Wound dressing and preparation method thereof
By setting a reflux channel in the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer of the wound dressing, the problems of excessive drying of the wound bed and excessive discharge of cytokines are solved, and the maintenance and healing of wound humidity are achieved.
Patent Information
- Application Number
- CN202411870787.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-05-02
AI Technical Summary
Existing wound dressings may cause excessive drying of the wound bed during liquid transfer, and excessive discharge of components such as cytokines and other components can affect wound healing.
A wound dressing is designed, including a first hydrophobic layer, a first hydrophilic layer and a second hydrophilic layer, and a reflux channel is provided at these levels so that the absorbed ooze can return to the wound, maintain the wound humidity while preventing excessive discharge of the ooze.
Through the design of the reflux channel, the wound humidity is maintained, the exudate is prevented from excessive discharge, the wound healing is promoted, and the effective drug development is achieved by loading drugs in the hydrophilic layer.
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Figure CN119908903A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of wound dressings, and particularly relates to a wound dressing and a preparation method thereof. Background Art
[0002] Wound dressings are materials used to cover wounds, cuts or other injuries. There are many types of wound dressings, and different wound dressings can be selected according to different requirements.
[0003] Dressings with different wettability on both sides can be used for unidirectional pumping of wound exudate. Such materials can effectively manage wound exudate, ensure that excess liquid is transferred unidirectionally to the absorption layer, maintain local moderate moisture in the wound, and promote healing.
[0004] However, the dressing has the following disadvantages:
[0005] 1. If the liquid transfer process is not properly controlled, it may cause excessive drying of the wound bed, which does not meet the requirements of an ideal healing environment.
[0006] 2. Wound exudate is rich in cytokines, proteases (such as matrix metalloproteinases (MMPs), neutrophils and macrophages, which have a positive effect on promoting the formation of fibroblasts and skin re-epithelialization. If they are discharged excessively, the speed and effect of wound healing will be affected.
[0007] Therefore, these factors need to be considered comprehensively when designing and applying such dressings to achieve the best therapeutic effect. Summary of the invention
[0008] The object of the present invention is to provide a wound dressing and a preparation method thereof, wherein a reflux channel is provided in the first hydrophobic layer and the first hydrophilic layer and the second hydrophilic layer, so that the absorbed exudate can flow back to the wound, maintain the moisture of the wound, and prevent excessive discharge of the exudate.
[0009] In order to achieve the above object, the present invention adopts the following technical solution:
[0010] A wound dressing comprises a first hydrophobic layer, wherein the first hydrophobic layer is provided with a dressing area, wherein the dressing area comprises a first hydrophilic layer and a second hydrophilic layer in sequence from the inside to the outside, wherein the first hydrophilic layer and the second hydrophilic layer are wrapped with the second hydrophobic layer, wherein the hydrophilicity of the second hydrophilic layer is greater than that of the first hydrophilic layer, and the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer are provided with a connected reflux channel.
[0011] The exudate is affected by the capillary force generated by the reflux channel of the first hydrophilic layer. The capillary force is greater than the weight of the exudate itself and the hydrophobic force of the first hydrophobic layer, so that the exudate moves unidirectionally from the first hydrophobic layer to the first hydrophilic layer. When the exudate of the first hydrophilic layer contacts the second hydrophilic layer with better hydrophilicity, the capillary force generated by the reflux channel of the second hydrophilic layer and the capillary force generated by the reflux channel of the first hydrophilic layer work together to move and diffuse the exudate from the first hydrophilic layer to the second hydrophilic layer. When the exudate accumulated in the first hydrophilic layer and the second hydrophilic layer reaches a certain amount, the gravity of the exudate itself is greater than the hydrophobic force between the first hydrophilic layer and the first hydrophobic layer, and the exudate can flow back to the wound surface.
[0012] Furthermore, the material of the first hydrophobic layer is a PCL fiber membrane, the material of the second hydrophobic layer is a PCL electrospun membrane, the material of the first hydrophilic layer is a polyether PU electrospun membrane, and the material of the second hydrophilic layer is a silk protein electrospun membrane.
[0013] PCL is a common raw material for wound dressings and has good hydrophobicity. The hydrophilicity of polyether PU electrospun membrane can be adjusted according to the structure of the soft segment of PU, making its hydrophilicity higher than that of PCL electrospun membrane and lower than that of silk protein electrospun membrane. Silk protein electrospun membrane has excellent hydrophilicity.
[0014] Furthermore, the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer are loaded with drugs.
[0015] During reflux, the drugs loaded on the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer can flow to the wound surface through the refluxed exudate. The drugs can be antibacterial and anti-inflammatory drugs such as quaternary ammonium salt cationic antibacterial agents, or growth factors to promote wound healing according to needs.
