A chuanxiong microsphere-containing dressing and a preparation method thereof
By preparing PLGA-coated Ligusticum striatum microspheres and semi-encapsulating them with pHEMA hydrogel, the problems of easy oxidation and difficult-to-control release rate of Ligusticum striatum extract in dressings were solved, achieving safe and precise release of Ligusticum striatum extract and wound repair effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 茂名市人民医院
- Filing Date
- 2024-12-26
- Publication Date
- 2026-06-26
AI Technical Summary
Ligusticum chuanxiong extract or ligustrazine is easily oxidized or decomposed in dressings, and the release rate is difficult to control, affecting efficacy and safety.
Ligusticum chuanxiong extract or ligustrazine was coated with PLGA to form microspheres, which were then partially encapsulated with pHEMA hydrogel to prepare a dressing containing Ligusticum chuanxiong microspheres. The microspheres were prepared by controlling the ratio of drug to polymer and the spray drying conditions. The sustained-release properties of pHEMA hydrogel were combined to optimize the Ligusticum chuanxiong extraction method to increase the ligustrazine content.
This technology enables the safe and precise release of Ligusticum chuanxiong extract, improves drug stability and efficacy, promotes wound repair and antibacterial effects, and enhances the therapeutic effect on wounds.
Smart Images
Figure CN122272875A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wound dressing instruments, specifically to a dressing containing Ligusticum chuanxiong microspheres and its preparation method. Background Technology
[0002] Ligusticum chuanxiong extract or ligustrazine possesses the following properties: anti-inflammatory and antioxidant, effectively inhibiting inflammatory responses and reducing oxidative stress; and promoting blood circulation, effectively dilating blood vessels and improving microcirculation. These multiple mechanisms make Ligusticum chuanxiong extract or ligustrazine suitable for treating refractory wounds. The difficulty in treating refractory wounds largely stems from chronic inflammation and infection, insufficient blood supply, and tissue loss and decreased regenerative capacity.
[0003] The application of Ligusticum chuanxiong extract or Ligustrazine in dressings is limited by the following challenges: Ligusticum chuanxiong extract or Ligustrazine is easily oxidized or decomposed, affecting efficacy, and requires a good protective and release matrix; the release rate of Ligusticum chuanxiong extract or Ligustrazine in dressings is difficult to control precisely, and too rapid drug release can lead to excessively high local drug concentration, causing side effects or irritation, while too slow release may reduce efficacy. Summary of the Invention
[0004] This invention provides a dressing containing Ligusticum striatum microspheres and its preparation method, in order to solve the problem of safe and precise application of Ligusticum striatum extract or ligustrazine in refractory wounds.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: A dressing containing Ligusticum striatum microspheres and its preparation method are disclosed. The dressing is composed of Ligusticum striatum microspheres loaded with pHEMA hydrogel as the main body. The Ligusticum striatum microspheres are formed by coating Ligusticum striatum extract or ligustrazine with PLGA. The pHEMA hydrogel partially encapsulates the Ligusticum striatum microspheres.
[0006] Furthermore, the drug loading of the Ligusticum chuanxiong extract is 1.5 mg / mg, and the drug loading of the ligustrazine is 0.8 mg / mg.
[0007] Furthermore, the preparation method of the Ligusticum chuanxiong microspheres is as follows: S11: Dissolve the extract of Ligusticum striatum or Ligustrazine and PLGA in ethyl acetate and dichloromethane solution according to the ratio of drug to polymer, and stir continuously until a homogeneous solution is formed. The concentration of PLGA is controlled between 10-30 mg / mL. S12: The prepared Ligusticum chuanxiong-PLGA solution is injected into a spray dryer, atomized, and then collected. S13: Centrifuge the collected microspheres to remove residual solvent, and then dry them in a desiccator.
[0008] Further, in step S11, the ratio of tetramethylpyrazine to polymer is 1:8; the ratio of ligusticum extract to polymer is 1:5; in step S12, the inlet air temperature is 60℃, the spray rate is 10ml / min, the atomization pressure is 1.3-3.0bar, and the drying gas is nitrogen.
