Nanofiber composite dressing for promoting wound healing and method of making the same

Abstract

The application discloses a kind of nanofiber composite dressings of promoting wound healing and preparation method thereof.The method is prepared by " one-pot method " 2-hydroxy-1,4-naphthoquinone is loaded on ZIF-8 to prepare composite nanoparticles LZIF-8, and then seabuckthorn petroleum ether active ingredient and LZIF-8 are loaded into polylactic acid fiber by electrospinning technology, and PLA LZIF‑8 / PEE Nanofiber composite dressing.The PLA LZIF‑8 / PEE The nanofiber composite dressing has excellent air permeability, antibacterial property and biocompatibility, can effectively improve inflammation, promote collagen deposition at a wound site, and has good application value for promoting wound healing.

Description

Technical Field

[0001] This invention belongs to the field of wound dressing technology, and relates to a nanofiber composite dressing that promotes wound healing and its preparation method. Background Technology

[0002] Globally, chronic wound management costs account for 3% of total healthcare expenditure, a situation exacerbated by low wound healing rates. Bacterial infection is one of the leading factors contributing to the difficulty in treating chronic wounds. To address this issue, researchers have developed various antibiotics and novel dressings to improve wound healing. However, overuse of antibiotics can lead to drug-resistant bacteria, severely hindering wound recovery. Different types of novel dressings also have their own limitations. For example, long-term use of hydrogel dressings can lead to penetration into surrounding skin tissue and require secondary fixation. Furthermore, some wound dressings may exhibit poor biocompatibility, explosive drug release, or low-release properties. Therefore, it is necessary to explore and develop novel antimicrobial materials to reduce the risk of bacterial infection while simultaneously decreasing the frequency of antibiotic use.

[0003] The use of bioactive nanomaterials in wound dressing design is attracting increasing attention from researchers. Among them, the zeolite imidazole ester framework material (ZIF-8) is composed of zinc ions (Zn... 2+ ZIF-8, formed by coordination with 2-methylimidazole, exhibits stability under physiological conditions but disintegrates under acidic conditions, making it an ideal carrier for drug delivery and sustained release. It is noteworthy that even without drug loading, ZIF-8 itself possesses antibacterial activity, and Zn... 2+As an endogenous cation in the human body, ZIF-8 exhibits superior biocompatibility, biodegradability, and stability. In recent years, research on ZIF-8 as a drug carrier for loading various antibacterial drugs has gradually emerged. The ZIF-8@gentamicin nanofiber membrane prepared by Yang et al. (Jun Yang, Chunli Liu, Yining Ding, et al. Synergistic antibacterial polyacrylonitrile / gelatin nanofibers coated with metal-organic frameworks for accelerating wound repair, Int. J. Biol. Macromol., 2021, 189:698-704) showed good antibacterial properties and effectively promoted wound healing. However, the use of gentamicin also brings certain side effects. Yan et al. (Fufeng Yan, Fang Cheng, Chuanpan Guo, et al. Curcumin-regulated constructing of defective zinc-based polymer-metal-organic framework as long-acting antibacterial platform for efficient woundhealing, J. Colloid Interface Sci., 2023, 641:59-69) prepared a zinc-based polymer-metal-organic framework that achieved efficient wound healing through the synergistic effect of releasing metal ions and curcumin. Furthermore, Zhang et al. (Qian Zhang, Yuhang Zou, Liqin Tang, et al. Stage-controlled antibacterial surgicalsutures based on curcumin@ZIF-8 functional coating for improved wound healing, Prog. Org. Coat., 2023, 184:107829) developed a functional suture loaded with curcumin and ZIF-8 that also promoted wound healing. However, the effective functions of these two materials have not yet been applied to wound dressings. Summary of the Invention

[0004] The purpose of this invention is to provide a nanofiber composite dressing that promotes wound healing and its preparation method. The nanofiber composite dressing of this invention has excellent breathability, high drug loading rate, and biocompatibility. It achieves a good sustained-release effect through the application of ZIF-8. Loading 2-hydroxy-1,4-naphthoquinone (Lawsone) onto ZIF-8 further enhances its antibacterial properties and has the effects of improving inflammation and promoting collagen deposition at the wound site.