[0016] A method for manufacturing a wound dressing comprises the following steps:
[0017] S1: The PCL melt is spun on the spinning platform through melt near-field direct spinning to produce a PCL fiber membrane, i.e., the first hydrophobic layer;
[0018] S2: Add the drug to the polyether PU spinning solution and spin it on the surface of the PCL fiber membrane through near-field direct melting of the melt to form a polyether PU electrospun membrane, i.e., the first hydrophilic layer;
[0019] S3: adding the drug to the silk protein spinning solution and spinning it on the polyether PU electrospun membrane through near-field direct melting to prepare the silk protein electrospun membrane, i.e., the second hydrophilic layer;
[0020] S4: Use a needle plate to align with the dressing area of the PCL fiber membrane, polyether PU electrospun membrane and silk protein electrospun membrane and penetrate to obtain a reflux channel;
[0021] S5: preparing a PCL electrospun membrane, i.e., the second hydrophobic layer, by electrospinning the PCL melt;
[0022] S6: Cover the PCL electrospun membrane prepared in S5 on the silk protein electrospun membrane, and composite the PCL fiber membrane and the PCL electrospun membrane by hot pressing.
[0023] The electrospun membrane prepared by electrospinning has irregular holes. The size and shape of the holes affect the capillary force on the exudate in the dressing. Generally speaking, the longer the spinning time, the smaller the holes. The first hydrophobic layer is prepared by the melt near-field direct beating method. The grid on the PCL fiber membrane has larger pores. The second hydrophobic layer is used to protect the first hydrophilic layer and the second hydrophilic layer, and has a waterproof effect.
[0024] The first hydrophilic layer and the second hydrophilic layer are located in the dressing area. The needle plate penetrates the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer to form a reflux channel.
[0025] Preferably, the specific method of S1 is as follows:
[0026] S1.1 Dissolve the drug and PCL powder in THF solution and stir until dissolved, pour into a mold, and shear after the solution surface forms a film to prepare PCL melt;
[0027] S1.2 The PCL melt is injected into the melt near-field direct spinning device for spinning on the spinning platform to produce a PCL electrospun membrane with a grid.
[0028] Preferably, in step S4, the needles on the needle plate are conical.
[0029] When the conical needle pierces the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer, a conical reflux channel is formed. The reflux channel has the largest diameter in the first hydrophobic layer, which produces a smaller capillary resistance to the exudate. As the exudate gradually enters the first hydrophilic layer and the second hydrophilic layer, the diameter of the reflux channel becomes smaller and the capillary force it is subjected to increases, thereby accelerating the transport of the exudate.
[0030] Preferably, the specific method of S2 is as follows:
[0031] S2.1 Dissolve the drug and polyether PU particles in a mixed solution of DMF and acetone and stir until dissolved to prepare a polyether PU spinning solution;
[0032] S2.2 The polyether PU spinning solution is injected into a syringe through electrospinning and spun onto the surface of the PCL electrospun membrane toward the dressing area to form a polyether PU electrospun membrane.
[0033] Preferably, the preparation method of polyether PU particles is as follows: TDI-terminated polyether polyurethane prepolymer is stirred with a chain extender and poured into a granulator for granulation to prepare polyether PU particles, wherein the chain extender includes a polyol chain extender, a carboxylic acid chain extender and a sulfonate chain extender.
[0034] The hydrophilicity of carboxylic acid chain extenders and sulfonate chain extenders is higher than that of polyol chain extenders. Therefore, when preparing polyether PU particles, changing the ratio of polyol chain extenders to carboxylic acid chain extenders and / or sulfonate chain extenders can change the hydrophilicity of polyether PU electrospun membranes.
[0035] Preferably, the specific method of S3 is as follows:
[0036] S3.1 Adding the drug and silk protein into hexafluoroisopropanol to obtain a silk protein spinning solution;
[0037] S3.2 is spun on a polyether PU electrospun membrane to produce a silk protein electrospun membrane, i.e., the second hydrophilic layer.
[0038] Preferably, the specific method of S4 is as follows: using the PCL melt prepared in S2, the PCL melt is injected into a syringe and spun on the surface of a spinning platform to prepare a PCL electrospun membrane.
[0039] Preferably, the specific method of S5 is as follows: remove the mold, use the PCL melt prepared in S2, inject the PCL melt into a syringe and spin it on the surface of the spinning platform to form a PCL electrospun membrane.
[0040] The first hydrophobic layer and the second hydrophobic layer are made of PCL electrospun membrane made of the same material, which is convenient for subsequent hot pressing molding.
