A preparation method of imitation skin dressing and imitation skin dressing

Abstract

The present invention discloses a method for preparing a skin-like dressing and a skin-like dressing, wherein the method part includes the following steps: S1 is a step for preparing a polyurethane layer by using an anionic aqueous polyurethane spinning solution and a cationic aqueous polyurethane spinning solution according to different specific gravities by using an electrostatic spinning process; S2 is a step for heat-treating the polyurethane layer by using a heat treatment process. S3 is a step for bonding an antibacterial layer to the polyurethane layer after heat treatment; S4 is a step for bonding a wound contact layer to the antibacterial layer. The method for preparing a skin-like dressing and the skin-like dressing disclosed in the present invention present a wrinkled appearance similar to that of skin, so that the polyurethane layer has high ductility, high elasticity and resilience, and can achieve dynamic bonding with the joint part.

Description

Technical Field

[0001] The invention relates to the technical field of medical dressings, in particular to a preparation method of a skin-imitation dressing and the skin-imitation dressing. Background Art

[0002] Human skin is soft and has good ductility, especially at joints, where the skin elongation rate exceeds 50%. There is a large amount of collagen in the skin. As an extracellular protein, collagen plays an important role in different stages of the wound healing process and is closely related to cell proliferation, differentiation, and migration.

[0003] The dressing products currently available in the market include a backing and a core. Generally, the backing surface structure is flat and the stretch length is limited, resulting in poor elasticity of the dressing and inability to achieve dynamic fit with the joint area. Summary of the invention

[0004] The purpose of the invention is to provide a preparation method of a skin-imitation dressing and the skin-imitation dressing.

[0005] The method for preparing the skin-imitation dressing provided by the present invention comprises the following steps:

[0006] S1 is a step for preparing a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities;

[0007] S2 is a step for heat treating the polyurethane layer by using a heat treatment process.

[0008] S3 is a step for bonding the antibacterial layer to the heat-treated polyurethane layer;

[0009] S4 is a step for attaching the wound contact layer to the antibacterial layer.

[0010] Preferably, the anionic waterborne polyurethane spinning solution is prepared by mixing 10-25% of anionic waterborne urethane, 0.5-5% of a crosslinking agent and a solvent.

[0011] Preferably, the cationic waterborne polyurethane spinning solution is prepared by mixing 10-25% of cationic waterborne urethane, 0.5-5% of a cross-linking agent, 2-10% of a hydrophobic agent and a solvent.

[0012] Preferably, the solvent is one of dimethylformamide, ethanol, water or dimethyl sulfoxide; the cross-linking agent is one of polycarbodiimide, aziridine, isocyanate or epoxy silane; the hydrophobic agent is one of polysiloxane, silane coupling agent or fluorine-free acrylic acid.

[0013] Preferably, the weight ratio of the anionic aqueous polyurethane spinning solution to the cationic aqueous polyurethane spinning solution is 6:4, 5:5 or 4:6. Those skilled in the art will appreciate that a different weight ratio can be used according to specific needs to obtain a polyurethane layer with the required ductility or support requirements.

[0014] Preferably, the step S1 is used to prepare a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities, and comprises:

[0015] S21 adopts a spinning voltage of 10-30 kV, a receiving distance of 10-15 cm, an injection speed of 0.6-2 mL / h, a temperature of 10-30° C., and a relative humidity of 25-70%, and uses three syringes to spin anionic waterborne polyurethane spinning solutions and cationic waterborne polyurethane spinning solutions side by side, and implements different proportions of spinning solutions by changing the injection speed. S22 interchanges the positions of the syringes injected with different waterborne polyurethane spinning solutions every 1-2 hours, and continues spinning to obtain a polyurethane layer.

[0016] Preferably, the antibacterial layer is made of hydrophilic polyurethane foam containing CHG (chlorhexidine gluconate), PHMB (polyhexamethylene biguanide hydrochloride) and silver ions.

[0017] Preferably, the heat treatment process is to use a vacuum oven, adjust the heating temperature to 40-80° C., and the pressure to 10-101 kPa, and heat the polyurethane layer for 10-120 minutes.

[0018] Preferably, the wound contact layer is made by electrospinning a mixture of 25-30% collagen, 15-20% acetic acid and a solvent.

[0019] Preferably, the wound contact layer is made of collagen nanofibers or gelatin nanofibers.

