Anti-inflammatory and healing-promoting electrospun wound dressing, preparation method and application thereof

Abstract

The present invention discloses an anti-inflammatory and healing-promoting electrospun wound dressing, a preparation method and an application thereof, belonging to the technical field of medical dressings, and comprising a double-layer structure of an inner layer and an outer layer; wherein, the outer layer is a hydrophilic nanofiber membrane prepared by single-nozzle electrospinning, and is used to absorb wound exudate; the inner layer is a nanofiber membrane with a core-shell structure prepared by coaxial electrospinning, and the shell layer of the core-shell structure is a hydrophobic material, and is used to guide the exudate to the outer layer; the core layer of the core-shell structure comprises hydrophilic thermosensitive macromolecules, healing-promoting growth factors and anti-inflammatory drugs; the shell layer is hydrophobic, and guides the wound exudate to the outer hydrophilic nanofiber membrane; the gelatin hydrophilic thermosensitive macromolecules in the core layer, when the wound inflammation causes the local temperature to be ≥37°C, the temperature change causes the drug-loaded thermosensitive phase change macromolecules to undergo different degrees of phase change, thereby achieving timely and controllable release of drugs and ensuring the healing of the wound surface.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical dressings, and in particular relates to an anti-inflammatory and healing-promoting electrospun wound dressing, a preparation method and applications thereof. Background Art

[0002] Chronic, difficult-to-heal wounds are often accompanied by persistent inflammation, excessive exudate, and impaired tissue regeneration, causing physical and mental distress to patients and increasing the financial burden. Promoting the healing of chronic, difficult-to-heal wounds primarily relies on controlling inflammation, promoting epidermal growth, and maintaining a suitable healing environment. Traditional wound dressings often utilize a one-time administration method, resulting in uncontrolled drug release and a short duration of action, making them unable to meet the long-term anti-inflammatory and healing needs of chronic wounds.

[0003] In the prior art, coaxial electrospinning technology has been applied to the development of sustained-release drug dressings due to its ability to construct core-shell structured fibers. For example, a prior article (International Journal of Pharmaceutics, 2021, 601:120525) discloses a coaxial electrospun nanofiber dressing composed of polyvinyl alcohol encapsulated with tea polyphenols as the inner core layer and polycaprolactone encapsulated with polylysine as the outer shell layer. This allows for the slow and sustained release of low levels of tea polyphenols from the inner core layer, reducing inflammatory responses in wounds and promoting wound healing. However, polyvinyl alcohol, the carrier of tea polyphenols, is not temperature-sensitive, so the amount of tea polyphenols released is independent of temperature.

[0004] Patent CN119055846B discloses an oral restoration membrane with antibacterial and bone-integration properties prepared by coaxial electrospinning. Its structure consists of a carrier inner layer, a bonding middle layer and an antibacterial outer layer. The carrier inner layer and the antibacterial outer layer are both made of nanofibers prepared by coaxial electrospinning technology. Although it achieves antibacterial and bone-integration effects, the release of drugs from the core layer of the fiber is unrelated to the environmental conditions.

[0005] Patent CN107137748A discloses the preparation of chitosan nanofiber dressings using coaxial electrospinning, in which the functional components of the core layer are released into the shell layer by natural diffusion and are not affected by external environmental factors.

[0006] Therefore, there is an urgent need to develop a dual-functional dressing that combines intelligent exudate management with temperature-responsive drug controlled release to improve the healing efficiency of chronic wounds. Summary of the Invention

[0007] To address the aforementioned issues in the prior art, the present invention provides an anti-inflammatory and healing-promoting electrospun wound dressing, a preparation method, and its application. This wound dressing utilizes a two-layer structure: an outer layer of a single-spun hydrophilic nanofiber membrane absorbs exudate; an inner layer of coaxially electrospun core-shell fibers. The hydrophobicity of the shell directs exudate to the outer layer, while the core layer contains thermosensitive gelatin, recombinant human epidermal growth factor, and mosiclocin. When wound inflammation causes the local temperature to reach ≥37°C, the temperature change triggers varying degrees of phase transition in the drug-loaded thermosensitive phase-change macromolecules, enabling timely and controlled drug release to ensure wound healing.

