Composite electret medical dressing and preparation method thereof

Abstract

The invention relates to the technical field of medical dressings, and discloses a composite electret medical dressing and a preparation method thereof.The composite electret medical dressing comprises a back supporting layer, an electret layer, a waterproof layer, a skin-friendly layer and an anti-sticking layer which are sequentially compounded; the back support layer is a breathable fiber layer; the electret layer is an organic polymer polarized material film layer subjected to polarization treatment; the waterproof layer is a fluorine-containing hydrophobic layer; the skin-friendly layer is a fiber cloth layer with biocompatibility, and the skin-friendly layer and the back support layer form a closed structure to wrap the electret layer; and the anti-sticking layer is an anti-sticking polyolefin layer. The use method of the composite electret medical dressing mainly comprises the following steps: tearing off the anti-sticking layer when the composite electret medical dressing is used, coating the medical dressing with the ointment for promoting wound repair, and then attaching the dressing coated with the ointment to a wound. Tests show that the effects of promoting repair and accelerating healing can be achieved by utilizing the physical effects of the electrostatic field and the micro-current and combining the drug effect.

Description

Technical Field

[0001] The present invention relates to the technical field of medical dressings, and mainly relates to a composite electret medical dressing and a preparation method thereof. The composite electret medical dressing can be used in conjunction with a variety of medical ointments, Chinese medicine patches or essential oils, has the characteristics of being skin-friendly and comfortable, and can enhance the effect of drugs. Background Art

[0002] At present, medical dressings used for wounds are mainly divided into: natural gauze, synthetic fiber dressings, foamed polymer dressings and alginate dressings, which are mainly used to cover wounds or injured parts. The problem with the commonly used dressing products is that they may partially adhere to the contacted parts during use, which may cause pre-infiltration allergies or even secondary damage to the surrounding skin. Commonly used dressings can absorb wound exudate and promote wound healing, but there is still much room for improvement in promoting absorption, wound healing and antibacterial. Summary of the invention

[0003] In view of this, the present invention provides a composite electret medical dressing and a preparation method thereof. The medical dressing provided by the present invention can loosen the stratum corneum structure and effectively enhance the efficacy of the added drugs, ointments and essential oils.

[0004] The present invention provides a composite electret medical dressing, which comprises a backing layer, an electret layer, a waterproof layer, a skin-friendly layer and an anti-adhesive layer which are composited in sequence;

[0005] The backing layer is a breathable fiber layer; the electret layer is a polarized organic polymer material film layer; the waterproof layer is a fluorine-containing hydrophobic layer; the skin-friendly layer is a biocompatible fiber cloth layer, and forms a closed structure with the backing layer to wrap the electret layer; the anti-sticking layer is an anti-sticking polyolefin layer.

[0006] Preferably, the backing layer is a breathable non-woven fabric layer or a breathable bio-fiber fabric layer.

[0007] Preferably, the electret layer is a film layer of polytetrafluoroethylene or its isomers that has been subjected to polarization treatment, or a film layer of polyperfluoroethylene-propylene or its isomers that has been subjected to polarization treatment.

[0008] Preferably, the electret layer has a thickness between 15 micrometers and 45 micrometers, and a surface potential between 1000V and 2000V.

[0009] Preferably, the waterproof layer is a polytetrafluoroethylene hydrophobic layer, preferably with a thickness of 10-25 microns.

[0010] Preferably, the skin-friendly layer is a biofiber cloth layer, a foamed polymer film or a collagen sponge.

[0011] Preferably, the water absorption rate of the skin-friendly layer is 10-35S / 5cm, and the liquid absorption rate is 800-1000%.

[0012] Preferably, the anti-adhesive layer is an anti-adhesive polypropylene layer or an anti-adhesive polyethylene layer; the anti-adhesive layer is removed during use and the drug is coated on the medical dressing.

[0013] The present invention provides a method for preparing the composite electret medical dressing as described above, comprising the following steps:

[0014] Compounding the air-permeable fiber layer with the organic polymer polarized material film, wherein the compounding method includes adhesive bonding, hot-melt film hot-pressing bonding or ultrasonic integral bonding;

[0015] The non-composite surface of the organic polymer polar material film is subjected to polarization treatment by using a corona charging device to form an electret layer;

[0016] The fluorine-containing hydrophobic layer and the biocompatible fiber cloth layer are compounded in sequence and wrapped with the electret layer, and finally an anti-sticking polyolefin layer is selected as the anti-sticking layer covering the entire film layer to obtain the composite electret medical dressing.