[0041] Preferably, the specific method of S6 is as follows:
[0042] S5.1 cut the PCL electrospun membrane prepared in S4 to the same size as the PCL electrospun membrane prepared in S1;
[0043] S5.2 covers the cut PCL electrospun membrane on top of the silk protein electrospun membrane, and composites the two layers of PCL electrospun membranes made from S1 and S4 by hot pressing, so that the polyether PU electrospun membrane and the silk protein electrospun membrane are sandwiched between the two layers of PCL electrospun membranes.
[0044] The PCL hot pressing temperature is generally 80°C, and the dressing area needs to be avoided during hot pressing.
[0045] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:
[0046] 1. By setting a reflux channel in the first hydrophobic layer and the first hydrophilic layer and the second hydrophilic layer, the absorbed exudate can flow back to the wound, thereby maintaining the moisture of the wound and preventing excessive discharge of the exudate.
[0047] 2. Medicines are arranged on the first hydrophilic layer and the second hydrophilic layer. When the exudate flows back, the medicines can play their role and promote wound healing.
[0048] 3. The exudate is affected by the capillary force generated by the reflux channel of the first hydrophilic layer. The capillary force is greater than the weight of the exudate itself and the hydrophobic force of the first hydrophobic layer, so the exudate moves unidirectionally from the first hydrophobic layer to the first hydrophilic layer. When the exudate of the first hydrophilic layer contacts the second hydrophilic layer with better hydrophilicity, the capillary force generated by the reflux channel of the second hydrophilic layer and the capillary force generated by the reflux channel of the first hydrophilic layer work together to move and diffuse the exudate from the first hydrophilic layer to the second hydrophilic layer. When the exudate accumulated in the first and second hydrophilic layers reaches a certain amount, the gravity of the exudate itself is greater than the hydrophobic force between the first hydrophilic layer and the first hydrophobic layer, and the exudate can flow back to the wound surface.
[0049] 4. The first hydrophilic layer and the second hydrophilic layer are located in the dressing area. The pore sizes of the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer gradually decrease. The reflux channel has the largest diameter in the first hydrophobic layer, which produces a smaller capillary resistance to the exudate. As the exudate gradually enters the first hydrophilic layer and the second hydrophilic layer, the diameter of the reflux channel decreases, and the capillary force it is subjected to increases, thereby accelerating the transport of the exudate.
[0050] 5. By setting a printing plate, a regularly arranged cone is set on the top of the printing plate, and the PCL electrospun membrane, the polyether PU electrospun membrane and the silk protein electrospun membrane are blocked by the cone, thereby forming a connected reflux channel. The size of the cone can be changed according to the actual absorption of the wound dressing, thereby adjusting the size of the reflux channel. BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The present invention will be further described below with reference to the accompanying drawings.
[0052] Figure 1 The present invention is a cross-sectional view of a wound dressing.
[0053] Figure 2 Schematic diagram of the structure of the needle plate.
[0054] Figure 3 This is a schematic diagram of the structure of the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer in the wound dressing. DETAILED DESCRIPTION
[0055] like Figure 1 A wound dressing shown in the figure comprises a first hydrophobic layer 1, the first hydrophobic layer 1 is provided with a dressing area 2, the dressing area 2 comprises a first hydrophilic layer 3 and a second hydrophilic layer 4 from the inside to the outside, the first hydrophilic layer 3 and the second hydrophilic layer 4 are wrapped with a second hydrophobic layer 5, wherein the hydrophilicity of the second hydrophilic layer 4 is greater than that of the first hydrophilic layer 3, and the first hydrophobic layer 1, the first hydrophilic layer 3 and the second hydrophilic layer 4 are provided with a connected reflux channel 6.
[0056] The first hydrophobic layer 1 and the second hydrophobic layer 5 are made of PCL electrospun membrane, the first hydrophilic layer 3 is made of PU electrospun membrane, and the second hydrophilic layer 4 is made of silk protein electrospun membrane. The first hydrophilic layer 3 and the second hydrophilic layer 4 are loaded with drugs.
[0057] like Figure 2 The needle plate 7 shown has a conical needle head 8 on the top thereof.
[0058] Example 1
[0059] A method for manufacturing a wound dressing comprises the following steps:
[0060] S1: Preparation of the first hydrophobic layer 1
[0061] S1.1 Dissolve zinc oxide and PCL powder in THF solution and stir until dissolved, pour into a mold, and shear after the solution surface forms a film to prepare a PCL melt.
[0062] S1.2 The PCL melt is injected into the melt near-field direct spinning device for spinning on the spinning platform to produce a PCL electrospun membrane with a grid.