[0008] The present invention is achieved through the following technical solutions:

[0009] In the first aspect, the present invention provides an anti-inflammatory and healing-promoting electrospun wound dressing, comprising a double-layer structure of an inner layer and an outer layer; wherein the outer layer is a hydrophilic nanofiber membrane prepared by single-nozzle electrospinning, which is used to absorb wound exudate; the inner layer is a nanofiber membrane with a core-shell structure prepared by coaxial electrospinning, and the shell layer of the core-shell structure is a hydrophobic material, which is used to guide the exudate to the outer layer; the core layer of the core-shell structure includes hydrophilic thermosensitive macromolecules, healing-promoting growth factors and anti-inflammatory drugs, and the temperature increase triggers the phase change of the thermosensitive macromolecules to achieve controlled sustained release of anti-inflammatory drugs, thereby promoting wound healing.

[0010] Furthermore, the thickness of the outer layer is 0.4 to 2 mm, and the thickness of the inner layer is 50 to 200 μm.

[0011] Furthermore, the temperature-sensitive macromolecule in the nuclear layer is gelatin, the healing-promoting growth factor is recombinant human epidermal growth factor, and the anti-inflammatory drug is mosiclocin.

[0012] Furthermore, the outer layer is composed of thermoplastic polyurethane, sodium carboxymethyl cellulose and polyvinyl pyrrolidone; and the shell of the inner layer is composed of polyvinyl butyral and polyvinyl pyrrolidone.

[0013] In a second aspect, the present invention provides a method for preparing an anti-inflammatory and healing-promoting electrospun wound dressing, which specifically comprises the following steps:

[0014] Step 1: Preparation of outer hydrophilic nanofiber membrane spinning precursor solution:

[0015] Thermoplastic polyurethane with a mass concentration of 6-8%, sodium carboxymethyl cellulose 1% and polyvinyl pyrrolidone 2% are dissolved in N,N-dimethylformamide to obtain a spinning precursor solution for the outer hydrophilic nanofiber membrane;

[0016] Step 2: Preparation of nanofiber membrane spinning precursor solution with inner core-shell structure:

[0017] a) Shell spinning precursor solution A: dissolving 6-7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 40-80% ethanol aqueous solution to obtain shell spinning precursor solution A;

[0018] b) Core layer spinning precursor solution B: dissolving 2% polyvinyl butyral, 1-2% polyvinyl pyrrolidone, 2-3% gelatin, 0.5% recombinant human epidermal growth factor, and 0.5% mosiclocin in a 20-60% ethanol aqueous solution to obtain core layer spinning precursor solution B;

[0019] Step 3: Single nozzle electrospinning to prepare the outer membrane:

[0020] The outer hydrophilic nanofiber membrane spinning precursor solution prepared in step 1 is taken and spun at a voltage of 10 to 20 kV, a collection distance of 10 to 20 cm, and a propulsion speed of 0.5 to 2 mL / h to obtain an outer hydrophilic nanofiber membrane;

[0021] Step 4: Coaxial electrospinning to prepare the inner layer membrane:

[0022] On the outer hydrophilic nanofiber membrane prepared in step three, the shell spinning precursor solution A and the core spinning precursor solution B prepared in step two are simultaneously advanced, and spinning is carried out at a voltage of 10-25 kV and a collection distance of 10-20 cm to prepare a nanofiber membrane with a core-shell structure, and finally an anti-inflammatory and pro-healing electrospun wound dressing is obtained.

[0023] Furthermore, in step 4, the propulsion speed of the shell layer spinning precursor solution A is 0.5-1 mL / h, and the propulsion speed of the core layer spinning precursor solution B is 1-2 mL / h.

[0024] Furthermore, in step three, the single needle model used in the single-nozzle electrospinning is 26-36G; in step four, the coaxial needle model used in the coaxial electrospinning is 23-18G / 19-14G.

[0025] In a third aspect, the present invention also provides an application of an anti-inflammatory and healing-promoting electrospun wound dressing in the preparation of auxiliary materials for treating diabetic ulcers, burns, and traumatic wounds.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] The present invention provides an anti-inflammatory and healing-promoting electrospun wound dressing, a preparation method and applications thereof.