[0009] Furthermore, the method for preparing the dressing is as follows: S21: Preparation of pHEMA prepolymer solution: Add 20 ml of HEMA monomer, 0.5 g of N,N'-methylenebisacrylamide, 1 g of ammonium persulfate, and 4.5 g of sodium dodecyl sulfate to a beaker. Slowly add distilled water and stir until homogeneous to form 120 mL of pHEMA prepolymer solution. Stir with a magnetic stirrer at 400 rpm for 20 min to ensure the formation of a homogeneous prepolymer solution. S22: Add 30g of Ligusticum striatum microspheres to the pHEMA prepolymer solution and stir at 200rpm for 15min to ensure that the Ligusticum striatum microspheres are evenly dispersed in the prepolymer solution; S23: Transfer the prepolymer liquid containing Ligusticum chuanxiong microspheres into a silicone mold, and place the mold in a constant temperature water bath at 65℃ for 4-5 hours to react; S24: After the reaction is complete, remove the hydrogel dressing, allow it to cool naturally to room temperature, gently rinse the surface of the hydrogel dressing 2-3 times with distilled water, and place it in a vacuum drying oven to dry at 40℃ for 6 hours.
[0010] Furthermore, the preparation method of the Ligusticum chuanxiong extract is as follows: S100: Grind the Ligusticum chuanxiong medicinal material into a fine powder using a grinder, and weigh out 50g of Ligusticum chuanxiong powder; S110: Prepare a buffer solution with a pH between 4.5 and 5.5; S120: Add 0.5g of cellulase and 0.5g of pectinase to a buffer solution, stir well, then add chuanxiong powder, and react in a constant temperature water bath at 40-50℃ for 1-2 hours. S130: After the enzymatic hydrolysis is complete, add 250-500 mL of ethanol solution to the system, and then place it in a 300-500 W ultrasonic cleaner for 30-60 min. S140: After extraction, filter the solution using filter paper and a funnel to remove medicinal residues. Transfer the filtered extract to a rotary evaporator for concentration, with the temperature set at 40-60℃ and the vacuum degree at 0.08-0.1MPa.
[0011] Furthermore, the content of tetramethylpyrazine in the chuanxiong extract is 0.8-1%.
[0012] Furthermore, human skin fibroblasts were cultured using the dressing, and the cell proliferation rate was 45% ± 2% after 72 hours.
[0013] Furthermore, the dressing was used in an antibacterial test against Staphylococcus aureus, and the antibacterial rate was 64% ± 3%.
[0014] Furthermore, the dressing was used in an antibacterial test against Escherichia coli, and the antibacterial rate was 76% ± 4%.
[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention uses microsphere technology to encapsulate ligusticum extract or tetramethylpyrazine, solving the problem of tetramethylpyrazine's easy oxidation and decomposition, and also controlling its release; pHEMA encapsulates PLGA microspheres in a semi-encapsulated form, which facilitates the release of the microspheres. This invention optimizes the extraction method of Ligusticum chuanxiong extract, thereby increasing the content of tetramethylpyrazine in the extract by approximately 158%. The dressing of the present invention has been verified in in vitro cell proliferation experiments and antibacterial experiments to have a proliferative effect on wound-related cells and a good antibacterial effect on common wound bacteria. The dressing of the present invention has been verified in animal experiments to have a significant effect on wound healing. Attached Figure Description
[0016] Figure 1 This is a photograph of the Ligusticum chuanxiong microspheres from Embodiment 1 of the present invention; Figure 2 This is a drug release curve of the Ligusticum chuanxiong microspheres in Example 1 of the present invention; Figure 3 This is a scanning electron microscope image of the dressing containing Ligusticum chuanxiong microspheres from Embodiment 1 of the present invention; Figure 4 This is a diagram showing the experimental results of the bacterial proliferation experiment in Example 3 of the present invention; Figure 5 This is a diagram showing the experimental results of the antibacterial test in Example 3 of the present invention; Figure 6 This is a photograph of the animal experiment in Example 4 of the present invention. Detailed Implementation
[0017] The present invention will now be further described with reference to the accompanying drawings and embodiments. Example
[0018] The dressing containing Ligusticum striatum microspheres is composed of Ligusticum striatum microspheres loaded with pHEMA hydrogel as the main body; wherein, the Ligusticum striatum microspheres are formed by coating Ligusticum striatum extract or ligustrazine with lactic acid-glycolic acid copolymer PLGA; the pHEMA hydrogel is in a semi-encapsulated form of Ligusticum striatum microspheres.
