Three-level Janus shell-core type nanofiber membrane, preparation method thereof and wound dressing

Abstract

The invention discloses a three-level Janus shell-core type nanofiber membrane, a preparation method thereof and a wound dressing, and aims to solve the problems that an existing nanofiber membrane is difficult to stably load various drugs and cannot realize sequential controlled release of different drugs at the same time. Each nanofiber forming the nanofiber membrane is composed of three levels of fibers; the first-stage fibers and the second-stage fibers form a parallel structure; the second-stage fiber wraps the third-stage fiber to form a shell-core structure; each grade of fiber comprises a polymer base material and functional molecules; both the first polymer base material and the third polymer base material are hydrophobic polymers with good electrospinning filamentation performance and good biocompatibility; the second polymer base material is a hydrophilic polymer with good electrospinning filamentation performance and good biocompatibility; the first functional molecule is an antibacterial functional molecule; the second functional molecule is an analgesic functional molecule; the third functional molecule is an antioxidant and anti-inflammatory functional molecule.

Description

Technical Field

[0001] This invention relates to the field of medical functional nanomaterials technology, and more specifically to a tertiary Janus shell-core type nanofiber membrane, its preparation method, and a wound dressing. Background Technology

[0002] Wound repair and healing processes are precisely regulated by cellular and molecular signaling networks. The extracellular matrix, while providing three-dimensional support, also actively guides cellular behavior through its biophysical and biochemical properties. Chronic inflammation caused by wound healing disorders disrupts microenvironmental homeostasis, hinders the repair process, and increases the risk of infection. Therefore, modern wound repair materials have shifted from passive covering to active regulation. New-generation functional dressings, by mimicking the structure and mechanical properties of the natural extracellular matrix, guide the directed migration, orderly proliferation, and differentiation of cells in the spatiotemporal dimensions, thereby achieving high-quality tissue reconstruction.

[0003] Electrospun nanofiber membranes, with their high specific surface area and extracellular matrix-like structure, offer significant advantages in wound hemostasis, exudate management, and drug loading. However, traditional single-fluid techniques have inherent limitations, including a limited library of spinnable polymers, difficulty in achieving multi-component time-sequential controlled release from single fibers, and the risk of uncontrolled distribution and burst release due to phase separation when active drugs are blended. Patent application CN106075539A addresses the shortcomings of single-fluid electrospinning by successfully inventing a method using coaxial spinning to improve drug loading; however, its single Centella asiatica loading mode still falls far short of meeting the diverse needs of complex wound repair.

[0004] To overcome the aforementioned limitations, a multi-component synergistic drug delivery strategy has emerged. Referring to our team's invention patent applications with publication numbers CN120989739A and CN121023659A, multi-fluid parallel electrospinning technology provides an ideal platform for realizing this strategy. Its core value lies in constructing chemically isolated micro-region structures within a single fiber by precisely controlling the flow behavior of each phase fluid within a coaxial or multi-channel spinneret. This one-step fabrication process not only avoids component mixing and interfacial compatibility issues caused by multi-step fabrication but, more importantly, achieves independent control over the scale, morphology, and spatial arrangement of each phase region, allowing for precise customization from nanoscale core-shell structures to micrometer-scale Janus configurations. However, this technology still faces challenges in finding polymers that can stably load multiple drugs using co-solvents while also possessing good biocompatibility, and in meeting the requirements for sequential drug release. Summary of the Invention

[0005] Due to the aforementioned deficiencies in the existing technology, the present invention provides a three-level Janus shell-core nanofiber membrane, its preparation method, and a wound dressing to solve the problem that existing nanofiber membranes are difficult to stably load multiple drugs and cannot simultaneously achieve the time-sequential controlled release of different drugs.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a three-level Janus core-shell nanofiber membrane, wherein each nanofiber constituting the nanofiber membrane is composed of three-level fibers; the first-level fibers and the second-level fibers form a parallel structure; the second-level fibers wrap around the third-level fibers to form a core-shell structure;

[0007] The first-level fiber comprises a first polymer substrate and a first functional molecule; the second-level fiber comprises a second polymer substrate and a second functional molecule; the third-level material comprises a third polymer substrate and a third functional molecule.