[0028] 1. Intelligent controlled-release drugs: The core layer of the core-shell structure of the present invention contains thermosensitive gelatin, which can respond to local temperature increases (≥37°C) caused by wound inflammation, triggering the accelerated release of anti-inflammatory drugs and growth factors in real time, achieving on-demand precise drug delivery and solving the problem of uncontrollable release of traditional dressings.

[0029] 2. Efficient management of exudate: Through the synergistic drainage mechanism of the hydrophobic shell and the hydrophilic outer layer, the exudate is absorbed into the outer layer in a directionally controlled manner to avoid wound maceration while maintaining a moist healing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0031] Figure 1 Schematic diagram of an anti-inflammatory and healing-promoting electrospun wound dressing of the present invention;

[0032] Figure 2 This is a schematic diagram of the working principle of an anti-inflammatory and healing-promoting electrospun wound dressing of the present invention;

[0033] Figure 3 This is a scanning electron microscope image of the outer hydrophilic nanofiber membrane of Example 1;

[0034] Figure 4 is the water contact angle of the outer hydrophilic nanofiber membrane of Example 1;

[0035] Figure 5 This is a scanning electron microscope image of the inner core-shell structure nanofiber membrane of Example 1;

[0036] Figure 6 The water contact angle of the inner core-shell nanofiber membrane of Example 1;

[0037] Figure 7 This is a scanning electron microscope image of the outer hydrophilic nanofiber membrane of Example 2;

[0038] Figure 8 is the water contact angle of the outer hydrophilic nanofiber membrane of Example 2;

[0039] Figure 9 This is a scanning electron microscope image of the inner core-shell structure nanofiber membrane of Example 2;

[0040] Figure 10 The water contact angle of the inner core-shell nanofiber membrane of Example 2;

[0041] Figure 11This is a scanning electron microscope image of the outer hydrophilic nanofiber membrane of Example 3;

[0042] Figure 12 is the water contact angle of the outer hydrophilic nanofiber membrane of Example 3;

[0043] Figure 13 This is a scanning electron microscope image of the inner core-shell structure nanofiber membrane of Example 3;

[0044] Figure 14 The water contact angle of the inner core-shell nanofiber membrane of Example 3;

[0045] Figure 15 To cover the wound healing photos of the dressings prepared in Comparative Example 1 and Example 1;

[0046] Figure 16 Graph showing the percentage of residual wound area of ​​the dressings prepared in Comparative Example 1 and Example 1. DETAILED DESCRIPTION

[0047] In order to clearly and completely describe the technical solution and specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings:

[0048] Example 1

[0049] This embodiment provides a method for preparing an anti-inflammatory and healing-promoting electrospun wound dressing, wherein the thickness of the outer layer is 0.8 mm and the thickness of the inner layer is 80 μm, and specifically comprises the following steps:

[0050] Step 1: Preparation of outer hydrophilic nanofiber membrane spinning precursor solution:

[0051] 7% by mass of thermoplastic polyurethane, 1% by mass of sodium carboxymethyl cellulose and 2% by mass of polyvinyl pyrrolidone were dissolved in N,N-dimethylformamide to obtain a spinning precursor solution for the outer hydrophilic nanofiber membrane.

[0052] Step 2: Preparation of nanofiber membrane spinning precursor solution with inner core-shell structure:

[0053] a) Shell spinning precursor solution A: 6% by mass concentration of polyvinyl butyral and 2% by mass concentration of polyvinyl pyrrolidone were dissolved in a 60% by mass concentration of ethanol aqueous solution to obtain shell spinning precursor solution A;

[0054] b) Core layer spinning precursor solution B: dissolving 2% polyvinyl butyral, 2% polyvinyl pyrrolidone, 2% gelatin, 0.5% recombinant human epidermal growth factor, and 0.5% mosiclocin in a 50% ethanol aqueous solution to obtain core layer spinning precursor solution B;

[0055] Step 3: Single nozzle electrospinning to prepare the outer membrane:

[0056] The outer hydrophilic nanofiber membrane spinning precursor solution was extracted with a syringe and spun at a voltage of 20 kV, a collection distance of 18 cm, and a propulsion speed of 1 mL / h to obtain the outer hydrophilic nanofiber membrane;

[0057] Step 4: Coaxial electrospinning to prepare the inner layer membrane:

[0058] On the outer hydrophilic nanofiber membrane prepared in step three, the shell layer spinning precursor solution A and the core layer spinning precursor solution B were extracted separately with a syringe, and a coaxial needle was connected. At a voltage of 20kV, the collection distance was 18cm, the shell layer spinning precursor solution A was 0.8ml / h, and the core layer spinning precursor solution B was 1ml / h to propel the syringe for spinning, and finally an anti-inflammatory and pro-healing electrospun wound dressing was obtained.