[0019] The drug loading of Ligusticum chuanxiong extract in Ligusticum chuanxiong microspheres is 1.5 mg / mg; the drug loading of tetramethylpyrazine is 0.8 mg / mg.
[0020] Specifically, the preparation method of the dressing is as follows: S1: Preparation of Ligusticum striatum microspheres S11: Dissolve the extract of Ligusticum striatum or Ligustrazine and PLGA in ethyl acetate and dichloromethane solution according to the ratio of drug to polymer, and stir continuously until a homogeneous solution is formed. The concentration of PLGA is controlled between 10-30 mg / mL. S12: The prepared Ligusticum chuanxiong-PLGA solution is injected into a spray dryer, atomized, and then collected. S13: Centrifuge the collected microspheres to remove residual solvent, and then dry them in a desiccator.
[0021] In step S11, the ratio of tetramethylpyrazine to polymer is 1:8; the ratio of ligusticum extract to polymer is 1:5; in step S12, the inlet air temperature is 60℃, the spray rate is 10ml / min, the atomization pressure is 1.3-3.0bar, and the drying gas is nitrogen.
[0022] The microspheres prepared in this embodiment are as follows: Figure 1 As shown, the obtained microspheres were subjected to drug release testing: the microspheres were placed in PBS buffer solution at pH 7.4 and placed in a constant temperature shaker at 37℃. Samples were taken periodically to determine the concentration of Ligusticum chuanxiong, and a drug release curve was plotted. The experimental results are shown below. Figure 2 As shown in the release curve, the overall release trend of Ligusticum chuanxiong microspheres in PBS solution at pH 7.4 is relatively stable.
[0023] S2: Preparation of dressings containing Ligusticum chuanxiong microspheres S21: Preparation of pHEMA prepolymer solution: Add 20 ml of HEMA monomer, 0.5 g of N,N'-methylenebisacrylamide, 1 g of ammonium persulfate, and 4.5 g of sodium dodecyl sulfate to a beaker. Slowly add distilled water and stir until homogeneous to form 120 mL of pHEMA prepolymer solution. Stir with a magnetic stirrer at 400 rpm for 20 min to ensure the formation of a homogeneous prepolymer solution. S22: Add 30g of Ligusticum striatum microspheres to the pHEMA prepolymer solution and stir at 200rpm for 15min to ensure that the Ligusticum striatum microspheres are evenly dispersed in the prepolymer solution; S23: Transfer the prepolymer liquid containing Ligusticum chuanxiong microspheres into a silicone mold, and place the mold in a constant temperature water bath at 65℃ for 4-5 hours to react; S24: After the reaction is complete, remove the hydrogel dressing, allow it to cool naturally to room temperature, gently rinse the surface of the hydrogel dressing 2-3 times with distilled water, and place it in a vacuum drying oven to dry at 40℃ for 6 hours.
[0024] The SEM image of the dressing obtained in this embodiment is as follows: Figure 3 As shown, the Ligusticum chuanxiong microspheres are partially encapsulated by pHEMA gel, which is beneficial for sustained drug release. Example 1
[0025] In this embodiment, Ligusticum chuanxiong extract was used, and this embodiment provides a method for obtaining Ligusticum chuanxiong extract from Ligusticum chuanxiong.
[0026] S100: Grind the Ligusticum chuanxiong medicinal material into a fine powder using a grinder, and weigh out 50g of Ligusticum chuanxiong powder; S110: Prepare a buffer solution with a pH between 4.5 and 5.5; S120: Add 0.5g of cellulase and 0.5g of pectinase to a buffer solution, stir well, then add chuanxiong powder, and react in a constant temperature water bath at 40-50℃ for 1-2 hours. S130: After the enzymatic hydrolysis is complete, add 250-500 mL of ethanol solution to the system, and then place it in a 300-500 W ultrasonic cleaner for 30-60 min. S140: After extraction, filter the solution using filter paper and a funnel to remove medicinal residues. Transfer the filtered extract to a rotary evaporator for concentration, with the temperature set at 40-60℃ and the vacuum degree at 0.08-0.1MPa.
[0027] The content of tetramethylpyrazine was tested using high performance liquid chromatography (HPLC). The test method will not be described in detail here. The test results showed that the content of tetramethylpyrazine in the extract of Ligusticum chuanxiong prepared by the method in this embodiment was 0.8-1%, which is about 158% higher than that of traditional extraction methods. Example 2
[0028] Based on Examples 1 and 2, in order to verify the dressing’s effects on promoting tissue repair and antibacterial and anti-inflammatory properties, in vitro cell proliferation and antibacterial experiments were conducted to evaluate the safety and efficacy of the dressing.
