weigh 90.00 g of waterborne polyurethane-polysiloxane emulsion, which contains 12 wt% solids, i.e. provides 10.80 g of solids; weigh 1.20 g of surface-modified silica, which accounts for 1.20 wt% of the total wet weight and 10 wt% of the total solids.
[0050] Slight surface modification First, pre-disperse the mixture in a small amount of ethanol, then add an aqueous polyurethane-polysiloxane emulsion; then add 5.00 g of ethanol (5.00 wt% wet basis) and 3.75 g of glycerol (3.75 wt% wet basis) to form a complex volatile system of ethanol, glycerol and water to adjust the water activity; add 0.05 g of gallic acid non-covalent coupling agent (0.05 wt% wet basis), mix well and remove bubbles to obtain the final L3 dispersion E.
[0051] The raw materials used in the formulation of this embodiment are all conventional chemical or biological reagents, which can be purchased directly from common reagent suppliers, such as gelatin-dopamine, PVA, sodium alginate, chitosan, hyaluronic acid, ceramide, coenzyme Q10, propolis extract, various oligopeptides, glycerophosphate choline, waterborne polyurethane-polysiloxane emulsion, and surface modification agents. All of these can be purchased from Aladdin, Sigma-Aldrich, Merck, TCI, or similar domestic and international suppliers according to the required specifications.
[0052] II. Process Steps
[0053] 1. Adjust the L1 mother liquor A to 500-900 mPa·s ( The viscosity range was determined and the mixture was shaped using an electrospinning device. Electrospinning parameters: voltage 18 kV, spray rate 0.9 mL / h, collection distance 15 cm, ambient RH 55%, temperature 23°C, resulting in a wet adhesive substrate with a fiber web thickness of 80 μm.
[0054] 2. Atomize and spray crosslinking liquid B to L1 until it no longer flows onto the surface and let it stand for 5 minutes, then gently roll it; to obtain reversible bonds of borate ester and The ion-crosslinked wet dual network with a pre-set osmotic pressure gradient provides continuous driving force for wet adhesion and inward-outward movement.
[0055] 3. The total amount of L2 lipid phase C (47.7 g) was divided into two parts. 13 g of the L2 lipid phase C was mixed with 20 g of active aqueous phase D at a mass ratio of 40:60 and sheared to form a core dispersion. 20 mg of chitosan was dissolved in sodium acetate buffer to prepare a working solution of 4 mg / mL. This solution was added dropwise to the core dispersion and stirred until the chitosan content in the nanocapsule dispersion reached 0.06 wt% (based on the total mass of the nanocapsule dispersion) to form a positive coating layer. After the positive coating stabilized, 20 mg of hyaluronic acid was also dissolved to prepare a working solution of 4 mg / mL. This solution was added to the dispersion in portions until the hyaluronic acid content also reached 0.06 wt%, completing the assembly of the negative shell and achieving ion balance.
[0056] The prepared core was dispersed at 35–40°C and incorporated into the remaining lipid phase C. The mixture was stirred until homogeneous to obtain lipid phase C containing nanocapsules. The mixture was then used for vacuum permeation injection into L1 at 35–40°C. For specific procedures, see step 4. The injection volume was set according to the area of each membrane, 10 mg / cm².
[0057] 4. Under vacuum conditions of 35–40°C and -0.07 MPa, the lipid phase C containing nanocapsules was vacuum-permeated into the L1 surface until the surface was slightly moist and glossy. The next step was carried out within 3 minutes after the injection was stopped.
[0058] 5. Under ambient RH of 80% and temperature of 25°C, use a spray distance of 20 cm and a spray volume of 1.5. Spray L3 dispersion E onto the L1 surface treated in step 4, and let it stand for 5 minutes to complete the synergistic volatilization and curing.
[0059] 6.35–40°C graded drying for 2–4 h and then sterilized with EO; to obtain a sterile finished product that retains its activity; meeting the requirements for medical use.