[0059] like Figure 1 As shown, the present embodiment provides an anti-inflammatory and healing-promoting electrospun wound dressing, comprising an inner and outer double-layer structure; wherein the outer layer is a hydrophilic nanofiber membrane prepared by single-nozzle electrospinning, which is used to absorb wound exudate; the inner layer is a core-shell nanofiber membrane prepared by coaxial electrospinning, and the shell layer of the core-shell structure is a hydrophobic material for directing the exudate to the outer layer; the core layer of the core-shell structure includes hydrophilic thermosensitive macromolecules, healing-promoting growth factors and anti-inflammatory drugs, and the temperature increase triggers the phase change of the thermosensitive macromolecules to achieve controlled sustained release of anti-inflammatory drugs, thereby promoting wound healing, as shown in FIG. Figure 2 The principle diagram is shown in the figure.

[0060] Example 2

[0061] This embodiment provides a method for preparing an anti-inflammatory and healing-promoting electrospun wound dressing, wherein the thickness of the outer layer is 1 mm and the thickness of the inner layer is 100 μm, and specifically comprises the following steps:

[0062] Step 1: Preparation of outer hydrophilic nanofiber membrane spinning precursor solution:

[0063] 7% by mass of thermoplastic polyurethane, 1% by mass of sodium carboxymethyl cellulose and 2% by mass of polyvinyl pyrrolidone were dissolved in N,N-dimethylformamide to obtain a spinning precursor solution for the outer hydrophilic nanofiber membrane.

[0064] Step 2: Preparation of nanofiber membrane spinning precursor solution with inner core-shell structure:

[0065] a) Shell spinning precursor solution A: 7% by mass concentration of polyvinyl butyral and 2% by mass concentration of polyvinyl pyrrolidone were dissolved in a 70% by mass concentration of ethanol aqueous solution to obtain shell spinning precursor solution A;

[0066] b) Core layer spinning precursor solution B: dissolving 2% polyvinyl butyral, 2% polyvinyl pyrrolidone, 3% gelatin, 0.5% recombinant human epidermal growth factor, and 0.5% mosiclocin in a 50% ethanol aqueous solution to obtain core layer spinning precursor solution B;

[0067] Step 3: Single nozzle electrospinning to prepare the outer membrane:

[0068] The outer hydrophilic nanofiber membrane spinning precursor solution was extracted with a syringe and spun at a voltage of 20 kV, a collection distance of 16 cm, and a propulsion speed of 1 mL / h to obtain the outer hydrophilic nanofiber membrane;

[0069] Step 4: Coaxial electrospinning to prepare the inner layer membrane:

[0070] On the outer hydrophilic nanofiber membrane prepared in step three, the shell layer spinning precursor solution A and the core layer spinning precursor solution B were extracted separately with a syringe, and a coaxial needle was connected. At a voltage of 20kV, the collection distance was 16cm, the shell layer spinning precursor solution A was 0.8ml / h, and the core layer spinning precursor solution B was 2ml / h to propel the syringe for spinning, and finally an anti-inflammatory and pro-healing electrospun wound dressing was obtained.

[0071] Example 3

[0072] This embodiment provides a method for preparing an anti-inflammatory and healing-promoting electrospun wound dressing, wherein the thickness of the outer layer is 1.2 mm and the thickness of the inner layer is 150 μm, and specifically comprises the following steps:

[0073] Step 1: Preparation of outer hydrophilic nanofiber membrane spinning precursor solution:

[0074] 8% by mass of thermoplastic polyurethane, 1% by mass of sodium carboxymethyl cellulose and 2% by mass of polyvinyl pyrrolidone were dissolved in N,N-dimethylformamide to obtain a spinning precursor solution for the outer hydrophilic nanofiber membrane.