[0017] Preferably, the vertical distance between the charging brush in the corona charging device and the non-composite surface of the organic polymer material film is 5-10 cm, the charging voltage is 10-20 kV, and the charging time is 5-10 min;

[0018] The fluorine-containing hydrophobic layer and the biocompatible fiber cloth layer are sequentially compounded in a manner including adhesive bonding, hot melt film hot pressing bonding or ultrasonic integral bonding.

[0019] Commonly used medical excipients have relatively simple effects and do not carry physical factors to enhance penetration or antibacterial effects.

[0020] Electret is a type of dielectric material that carries electric charge and has electrostatic field effect and microcurrent effect. Electrets that carry negative charge can effectively promote the migration of fibroblasts, promote cell proliferation and inhibit bacterial growth, and have certain application prospects in the field of medicine and health. Since the first artificial electret prepared by Japanese physicist Eguchi in 1918, it has been proved that it has extremely strong electrostatic storage capacity. A series of subsequent studies have proved that electret can improve blood microcirculation, improve vascular microenvironment and promote wound healing.

[0021] Electrets are mainly divided into organic electrets, inorganic electrets, bio-electrets and composite electrets, etc. Among them, common organic electrets include polymers such as polypropylene, polytetrafluoroethylene, polychlorotrifluoroethylene and fluorinated ethylene propylene.

[0022] The main key point of the present invention is to use a composite electret film as the core, and the electret film is compositely arranged between the backing layer and the waterproof layer. The electrostatic field and microcurrent can act on the medicine or essential oil on the skin-friendly layer, promote the absorption of human skin, and form a physical field to enhance the cell repair of the wound. The medical dressing structure described in the present invention includes a multi-layer composite structure containing an electret layer, which is a structure composited by polytetrafluoroethylene and its isomers, or polyperfluoroethylene propylene and its isomers, etc., which can provide an electrostatic field more permanently. In addition, it is preferred to use a polytetrafluoroethylene film or a polytetrafluoroethylene film that has been expanded as a waterproof layer to ensure that the medicine or essential oil applied during subsequent use does not affect the key to charge loss. The selection of the skin-friendly layer in the present invention is preferably a natural fiber film or a foamed polymer film. After testing and verification, it is selected to have good air permeability and strong water absorption, biocompatibility, and no allergy.

[0023] The main steps of using the composite electret medical dressing of the present invention are: tear off the anti-adhesive layer when using it, apply the ointment that promotes wound repair on the medical dressing, and then attach the dressing coated with the ointment to the wound. According to tests, the physical effects of the electrostatic field and microcurrent combined with the drug effect can achieve the effect of promoting repair and accelerating healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of a medical dressing containing a composite electret in some embodiments of the present invention;

[0025] Figure 2 The figures show the healing conditions of mouse wounds at different times in the examples of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0027] The present invention provides a composite electret medical dressing, which comprises a backing layer, an electret layer, a waterproof layer, a skin-friendly layer and an anti-adhesive layer which are composited in sequence;

[0028] The backing layer is a breathable fiber layer; the electret layer is a polarized organic polymer material film layer; the waterproof layer is a fluorine-containing hydrophobic layer; the skin-friendly layer is a biocompatible fiber cloth layer, and forms a closed structure with the backing layer to wrap the electret layer; the anti-sticking layer is an anti-sticking polyolefin layer.

[0029] The medical dressing provided by the present invention can loosen the stratum corneum structure and effectively enhance the efficacy of the added medicine, ointment and essential oil.

[0030] See also Figure 1 , Figure 1 Schematic diagram of the structure of medical dressings containing composite electrets in some embodiments of the present invention. Figure 1 In the figure, 1 is a backing layer, 2 is an electret layer, 3 is a waterproof layer, 4 is a skin-friendly layer, and 5 is an anti-adhesive layer. The present invention discloses a composite electret medical dressing and a preparation method thereof, wherein the medical dressing is prepared by compositely preparing five layers of thin layer materials, such as Figure 1 As shown, there are a backing layer 1, an electret layer 2, a waterproof layer 3, a skin-friendly layer 4 and an anti-sticking layer 5 in sequence.