[0008] Both the first and third polymer substrates are hydrophobic polymers with good electrospinning properties and good biocompatibility; the second polymer substrate is a hydrophilic polymer with good electrospinning properties and good biocompatibility.

[0009] The first functional molecule is an antibacterial functional molecule; the second functional molecule is an analgesic functional molecule; and the third functional molecule is an antioxidant and anti-inflammatory functional molecule.

[0010] The above technical solution constructs a time-controlled release system. By loading three active ingredients—antibacterial, analgesic, and antioxidant / anti-inflammatory molecules—into carrier materials with different water-wetting properties, precise regulation of the entire wound healing process is achieved. The antibacterial molecules are not only dispersed on the surface of the outer hydrophobic polymer but also encapsulated within the outer hydrophobic carrier. On one hand, the antibacterial molecules distributed on the surface are rapidly released upon contact with wound exudate, exerting an early antibacterial effect. On the other hand, the antibacterial molecules within the fibers are released with delayed release due to the slow erosion of the hydrophobic carrier, achieving a sustained antibacterial effect. The analgesic molecules are encapsulated in parallel hydrophilic regions, producing a rapid analgesic effect in the early stages of treatment. Meanwhile, the antioxidant / anti-inflammatory molecules are continuously released as the internal hydrophobic polymer slowly degrades, maintaining antioxidant and anti-inflammatory effects in the later stages of healing. This material-based delivery design allows the release kinetics of the three components to be highly matched with the physiological process of wound healing. Antibacterial and analgesic functional molecules synergistically control infection and relieve pain during the acute phase, while antibacterial, antioxidant and anti-inflammatory functional molecules continuously promote repair during the tissue remodeling phase, ultimately forming a complete treatment platform that can intelligently respond to the needs of each stage of healing.

[0011] In one embodiment, the first polymer substrate and the third polymer substrate are the same polymer substrate, which is one of polylactic acid, polylactic acid-glycolic acid copolymer, polylactic acid-polycaprolactone copolymer, polycaprolactone, polyphosphate, polycarbonate and polyanhydride.

[0012] In one embodiment, the second polymer substrate is gelatin, and the analgesic functional molecule is lidocaine.

[0013] In one embodiment, the antibacterial functional molecule is berberine, a traditional Chinese medicine extract, or nano-copper oxide; the antioxidant and anti-inflammatory functional molecule is matrine, a traditional Chinese medicine extract.

[0014] Secondly, the present invention provides a method for preparing the tertiary Janus core-shell nanofiber membrane as described above, comprising the following steps:

[0015] A first spinning solution, a second spinning solution, and a third spinning solution are prepared respectively; the first spinning solution is a homogeneous solution or dispersion containing a first polymer and a first functional molecule; the second spinning solution is a homogeneous solution containing a second polymer and a second functional molecule; and the third spinning solution is a homogeneous solution containing a third polymer and a third functional molecule.

[0016] A three-stage Janus shell-core nanofiber membrane was prepared using multifluid electrospinning technology based on a three-stage needle: the three-stage needle is connected to a first syringe, a second syringe, and a third syringe. The first spinning solution, the second spinning solution, and the third spinning solution are added to the first syringe, the second syringe, and the third syringe, respectively, and the three-stage Janus shell-core nanofiber membrane is prepared by electrospinning.

[0017] Compared to traditional blend spinning, multifluid co-spinning technology simultaneously constructs multiple independent functional regions within a single fiber in a one-step process. This allows for the partitioning and loading of components with different physicochemical properties, completely eliminating mutual interference between components with different physicochemical properties. This ensures that various drugs maintain chemical stability during processing, and the drug loading of each phase can be independently optimized, significantly improving overall drug loading efficiency and encapsulation rate. Furthermore, by programmatically designing the degradation rate and response characteristics of each phase carrier, the time-sequential release of drugs with different efficacies can be achieved.

[0018] In one embodiment, the mass-to-volume concentration ratio of functional molecules to polymers in each spinning solution is 1:2 to 1:12. This allows the proportion of functional molecules to meet spinning requirements while also being adjustable within a certain range to suit different applications.