[0005] The technical solution for achieving the objective of this invention is as follows:

[0006] A method for preparing a wound-healing nanofiber composite dressing includes the following steps:

[0007] (1) Preparation of LZIF-8 nanoparticles: Zinc nitrate hexahydrate and 2-hydroxy-1,4-naphthoquinone were dissolved in anhydrous methanol, and the pH was adjusted to 8 with sodium hydroxide to obtain a mixed solution; 2-methylimidazole was dissolved in anhydrous ethanol at a ratio of 3.3g:100ml to obtain a 2-methylimidazole solution; the mixed solution was slowly added to the 2-methylimidazole solution, and the reaction was stirred. After the reaction was completed, the orange-yellow suspension was centrifuged, the supernatant was discarded, anhydrous methanol was added and the precipitate was dispersed by shaking. The centrifugation and resuspension steps were repeated, and the LZIF-8 particles were obtained after drying.

[0008] (2) Extraction of active ingredients of sea buckthorn: After crushing sea buckthorn fruit into powder, add 95% ethanol at a ratio of 1g:5mL and heat and reflux for extraction. After extraction, filter and collect the filtrate, and continue to heat and reflux extract the residue. After multiple extractions, concentrate all the filtrates by rotary evaporation under reduced pressure, and freeze-dry to obtain sea buckthorn crude ethanol extract (EE). Dissolve sea buckthorn crude ethanol extract in hot water at 60-80℃ at a ratio of 1g:20mL, add an equal volume of petroleum ether for extraction, and extract multiple times. Concentrate the collected petroleum ether extract by rotary evaporation under reduced pressure and freeze-dry to obtain sea buckthorn petroleum ether extract (PEE).

[0009] (3) Preparation of electrospinning solution: Polylactic acid (PLA) is dissolved in a mixed solution of dichloromethane (DCM) and dimethylamide (DMF) in a volume ratio of 4:1 to obtain a polymer solution. Then LZIF-8 and PEE are added and stirred until fully dispersed to obtain an electrospinning solution.

[0010] (4) Preparation of nanofiber composite dressing: The electrospinning solution was electrospinned at a voltage of 35 kV, a receiving distance of 15 cm, a roller speed of 120 rpm / min, a feed rate of 0.2 mL / h, a spinning humidity of 50 ± 2%, and a spinning temperature of 25 ± 1 ℃. After spinning, the residual solvent was removed by drying to obtain PLA. LZIF-8 / PEE Nanofiber composite dressing.

[0011] Preferably, in step (1), the ratio of zinc nitrate hexahydrate, 2-hydroxy-1,4-naphthoquinone, and anhydrous methanol is 1.5g:0.2g:50ml. Increasing the concentration of 2-hydroxy-1,4-naphthoquinone in the system reduces the effectiveness of ZIF-8 in encapsulating 2-hydroxy-1,4-naphthoquinone.

[0012] Preferably, in step (1), the stirring speed is 150 rpm and the mixing reaction time is 24 h.

[0013] Preferably, in step (1), the centrifugation speed is 10,000 rpm, the centrifugation time is 10 min, and the centrifugation resuspension step is repeated three times.

[0014] Preferably, in step (1), the drying temperature is 40°C and the drying time is 3 hours.

[0015] Preferably, in step (3), the electrospinning solution has a polylactic acid mass-volume fraction of 6%, an LZIF-8 mass-volume fraction of 5%, and a PEE mass-volume fraction of 5%.

[0016] Preferably, in step (3), the stirring temperature is 50°C and the stirring time is overnight.

[0017] This invention also provides PLA prepared by the above method. LZIF-8 / PEE Nanofiber composite dressing.

[0018] Furthermore, the present invention provides the above-mentioned PLA. LZIF-8 / PEE Application of nanofiber composite dressings as wound healing dressings.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) This invention uses electrospinning technology to load PEE active components and LZIF-8 into PLA fibers to obtain PLA fibers. LZIF-8 / PEE Nanofiber composite dressings have good breathability, and most of their fibers have a diameter in the range of 250-450nm, which helps promote cell growth.

[0021] (2) This invention synthesizes LZIF-8 and Zn metal ions via a one-pot method. 2+ It forms a coordination bond with the oxonium in protonated 2-hydroxy-1,4-naphthoquinone, preferentially coordinating Zn in Zn(NO3)2·6H2O under alkaline conditions. 2+Subsequently, 2-MIN was added as a ligand to form the ZIF-8 framework, ensuring that 2-hydroxy-1,4-naphthoquinone was encapsulated within ZIF-8, achieving a drug loading rate of 14.15 ± 2.41%. This resulted in a sustained-release effect under acidic conditions and avoided cytotoxicity caused by burst drug release.