[0031] In the embodiment of the present invention, the backing layer 1 mainly plays a supporting role and can also be called a backing layer; the backing layer 1 is a breathable fiber layer, and can be made of non-woven fabrics with good air permeability, biological fiber fabrics (including natural fiber fabrics). In some examples, the breathable non-woven fabric layer used as the backing layer is preferably a spunlace non-allergenic breathable and comfortable non-woven fabric made of polyester fiber, with a pore size of 2-3 microns.

[0032] In an embodiment of the present invention, the electret layer 2 is a polarized organic polymer polarized material film layer, which is composited on a surface of the backing layer 1. The electret layer described in the embodiment of the present invention preferably uses polytetrafluoroethylene (PTFE) and its isomers, or polyperfluoroethylene propylene (FEP, fluorinated ethylene propylene copolymer) and its isomers. This film material is polarized by corona charging, which can provide microcurrent and strong electrostatic field, thereby forming the composite electret medical dressing. The polarization treatment is preferably a corona charging method, which uses the corona discharge formed by the local breakdown of the air caused by the non-uniform electric field at the tip to deposit the generated charged particles on the polymer, so that the polymer carries the charge, which is a commonly used electret polarization treatment method.

[0033] Preferably, the thickness of the electret layer is between 15 microns and 45 microns, and the surface potential is between 1000-2000V. The embodiment of the present invention can use commercially available organic polymer polarized material membranes. If PTFE is selected as a porous material, the pore size is 0.1-0.3 microns, the porosity is 80%, and the strength is moderate. It can also be a thin film material with a thickness of generally 10 to 50 μm. The electret layer can be a two-layer film composite structure; preferably, a polytetrafluoroethylene film with a thickness of 15 μm is selected as the lower layer, and a polytetrafluoroethylene film with a thickness of 15 μm is selected as the upper layer, and an adhesive is used to bond to form a composite film; the two layers of film can be the same, and the adhesive can be PUR polyurethane glue or ordinary hot melt adhesive. PUR glue is preferably used for better bonding. Using an electrostatic electret device, a 15kV potential can be used for charging for 5 minutes. The distance between the electrostatic rod and the composite film is 5 cm. The surface potential of the composite film after electret is 1000V.

[0034] In addition, the embodiment of the present invention uses a fluorine-containing hydrophobic layer as the waterproof layer 3, preferably with a thickness of 10-25 microns, which is compositely covered on the electret layer 2. Specifically, the waterproof layer 3 is made of polytetrafluoroethylene or other similar fluorine-containing hydrophobic materials, which have a similar structure to the electret material, can assist the movement of electrons, exert the effect of the electrostatic field, and has strong hydrophobicity, which can isolate liquid from entering the electret layer 2. The waterproof layer is made of a polytetrafluoroethylene film with a thickness of 15-25 microns or a polytetrafluoroethylene film that has been expanded.

[0035] In the embodiment of the present invention, the skin-friendly layer 4 is a fiber cloth layer with biocompatibility, and forms a closed structure with the backing layer 1 to wrap the electret layer 2; the skin-friendly layer 4 covers the waterproof layer 3, and is further compounded with an anti-adhesive layer 5. The anti-adhesive layer is generally a polyolefin film layer such as an anti-adhesive polypropylene layer or an anti-adhesive polyethylene layer. When used, the anti-adhesive layer 5 is removed to allow the drug to be coated on the medical dressing.

[0036] Among them, the skin-friendly layer 4 is made of non-allergenic, air-permeable and highly water-absorbent materials, which can be coated with drugs or essential oils later, and has good biocompatibility, such as biofiber cloth (including natural biocloth), foamed polymer film and collagen sponge; further, the water absorption rate of the skin-friendly layer is 10-35S / 5cm, and the liquid absorption rate is 800-1000%. The skin-friendly layer is made of biofiber cloth with a thickness of 25-50 microns, or non-woven fabric, preferably biofiber cloth, which has strong water absorption and biocompatibility. In addition, the anti-adhesive layer 5 mainly uses anti-adhesive film materials such as polypropylene and polyethylene.