[0019] In one embodiment, the first and third polymers are polycaprolactone; the second polymer is gelatin; the first functional molecule is berberine or nano-copper oxide; the second functional molecule is lidocaine; the third functional molecule is matrine, a traditional Chinese medicine extract; the solvent for the first and third spinning solutions is 2,2,2-trifluoroethanol; and the solvent for the second spinning solution is hexafluoroisopropanol. The optimal selection of the co-solvent is crucial for achieving a complete fiber structure during the spinning process. This is because, in fiber preparation processes such as electrospinning, the type and ratio of the co-solvent significantly affect the solution's viscosity, conductivity, surface tension, and solvent evaporation rate, thereby directly determining the fiber's morphology, continuity, and structural integrity.

[0020] In one embodiment, the mass-to-volume concentration ratio of the first functional molecule to the first polymer in each spinning solution is 1:12; the mass-to-volume concentration ratio of the second functional molecule to the second polymer in each spinning solution is 1:4; the mass-to-volume concentration ratio of the third functional molecule to the third polymer in each spinning solution is 1:12; and the spinning solution flow rate of the first and third injectors is three times that of the spinning solution flow rate of the second injector. Thus, by controlling the flow rate ratio of the fluids in the three channels within the spinning head, the high-viscosity first polymer solution and the third polymer solution can form a stable conical Taylor cone at the spinning head outlet, stably confining the low-viscosity second polymer solution in the middle region. The 3:1 ratio of the spinning solution flow rates of the first and third injectors to that of the second injector ensures that the outer crescent-shaped fluid (first polymer solution) and the outer crescent-shaped fluid (third polymer solution) preferentially solidify and shape during fiber curing, avoiding structural collapse caused by rapid solvent diffusion in the middle layer (second polymer solution), ultimately obtaining a special three-chamber composite fiber with uniform diameter, smooth surface, and clear core-sheath interface.

[0021] Thirdly, the present invention provides a tertiary Janus core-shell nanofiber membrane prepared by the preparation method described above.

[0022] Finally, the present invention provides a wound dressing comprising the tertiary Janus shell-core type nanofiber membrane as described above.

[0023] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0024] The above invention has the following advantages or beneficial effects:

[0025] (1) The nanofibers of the present invention have three independent and interconnected chambers, which can achieve: 1) selecting drug active ingredients based on the biological mechanism of wound healing, while loading and encapsulating drugs with different effects; 2) avoiding interactions between drugs and maintaining drug activity; 3) the complex structural hierarchy provides different delivery areas for drug release, enabling drug administration by time and by region; 4) matching polymer carriers and drugs according to the solubility parameter theory, and optimizing the spinning solution performance through rheological regulation.

[0026] (2) This invention successfully achieved the spatial integration of hydrophilic and hydrophobic polymers in a single fiber by constructing a tertiary structure nanofiber with a clear interface separation. This unique structural design endows the material with multiple functional properties: First, the fiber has both the wetting regulation ability of the hydrophilic region and the liquid barrier function of the hydrophobic region, which can maintain the appropriate humidity of the wound and effectively prevent the penetration of external liquids; Second, by utilizing the difference in degradation rate of different polymers, the time-controlled release of analgesic, antibacterial and antioxidant drugs is achieved—rapid drug release in the hydrophilic region meets the needs of early treatment, and continuous drug release in the hydrophobic region ensures long-term efficacy.

[0027] (3) The multi-level structural design of this invention enables the nanofiber membrane to possess excellent air permeability, moisture retention, and waterproofing, forming an ideal wound microenvironment management system. More importantly, based on the differentiation of polymer degradation characteristics and the spatial distribution of drugs, a spatiotemporal drug release mode for on-demand administration is established, which can precisely address the biological needs of different stages of wound healing. This technical solution successfully integrates multiple therapeutic functions such as antibacterial, analgesic, anti-inflammatory, and antioxidant effects. At the same time, through the synergistic effect of physical barriers and controlled drug release, it provides a complete solution for wound pain management and tissue regeneration.

[0028] (4) Experimental data show that, compared with existing wound dressings, the three-level Janus shell-core nanofiber membrane of the present invention can significantly shorten the wound healing cycle and significantly improve the wound repair quality and tissue regeneration efficiency. In addition, the preparation device of the present invention is simple, and the height of the spinneret is adjustable and designable, which has the potential for mass production. Attached Figure Description

[0029] The invention, its features and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the cross-sectional structure of a three-level Janus shell-core nanofiber in one embodiment of the present invention;

[0031] Figure 2 This is an image of the liquid outlet on the bottom surface of a three-stage needle used in multi-fluid electrospinning technology according to an embodiment of the present invention;

[0032] Figure 3 This is an image showing the stretching process of multiple fluids under the action of an electric field during the preparation of Janus core-shell nanofibers in one embodiment of the present invention.