[0022] (3) PLA prepared by the present invention LZIF-8 / PEE Nanofiber composite dressings exhibit good biocompatibility. At low concentrations, LZIF-8 nanoparticles show approximately twice the inhibitory efficiency against Escherichia coli and Staphylococcus aureus compared to ZIF-8. Compared to ZIF-8, LZIF-8, in addition to releasing Zn... 2+ It disrupts bacterial biofilms and nucleic acid expression, and also induces reactive oxygen species in bacterial cells to produce reactive oxygen species by releasing 2-hydroxy-1,4-naphthoquinone, accelerating DNA damage, thus exhibiting better antibacterial effects. LZIF-8 / PEE The nanofiber composite dressing achieved antibacterial rates of 96.61±3.12% and 94.91±3.24% against E. coli and S. aureus, respectively.

[0023] (4) PLA prepared by the present invention LZIF-8 / PEE Nanofiber composite dressings have the effect of promoting wound healing. When used to treat wound infections in rats, they can effectively improve inflammation, promote collagen deposition at the wound site, and accelerate wound healing. On the 14th day of treatment, the healing rate can reach 99.81±0.32%. Attached Figure Description

[0024] Figure 1 SEM image of LZIF-8 powder (A), IR spectra of 2-hydroxy-1,4-naphthoquinone, ZIF-8 and LZIF-8 powders (B), XRD patterns of ZIF-8 and LZIF-8 powders (C), PLA PEE (D), PLA LZIF-8 (E), PLA LZIF-8 / PEE (F) SEM image of nanofibers;

[0025] Figure 2 For PLA PEE PLA LZIF-8 PLA LZIF-8 / PEE Porosity results (A) and water vapor transmission rate results (B) for PLA at different mass concentrations ZIF-8 PLA LZIF-8 and PLA LZIF-8 / PEE Effects of fiber dressings on L929 cell viability (C) and PLA LZIF-8 / PEE Drug release curve of nanofiber composite dressing in PBS solution (D);

[0026] Figure 3 The graphs show the antibacterial effects of ZIF-8 and LZIF-8 (A and B represent the antibacterial efficiencies at different mass concentrations, respectively). PLA PEE PLA ZIF-8 PLA LZIF-8 and PLA LZIF-8 / PEE The antibacterial effect of nanofiber composite dressing (C);

[0027] Figure 4 For MOD, PLA PEE PLA LZIF-8 and PLA LZIF-8 / PEE Images of the dynamic contraction process of the wound within predetermined time intervals, and dynamic wound tracking charts (A) and bar charts (B) of the wound healing rate of rats in the four groups during the 14-day treatment process, MOD, PLA PEE PLA LZIF-8 and PLA LZIF-8 / PEE Bar charts of collagen density quantitative analysis on days 7 and 14 (C), and H&E and Masson staining charts (D);

[0028] Figure 5 For CON, MOD, PLA PEE PLA LZIF-8 and PLA LZIF-8 / PEE The bar chart shows the expression levels of two inflammatory factors, IL-1β (A for day 3, B for day 7) and IL-6, measured on days 3 and 7 (C for day 3, D for day 7). Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0030] Example 1

[0031] The steps for extracting PEE are as follows:

[0032] Weigh 200g of sea buckthorn, add 1L of 95% ethanol, heat under reflux for 1h, then add another 1L of 95% ethanol and continue heating under reflux for 1h. Concentrate by rotary evaporation and then freeze-dry to obtain a crude ethanol extract of sea buckthorn. Dissolve the crude ethanol extract in 200mL of hot water and extract three times, adding 200mL of petroleum ether each time. Concentrate the collected petroleum ether extract by rotary evaporation and then freeze-dry to obtain PEE.

[0033] Example 2

[0034] The preparation steps of LZIF-8 nanoparticles are as follows:

[0035] First, dissolve 1.5g of zinc nitrate hexahydrate in 50mL of anhydrous methanol, then add 0.2g of 2-hydroxy-1,4-naphthoquinone. Adjust the pH to 8 with 1mol / L sodium hydroxide to obtain a mixed solution. Separately, dissolve 3.3g of 2-methylimidazole in 100mL of anhydrous ethanol to obtain a 2-methylimidazole solution. Use an ultrasonic oscillator to sonicate for 3 minutes to accelerate the dissolution of both solutes. Slowly add the mixed solution to the 2-methylimidazole solution while magnetically stirring at 150rpm, allowing the two solutions to react for 24 hours. The solution changes from a clear red color to a suspension with an orange-yellow precipitate. Place the orange-yellow suspension, stirred for 24 hours, into a 50mL centrifuge tube and centrifuge at 10000rpm for 10 minutes. Discard the supernatant, add anhydrous methanol again, and oscillate to redisperse the orange-yellow precipitate. Repeat this centrifugation and resuspension process three times. The LZIF-8 nanoparticles that were collected after three centrifugations and resuspended were placed in a vacuum drying oven and dried at 40°C for 3 hours to obtain dried orange-yellow LZIF-8 nanoparticles.

