Multifunctional wound dressing with asymmetric wettability and preparation method thereof

Abstract

The invention aims to provide a multifunctional wound dressing with asymmetric wettability and a preparation method of the multifunctional wound dressing, namely a double-layer micro / nano fiber dressing with antibacterial, anti-inflammatory, anti-oxidation, electrical stimulation and exudate exporting functions, and wound healing can be effectively promoted. According to the multifunctional wound dressing provided by the invention, the air permeability is improved, a wound is prevented from being infiltrated in percolate, and the multifunctional wound dressing has the properties of unidirectional moisture conduction, electrical stimulation, inflammation resistance, bacteria resistance, oxidation resistance and in-vivo healing promotion and can be used as a medical material for treating traumatic wounds.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical products, and in particular relates to a multifunctional wound dressing with asymmetric wettability and a preparation method thereof. Background Art

[0002] With the aging population and the increasing prevalence of chronic diseases, difficult-to-heal wounds are becoming an unbearable burden for the medical system and patients. Excessive wound exudate, damaged endogenous electric field, bacterial infection, long-term inflammation and oxidative stress are key factors that hinder wound healing. Excessive exudate will soak the wound, prolong the inflammation period, breed bacteria, and hinder healing. At the same time, the damaged endogenous electric field in difficult-to-heal wounds weakens cell proliferation and migration. Therefore, there is an urgent need to develop a multifunctional wound dressing that integrates wound exudate extraction, stimulation of damaged endogenous electric field, antibacterial, anti-inflammatory, antioxidant and other functions to solve the comprehensive problem of wound healing in one stop and reduce the burden on patients and the medical system.

[0003] By constructing asymmetric wettability in the thickness direction of the material, the liquid can be transported directionally from hydrophobic to hydrophilic. Solution blowing spinning uses high-speed airflow as a driving force to stretch the spinning solution to generate a jet, and the solvent evaporates in the airflow to finally obtain polymer micro-nano fibers, which has good prospects in the large-scale preparation of micro-nano fibers. Screen printing is a mature printing and dyeing processing method. The preparation process is relatively simple and economical. It can be applied to substrates of different sizes and shapes, and can be prepared over a large area and with high throughput. It shows good potential in the preparation of microelectrodes. Summary of the invention

[0004] The purpose of the present invention is to provide a multifunctional wound dressing with asymmetric wettability and a preparation method thereof, that is, a double-layer micro / nano fiber dressing with antibacterial, anti-inflammatory, antioxidant, electrical stimulation and exudate extraction properties, which can effectively promote wound healing.

[0005] The wound dressing provided by the present invention comprises the following steps:

[0006] 1) dissolving polyvinyl pyrrolidone in anhydrous ethanol to prepare a spinning solution with a mass percentage concentration of 10%, and stirring to obtain a uniform and transparent spinning solution for use;

[0007] 2) blowing the prepared spinning solution into filaments to prepare a polyvinyl pyrrolidone film by solution blow spinning, wherein the injection speed is 5 mL / h, the receiving distance is 17 cm, the air flow rate is 35-45 slp, the temperature is 25-30° C., and the humidity is 10% RH;

[0008] 3) heat treating the prepared polyvinyl pyrrolidone film in an oven at 160° C.;

[0009] 4) preparing a carboxymethyl cellulose aqueous solution with a mass percentage concentration of 1.5% as a slurry base, adding silver nanoparticles and zinc nanoparticles to the prepared slurry base, and forming a uniform printing slurry solution after ultrasonic treatment of the solution;

[0010] 5) Place the printing paste upside down on the printing screen (200 mesh), start the printing press and apply it once;

[0011] 6) Thermoplastic polyurethane was dissolved in NN dimethylformamide to prepare a solution with a concentration of 20 wt%, and stirred at room temperature to form a uniform spinning solution.