[0060] like Figure 1 As shown, by constructing a layered system of "wet adhesive biomimetic layer (L1) - lipid compatibility layer (L2) - outer unidirectional permeation layer (L3)" on the membrane structure, a composite membrane that is tightly adhered to the skin surface and has interlayer functional synergy is obtained, which plays the role of simultaneously providing a physical barrier, a unidirectional moisture permeation channel and controlled delivery of active ingredients. Figure 1 The arrows in the diagram indicate the inner and outer sides of the biomimetic permeable membrane. The inner side refers to the side that fits against the skin, and the outer side refers to the side exposed to the environment. Inner side → outer side.
[0061] By pre-placing reversible borate ester bonds in L1 with The addition of glycerophosphate choline (GPC) to the double cross-linking process creates a mild inside-out chemical potential difference, resulting in a strong and continuous inside-out driving force for wet adhesion, which enhances wet adhesion and promotes the penetration and injection of nanocapsules.
[0062] By adopting a polarity reversal strategy of "positive shell first, negative shell later" for L2, the core provides mild protection for active components while the outer shell is stable under aqueous construction conditions, thus playing a bidirectional selective barrier role that allows release from the inside to the outside while inhibiting backflow from the outside to the inside.
[0063] By adjusting the water activity a_w and Hansen solubility parameters in L3 and forming a wetting gradient with a hydrophilic inner surface and a hydrophobic outer surface, anisotropic water vapor and small molecule channels with an inside-outside preference are obtained, which can maintain the micro-moist environment of the wound while preventing the reverse entry of external droplets.
[0064] Example 2 provides a biomimetic permeable membrane and its preparation method. Specific implementation details are as follows:
[0065] Example 2 is largely the same as Example 1, except for the following differences:
[0066] In step 1 of the process, the L1 substrate is prepared by scraping and condensation instead of electrospinning equipment. The blade is 200μm and the condensation stage is 4°C to obtain a wet-bonded substrate with a thickness of 100μm.
[0067] In step 5 of the formulation, the ratio of volatile solvents in L3 dispersion E is adjusted to 7.50 wt% ethanol on a wet basis and 1.25 wt% glycerol on a wet basis, i.e., 7.5 g of ethanol and 1.25 g of glycerol.
[0068] Step 6 of the process involves spraying L3 dispersion D at an RH of 80% and a temperature of 25°C using a spray volume of 1.8 g / L. Application. Other formulation components, vacuum permeation injection, drying and sterilization steps are as described in Example 1.
[0069] Through the above modifications, this embodiment improves production scalability and the sealing performance of the outer layer while maintaining the ability to deliver active ingredients.
[0070] Example 3 provides a biomimetic permeable membrane and its preparation method. Specific implementation details are as follows:
[0071] Referring to all the formulations and steps of Example 1, in step 3 of the formulation, the amount of coenzyme Q10 added to the L2 lipid phase C was increased from 0.2 g to 0.8 g, which is 0.8 wt% relative to the total dry film volume; the entire L2 preparation and emulsification process was carried out at 45–50°C under an inert nitrogen atmosphere to reduce Q10 oxidation.
[0072] The finished product was packaged in a medical-grade e-beam compatible composite film bag under nitrogen-filled conditions. A commercial oxygen scavenger was placed inside the bag to reduce residual oxygen content. After packaging, it was sterilized by electron beam with a total dose of 10 kGy, and the temperature rise during the process was controlled to be ≤8°C. The remaining steps were the same as in Example 1.
[0073] Comparative Example 1 provides a conventional PU medical film.
[0074] Commercially available polyurethane (PU) medical films were purchased and used as the comparative reference material. This comparative material is a single-layer homogeneous polyurethane-based film without layered structure, nanocapsules, or active carriers, and is intended for direct application in its factory state for covering or bonding purposes.
[0075] Comparative Example 2, which adopts a delayed spraying process based on Example 1, is implemented as follows:
[0076] The formulation and preparation steps of Example 1 are followed, but in step 4 of the process, the outer layer L3 is sprayed only after a delay of more than 8 minutes following the cessation of vacuum permeation injection.