[0075] Step 2: Preparation of nanofiber membrane spinning precursor solution with inner core-shell structure:

[0076] a) Shell spinning precursor solution A: dissolving 7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 80% ethanol aqueous solution to obtain shell spinning precursor solution A;

[0077] b) Core layer spinning precursor solution B: dissolving 2% polyvinyl butyral, 2% polyvinyl pyrrolidone, 2.5% gelatin, 0.5% recombinant human epidermal growth factor, and 0.5% mosiclocin in a 60% ethanol aqueous solution to obtain core layer spinning precursor solution B;

[0078] Step 3: Single nozzle electrospinning to prepare the outer membrane:

[0079] The outer hydrophilic nanofiber membrane spinning precursor solution was extracted with a syringe and spun at a voltage of 20 kV, a collection distance of 18 cm, and a propulsion speed of 1 mL / h to obtain the outer hydrophilic nanofiber membrane;

[0080] Step 4: Coaxial electrospinning to prepare the inner layer membrane:

[0081] On the outer hydrophilic nanofiber membrane prepared in step three, the shell layer spinning precursor solution A and the core layer spinning precursor solution B were extracted separately with a syringe, and a coaxial needle was connected. At a voltage of 20kV, the collection distance was 16cm, the shell layer spinning precursor solution A was 1ml / h, and the core layer spinning precursor solution B was 2ml / h to propel the syringe for spinning, and finally an anti-inflammatory and pro-healing electrospun wound dressing was obtained.

[0082] Water contact test

[0083] The hydrophilic layer and the hydrophobic layer of the dressings prepared in Examples 1-3 were subjected to water contact tests using a contact angle tester (DSA30, KRÜSS, Germany). A 5 μL water droplet was dropped onto the hydrophobic layer or the hydrophilic layer of the dressing to test the dynamic apparent contact angle of the dressing.

[0084] from Figure 4 It can be seen that the water contact angle of the outer hydrophilic nanofiber membrane of Example 1 is 48.4°, indicating that the outer hydrophilic nanofiber membrane of Example 1 has strong water absorption.

[0085] from Figure 6 It can be seen that the water contact angle of the inner core-shell structure nanofiber membrane of Example 1 is 89.71°, indicating that the inner core-shell structure nanofiber membrane of Example 1 has strong hydrophobicity.

[0086] from Figure 8 It can be seen that the water contact angle of the outer hydrophilic nanofiber membrane of Example 2 is 51.1°, indicating that the outer hydrophilic nanofiber membrane of Example 2 has strong water absorption.

[0087] from Figure 10 It can be seen that the water contact angle of the inner core-shell structure nanofiber membrane of Example 2 is 109.07°, indicating that the inner core-shell structure nanofiber membrane of Example 2 has strong hydrophobicity.

[0088] from Figure 12 It can be seen that the water contact angle of the outer hydrophilic nanofiber membrane of Example 3 is 60.2°, indicating that the outer hydrophilic nanofiber membrane of Example 3 has strong water absorption.

[0089] from Figure 14 It can be seen that the water contact angle of the inner core-shell structure nanofiber membrane of Example 3 is 111.95°, indicating that the inner core-shell structure nanofiber membrane of Example 3 has strong hydrophobicity.

[0090] Surface morphology characterization

[0091] The surface morphologies of the hydrophilic and hydrophobic layers of the dressings prepared in Examples 1-3 were characterized by scanning electron microscopy (SEM, JSM-6510, JEOL, Japan) at an accelerating voltage of 20 kV.

[0092] from Figure 3 , Figure 7 , Figure 11 It can be seen from the scanning electron microscope images that the outer hydrophilic nanofibers of Example 1, Example 2, and Example 3 are uniform in thickness.

[0093] from Figure 5 , Figure 9 , Figure 13 It can be seen from the scanning electron microscope images that the inner core-shell structure nanofibers of Example 1, Example 2, and Example 3 are uniform in thickness.