[0012] 7) adding myricetin into the spinning solution to prepare a spinning solution containing myricetin;

[0013] 8) Using polyvinyl pyrrolidone printed with silver zinc particles as the substrate, spinning solution containing myricetin was spun by solution blowing technology, and vacuum dried to form a composite fiber membrane, wherein the receiving distance was 17 cm, the air flow velocity was 65-70 slp, the spinning solution injection speed was 0.8 mL / h, and the temperature was 25-30° C. and the humidity was 25% RH;

[0014] Furthermore, antimicrobial peptides are also added in step 7);

[0015] A specific amino acid sequence of the antimicrobial peptide is NFYDGAKQRE (SEQ ID NO: 1).

[0016] The multifunctional wound dressing provided by the present invention improves air permeability, prevents the wound from being soaked in exudate, has the properties of unidirectional moisture conduction, electrical stimulation, anti-inflammatory, antibacterial, anti-oxidation and in vivo healing promotion, and can be used as a medical material to treat traumatic wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : Scanning electron micrographs of multifunctional double-layer fiber membranes, (a) schematic diagram of the double-layer membrane; (b) the thermoplastic polyurethane / myricetin side of the double-layer membrane; (c) cross section; (d) the polyvinyl pyrrolidone side.

[0018] Figure 2 : One-way liquid export diagram of multifunctional double-layer fiber membrane.

[0019] Figure 3 : Antioxidative properties of multifunctional double-layer fiber membranes.

[0020] Figure 4 : Antibacterial activity of the screened peptides against Escherichia coli and Staphylococcus aureus.

[0021] Figure 5: Antibacterial properties of double-layer fiber membranes containing different components, (a) Escherichia coli; (b) Salmonella; (c) Staphylococcus aureus; (d) Streptococcus. DETAILED DESCRIPTION

[0022] The present invention is described in detail below in conjunction with specific embodiments and drawings.

[0023] Example 1: Preparation of multifunctional double-layer fiber membrane

[0024] 1. Weigh a certain weight of polyvinyl pyrrolidone and dissolve it in anhydrous ethanol to prepare a 10wt.% spinning solution. Stir for 24 hours to obtain a uniform and transparent solution for use.

[0025] 2. The prepared spinning solution is blown into filaments by solution blowing spinning. The injection speed is 5 mL / h, the receiving distance is 17 cm, the air flow speed is 35-45 slp, the temperature is 25-30° C., and the humidity is 10% RH.

[0026] 3. Heat treat the polyvinyl pyrrolidone film in an oven at 160°C for 6 hours and then take it out.

[0027] 4. Preparation of printing paste: Prepare 1.5wt.% carboxymethyl cellulose aqueous solution as the paste base. Silver electrode paste: Add 10wt.% silver nanoparticles to the prepared paste base; zinc electrode paste: Add 20wt.% zinc nanoparticles to the prepared paste base, ultrasonicate the solution for 2h and stir for 4-6h to form a uniform solution.

[0028] 5. Printing of microelectrodes: Place the printing slurry upside down on the customized pattern printing screen (200 mesh), behind the scraper, start the printer, and scrape once.

[0029] 6. Dissolve the thermoplastic polyurethane in NN dimethylformamide to prepare a solution with a concentration of 20 wt.%, and stir at room temperature for 24 hours to form a uniform spinning solution.

[0030] 7. Add 7% myricetin to the spinning solution in a mass ratio of 7% to the thermoplastic polyurethane, and stir at room temperature for 24 hours to prepare spinning solutions containing different concentrations of myricetin.

[0031] 8. The spinning solution was spun using solution blowing technology, and the polyvinyl pyrrolidone printed with silver zinc particles was used as the substrate for receiving. The receiving distance was 17 cm, the air flow rate was 65-70 slp, the spinning solution injection rate was 0.8 mL / h, and the temperature was 25-30 ° C and the humidity was 25% RH. Finally, the composite fiber membrane was dried in a vacuum drying oven at 30 ° C to obtain a double-layer fiber membrane with anti-inflammatory and antioxidant functions, carrying an exogenous electric field, and asymmetric wettability.