[0063] The spinning temperature was 100°C, the gas pressure was 200 kPa, and the voltage was 5 kV.
[0064] S2: Preparation of the first hydrophilic layer 3
[0065] S2.1 The TDI-terminated polyether polyurethane prepolymer and the chain extender are stirred and poured into a granulator for granulation at a granulation temperature of 90°C to prepare polyether PU particles. The mass fraction ratio of the TDI-terminated polyether polyurethane prepolymer to the chain extender is 100:20, and the chain extender is glycerol and dihydroxymethylpropionic acid in a mass fraction ratio of 5:2.
[0066] S2.2 Dissolve the cationic quaternary ammonium salt antibacterial agent and polyether PU particles in a mixed solution of DMF and acetone in a mass ratio of 1:1 and stir until dissolved to prepare a polyether PU spinning solution with a mass fraction of 50%.
[0067] S2.3 Inject the polyether PU spinning solution into the syringe and spin it on the surface of the PCL electrospun membrane towards the dressing area to form a polyether PU electrospun membrane.
[0068] The spinning voltage was 5-7 kV, the spinning rate was 20 mm / s, and the spinning time was 5 min.
[0069] S3: Preparation of the second hydrophilic layer 4
[0070] S3.1 adding silk protein to hexafluoroisopropanol to obtain a 5% by mass silk protein solution, and then adding an anti-inflammatory drug IBU to obtain a silk protein spinning solution;
[0071] S3.2 Spinning is performed on the polyether PU electrospun membrane in the dressing area to form a silk protein electrospun membrane, namely the second hydrophilic layer 4.
[0072] The spinning voltage was 5-7 kV, the spinning rate was 20 mm / s, and the spinning time was 8 min.
[0073] S4: The needle 8 on the needle plate 7 is aligned with the first hydrophobic layer 1, i.e., the PCL fiber membrane, the first hydrophilic layer 3, i.e., the polyether PU electrospun membrane, and the second hydrophilic layer 4, i.e., the silk protein electrospun membrane, and penetrates the dressing area 2 to obtain a reflux channel 6, such as Figure 1 and Figure 3 shown.
[0074] The needle 8 size is 1 micron at the top and 5 microns at the bottom.
[0075] S5: Preparation of the second hydrophobic layer 5
[0076] The PCL melt prepared by S1 was dissolved in a THF solution to prepare a PCL spinning solution with a mass fraction of 50%, and the PCL spinning solution was spun on the surface of a spinning platform by electrospinning to prepare a PCL electrospun membrane.
[0077] The spinning temperature was 100°C, the gas pressure was 200 kPa, and the voltage was 5 kV.
[0078] S6: Composite first hydrophobic layer 1 and second hydrophobic layer 5
[0079] S6.1 cut the PCL electrospun membrane prepared in S5 to the same size as the PCL fiber membrane prepared in S1;
[0080] S6.2 Cover the cut PCL electrospun membrane on top of the silk protein electrospun membrane, and composite the PCL fiber membrane and the PCL electrospun membrane by hot pressing at a temperature of 90°C. The polyether PU electrospun membrane and the silk protein electrospun membrane are sandwiched between the two layers of PCL electrospun membrane.
[0081] Example 2
[0082] A method for manufacturing a wound dressing is similar to Example 1 in most respects, except that the size is 2 microns at the top and 8 microns at the bottom.
[0083] Example 3
[0084] A method for manufacturing a wound dressing is similar to that of Example 1, except that the size of the needle 8 is 1 micron at the top and 3 microns at the bottom.
[0085] Comparative Example 1
[0086] A method for manufacturing a wound dressing, wherein the raw material ratio of a first hydrophobic layer 1, a first hydrophilic layer 3, a second hydrophilic layer 4, and a second hydrophobic layer 5 is the same as that in Example 1, except that each layer is prepared by electrospinning, with a spinning voltage of 5-7 kV, a spinning rate of 20 mm / s, and a spinning time of 15 min.
[0087] The liquid conducting performance of Examples 1-3 and Comparative Example 1 was tested, and the test results are shown in Table 1.
[0088] The liquid reflux test method is as follows:
[0089] 1. Put the wound dressing into the water with pigment and take it out after it is fully absorbed.
[0090] 2. Place the wound dressing on a container filled with clean water, so that the dressing area of the wound dressing is in contact with the clean water, and observe whether the clean water changes color.
[0091] Table 1: Test results of liquid conduction performance of Examples 1-3 and Comparative Example 1.