[0094] Comparative Example 1

[0095] A method for preparing a wound dressing, which differs from Example 1 only in that: Step 2: preparing a nanofiber membrane spinning precursor solution with an inner core-shell structure:

[0096] a) Shell spinning precursor solution A: dissolving 7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 80% ethanol aqueous solution to obtain shell spinning precursor solution A;

[0097] b) Core layer spinning precursor solution B: 2% by mass concentration of polyvinyl butyral, 4% by mass concentration of polyvinyl pyrrolidone, 0.5% by mass concentration of recombinant human epidermal growth factor, and 0.5% by mass concentration of mosiclocin were dissolved in a 60% by mass concentration of ethanol aqueous solution to obtain core layer spinning precursor solution B.

[0098] Comparative Example 2

[0099] A method for preparing a wound dressing, which differs from Example 2 only in that: Step 2: preparing a nanofiber membrane spinning precursor solution with an inner core-shell structure:

[0100] a) Shell spinning precursor solution A: dissolving 7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 80% ethanol aqueous solution to obtain shell spinning precursor solution A;

[0101] b) Core layer spinning precursor solution B: 2% by mass concentration of polyvinyl butyral, 5% by mass concentration of polyvinyl pyrrolidone, 0.5% by mass concentration of recombinant human epidermal growth factor, and 0.5% by mass concentration of mosiclocin were dissolved in a 60% by mass concentration of ethanol aqueous solution to obtain core layer spinning precursor solution B.

[0102] Comparative Example 3

[0103] A method for preparing a wound dressing, which differs from Example 2 only in that: Step 2: preparing a nanofiber membrane spinning precursor solution with an inner core-shell structure:

[0104] a) Shell spinning precursor solution A: dissolving 7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 80% ethanol aqueous solution to obtain shell spinning precursor solution A;

[0105] b) Core layer spinning precursor solution B: 2% by mass concentration of polyvinyl butyral, 4.5% by mass concentration of polyvinyl pyrrolidone, 0.5% by mass concentration of recombinant human epidermal growth factor, and 0.5% by mass concentration of mosiclocin were dissolved in a 60% by mass concentration of ethanol aqueous solution to obtain core layer spinning precursor solution B.

[0106] Drug release testing

[0107] Different concentrations of mosirocin were dissolved in phosphate buffer solution, and the absorbance of the solutions was measured using a UV-visible spectrophotometer to establish a standard curve. Fifty grams of fiber were then immersed in 5 mL of phosphate buffer at 30°C, 32°C, 34°C, 36°C, 38°C, and 40°C for six hours. The absorbance of the immersion solution was measured, and the corresponding drug release amount was determined using the standard curve. Three measurements were performed for each sample, and the average was calculated.

[0108] Table 1 Drug release test results of dressing

[0109]

[0110] As can be seen from Table 1, the core layer of Examples 1-3 contains gelatin, and the drug release can be controlled as the experimental temperature changes. However, the core layer of Comparative Documents 1-3 does not contain gelatin, and the drug value of the dressing remains basically unchanged as the temperature changes, and controllable drug release cannot be achieved.

[0111] Wound healing evaluation

[0112] The dressings prepared in Comparative Example 1 and Example 1 were subjected to an in vitro wound healing experiment, and the specific steps were as follows: 2 rats purchased from Liaoning Changsheng Biotechnology Co., Ltd. were selected, and a type II diabetes model was established in the rats. After the diabetic rats were given a normal diet and free drinking water for 5 days, the rats were anesthetized with gas, and then the diabetic rats were fixed on the operating table and depilated with a razor and depilatory cream to fully expose the back. The surgical site was disinfected with 75% alcohol. A 1cm×1.5cm square defect wound of the full-thickness skin was made on the back of the rat, and then the wound was covered with the dressings prepared in Comparative Example 1 and Example 1, respectively, and the dressing was changed every three days. A digital camera was used to observe and record the macroscopic images of each group of wounds on days 0, 3, 9 and 14. The calculation formula for the residual wound area is as follows:

[0113]

[0114] Where W0 is the wound exposure area on day 0, W x is the wound exposure area on day x (x = 3, 9, 14).