[0032] Example 2: Determination of properties of multifunctional double-layer fiber membrane

[0033] 1. Stability

[0034] The surface and cross-section of Example 1 were analyzed using a scanning electron microscope. Figure 1 The results show that a relatively stable double-layer composite structure is formed.

[0035] 2. Hydrophobicity

[0036] The prepared 1wt.% sodium fluorescein was contacted with 10μL of liquid from the hydrophilic side and the hydrophobic side of the embodiment, and the liquid transfer process was recorded by a Nikon digital camera. Figure 2 . When the fluorescent droplets touch the bottom of the hydrophobic surface of the double-layer fiber membrane, the droplets will be drawn up through the hydrophobic layer and spread to the other side. When the fluorescent droplets touch the hydrophilic layer of the double-layer fiber membrane, the droplets are quickly absorbed but cannot penetrate the dressing. It is proved that through the composite of the hydrophilic and hydrophobic layers, the multifunctional double-layer fiber membrane can realize the anti-gravity unidirectional transport of liquid. Compared with cotton gauze, the liquid quickly soaks both sides after contact.

[0037] 3. Antioxidant

[0038] The antioxidant activity of the prepared samples was evaluated by DPPH scavenging method. The results were analyzed by UV spectrophotometer. Figure 3 , Figure 3 The antioxidant efficiency diagram of three types of double-layer cellulose membranes: ordinary double-layer fiber membrane, double-layer fiber membrane loaded with myricetin, and double-layer cellulose membrane loaded with myricetin and silver-zinc electrode. The results show that the myricetin-loaded membrane has excellent antioxidant effect. Similarly, the multifunctional cellulose membrane loaded with myricetin and silver-zinc electrode has a moderate active oxygen scavenging rate, which helps to balance the level of active oxygen in wounds.

[0039] Example 3: Preparation of polypeptides with antibacterial function

[0040] Take clean golden pomfret fish tissue, freeze-dry it, grind it into powder, pass it through a 40-mesh sieve, take the golden pomfret powder and add a certain amount of water to dissolve it, then add papain at a volume ratio of 10:1, adjust the solution pH to 7, maintain the temperature at 55°C, and react for 6 hours. After the reaction is completed, boil the enzymatic solution for 10 minutes to kill the enzyme, then centrifuge it at 10000r / min for 15 minutes, take the supernatant, concentrate it, and dry it to obtain golden pomfret polypeptide dry powder.

[0041] The peptides were separated by Sephadex G25 gel column chromatography. The Sephadex-G-25 gel was activated and loaded into a 25 cm high column. Ultrapure water was used as the buffer for the purification process. The flow rate was set to 1 mL / min, and one tube was collected every 5 minutes, for a total of 80 tubes.

[0042] The golden pomfret peptide was separated and purified by reversed-phase high performance liquid chromatography, with a flow rate of 1 mL / min, mobile phase: liquid A: 0.1% TFA, liquid B: 99.9% acetonitrile-0.1% TFA, elution conditions: 0-100% B, 20 min. The peptide sequence structure was then detected by UHPLC. The obtained peptide sequence was input into the BIOPEP-UWM bioactive peptide database for activity prediction, and the two most active peptides, EQNTHYPEDSLK and NFYDGAKQRE, were screened out.

[0043] It was sent to Shanghai Sangon Biotech Co., Ltd. for synthesis, and the antibacterial properties of the two peptides were tested using Escherichia coli and Staphylococcus aureus. Figure 3 The antibacterial results of the two most active polypeptides show that polypeptide a has no antibacterial activity, while polypeptide b has good resistance to both Escherichia coli and Staphylococcus aureus. Therefore, polypeptide b was selected as the antimicrobial peptide to be added to the double-layer fiber membrane, and its amino acid sequence is NFYDGAKQRE (SEQ ID NO: 1).