[0036] Example 3

[0037] PLA LZIF-8 / PEE The preparation steps of the nanofiber composite dressing are as follows:

[0038] (1) Weigh 0.6 g PLA using an electronic balance and add it to 10 mL of a mixed solution of DCM and DMF (DCM to DMF volume ratio of 4:1) to prepare a polymer solution with a mass-volume fraction of 6% (w / v). Based on this polymer solution, add 5% (w / v) LZIF-8 and then 5% (w / v) PEE. Place the prepared solution on a magnetic stirrer and stir overnight at 50°C until fully dispersed, thus obtaining the spinning solution.

[0039] (2) Pour the prepared homogeneous spinning solution into a 10 mL syringe, and then insert the syringe into the electrospinning system. The spinning parameters during the electrospinning process are as follows: the voltage applied to the needle tip and the roller is +30 kV and -5 kV, respectively; the distance between the needle tip and the roller and the rotation speed of the roller are fixed at 15 cm and 120 rpm / min, respectively; the advance speed of the syringe is fixed at 0.2 mL / h; and the spinning humidity and temperature are controlled at 50 ± 2% and 25 ± 1℃, respectively. After electrospinning is completed, remove the fiber dressing from the roller and place it in a 37℃ oven to dry and remove residual solvent, obtaining PLA. LZIF-8 / PEE Nanofiber composite dressing.

[0040] Comparative Example 1

[0041] This comparative example is largely the same as Example 3, except that LZIF-8 is not added to the spinning solution to obtain PLA. PEE Nanofiber composite dressing.

[0042] Comparative Example 2

[0043] This comparative example is largely the same as Example 3, except that PEE is not added to the spinning solution, and LZIF-8 nanoparticles are replaced with ZIF-8 nanoparticles (i.e., ZIF-8 without 2-hydroxy-1,4-naphthoquinone loading) to obtain PLA. ZIF-8 Nanofiber composite dressing.

[0044] Comparative Example 3

[0045] This comparative example is largely the same as Example 3, except that PEE is not added to the spinning solution to obtain PLA. LZIF-8 Nanofiber composite dressing.

[0046] Example 4

[0047] (1) Scanning electron microscopy image analysis, infrared spectroscopy analysis and X-ray diffraction analysis

[0048] LZIF-8 powder and PLA were analyzed using scanning electron microscopy (FE-SEM). PEE PLA LZIF-8 PLA LZIF-8 / PEE The surface microstructure of the nanofibers was analyzed. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were used to characterize ZIF-8 and LZIF-8 powders.

[0049] like Figure 1 As shown in Figure B, the FTIR spectrum of LZIF-8 nanoparticles only showed all the characteristic peaks of ZIF-8, and did not show the very obvious characteristic peaks of 2-hydroxy-1,4-naphthoquinone. Figure 1 As shown in Figure C, the diffraction characteristic peaks of the two crystals match well. This indicates that the LZIF-8 synthesized via the "one-pot method" completely encapsulates 2-hydroxy-1,4-naphthoquinone within ZIF-8 nanoparticles, and that the encapsulation of 2-hydroxy-1,4-naphthoquinone into ZIF-8 nanoparticles does not alter the molecular structure and crystal configuration of ZIF-8. Figure 1 As shown in the DF diagram, PLA LZIF-8 / PEE The average diameter of the fibers is 387.13 ± 121.1 nm. Most fibers have diameters in the nanoscale range of 250-450 nm, which effectively mimics the ECM and helps promote cell growth.

[0050] (2) Analysis of porosity, water vapor transmission rate, biocompatibility and drug release

[0051] The fiber dressing was cut into 2×2cm squares, its thickness was measured and it was weighed. It was then immersed in an appropriate amount of n-butanol for 15 minutes, removed, and excess liquid was blotted off with filter paper before being weighed again. The porosity was calculated. The results are as follows: Figure 2 As shown in Figure A, PLA LZIF-8 / PEE The porosity of the nanofibers was 58.76% ± 2.36%, and all three types of fiber dressings exhibited excellent porosity.