[0092]
[0093] It can be seen from Table 1 that the provision of the reflux channel 6 enables the wound dressing to have good resistance to clean water pressure difference and unidirectional transport index, and has liquid reflux, wherein the effect is best when the reflux channel 6 is closer to the wound and the aperture is larger. However, the spinning time of Comparative Example 1 is longer, and there is no obvious reflux channel 6, resulting in poor unidirectional transport performance and reflux performance of the wound dressing.
[0094] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.
Claims
1. A wound dressing, characterized in that: It comprises a first hydrophobic layer, the first hydrophobic layer is provided with a dressing area, the dressing area comprises a first hydrophilic layer and a second hydrophilic layer in sequence from the inside to the outside, the first hydrophilic layer and the second hydrophilic layer are wrapped with the second hydrophobic layer, wherein the hydrophilicity of the second hydrophilic layer is greater than that of the first hydrophilic layer, and the first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer are provided with a connected reflux channel.
2. A wound dressing according to claim 1, characterized in that: The first hydrophobic layer material is a PCL fiber membrane, the second hydrophobic layer material is a PCL electrospun membrane, the first hydrophilic layer material is a polyether PU electrospun membrane, and the second hydrophilic layer material is a silk protein electrospun membrane.
3. A wound dressing according to claim 1, characterized in that: The first hydrophobic layer, the first hydrophilic layer and the second hydrophilic layer are loaded with drugs.
4. The method for manufacturing a wound dressing according to claim 1, characterized in that: The steps include: S1: The PCL melt is spun on a spinning platform by melt near-field direct writing to produce a PCL fiber membrane, i.e., the first hydrophobic layer; S2: adding the drug to the polyether PU spinning solution and spinning it on the dressing area surface of the PCL fiber membrane through electrospinning to form a polyether PU electrospun membrane, i.e., the first hydrophilic layer; S3: adding the drug to the silk protein spinning solution and spinning it on the polyether PU electrospun membrane through electrospinning to prepare the silk protein electrospun membrane, i.e., the second hydrophilic layer; S4: Use a needle plate to align with the dressing area of the PCL fiber membrane, polyether PU electrospun membrane and silk protein electrospun membrane and penetrate to obtain a reflux channel; S5: preparing a PCL electrospun membrane, i.e., the second hydrophobic layer, by electrospinning the PCL melt; S6: Cover the PCL electrospun membrane prepared in S5 on the silk protein electrospun membrane, and composite the PCL fiber membrane and the PCL electrospun membrane by hot pressing.
5. The method for manufacturing a wound dressing according to claim 4, characterized in that: S1 specific method is as follows: S1.1 Dissolve the drug and PCL powder in THF solution and stir until dissolved, pour into a mold, and shear after the solution surface forms a film to prepare PCL melt; S1.2 The PCL melt is injected into the melt near-field direct writing device for spinning on the spinning platform to produce a PCL electrospun membrane with a grid.
6. The method for manufacturing a wound dressing according to claim 4, characterized in that: The specific method of S2 is as follows: In step S4, the needle head on the needle plate is conical.
7. The method for manufacturing a wound dressing according to claim 4, characterized in that: The specific method of S2 is as follows: S2.1 Dissolve the drug and polyether PU particles in a mixed solution of DMF and acetone and stir until dissolved to prepare a polyether PU spinning solution; S2.2 Inject the polyether PU spinning solution into the syringe and spin it on the surface of the PCL electrospun membrane towards the dressing area to form a polyether PU electrospun membrane.
8. The method for manufacturing a wound dressing according to claim 6, characterized in that: The preparation method of the polyether PU particles is as follows: TDI-terminated polyether polyurethane prepolymer is stirred with a chain extender and poured into a granulator for granulation to prepare polyether PU particles, wherein the chain extender includes a polyol chain extender, a carboxylic acid chain extender and a sulfonate chain extender.
9. The method for manufacturing a wound dressing according to claim 4, characterized in that: The specific method of S3 is as follows: S3.1 Adding the drug and silk protein into hexafluoroisopropanol to obtain a silk protein spinning solution; S3.2 is spun on a polyether PU electrospun membrane to produce a silk protein electrospun membrane, i.e., the second hydrophilic layer.
10. The method for manufacturing a wound dressing according to claim 4, characterized in that: S5 specific methods are as follows: S5.1 cuts the PCL electrospun membrane prepared by S4 to the same size as that of the PCL electrospun membrane prepared by S1; S5.2 covers the cut PCL electrospun membrane on top of the silk protein electrospun membrane, and composites the two layers of PCL electrospun membranes made of S1 and S4 by hot pressing, with the polyether PU electrospun membrane and the silk protein electrospun membrane sandwiched between the two layers of PCL electrospun membranes.