[0044] Example 4: Antibacterial properties of double-layer fiber membranes containing different components

[0045] The test bacteria (Escherichia coli, Salmonella, Staphylococcus aureus, Streptococcus) were selected and made into a bacterial suspension in a small amount of physiological saline. The bacterial suspension was spread on the surface of the flat culture medium with a sterile cotton swab. Ordinary double-layer fiber membrane (TP), double-layer fiber membrane loaded with myricetin (TPM), double-layer fiber membrane loaded with myricetin and silver-zinc electrode (TPME), and double-layer fiber membrane loaded with myricetin, silver-zinc electrode and antimicrobial peptide (TPMES) were used. They were cut into the size of drug-sensitive paper by punching holes. The four double-layer fiber membranes were evenly spread on the surface of the culture medium, and the size of the inhibition zone was observed after culturing under appropriate conditions for 16 hours.

[0046] Figure 5 It can be seen that ordinary TP has no antibacterial activity against Escherichia coli, Salmonella, Staphylococcus aureus, and Streptococcus, while TPM has a certain antibacterial activity due to the loading of myricetin, but the inhibition zone is small. After TPME adds the loading of silver-zinc electrode, the antibacterial activity of myricetin is activated, and the antibacterial performance is significantly expanded compared with TPM. TPMES with the addition of antimicrobial peptide (SEQ ID NO: 1) has the best antibacterial performance, showing good antibacterial activity against Escherichia coli, Salmonella, Staphylococcus aureus, and Streptococcus, and the antibacterial performance is higher than TPME.

[0047] The double-layer fiber membrane provided by the present invention has antibacterial, anti-oxidative, anti-inflammatory and other properties, and uses silver-zinc nanoparticles as electrodes to generate an exogenous electric field to stimulate wound healing.

Claims

1. A multifunctional wound dressing with asymmetric wettability, characterized in that: The wound dressing, the preparation method thereof comprises the following steps: 1) dissolving polyvinyl pyrrolidone in anhydrous ethanol to prepare a spinning solution for later use; 2) blowing the prepared spinning solution into filaments to form a polyvinyl pyrrolidone film by solution blowing spinning, 3) heat treating the prepared polyvinyl pyrrolidone film in an oven at 160° C.; 4) preparing a carboxymethyl cellulose aqueous solution as a slurry base, adding silver nanoparticles and zinc nanoparticles to the prepared slurry base, and forming a uniform printing slurry solution after ultrasonic treatment of the solution; 5) Place the printing slurry upside down on the printing screen and start the printing machine for scraping; 6) dissolving thermoplastic polyurethane in NN dimethylformamide and stirring at room temperature to form a uniform spinning solution; 7) adding myricetin into the spinning solution to prepare a spinning solution containing myricetin; 8) Using polyvinyl pyrrolidone printed with silver-zinc particles as a substrate, a spinning solution containing myricetin was spun using a solution blowing technique, and then vacuum dried to prepare a composite fiber membrane.

2. The wound dressing according to claim 1, characterized in that The spinning solution in 1) has a mass percentage concentration of polyvinyl pyrrolidone of 10%.

3. The wound dressing according to claim 1, characterized in that In the above 2), the injection speed is 5 mL / h, the receiving distance is 17 cm, the air flow speed is 35-45 slp, and the temperature is 25-30° C. and the humidity is 10% RH.

4. The wound dressing according to claim 1, characterized in that The mass percentage concentration of the carboxymethyl cellulose aqueous solution in 4) is 1.5%.

5. The wound dressing according to claim 1, characterized in that The mesh number of the printing screen in the above 5) is 200 meshes.

6. The wound dressing according to claim 1, characterized in that The concentration of the thermoplastic polyurethane in the above 6) is 20%.

7. The wound dressing according to claim 1, characterized in that The receiving distance in the above 7) is 17 cm, the air flow velocity is 65-70 slp, the spinning solution injection rate is 0.8 mL / h, and the temperature is 25-30° C. and the humidity is 25% RH.

8. The wound dressing according to claim 1, characterized in that Antimicrobial peptides are also added in step 7).

9. The wound dressing according to claim 8, characterized in that The amino acid sequence of the antimicrobial peptide is SEQ ID NO:

1.

10. Use of the wound dressing according to claim 1 in preparing a product for treating traumatic wounds.

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