[0052] Add ultrapure water to a small glass vial, weigh it, cut the fiber dressing to a suitable size, cover the vial opening and secure it; place it in an incubator at 37℃ and 40%-50% relative humidity for 24 hours, remove the fiber dressing, weigh it, and calculate the water vapor permeation efficiency. Figure 2 As shown in Figure B, all three fiber dressings have good water vapor permeability, PLA LZIF-8 / PEE The water vapor transmission rate was 1332.30±79.84%, slightly lower than the other two fiber dressings. This indicates that the amount of LZIF-8 added has little effect on the water vapor transmission rate of the composite fiber dressing.

[0053] Cell viability was measured after co-culturing mouse fibroblasts (L929) with fiber dressings of different qualities for 24 hours. Figure 2 As shown in Figure C, at the highest concentration of 1000 μg / mL, the three fiber dressings were non-toxic to L929 cells.

[0054] Weigh out 100mg of PLA LZIF-8 / PEE Fiber dressings were placed in 10 mL of phosphate buffer solution at pH 7.4 and pH 6.4, respectively. Periodically, 1 mL of dissolution medium was taken and 1 mL of the corresponding phosphate buffer solution was added. The dissolved samples were filtered, and the content of 2-hydroxy-1,4-naphthoquinone was determined by high-performance liquid chromatography (HPLC). Drug release curves were then plotted. Figure 2 As shown in Figure D, PLA under pH = 7.4 conditions... LZIF-8 / PEE The release of 2-hydroxy-1,4-naphthoquinone from the fiber dressing was very low. At pH 6.4, 2-hydroxy-1,4-naphthoquinone initially exhibited a burst release, which gradually slowed down after 56 hours. This is because LZIF-8 is further exposed only after the PLA fibers degrade, thus slowing the drug release rate.

[0055] (3) Antibacterial test

[0056] The antibacterial properties of ZIF-8 and LZIF-8 at different concentrations were evaluated after culturing with E. coli and S. aureus for 24 hours. Figure 3As shown in Figure AB, both have certain antibacterial effects, but at a lower concentration (500 μg / mL), LZIF-8's inhibitory efficiency against E. coli and S. aureus is about twice that of ZIF-8.

[0057] The prepared fiber dressing was mixed with E. coli and S. aureus for 24 hours, and the bacterial solution was diluted 10. 6 The antibacterial effect was calculated using double-coating plates. For example... Figure 3 As shown in Figure C, all three nanomembranes with added ZIF-8 exhibited good antibacterial effects, but the PLA nanomembrane with LZIF-8 showed the best results. LZIF-8 PLA LZIF-8 / PEE The antibacterial effect of fiber dressings is significantly better than that of PLA. ZIF-8 Fiber dressings. PLA LZIF-8 / PEE The antibacterial rates of the fiber dressing against E. coli and S. aureus were 96.61±3.12% and 94.91±3.24%, respectively. Comparison showed that PLA... LZIF-8 / PEE Fiber dressings have higher antibacterial potential.

[0058] (4) Verification of wound healing effect

[0059] A full-thickness wound model with a diameter of 1.5 cm was established in male SD rats. The wound was then infected with S. aureus. The experimental groups were treated with PLA. PEE PLA LZIF-8 and PLA LZIF-8 / PEE A fibrous dressing was applied to the wound. The model group (MOD) received no treatment and was fed routinely postoperatively. Wound healing was observed and assessed.

[0060] like Figure 4 As shown in Figure A, PLA LZIF-8 / PEE The group showed no obvious signs of infection, and the wounds exhibited significant contraction. Figure 4 As shown in Figure B, PLA during treatment LZIF-8 Group and PLA LZIF-8 / PEE The group with the highest wound healing rate, PLA LZIF-8 / PEE The group with the best healing effect, PLA PEE The healing rate was lower in both the group treated with the MOD treatment. After 14 days of treatment, PLA... LZIF-8 / PEE The group has achieved complete healing at 99.81±0.32%, meaning the superficial wound has completely healed without scab formation, indicating that PLA... LZIF-8 / PEE Fiber dressings can promote wound healing.

[0061] H&E staining and Masson staining were performed on the skin tissue of infected rats on days 7 and 14. Figure 4 As shown in the CD diagram, on day 7, PLALZIF-8 / PEE The collagen fibers at the site of the scar first change from low density to high density. On day 14, PLA... LZIF-8 / PEE The group with the highest collagen density had well-organized collagen fibers that were forming. In contrast, the collagen fibers in the scar areas of other groups were loosely and disorganized, with lower collagen density. This indicates the use of PLA. LZIF-8 / PEE Dressings can promote collagen deposition at the wound site.