[0033] Figure 4 This is a scanning electron microscope image of the three-level Janus shell-core nanofiber membrane prepared in Example 1 of the present invention.

[0034] Figure 5 This is a diameter statistical diagram of the tertiary Janus shell-core nanofibers obtained in Example 1 of the present invention;

[0035] Among them, 11, first polymer substrate; 12, second polymer substrate; 13, third polymer substrate; 21, antibacterial functional molecule; 22, analgesic functional molecule; 23, antioxidant and anti-inflammatory functional molecule; 1, first spinning solution outlet; 2, second spinning solution outlet; 3, third spinning solution outlet. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0037] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features.

[0038] The reaction apparatus, monomer compounds, and solvents involved in the following examples and embodiments are all commercially available. The detection instruments involved in the following effect examples are all commercially available, and the detection methods used are existing technologies that can be found; and the technologies not described in detail in the following effect examples are existing technologies that can be found.

[0039] See Figure 1 The present invention first provides a three-level Janus shell-core type nanofiber membrane, wherein each nanofiber of the nanofiber membrane is composed of three-level fibers; the first-level fibers and the second-level fibers form a parallel structure; the second-level fibers wrap the third-level fibers to form a shell-core structure;

[0040] The first-level fiber includes a first polymer substrate 11 and a first functional molecule 21; the second-level fiber includes a second polymer substrate 12 and a second functional molecule 22; the third-level material includes a third polymer substrate 13 and a third functional molecule 23.

[0041] Both the first polymer substrate 11 and the third polymer substrate 13 are hydrophobic polymers with good electrospinning properties and good biocompatibility; the second polymer substrate 12 is a hydrophilic polymer with good electrospinning properties and good biocompatibility.

[0042] The first functional molecule is an antibacterial molecule 21; the second functional molecule is an analgesic molecule 22; and the third functional molecule is an antioxidant and anti-inflammatory molecule 23.

[0043] The nanofibers of this invention have three independent but interconnected chambers, enabling: 1) the selection of active pharmaceutical ingredients based on the biological mechanisms of wound healing, while simultaneously loading and encapsulating drugs with different efficacies; 2) prevention of interactions between drugs, maintaining drug activity; 3) a complex hierarchical structure providing different delivery regions for drug release, enabling time- and region-specific drug administration; and 4) matching polymer carriers and drugs based on solubility parameter theory, and optimizing spinning solution performance through rheological regulation. Simultaneously, this invention successfully achieves spatial integration of hydrophilic and hydrophobic polymers within a single fiber. This unique structural design endows the material with multiple functional properties: First, the fiber simultaneously possesses the wetting control capability of the hydrophilic region and the liquid barrier function of the hydrophobic region, maintaining suitable humidity on the wound surface while effectively preventing external liquid penetration; this gives the nanofiber membrane excellent breathability, moisture retention, and waterproofing, forming an ideal wound microenvironment management system. Second, by utilizing the differences in degradation rates of different polymers, the time-controlled release of analgesic, antibacterial, and antioxidant drugs is achieved—rapid drug release in the hydrophilic region meets early treatment needs, while continuous drug release in the hydrophobic region ensures long-term efficacy. Furthermore, based on the differences in polymer degradation characteristics and the spatial distribution of drugs, a spatiotemporal drug release mode for on-demand administration was established, which can precisely address the biological needs of different stages of wound healing. This technical solution successfully integrates multiple therapeutic functions such as antibacterial, analgesic, anti-inflammatory, and antioxidant effects. At the same time, through the synergistic effect of physical barriers and controlled drug release, it provides a complete solution for wound pain management and tissue regeneration.

[0044] As an example, the first polymer substrate 11 and the third polymer substrate 13 are made of the same polymer substrate, which is one of polylactic acid, polylactic acid-glycolic acid copolymer, polylactic acid-polycaprolactone copolymer, polycaprolactone, polyphosphate, polycarbonate, and polyanhydride. The second polymer substrate 12 is gelatin, and the analgesic functional molecule 22 is lidocaine. The antibacterial functional molecule 21 is berberine, a traditional Chinese medicine extract with low side effects, or nano-copper oxide with photoresponsive antibacterial effects; the antioxidant and anti-inflammatory functional molecule 23 is matrine, a traditional Chinese medicine extract.