[0029] Cell proliferation experiment Human skin fibroblasts were selected for the experiment in DMEM medium containing 10% fetal bovine serum. The dressings were cut and used after disinfection and rinsing. The observation times were 24h, 48h, and 72h. Other steps are not described in detail.
[0030] The experimental results are recorded as follows: Time point average absorbance value of control group Average absorbance value of the experimental group 24h 0.25±0.05 0.32±0.04 48h 0.38±0.02 0.53±0.07 72h 0.55±0.03 0.78±0.06 The calculated cell proliferation rates were 28%, 39%, and 42%, respectively. Figure 4 As shown, the dressing formed by encapsulating Ligusticum chuanxiong microspheres with pHEMA hydrogel promotes the proliferation of human skin fibroblasts, and the cell proliferation rate gradually increases over time.
[0031] Antibacterial test Staphylococcus aureus and Escherichia coli were selected as experimental groups 1 and 2, respectively. The dressing samples were cut into 5×5cm sizes for use. No dressing samples were placed in the control group. Other steps will not be described in detail.
[0032] The experimental results are shown below: strain Average colony count in control group Average colony count in the experimental group Staphylococcus aureus 50±3 18±5 E. coli 45±6 11±3 Calculations showed that the antibacterial rates against Staphylococcus aureus and Escherichia coli were 64±3% and 76±4%, respectively. Figure 5 As shown, the dressing formed by encapsulating Ligusticum chuanxiong microspheres with pHEMA hydrogel has a good antibacterial effect, especially against Staphylococcus aureus and Escherichia coli, which are common pathogens in wound infections. Example 3
[0033] Further evaluation of the dressing is achieved through animal experiments, which is also the final stage before clinical trials. In this embodiment, a full-thickness skin resection wound model of diabetic rabbits was constructed using New Zealand rabbits as a model.
[0034] Diabetic rabbit modeling: Animals were anesthetized using 3% sodium pentobarbital via intramuscular injection (IM) at a dose of 30 mg / kg. A 5% (w / v) saline solution of alloxan was prepared, filtered through a 0.22 μm filter, and then injected intravenously via the ear vein at a rate of 0.8 mL / min at a dose of 100 mg / kg. This was used to induce anesthesia in 16 New Zealand rabbits.
[0035] Immediately after the injection, provide the rabbit with sugar water to drink, and add the syrup to its feed for 24 hours to prevent hypoglycemia.
[0036] Within one week post-surgery, the rabbits' blood glucose levels were monitored daily in the morning. A blood glucose level consistently above 11 mmol / L for one week indicated successful model establishment. Blood glucose was then monitored weekly. If the rabbits experienced weight loss or hyperglycemia (above 19 mmol / L), insulin was administered at the following dosage: When the blood glucose level (BGL) is 19-22 mmol / L, administer 1 U / kg of insulin; When BGL is 22-28 mmol / L, administer 2 U / kg of insulin; When BGL is 27-33 mmol / L, administer 3 U / kg of insulin; When BGL is greater than 33 mmol / L, administer 4 U / kg of insulin.
[0037] If the blood glucose level is greater than 27 mmol / L in the afternoon, administer half of the morning insulin dose at 5:00 PM.
[0038] Wound modeling in diabetic rabbits: Animals were fasted and deprived of water for 12 hours prior to surgery. Anesthesia was administered intravenously (IV) with 3% sodium pentobarbital at a dose of 30 mg / kg. The hair in the surgical area was clipped, followed by depilation with an 8% sodium sulfide solution. Routine disinfection and draping were performed 3-5 minutes later. A 3cm x 3cm incision was made on the back of each diabetic rabbit through a full-thickness skin incision. The control group received routine bandaging with medical gauze, while the experimental group received bandaging with a specific dressing.
[0039] Observation Record: Record the wound healing status of the animal on day 1 and day 7. This can be visually demonstrated by taking photos of the animal's wound healing, such as... Figure 6 As shown.
[0040] The above embodiments only illustrate several specific implementations of the present invention, and are not intended to limit the scope of the invention patent. It should be understood that those skilled in the art can make different improvements based on these drawings and embodiments without creative effort, and these improvements should all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope of the claims.
