Electrostatic spinning drug-loaded polyester dressing and preparation method thereof

Abstract

According to the electrostatic spinning drug-loaded polyester dressing provided by the invention, a nanofiber membrane provided by the invention takes polyester and an iteration product thereof as a base material and has the characteristics of no toxicity and economy, layering of an inner layer and an outer layer is avoided in a spinning process, phillyrin and antibacterial polypeptide are introduced, hydrophilicity and antibacterial performance are increased, and a wound surface is ensured to be dry while the wound surface is protected from being damaged. Traditional Chinese medicine factors are released to act on wounds, exudate is effectively managed, the inflammation cycle is shortened, and wound healing is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedical products, and particularly relates to an electrostatically spun drug-loaded polyester dressing and a preparation method thereof. Background Art

[0002] When the skin is injured, the wound exposed to a complex environment is easily contaminated by dust and bacteria in the air, which brings trouble to wound healing. Inflammation is the most critical part of the wound healing process. The cell fluid produced during the inflammation process seeps out from the damaged and over-expanded blood vessel walls. The wound exudate can promote the migration and proliferation of fibroblasts to a certain extent, but excessive exudate will aggravate inflammation and ultimately delay wound healing. People generally add inorganic antimicrobial agents to give dressings the ability to promote healing, but there are also disadvantages such as uncontrollable cytotoxicity. Therefore, the use of biological dressings with natural antimicrobial agents to promote wound healing has become a major trend.

[0003] Forsythiaside is a natural substance extracted from plants of the Oleaceae family, which has excellent biocompatibility, anti-inflammatory, antibacterial and antioxidant effects. At the same time, forsythiaside is hydrophilic and can also be dissolved in organic solvents, which can significantly reduce the difficulty of spinning during the spinning process. Based on this, the introduction of forsythiaside into the nanofiber membrane can help the spinning solution to stretch into a membrane on the one hand, and on the other hand, it can help shorten the inflammation period and accelerate wound healing.

[0004] Electrospinning is a process in which a voltage is applied to an injection device, and the spinning solution is stretched under the action of Coulomb force to form a nanofiber membrane on a collecting device. Electrospinning nanofiber membranes are often used as wound dressings due to their high specific surface area and porosity, super fiber structure, and controllable mechanical properties. Summary of the invention

[0005] The purpose of the present invention is to provide an electrospun drug-loaded polyester dressing and a preparation method thereof, namely a polyester drug-loaded nanofiber membrane dressing with strong antibacterial, high anti-inflammatory and antioxidant properties, which can be used for wound repair.

[0006] The preparation method of the drug-loaded polyester dressing provided by the present invention comprises the following steps:

[0007] 1) Preparation of inner layer spinning solution

[0008] A polyester hexafluoroisopropanol solution with a mass percentage concentration of 10% was prepared and stirred on a magnetic stirrer until the polyester was completely dissolved and evenly distributed.

[0009] Adding forsythiaside to the prepared polyester hexafluoroisopropanol solution at a mass percentage concentration (g / ml) of 2.5-10%;

[0010] 2) Preparation of outer spinning solution

[0011] A 12% by mass concentration of iterative polyester hexafluoroisopropanol solution was prepared, and the iterative polyester was stirred on a magnetic stirrer until the iterative polyester was completely dissolved and evenly distributed;

[0012] 3) The inner and outer spinning solutions are spun in sequence using electrospinning technology to obtain the above-mentioned nanofiber membrane with high antibacterial, high anti-inflammatory and high antioxidant properties.

[0013] Furthermore, antimicrobial peptides are also added to the inner spinning solution of step 1);

[0014] A specific amino acid sequence of the antimicrobial peptide is DKHLDETY (SEQ ID NO: 1).

[0015] The nanofiber membrane provided by the present invention uses polyester and its iterative products as the base material, has the characteristics of being non-toxic and economical, and there will be no stratification of the inner and outer layers during the spinning process. The introduction of forsythia glycosides and antibacterial peptides increases the hydrophilicity and antibacterial properties, while ensuring the drying of the wound surface, releasing traditional Chinese medicine factors to act on the wound, effectively managing exudate, reducing the inflammatory cycle, and promoting wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : Scanning electron microscope images of polyester nanofiber membranes, (a) are polyester nanofibers, (b) are polyester nanofibers loaded with forsythiaside, (c) are outer layer C-type iterative polyester nanofibers, and (d) are cross-sectional views of the composite nanofiber membrane of Example 1.