[0045] Both polycaprolactone (PCL) and gelatin are preferred materials for electrospun wound dressings, and their combination using multifluid technology offers significant complementary advantages. On one hand, PCL, as a biodegradable synthetic polymer, provides a stable structural framework and maintains long-term scaffold function. On the other hand, gelatin, as a natural extracellular matrix component, promotes cell adhesion and proliferation through its arginine-glycine-aspartic acid sequence. The difference in their degradation rates creates a natural synergy: gelatin releases active ingredients earlier, while PCL provides mechanical support later. Their blended system can adjust the rheology and conductivity of the solution, achieving uniform drug dispersion and programmed release.

[0046] Example 1

[0047] The three-stage Janus shell-core nanofiber membrane of the present invention is obtained by simultaneous high-voltage electrospinning of three spinning solutions. The high-voltage electrospinning equipment is a conventional high-voltage electrospinning device equipped with a specific microfluidic spinning head. Referring to the patent applications previously filed by the technical team (publication numbers CN120989739A and CN121023659A), the high-voltage electrospinning steps include:

[0048] A first spinning solution, a second spinning solution, and a third spinning solution are prepared respectively; the first spinning solution is a homogeneous solution or dispersion containing a first polymer and a first functional molecule; the second spinning solution is a homogeneous solution containing a second polymer and a second functional molecule; and the third spinning solution is a homogeneous solution containing a third polymer and a third functional molecule.

[0049] A three-stage Janus shell-core nanofiber membrane was prepared by using multifluid electrospinning technology based on a three-stage needle-initiated composite Taylor cone: the three-stage needle is connected to a first syringe, a second syringe and a third syringe, and the first spinning solution, the second spinning solution and the third spinning solution are respectively added to the first syringe, the second syringe and the third syringe, and electrospinning is performed to prepare the three-stage Janus shell-core nanofiber membrane.

[0050] See Figure 2The spinneret for preparing tertiary Janus core-sheath structured nanofibers mainly consists of three parts: the first part is the outer layer, used to introduce the first spinning solution, which is drawn out through the first spinning solution outlet 1; the second part is the middle layer, used to introduce the second spinning solution, which is drawn out through the second spinning solution outlet 2; and the third part is the core layer, used to introduce the third spinning solution, which is drawn out through the third spinning solution outlet 3. The three spinning solutions converge at the spinneret output end and are stretched into continuous fibers under the action of an electric field.

[0051] Using the self-designed three-stage Janus core-sheath structure spinning needle, the inventors successfully constructed a dedicated device for preparing Janus core-sheath structured nanofibers. Three functional fluids are introduced into the three feed channels of the spinning head via independent syringe-hose delivery systems, ultimately forming a well-defined composite Taylor cone at the output end. Under the action of a high-voltage electrostatic field, this composite Taylor cone can be precisely stretched into a structurally complete solid nanofiber within milliseconds. Furthermore, based on the biological mechanisms of wound healing, active pharmaceutical ingredients are selected, and polymer carriers and drugs are matched according to solubility parameter theory. The properties of the spinning solution are optimized through rheological control. This systematic design scheme not only follows the basic laws of materials science but also satisfies the process characteristics of electrohydrodynamic forming, thereby achieving stable and continuous operation of the electrospinning process and providing key technical guarantees for obtaining functional nanofibers with precise and controllable structures.

[0052] A specific example method for preparing a three-stage Janus core-shell nanofiber membrane using the above-mentioned spinning equipment includes the following steps:

[0053] (1) Prepare spinning solution;

[0054] The first, second, and third spinning solutions were prepared as follows: 1.2 g of polycaprolactone was added to 10 mL of 2,2,2-trifluoroethanol solution and stirred continuously for 24 h. Then, 0.1 g of berberine (98% purity, purchased from Shanghai Sinopharm Chemical Reagent Co., Ltd., China) was added to the above solution and stirred continuously for 12 h to obtain the first spinning solution, which is a 12% (w / v) polycaprolactone solution and a 1% (w / v) berberine solution in 2,2,2-trifluoroethanol.