[0020] The skin-imitation dressing provided by the present invention comprises a polyurethane layer (1) and an antibacterial layer (2); the antibacterial layer (2) is attached to one side of the polyurethane layer (1); and the polyurethane layer (1) has an irregular wrinkle structure.

[0021] Preferably, the pleated structures are arranged at irregular intervals.

[0022] Preferably, the skin-imitation dressing provided by the present invention further comprises an adhesive layer (3); the size of the adhesive layer (3) is the same as the size of the polyurethane layer (1).

[0023] Preferably, the skin-imitation dressing provided by the present invention further comprises a wound contact layer (4); the wound contact layer (4) is attached to the side of the adhesive layer (3) away from the antibacterial layer (2).

[0024] Preferably, the size of the wound contact layer (4) is the same as the size of the antibacterial layer (2).

[0025] The present invention provides a method for preparing a skin-like dressing and a skin-like dressing, which presents a skin-like wrinkled structure, so that the polyurethane layer has high ductility, high elasticity and resilience, and the dressing can achieve dynamic fitting with the joint part. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic flow chart of a method for preparing a skin-mimicking dressing according to Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic cross-sectional structure diagram of the skin-imitation dressing according to the second embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the top view of the polyurethane layer described in Example 2 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1

[0031] like Figure 1-3 As shown, the preparation method of the skin-imitation dressing provided in this embodiment comprises the following steps:

[0032] S1 is a step for preparing a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities;

[0033] S2 is a step for heat treating the polyurethane layer by using a heat treatment process.

[0034] S3 is a step for bonding the antibacterial layer to the heat-treated polyurethane layer;

[0035] S4 is a step for attaching the wound contact layer to the antibacterial layer.

[0036] Those skilled in the art can understand that by heat-treating the polyurethane layer, due to the different shrinkage rates of the anionic water-based urethane nanofibers and the cationic water-based urethane nanofibers in the polyurethane layer, the two will present different shrinkage ratios under tension-free conditions, and the two will restrict each other, so that the skin-imitation dressing provided in this embodiment presents a skin-imitation wrinkle structure, and the polyurethane layer has high ductility, high elasticity and resilience, and can achieve dynamic fit with the joints.

[0037] Furthermore, the anionic waterborne polyurethane spinning solution is prepared by mixing 10-25% of anionic waterborne urethane, 0.5-5% of a crosslinking agent and a solvent.

[0038] Furthermore, the cationic waterborne polyurethane spinning solution is prepared by mixing 10-25% of cationic waterborne urethane, 0.5-5% of a crosslinking agent, 2-10% of a hydrophobic agent and a solvent.

[0039] Furthermore, the solvent is one of dimethylformamide, ethanol, water or dimethyl sulfoxide; the cross-linking agent is one of polycarbodiimide, aziridine, isocyanate or epoxy silane; and the hydrophobic agent is one of polysiloxane, silane coupling agent or fluorine-free acrylic acid.

[0040] Furthermore, the weight ratio of the anionic aqueous polyurethane spinning solution to the cationic aqueous polyurethane spinning solution is 6:4, 5:5 or 4:6. Those skilled in the art will appreciate that different weight ratios can be used according to specific requirements to obtain a polyurethane layer with the required ductility or support.

[0041] Furthermore, the step S1 is used to prepare a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities, and comprises:

[0042] S21 uses a spinning voltage of 10-30kV, a receiving distance of 10-15cm, an injection speed of 0.6-2mL / h, a temperature of 10-30°C, and a relative humidity of 25-70%. Three syringes are used to spin anionic water-based polyurethane spinning solution and cationic water-based polyurethane spinning solution side by side, and the steps of different proportions of the spinning solution are implemented by changing the injection speed.

[0043] S22 is a step of exchanging the positions of the syringes filled with different water-based urethanes every 1-2 hours, and continuing the spinning to obtain a polyurethane layer.

[0044] Those skilled in the art will appreciate that the skin-like properties of the polyurethane layer can be improved by periodically exchanging the spinning positions.

[0045] Furthermore, the antibacterial layer is made of hydrophilic polyurethane foam containing CHG (chlorhexidine gluconate), PHMB (polyhexamethylene biguanide hydrochloride) and silver ions. Those skilled in the art will understand that the antibacterial layer is a hydrophilic polyurethane foam containing antibacterial drugs (CHG, PHMB, silver ions, etc.) to absorb wound exudate and manage microorganisms in the absorbed liquid.