[0115] The wound healing photos of the dressings prepared by Comparative Example 1 and Example 1 are shown in FIG. Figure 15 As shown in FIG. 1 , the percentage of residual wound area of ​​the dressing prepared by comparative example 1 and example 1 is shown in FIG. Figure 16 As shown. Figure 15 It can be seen that the wounds of rats covered with the dressing prepared in Example 1 healed significantly better than those covered with the dressing prepared in Comparative Example 1. Figure 16 It can be seen that on the 14th day, the percentage of residual area of ​​the rat wound covered with the dressing prepared in Example 1 was 20%, and the percentage of residual area of ​​the rat wound covered with the dressing prepared in Comparative Example 1 was 41%. Therefore, it can be seen that the dressing prepared in Example 1 has the ability to promote healing of rat wounds.

[0116] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0117] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0118] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An anti-inflammatory and healing-promoting electrospun wound dressing, characterized in that: The device comprises a double-layer structure of an inner layer and an outer layer; wherein the outer layer is a hydrophilic nanofiber membrane prepared by single-nozzle electrospinning, which is used to absorb wound exudate; the inner layer is a core-shell nanofiber membrane prepared by coaxial electrospinning, and the shell layer of the core-shell structure is a hydrophobic material, which is used to guide the exudate to the outer layer; the core layer of the core-shell structure includes hydrophilic thermosensitive macromolecules, healing-promoting growth factors and anti-inflammatory drugs. The temperature rise triggers the phase change of the thermosensitive macromolecules, achieving controlled sustained release of the anti-inflammatory drugs, thereby promoting wound healing; The anti-inflammatory and healing-promoting electrospun wound dressing is prepared by the following method, which specifically comprises the following steps: Step 1: Preparation of outer hydrophilic nanofiber membrane spinning precursor solution: Thermoplastic polyurethane with a mass concentration of 6-8%, 1% sodium carboxymethyl cellulose and 2% polyvinyl pyrrolidone are dissolved in N,N-dimethylformamide to obtain a spinning precursor solution for the outer hydrophilic nanofiber membrane; Step 2: Preparation of nanofiber membrane spinning precursor solution with inner core-shell structure: a) Shell spinning precursor solution A: dissolving 6-7% polyvinyl butyral and 2% polyvinyl pyrrolidone in 40-80% ethanol aqueous solution to obtain shell spinning precursor solution A; b) Core layer spinning precursor solution B: dissolving 2% polyvinyl butyral, 1-2% polyvinyl pyrrolidone, 2-3% gelatin, 0.5% recombinant human epidermal growth factor, and 0.5% mosiclocin in a 20-60% ethanol aqueous solution to obtain a core layer spinning precursor solution B; Step 3: Single nozzle electrospinning to prepare the outer membrane: The outer hydrophilic nanofiber membrane spinning precursor solution prepared in step 1 is taken and spun at a voltage of 10 to 20 kV, a collection distance of 10 to 20 cm, and a propulsion speed of 0.5 to 2 mL / h to obtain an outer hydrophilic nanofiber membrane; Step 4: Coaxial electrospinning to prepare the inner layer membrane: On the outer hydrophilic nanofiber membrane prepared in step three, the shell spinning precursor solution A and the core spinning precursor solution B prepared in step two are simultaneously advanced, and spinning is carried out at a voltage of 10-25 kV and a collection distance of 10-20 cm to prepare a nanofiber membrane with a core-shell structure, and finally an anti-inflammatory and pro-healing electrospun wound dressing is obtained.

2. The anti-inflammatory and healing-promoting electrospun wound dressing according to claim 1, characterized in that: The thickness of the outer layer is 0.4-2 mm, and the thickness of the inner layer is 50-200 μm.

3. The anti-inflammatory and healing-promoting electrospun wound dressing according to claim 1, characterized in that: In step 4, the propulsion speed of the shell layer spinning precursor solution A is 0.5-1 mL / h, and the propulsion speed of the core layer spinning precursor solution B is 1-2 mL / h.

4. The anti-inflammatory and healing-promoting electrospun wound dressing according to claim 1, characterized in that: In step 3, the single nozzle electrospinning uses a single needle model of 26-36G; in step 4, the coaxial needle model used for coaxial electrospinning is 23-18G / 19-14G.

5. Use of the anti-inflammatory and healing-promoting electrospun wound dressing according to claim 1 in the preparation of dressings for treating diabetic ulcers, burns, and traumatic wounds.

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