[0055] 0.2 g of gelatin was added to 10 mL of hexafluoroisopropanol and stirred continuously for 24 h. Then, 0.05 g of lidocaine (purity 97.5%, purchased from Shanghai Sinopharm Chemical Reagent Co., Ltd., China) was added to the above solution and stirred continuously for 12 h to prepare the second spinning solution, which is a hexafluoroisopropanol solution with a mass-volume concentration of 2% gelatin and 0.5% lidocaine.

[0056] 1.2 g of gelatin was added to 10 mL of 2,2,2-trifluoroethanol solution and stirred continuously for 24 h. Then, 0.1 g of matrine (purity 98%, purchased from Shanghai Sinopharm Chemical Reagent Co., Ltd., China) was added to the above solution and stirred continuously for 12 h to prepare the third spinning solution, which is a 2,2,2-trifluoroethanol solution of 12% gelatin solution and 1% matrine solution.

[0057] It is understandable that the mass-volume ratio of functional molecules to polymers in each spinning solution can be 1:4 to 1:12, which satisfies the spinning requirements and can be adjusted within a certain range according to different application needs.

[0058] (2) Add the first, second and third spinning solutions obtained in step (1) into the corresponding syringes, and then turn on the three injection pumps at the same time; the spinning solution flow rate of the first and third syringes is 1.5 mL / h, the spinning solution flow rate of the second syringe is 0.5 mL / h, the receiving distance is 15 cm, and the spinning voltage is 13 kV to obtain a three-stage Janus shell-core nanofiber membrane.

[0059] By filming the electrospinning process, the dynamic forming mechanism of multifluids in a high-voltage electrostatic field was captured. For example... Figure 3 As shown, the composite Taylor cone structure formed by the fusion of three fluids is clearly demonstrated. The entire spinning process remains stable, fully showcasing the three typical stages: Taylor cone formation, the stable section of the straight jet, and the high-frequency whipping region.

[0060] This invention validated the performance and therapeutic effects of the tertiary Janus core-sheath structured nanofiber membrane through systematic characterization and animal experiments. See also... Figure 4 Scanning electron microscopy analysis revealed that the fibrous membrane exhibited a regular three-dimensional network morphology, with uniform fiber distribution and an ideal porous structure. (See also...) Figure 5 The diameter distribution statistics measured by Image J show that the fiber size is uniform, with an average diameter of 1.28 ± 0.60 µm.

[0061] Material performance testing showed that the prepared nanofiber membrane possesses excellent hydrophilicity, allowing droplets to rapidly penetrate upon contact. Simultaneously, air permeability testing confirmed that the nanofiber membrane exhibits good gas permeability. In animal experiments, a full-thickness skin defect model established using SD rats showed that using the nanofiber membrane of this invention as a wound dressing resulted in a 90% wound healing rate within 48 hours, with no scab formation during the healing process. In contrast, commercially available ordinary wound dressings required nearly 7 days to achieve the same level of healing. Data indicates that the wound healing rate of the nanofiber membrane of this invention is 3.5 times that of commercially available products, demonstrating a significant repair advantage.

[0062] Example 2

[0063] This embodiment provides a preparation process for a three-tiered Janus core-shell nanofiber membrane. The equipment and steps are similar to those in Example 1, except that berberine in the first spinning solution is replaced by nano-copper oxide (purity greater than 99%, purchased from Shanghai Sinopharm Chemical Reagent Co., Ltd., China), and the first spinning solution is a 2,2,2-trifluoroethanol dispersion with a mass-to-volume ratio of 12% polycaprolactone and 1% nano-copper oxide. The three-tiered Janus core-shell nanofiber membrane prepared in this embodiment demonstrates relevant properties and wound healing function as a wound dressing. Results show that the three-tiered Janus core-sheath nanofiber membrane constructed in this invention significantly outperforms commercially available products in wound healing efficiency. The experimental group reached 90% healing in just 22 hours, compared to 7 days for the control group, achieving 90% healing time approximately 87% earlier, and the complete healing time was shortened by more than 6 times.