[0046] Furthermore, the heat treatment process is to use a vacuum oven, adjust the heating temperature to 40-80°C, the pressure to 10-101 kPa, and heat the polyurethane layer for 10-120 minutes. Those skilled in the art will understand that the two urethane materials in the polyurethane layer have different shrinkage rates, and wrinkles appear on the fiber membrane.

[0047] Further, the wound contact layer is made by electrospinning after mixing 25-30% collagen, 15-20% acetic acid and solvent. Those skilled in the art will understand that the electrospinning conditions of the wound contact layer are spinning voltage: 10-30kV, receiving distance: 15-20cm, perfusion speed: 1-4mL / h, temperature 20-30°C, relative humidity: 25-70%. Collagen is collagen or gelatin.

[0048] Furthermore, the wound contact layer is made of collagen nanofibers or gelatin nanofibers. Those skilled in the art can understand that the wound contact layer simulates the natural extracellular matrix, and the void structure is conducive to cell adhesion and growth. The dressing can imitate the natural skin tissue structure in terms of raw materials and structure, and can promote cell survival and growth.

[0049] Embodiment 2

[0050] The skin-imitation dressing provided in this embodiment includes a polyurethane layer 1 and an antibacterial layer 2; the antibacterial layer 2 is attached to one side of the polyurethane layer 1; the polyurethane layer 1 has a wrinkled structure. Those skilled in the art can understand that the skin-imitation dressing provided in this embodiment has a wrinkled appearance like skin, so that the polyurethane layer 1 has high ductility, high elasticity and recovery, and can achieve dynamic adhesion with the joint part.

[0051] Those skilled in the art can understand that the polyurethane layer is made of anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution at different specific gravities by electrospinning, and the polyurethane layer is heat-treated. Since the shrinkage rates of anionic aqueous urethane and cationic aqueous urethane in the polyurethane layer are different, the two will present different shrinkage ratios in a tension-free state, and the two restrict each other, so that the skin-imitation dressing provided in this embodiment presents a skin-imitation wrinkled structure.

[0052] Those skilled in the art will appreciate that the anionic aqueous polyurethane spinning solution is made by mixing anionic aqueous urethane with a proportion of 10-25%, a cross-linking agent with a proportion of 0.5-5%, and a solvent. The cationic aqueous polyurethane spinning solution is made by mixing a cationic aqueous urethane with a proportion of 10-25%, a cross-linking agent with a proportion of 0.5-5%, a hydrophobic agent with a proportion of 2-10%, and a solvent. The solvent is one of dimethylformamide, ethanol, water, or dimethyl sulfoxide; the cross-linking agent is one of polycarbodiimide, aziridine, isocyanate, or epoxy silane; the hydrophobic agent is one of polysiloxane, silane coupling agent, or fluorine-free acrylic acid. The weight ratio of the anionic aqueous polyurethane spinning solution and the cationic aqueous polyurethane spinning solution is 6:4, 5:5, or 4:6. Those skilled in the art will appreciate that a ratio method without specific gravity can be adopted according to specific needs to obtain a polyurethane layer with the required ductility or support requirements.

[0053] Those skilled in the art will appreciate that the antibacterial layer 2 is made of hydrophilic polyurethane foam containing CHG chlorhexidine gluconate, PHMB polyhexamethylene biguanide hydrochloride and silver ions. The hydrophilic polyurethane foam is used to absorb wound exudate, and the CHG, PHMB and silver ions contained therein simultaneously manage microorganisms in the absorbed liquid.

[0054] Furthermore, the pleated structures are arranged at irregular intervals.

[0055] Furthermore, the skin-imitation dressing provided in this embodiment further includes an adhesive layer 3; the size of the adhesive layer 3 is the same as the size of the polyurethane layer 1. Those skilled in the art can understand that the skin-imitation dressing provided in this embodiment is fixed on the wound by attaching the adhesive layer 3 to the antibacterial layer 2 and the polyurethane layer 1.

[0056] Furthermore, the skin-imitation dressing provided in this embodiment also includes a wound contact layer 4; the wound contact layer 4 is attached to the side of the adhesive layer 3 away from the antibacterial layer 2. Those skilled in the art can understand that the wound contact layer 4 is made by electrospinning after mixing 25-30% collagen, 15-20% acetic acid and solvent. Collagen is collagen or gelatin, and the wound contact layer 4 is collagen nanofiber or gelatin nanofiber, which simulates the natural extracellular matrix. The void structure is conducive to cell adhesion and growth. The dressing can imitate the natural skin tissue structure from both the raw material and structure, and can promote cell survival and growth.