Claims
1. A dressing containing Ligusticum chuanxiong microspheres and its preparation method, characterized in that, The dressing is composed of pHEMA hydrogel as the main body and loaded with Ligusticum striatum microspheres. The Ligusticum striatum microspheres are formed by PLGA coating of Ligusticum striatum extract or ligustrazine. The pHEMA hydrogel is semi-encapsulated in the Ligusticum striatum microspheres.
2. The dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The drug loading of the Ligusticum chuanxiong extract is 1.5 mg / mg, and the drug loading of the ligustrazine is 0.8 mg / mg.
3. The dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The preparation method of the Ligusticum chuanxiong microspheres is as follows: S11: Dissolve the extract of Ligusticum striatum or Ligustrazine and PLGA in ethyl acetate and dichloromethane solution according to the ratio of drug to polymer, and stir continuously until a homogeneous solution is formed. The concentration of PLGA is controlled between 10-30 mg / mL. S12: The prepared Ligusticum chuanxiong-PLGA solution is injected into a spray dryer, atomized, and then collected. S13: Centrifuge the collected microspheres to remove residual solvent, and then dry them in a desiccator.
4. The dressing containing Ligusticum chuanxiong microspheres according to claim 3 and its preparation method, characterized in that, In step S11, the ratio of tetramethylpyrazine to polymer is 1:8; the ratio of ligusticum extract to polymer is 1:5; in step S12, the inlet air temperature is 60℃, the spray rate is 10ml / min, the atomization pressure is 1.3-3.0bar, and the drying gas is nitrogen.
5. The dressing of Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The preparation method of the dressing is as follows: S21: Preparation of pHEMA prepolymer solution: Add 20 ml of HEMA monomer, 0.5 g of N,N'-methylenebisacrylamide, 1 g of ammonium persulfate, and 4.5 g of sodium dodecyl sulfate to a beaker. Slowly add distilled water and stir until homogeneous to form 120 mL of pHEMA prepolymer solution. Stir with a magnetic stirrer at 400 rpm for 20 min to ensure the formation of a homogeneous prepolymer solution. S22: Add 30g of Ligusticum striatum microspheres to the pHEMA prepolymer solution and stir at 200rpm for 15min to ensure that the Ligusticum striatum microspheres are evenly dispersed in the prepolymer solution; S23: Transfer the prepolymer liquid containing Ligusticum chuanxiong microspheres into a silicone mold, and place the mold in a constant temperature water bath at 65℃ for 4-5 hours to react; S24: After the reaction is complete, remove the hydrogel dressing, allow it to cool naturally to room temperature, gently rinse the surface of the hydrogel dressing 2-3 times with distilled water, and place it in a vacuum drying oven to dry at 40℃ for 6 hours.
6. The dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The preparation method of the Ligusticum chuanxiong extract is as follows: S100: Grind the Ligusticum chuanxiong medicinal material into a fine powder using a grinder, and weigh out 50g of Ligusticum chuanxiong powder; S110: Prepare a buffer solution with a pH between 4.5 and 5.5; S120: Add 0.5g of cellulase and 0.5g of pectinase to a buffer solution, stir well, then add chuanxiong powder, and react in a constant temperature water bath at 40-50℃ for 1-2 hours. S130: After the enzymatic hydrolysis is complete, add 250-500 mL of ethanol solution to the system, and then place it in a 300-500 W ultrasonic cleaner for 30-60 min. S140: After extraction, filter the solution using filter paper and a funnel to remove medicinal residues. Transfer the filtered extract to a rotary evaporator for concentration, with the temperature set at 40-60℃ and the vacuum degree at 0.08-0.1MPa.
7. A dressing containing Ligusticum chuanxiong microspheres according to claim 6 and its preparation method, characterized in that, The content of tetramethylpyrazine in the chuanxiong extract is 0.8-1%.
8. The dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, Human skin fibroblasts were cultured using the dressing described above, and the cell proliferation rate was 45% ± 2% after 72 hours.
9. A dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The antibacterial test of the dressing against Staphylococcus aureus showed an antibacterial rate of 64% ± 3%.
10. A dressing containing Ligusticum chuanxiong microspheres according to claim 1 and its preparation method, characterized in that, The antibacterial test of the dressing on Escherichia coli showed an antibacterial rate of 76% ± 4%.