[0017] Figure 2 : The antioxidant performance graphs of three nanofiber membranes of pure polyester, forsythia glycoside-loaded polyester, and a composite of drug-loaded polyester and iterative polyester at different times. The upper figure is the antioxidant performance graph of the three nanofiber membranes observed on the surface, and the lower figure is the antioxidant performance data graph of the three nanofiber membranes.

[0018] Figure 3 : Antibacterial effect diagram of the three isolated peptides.

[0019] Figure 4 : The antibacterial effect diagram of forsythiaside loaded nanofibers.

[0020] Figure 5 : Cell compatibility diagram of polyester nanofiber membrane loaded with forsythiaside. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with specific embodiments and drawings.

[0022] Example 1: Preparation of drug-loaded nanofiber membrane

[0023] (1) Preparation of spinning solution: Take 1g of polyester chips, dissolve them in 9g of hexafluoroisopropanol solution, stir them on a magnetic stirrer for 12 hours, add 0.1g of forsythiaside after they are completely dissolved, and continue to stir them on a magnetic stirrer for 5-6 hours. Take another 1g of C-type iterative polyester chips, dissolve them in 9g of hexafluoroisopropanol solution, and stir them on a magnetic stirrer for 6-8 hours.

[0024] (2) The spinning solution is prepared into a nanofiber membrane by electrospinning.

[0025] (3) The spinning steps are as follows

[0026] a) Adjust the spinning conditions to a temperature of 20-30°C and a humidity of 10-30%.

[0027] b) After the external conditions reach the spinning conditions, take a 30cm section of tin foil and stick it on the receiving roller.

[0028] c) Pour the solution into a 10 ml syringe and connect the other end to a 21G needle. Then use the control panel to adjust the syringe pump until droplets of liquid overflow from the needle tip.

[0029] d) The pushing speed of the syringe pump was set to 0.8 ml / h, the distance between the needle and the receiver was 18 cm, and the drum speed was 110 rad / min.

[0030] e) Clamp the positive voltage clamp on the needle tip and adjust the voltage to 16kV.

[0031] f) Electrospinning was performed for 8-10 hours, and then the voltage was adjusted to 0, the spinning was stopped, and the sample on the tin foil was removed.

[0032] e) After the spinning of the polyester solution is completed, the spinning of C-type iterative polyester is carried out on the basis of the polyester fiber membrane, and the voltage is adjusted to 12Kv.

[0033] (4) Dry the prepared nanofiber membrane in a vacuum drying oven for 12 h to remove the residual organic solvent.

[0034] Example 2: Determination of the properties of drug-loaded nanofiber membranes

[0035] 1. Structure under electron microscope

[0036] The cross-sections of the common fiber membrane, the drug-loaded fiber membrane, and the drug-loaded iterative polyester nanofiber membrane in Example 1 were analyzed using a scanning electron microscope. Figure 1 (a) is a pure polyester nanofiber membrane, (b) is a nanofiber membrane loaded with forsythiaside, (c) is a C-type iterative polyester nanofiber membrane, and (d) is a cross-sectional view of a composite nanofiber membrane. The results show that loading forsythiaside can improve the morphology of the nanofiber membrane, and the nanofiber membrane loaded with forsythiaside was successfully prepared.

[0037] 2. Antioxidant

[0038] The antioxidant activity of the prepared samples was evaluated by scavenging stable 2,2-diphenyl-2-pyridinylhydrazine (DPPH) free radicals. The results were analyzed by UV spectrophotometer. Figure 2 , Figure 2 The antioxidant efficiency diagram and optical picture of ordinary fiber membrane and drug-loaded fiber membrane show that the loaded forsythiaside has excellent antioxidant effect.