[0064] As can be seen from the above description, the wound dressing prepared by this invention is significantly superior to existing products in terms of therapeutic effect. This advantage is due to the Janus core-shell nanofibers constructed using multifluid electrospinning technology. Their unique multi-level structure not only achieves efficient loading and synergistic release of multiple functional drugs, but also forms functional complementarity through the orderly arrangement of each component.

[0065] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0066] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A tertiary Janus core-shell nanofiber membrane, characterized in that: Each nanofiber that makes up the nanofiber membrane is composed of tertiary fibers; the first-level fibers and the second-level fibers form a parallel structure; the second-level fibers wrap the third-level fibers to form a core-shell structure; The first-level fiber comprises a first polymer substrate and a first functional molecule; the second-level fiber comprises a second polymer substrate and a second functional molecule; the third-level material comprises a third polymer substrate and a third functional molecule. Both the first and third polymer substrates are hydrophobic polymers with good electrospinning properties and good biocompatibility; the second polymer substrate is a hydrophilic polymer with good electrospinning properties and good biocompatibility. The first functional molecule is an antibacterial functional molecule; the second functional molecule is an analgesic functional molecule; and the third functional molecule is an antioxidant and anti-inflammatory functional molecule.

2. The tertiary Janus core-shell nanofiber membrane according to claim 1, characterized in that, The first polymer substrate and the third polymer substrate are the same polymer substrate, which is one of polylactic acid, polylactic acid-glycolic acid copolymer, polylactic acid-polycaprolactone copolymer, polycaprolactone, polyphosphate, polycarbonate and polyanhydride.

3. A tertiary Janus core-shell nanofiber membrane according to claim 1 or 2, characterized in that, The second polymer substrate is gelatin, and the analgesic molecule is lidocaine.

4. The tertiary Janus core-shell nanofiber membrane according to claim 2, characterized in that, The antibacterial functional molecule is berberine, a traditional Chinese medicine extract, or nano-copper oxide; the antioxidant and anti-inflammatory functional molecule is matrine, a traditional Chinese medicine extract.

5. A method for preparing a tertiary Janus core-shell nanofiber membrane as described in any one of claims 1 to 4, characterized in that, Includes the following steps: A first spinning solution, a second spinning solution, and a third spinning solution are prepared respectively; the first spinning solution is a homogeneous solution or dispersion containing a first polymer and a first functional molecule; the second spinning solution is a homogeneous solution containing a second polymer and a second functional molecule; and the third spinning solution is a homogeneous solution containing a third polymer and a third functional molecule. A three-stage Janus shell-core nanofiber membrane was prepared using multifluid electrospinning technology based on a three-stage needle: the three-stage needle is connected to a first syringe, a second syringe, and a third syringe. The first spinning solution, the second spinning solution, and the third spinning solution are added to the first syringe, the second syringe, and the third syringe, respectively, and the three-stage Janus shell-core nanofiber membrane is prepared by electrospinning.

6. The method for preparing a tertiary Janus core-shell nanofiber membrane according to claim 5, characterized in that, The mass-volume concentration ratio of functional molecules to polymers in each spinning solution is 1:2 to 1:

12.

7. The method for preparing a tertiary Janus core-shell nanofiber membrane according to claim 6, characterized in that, The first and third polymers are polycaprolactone; the second polymer is gelatin; the first functional molecule is berberine or nano-copper oxide; the second functional molecule is lidocaine; the third functional molecule is matrine, a traditional Chinese medicine extract; the solvent for the first and third spinning solutions is 2,2,2-trifluoroethanol; and the solvent for the second spinning solution is hexafluoroisopropanol.

8. The method for preparing a tertiary Janus core-shell nanofiber membrane according to claim 6, characterized in that, The mass-volume concentration ratio of the first functional molecule to the first polymer in each spinning solution is 1:12; the mass-volume concentration ratio of the second functional molecule to the second polymer in each spinning solution is 1:4; the mass-volume concentration ratio of the third functional molecule to the third polymer in each spinning solution is 1:12; the spinning solution flow rate of the first syringe and the third syringe is 3 times that of the spinning solution flow rate of the second syringe.

9. A tertiary Janus core-shell nanofiber membrane prepared by the preparation method according to any one of claims 5 to 8.

10. A wound dressing, characterized in that, Includes the tertiary Janus shell-core type nanofiber membrane as described in any one of claims 1 to 4 or 9.

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