[0062] (5) Analysis of inflammatory factor levels

[0063] The expression levels of IL-1β and IL-6 inflammatory factors in newly formed wound tissues of different groups on days 3 and 7 were analyzed by RT-qPCR. Figure 5 As shown in the AD diagram, compared to the MOD group, PLA LZIF-8 / PEE The group significantly reduced the levels of IL-1β and IL-6 inflammatory factors in newly formed skin tissue. This indicates that PLA LZIF-8 / PEE Dressings can effectively reduce inflammation, accelerate the inflammatory process, and thus promote wound healing and improve skin regeneration.

Claims

1. A method for preparing a wound-healing nanofiber composite dressing, characterized in that, Includes the following steps: (1) Preparation of LZIF-8 nanoparticles: Zinc nitrate hexahydrate and 2-hydroxy-1,4-naphthoquinone were dissolved in anhydrous methanol, and the pH was adjusted to 8 with sodium hydroxide to obtain a mixed solution; 2-methylimidazole was dissolved in anhydrous ethanol at a ratio of 3.3 g: 100 ml to obtain a 2-methylimidazole solution; the mixed solution was slowly added to the 2-methylimidazole solution, and the reaction was stirred. After the reaction was completed, the orange-yellow suspension was centrifuged, the supernatant was discarded, anhydrous methanol was added and the precipitate was dispersed by shaking. The centrifugation and resuspension steps were repeated, and the LZIF-8 particles were obtained after drying. (2) Extraction of active ingredients of sea buckthorn: After crushing sea buckthorn fruit into powder, add 95% ethanol at a ratio of 1 g: 5 mL and heat and reflux for extraction. After extraction, filter and collect the filtrate, and continue to heat and reflux extract the residue. After multiple extractions, concentrate all the filtrates by rotary evaporation under reduced pressure, freeze-dry to obtain crude ethanol extract of sea buckthorn. Dissolve the crude ethanol extract of sea buckthorn in hot water at 60~80℃ at a ratio of 1 g: 20 mL, add an equal volume of petroleum ether for extraction, extract multiple times, concentrate the collected petroleum ether extract by rotary evaporation under reduced pressure, and freeze-dry to obtain petroleum ether extract of sea buckthorn. (3) Preparation of electrospinning solution: Polylactic acid is dissolved in a mixed solution of dichloromethane and dimethylamide in a volume ratio of 4:1 to obtain a polymer solution. Then LZIF-8 and PEE are added and stirred until fully dispersed to obtain an electrospinning solution. (4) Preparation of nanofiber composite dressing: The electrospinning solution was electrospinned at a spinning voltage of 35 kV, a receiving distance of 15 cm, a roller speed of 120 rpm / min, a feed speed of 0.2 mL / h, a spinning humidity of 50±2%, and a spinning temperature of 25±1℃. After spinning, the residual solvent was removed by drying to obtain PLA. LZIF-8 / PEE Nanofiber composite dressing.

2. The preparation method according to claim 1, characterized in that, In step (1), the ratio of zinc nitrate hexahydrate, 2-hydroxy-1,4-naphthoquinone, and anhydrous methanol was 1.5 g: 0.2 g: 50 ml. After increasing the concentration of 2-hydroxy-1,4-naphthoquinone in the system, the effect of ZIF-8 encapsulating 2-hydroxy-1,4-naphthoquinone decreased.

3. The preparation method according to claim 1, characterized in that, In step (1), the stirring speed is 150 rpm and the mixing reaction time is 24 h.

4. The preparation method according to claim 1, characterized in that, In step (1), the centrifugation speed is 10,000 rpm, the centrifugation time is 10 min, and the centrifugation resuspension step is repeated three times.

5. The preparation method according to claim 1, characterized in that, In step (1), the drying temperature is 40℃ and the drying time is 3 h.

6. The preparation method according to claim 1, characterized in that, In step (3), the electrospinning solution has a mass volume fraction of 6% for polylactic acid, 5% for LZIF-8, and 5% for PEE.

7. The preparation method according to claim 1, characterized in that, In step (3), the stirring temperature is 50°C and the stirring time is overnight.

8. PLA prepared by the method according to any one of claims 1 to 7 LZIF-8 / PEE Nanofiber composite dressing.

9. The PLA according to claim 8 LZIF-8 / PEE Application of nanofiber composite dressings as wound healing dressings.

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