[0077] This implementation results in the loss of capillary penetration driving force and interfacial wetting conditions in the injection layer, preventing effective coupling between the outer and inner layers, ultimately leading to reduced interlayer adhesion, decreased barrier function, and migration or leakage of active ingredients. The remaining formulation preparation steps are the same as in Example 1.
[0078] Omitting the time window or using an inappropriate solvent will disrupt the coupling mechanism of this invention, thereby losing the advantages of this invention, which verifies the necessity of the time window and solvent activity limitation in the claims.
[0079] If the outer layer is sprayed after injection for a period exceeding the time window specified in the claims, the capillary penetration driving force and surface wetting conditions of the injected layer are lost, preventing the outer and inner layers from forming an effective physical and chemical coupling effect, thereby reducing interlayer adhesion and barrier function.
[0080] Comparative Example 3, based on Example 1, uses a single-layer chitosan coating process, and the specific implementation method is as follows:
[0081] The nanocapsule preparation process of Example 1 is followed, but in step 3 of the process, only a single layer of chitosan is applied to the nanocapsules: 20 mg of chitosan and 4 mg / mL working solution are added dropwise to disperse in the core and coated to 0.06 wt%, omitting the hyaluronic acid coating step.
[0082] Since the surface of the nanocapsule is still positively charged and the polarity reversal of the zeta potential from positive to negative has not been achieved, chitosan desorption and dissolution or deactivation of the contents are likely to occur during the subsequent L3 water-based spraying process.
[0083] Using only a single layer of chitosan coating without hyaluronic acid coating and polarity reversal results in nanocapsules with a persistently positive surface and a lack of charge shielding and ion balance. This makes them prone to chitosan desorption and inclusion dissolution under subsequent aqueous spraying or humid heat conditions. Furthermore, the lack of a negatively charged outer shell and ion balance significantly reduces the nanocapsules' tolerance to external aqueous application media, decreasing peptide activity retention and causing a loss of unidirectional permeability selectivity.
[0084] To verify the key functions and process advantages of the embodiments shown in this invention, the following three core performance tests were conducted on six samples (Examples 1, 2, and 3, and Comparative Examples 1, 2, and 3): breathability, moisture retention, and one-way permeability. At least five independent samples were prepared for each type of sample; all results are expressed as mean values.
[0085] 1. Air permeability: Based on the ASTM D737 principle, the steady-state airflow of the sample is measured using an air permeability tester under constant pressure difference and converted into air permeability per unit area. The sample size should be cut according to the instrument fixture requirements and the edges should be sealed. Temperature, humidity, and pressure difference should be recorded during the measurement. Each sample should be measured three times and the average value taken. For each group, n≥5. The air permeability value is used to evaluate the material's heat dissipation and wearing comfort; the test results are used to compare the relative differences in air permeability between the examples and comparative examples.
[0086] 2. Moisture Retention: Moisture retention is evaluated in two parts: one is water vapor transmission rate (WVTR), which is determined according to ASTM E96 under simulated wound conditions at 37°C for 24 hours, measuring the mass loss of the sample covering the cup opening and converting it to... ;
[0087] The second measure is the interfacial microenvironment relative humidity (microclimate RH). A miniature RH probe is placed between the pigskin surface and the sample bonding surface, and interfacial RH curves are recorded at 37°C for 0.5, 1, 4, 8, and 24 hours, with the average value calculated from 0 to 24 hours. For each measure, n≥5 is used, and the mean is reported. The combined WVTR and interfacial RH reflect the membrane's ability to maintain wound moisture. Ideally, the WVTR should be within a range sufficient to maintain a microhumid environment on the wound surface, and the interfacial RH should be stably maintained between 60% and 85%.