[0057] Furthermore, the size of the wound contact layer 4 is the same as that of the antibacterial layer 2. Those skilled in the art will understand that if the size of the wound contact layer 4 is too large, it will adhere to the polyurethane layer, resulting in a reduction in the contact surface between the polyurethane layer and the skin, which will affect the adhesion effect of the dressing and increase the material consumption and enterprise costs; if the size is too small, it will not have a good effect in promoting wound healing.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a skin-imitation dressing, characterized in that: The steps include: S1 is a step for preparing a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities; S2 is a step for heat treating the polyurethane layer using a heat treatment process; S3 is a step for bonding the antibacterial layer to the heat-treated polyurethane layer; S4 is a step for attaching the wound contact layer to the antibacterial layer; The anionic waterborne polyurethane spinning solution is prepared by mixing 10-25% of anionic waterborne urethane, 0.5-5% of a crosslinking agent and a solvent; The cationic waterborne polyurethane spinning solution is prepared by mixing 10-25% of cationic waterborne urethane, 0.5-5% of a crosslinking agent, 2-10% of a hydrophobic agent and a solvent; The solvent is one of dimethylformamide, ethanol, water or dimethyl sulfoxide; the cross-linking agent is one of polycarbodiimide, aziridine, isocyanate or epoxy silane; the hydrophobic agent is one of polysiloxane, silane coupling agent or fluorine-free acrylic acid; The weight ratio of the anionic aqueous polyurethane spinning solution to the cationic aqueous polyurethane spinning solution is 6:4, 5:5 or 4:6; The step S1 is used to prepare a polyurethane layer by electrospinning anionic aqueous polyurethane spinning solution and cationic aqueous polyurethane spinning solution according to different specific gravities, and comprises: S21 uses a spinning voltage of 10-30 kV, a receiving distance of 10-15 cm, an injection speed of 0.6-2 mL / h, a temperature of 10-30 ° C, and a relative humidity of 25-70%. Three syringes are used to spin anionic waterborne polyurethane spinning solution and cationic waterborne polyurethane spinning solution side by side, and the steps of different proportions of the spinning solution are implemented by changing the injection speed; S22 is a step of exchanging the positions of the syringes filled with different aqueous urethane spinning solutions every 1-2 hours, and continuing the spinning to obtain a polyurethane layer.

2. The method for preparing the skin-imitation dressing according to claim 1, characterized in that: The antibacterial layer is made of hydrophilic polyurethane foam containing CHG (chlorhexidine gluconate), PHMB (polyhexamethylene biguanide hydrochloride) and silver ions.

3. The method for preparing the skin-imitation dressing according to claim 2, characterized in that: The heat treatment process is to use a vacuum oven, adjust the heating temperature to 40-80° C., and the pressure to 10-101 kPa, and heat the polyurethane layer for 10-120 minutes.

4. The method for preparing the skin-imitation dressing according to claim 3, characterized in that: The wound contact layer is made by electrospinning a mixture of 25-30% collagen, 15-20% acetic acid and a solvent.

5. The method for preparing the skin-imitation dressing according to claim 4, characterized in that: The wound surface contact layer is made of collagen nanofibers or gelatin nanofibers.

6. A skin-imitation dressing, characterized in that: The imitation skin dressing is prepared by the preparation method of the imitation skin dressing according to claim 5; the imitation skin dressing comprises a polyurethane layer (1) and an antibacterial layer (2); the antibacterial layer (2) is attached to one side of the polyurethane layer (1); and the polyurethane layer (1) has a pleated structure.

7. The skin-imitation dressing according to claim 6, characterized in that: The pleated structures are arranged at irregular intervals.

8. The skin-imitation dressing according to claim 7, characterized in that: It also comprises an adhesive layer (3); the size of the adhesive layer (3) is the same as the size of the polyurethane layer (1).

9. The skin-imitation dressing according to claim 8, characterized in that: It also comprises a wound surface contact layer (4); the wound surface contact layer (4) is attached to a side of the adhesive layer (3) away from the antibacterial layer (2).

10. The skin-imitation dressing according to claim 9, characterized in that: The size of the wound contact layer (4) is the same as that of the antibacterial layer (2).

Images