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

[0040] Take clean scallop skirt tissue, freeze-dry, grind and pass through a 50-mesh sieve. Add ddH2O and an appropriate amount of neutral protease to the obtained scallop skirt powder, adjust the solution pH to 7.0, and hydrolyze at 45°C for 4 hours. After the enzymatic hydrolysis is completed, boil for 15 minutes to inactivate the enzyme, then centrifuge at 8000r / min for 15 minutes, take the supernatant for concentration and drying, and obtain scallop polypeptide dry powder. Take an appropriate amount of crude product, add acetonitrile and ultrasonicate until clear, filter and remove impurities, and collect samples in sections using a preparative liquid chromatograph. Use an analytical chromatograph for gradient analysis, retain samples that have reached the required purity, and perform freeze-drying. Finally, the peptides were identified by high performance liquid chromatography and mass spectrometry, wherein the liquid chromatography analysis conditions were: C18 column (4.6x250mm, 5μm), mobile phase A was acetonitrile solution containing 0.1% trifluoroacetic acid, mobile phase B was pure water containing 0.1% TFA, detection wavelength was 220nm, flow rate was 1.0ml / min, injection volume was 20μl, and gradient elution was performed. The obtained peptide sequences were input into the BIOPEP-UWM bioactive peptide database for activity prediction, and the most active peptides were screened out, and their sequences were: GPFTHLIDE (peptide a), DKHLDETY (peptide b) and QDFGHPS (peptide c) three polypeptides, which were sent to Sangon Biotech (Shanghai) Co., Ltd. for synthesis, and the antibacterial properties of the three polypeptides were tested using Escherichia coli and Staphylococcus aureus. Figure 3 The results showed that polypeptide a had no antibacterial effect on Escherichia coli and Staphylococcus aureus, while polypeptide b and polypeptide c both produced antibacterial zones, and the antibacterial effect of polypeptide b was higher than that of polypeptide c. Therefore, polypeptide b was selected as the target polypeptide and added to the preparation process of drug-loaded nanofiber membrane. Its sequence was DKHLDETY (SEQID NO: 1).

[0041] Example 4: Antibacterial effect and biocompatibility of drug-loaded nanofiber membrane

[0042] 1. Antibacterial properties

[0043] The nanofiber membrane of Example 1 and the nanofiber membrane with added antimicrobial peptide were tested for Escherichia coli and Staphylococcus aureus using the dynamic contact method, and the antimicrobial effect was analyzed by counting the number of colonies. Figure 4 The results showed that the nanofiber membrane loaded with forsythiaside had a good antibacterial effect, with an antibacterial effect of about 90%. After adding antibacterial peptides, the antibacterial effect of the nanofiber membrane was improved, with an antibacterial effect of 99%.

[0044] The biocompatibility of the nanofiber membrane of Example 1 was analyzed by CCK-8 method. Figure 5 , Figure 5 The biocompatibility effect diagram of the nanofiber membrane in Example 1 and the nanofiber membrane with added antimicrobial peptides shows that the prepared nanofiber membranes have good biocompatibility.

Claims

1. A drug-loaded polyester dressing, characterized in that: The preparation method of the drug-loaded polyester dressing comprises the following steps: 1) Preparation of inner layer spinning solution A polyester hexafluoroisopropanol solution is prepared, and the polyester is stirred on a magnetic stirrer until the polyester is completely dissolved and evenly distributed, and forsythiaside is added to the prepared polyester hexafluoroisopropanol solution; 2) Preparation of outer spinning solution Prepare an iterative polyester hexafluoroisopropanol solution, and stir on a magnetic stirrer until the iterative polyester is completely dissolved and evenly distributed; 3) The inner and outer spinning solutions are spun in sequence by electrospinning to obtain a nanofiber membrane.

2. The drug-loaded polyester dressing according to claim 1, characterized in that: The concentration of the polyester hexafluoroisopropanol solution in 1) is 10%.

3. The drug-loaded polyester dressing according to claim 1, characterized in that: The concentration of forsythiaside added in the above 1) is 2.5-10%.

4. The drug-loaded polyester dressing according to claim 1, characterized in that: The concentration of the iterative polyester hexafluoroisopropanol solution in 2) is 12%.

5. The drug-loaded polyester dressing according to claim 1, characterized in that: Antimicrobial peptides are also added to the inner spinning solution in step 1).

6. The drug-loaded polyester dressing according to claim 5, characterized in that: The amino acid sequence of the antimicrobial peptide is SEQ ID NO: 1.

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