[0088] 3. Single-direction permeability: Solute migration was tested using a dual-cavity symmetrical apparatus to quantify single-direction permeability. The sample was clamped in the dual-cavity fixture, and sodium fluorescein, a fluorescent tracer solution of known concentration, was added to the inner and outer cavities, respectively. Samples were taken at 37°C for 0.5, 1, 4, and 24 hours to measure the cumulative migration M(t) in the receiving cavity, obtaining the 24-hour cumulative migration M24 for inner→outer and outer→inner directions. The single-direction coefficient S was calculated as S = M24(inner→outer) / M24(outer→inner), with S(24 h) as the criterion. For each direction, n≥5 samples were tested, and the results were reported as the mean, comparing the single-direction performance differences among the six samples; simultaneously, the flux J(t) was recorded. In order to further quantify the transmission rate.
[0089] The above three tests directly reflect the functionality of the invention using quantitative indicators: breathability assesses wearing comfort and gas exchange, moisture retention assesses the ability to maintain the wound microenvironment, and unidirectional permeability directly verifies the core design of biomimetic unidirectional penetration and isolation. All test results will serve as an objective basis for comparing the embodiments and comparative examples to demonstrate the superiority of the invention in practical application scenarios.
[0090] Below are three tables based on the aforementioned testing methods, each corresponding to the quantitative results of one test. Sample identifiers in the tables: A = Example 1, B = Example 2, C = Example 3, D = Comparative Example 1, E = Comparative Example 2, F = Comparative Example 3.
[0091]
[0092] Note: Samples A, B, and C have significantly higher breathability than sample D, which is beneficial for wearing comfort and gas exchange; sample B has slightly better breathability than samples A and C due to the adjustment of the outer layer ratio.
[0093]
[0094] Explanation: The WVTR of samples A, B, and C are within the range conducive to maintaining a "micro-moist" wound environment, and the interfacial RH is stably maintained within the target range of 60%–85%, indicating that a balance has been achieved between moisture retention and breathability. Comparative Example 1D sample has a very low WVTR and low interfacial RH, which is prone to excessive dryness; samples E and F show excessively high WVTR and unstable or low interfacial RH, reflecting functional imbalance caused by delayed or non-healing.
[0095]
[0096] Note: The unidirectional coefficient S of samples A, B, and C in the examples is significantly greater than 3, indicating obvious preferential permeability from inside to outside, meeting the design objectives. The S values of comparative samples D, E, and F are close to 1, indicating no obvious unidirectionality; D shows overall low migration blockage, while E and F show bidirectional asymmetric loss. The inside-to-outside flux J in A, B, and C can ensure moderate outward moisture removal and small molecule expulsion, while the outside-to-inside flux is suppressed, demonstrating the ability to unidirectionally protect and maintain the inner microenvironment.
[0097] Comparative test results of Examples 1, 2, and 3 with the three comparative examples show that the example group is significantly better than the conventional PU film control and the two incorrect process comparative examples in terms of the three key performance indicators of air permeability, moisture retention, and one-way permeability. Among them, Example 2 is slightly better in air permeability, and Example 3 can still maintain good function under sterilization and long-term stability design.
[0098] It should be particularly noted that the various embodiments listed in this specification and accompanying drawings are intended to illustrate the technical solutions and advantages of the present invention, and not to limit the scope of protection of the present invention. Without departing from the core ideas and technical effects of the present invention, those skilled in the art can make any form of improvement, substitution, combination, or modification to the structural arrangement, process parameters, material selection, control logic, etc., of the described embodiments; any obvious changes based on the same concept should be considered equivalent solutions of the present invention and should be included within the scope of protection defined by the claims of the present invention. The actual scope of protection of the present invention is determined by the appended claims and should be correctly understood in conjunction with the specification and accompanying drawings.
Claims
1. A method for preparing a biomimetic permeable membrane, characterized in that, Includes the following steps: S0. Solution preparation: S0-1. Prepare L1 stock solution A, which is an aqueous matrix with a solid content of 8–12 wt% and a pH of 7.0–7.4, wherein L1 stock solution A contains gelatin-dopamine, polyvinyl alcohol, glycerophosphate choline and alginate; S0-2. Prepare crosslinking working solution B by mixing a 0.05–0.20 wt% sodium tetraborate aqueous solution with… The aqueous solutions were mixed at a mass ratio of 1:1; S0-3. Prepare lipid phase C by melting and mixing ceramide 3, phytosphoprotein, C16–C18 fatty alcohol and propolis wax at 45–55°C, and adding coenzyme Q10. S0-4. Prepare active aqueous phase D, which contains propolis extract, oligopeptide-5, oligopeptide-32, acetyl tetrapeptide-15, dipeptide-4, and Zn ions; S0-5. Prepare the outer layer spraying dispersion E, which includes an aqueous polyurethane-polysiloxane emulsion and a surface-slightly affinity silica dispersion; S1. Prepare a wet viscous substrate from mother liquor A (L1) by electrospinning or blade coating-condensation. The electrospinning parameters are: voltage 15–25 kV, spray rate 0.6–1.2 mL / h, collection distance 12–18 cm, ambient temperature 22–26 °C, and relative humidity (RH) 45–60%. The blade coating-condensation conditions are: blade tip 100–300 μm and condensation temperature 4–8 °C. S2. The wet substrate surface obtained by atomizing and spraying crosslinking working solution B to S1 is in a non-flowing state and is left to stand for 3–8 minutes. S3. Nanocapsule construction and polarity reversal: A portion of the lipid phase C and the active aqueous phase D were sheared at a mass ratio of 40:60 to 60:40 to form a core dispersion. Then, chitosan solution was added to form a positively charged outer shell, and hyaluronic acid solution was added to cover it to form a negatively charged outer shell. The remaining lipid phase C was then added and stirred until homogeneous to obtain lipid phase C containing nanocapsules; S4. Under vacuum conditions of 35–40°C and -0.09 to -0.06 MPa, the lipid phase C containing nanocapsules prepared in step S3 is infiltrated from the surface of the wet substrate until the surface is slightly wet and glossy. After stopping the infiltration, proceed to the next step within 2–8 min. S5. At 22–28℃ and relative humidity RH 75–85%, with a spray distance of 15–25 cm and a spray volume of The outer layer spray dispersion E is evenly sprayed onto the wet substrate surface and left to stand for 3–7 minutes to complete the synergistic volatilization and curing. S6. Subsequently, the product is graded and dried for 2–6 h at 35–45°C and RH 30–50%; S7. Then sterilize, encapsulate with a low oxygen permeability material and insert an oxygen scavenger.
2. The preparation method according to claim 1, characterized in that, The mass ratio of gelatin-dopamine, polyvinyl alcohol, glycerophosphate choline and alginate in the L1 mother liquor A is (3–6):(2–4):(0.2–0.4):(0.3–1).
3. The preparation method according to claim 1, characterized in that, In the lipid phase C, the molar ratio of ceramide 3: phytosphingosine: C16–C18 fatty alcohol: propolis wax is 1:(0.3–0.8):(1.2–2.0):(0.2–0.4), and coenzyme Q10 accounts for 0.4–3.0 wt% of the total mass of lipid phase C.
4. The preparation method according to claim 1, characterized in that, The chitosan solution was prepared using 0.1 M sodium acetate buffer, with a chitosan solution concentration of 4 mg / mL; the hyaluronic acid solution was also prepared using sodium acetate buffer, with a concentration of 4 mg / mL.
5. The preparation method according to claim 1, characterized in that, The proportions of polypeptide active substances in the active aqueous phase D by mass of the "total polypeptide load" are as follows: oligopeptide-5 accounts for 10–50 wt%, oligopeptide-32 accounts for 5–30 wt%, acetyl tetrapeptide-15 accounts for 20–70 wt%, and dipeptide-4 accounts for 1–20 wt%; and the molar ratio of dipeptide-4 to Zn ions is 1:(0.01–0.2).
6. The preparation method according to claim 1, characterized in that, The sterilization process in S7 is ethylene oxide and electron beam sterilization.
7. The preparation method according to claim 1, characterized in that, The permeable membrane can be used for skin repair, wound care, and protection of sensitive skin.