[0037] The biological fiber cloth is mainly made of fiber bodies made by natural fermentation of Acetobacter xylinum, with a fiber diameter of about 0.05 to 0.08 microns, and presents a 3D staggered structure, which allows air to pass through, is soft and has excellent toughness. If the waterproof layer and the skin-friendly layer are not compounded, the charge on the electret film will be easily lost after contacting the skin.

[0038] After testing, the present invention can loosen the stratum corneum structure by utilizing the physical properties of the electret itself, through electrostatic field and microcurrent, and effectively enhance the efficacy of the added drugs, ointments and essential oils. The composite electret medical dressing has an antibacterial effect, which can provide an electrostatic field of a certain intensity and a microcurrent of 5-10mA, which can damage the cell wall and cell membrane of bacteria, affect the biological stability inside and outside the bacterial membrane, and effectively inhibit bacterial growth. Among them, the antibacterial rate of the composite electret film against Escherichia coli can be 70%, and the antibacterial rate against Staphylococcus aureus is about 50%.

[0039] The present invention provides a method for preparing the composite electret medical dressing as described above, comprising the following steps:

[0040] Compounding the air-permeable fiber layer with the organic polymer polarized material film, wherein the compounding method includes adhesive bonding, hot-melt film hot-pressing bonding or ultrasonic integral bonding;

[0041] The non-composite surface of the organic polymer polar material film is subjected to polarization treatment by using a corona charging device to form an electret layer;

[0042] The fluorine-containing hydrophobic layer and the biocompatible fiber cloth layer are compounded in sequence and wrapped with the electret layer, and finally an anti-sticking polyolefin layer is selected as the anti-sticking layer covering the entire film layer to obtain the composite electret medical dressing.

[0043] In a specific embodiment of the present invention, the preparation process and main steps of the composite electret medical auxiliary material include:

[0044] Firstly, a polytetrafluoroethylene film or its isomer film is compounded by adhesive bonding, hot melt film hot pressing bonding and ultrasonic integral bonding, etc., and then a non-woven fabric with good air permeability is selected to compound the compounded electret film again to form an overall composite film. The polytetrafluoroethylene film adopts a high-density and tight structure and has a strong electrostatic storage capacity, and the preferred thickness is between 15 microns and 45 microns.

[0045] Secondly, the composite film is polarized using a corona charging device. The vertical distance between the charging brush and the composite film can be 5cm-10cm, the charging voltage range is 10kV-20kV, and the charging time range is 5min-10min. This enables the electret film to carry a surface potential between 1000-2000V, ensuring that it has a strong electrostatic field, which is beneficial to the penetration and antibacterial properties of the substance.

[0046] Furthermore, another polytetrafluoroethylene film or its isomer can be compounded with the skin-friendly layer, and the compounding methods include gluing, hot pressing bonding and ultrasonic bonding. The polytetrafluoroethylene film preferably uses a polytetrafluoroethylene film material that has been expanded or stretched, which has the sealing property of polytetrafluoroethylene and can ensure the transmission effect of electric field potential energy, and the preferred thickness is 10-25 microns. The skin-friendly layer material preferably has strong water absorption, and further preferred are biofiber cloth, foamed polymer film and collagen sponge, with a water absorption rate of 10-35S / 5cm and a liquid absorption rate of 800-1000%.

[0047] Next, the waterproof and skin-friendly composite film in the above step is further compounded with the composite film after electret polarization, and the compounding methods include gluing, hot pressing bonding and ultrasonic bonding, etc.; finally, an anti-sticking polypropylene or polyethylene film is selected as an anti-sticking layer, and the anti-sticking layer is covered on the surface of the skin-friendly layer of the above composite film to form a final complete composite electret medical dressing.

[0048] The overall thickness of the composite electret medical dressing of the embodiment of the present invention is in the range of 100-300 microns, and the density can be 2.8-3.5 g / cm 3 The main steps of using the composite electret medical dressing are as follows: tear off the anti-adhesive layer when using, apply the ointment that promotes wound repair on the medical dressing, and then attach the dressing coated with the ointment to the wound, wherein the ointment is uniform, delicate, soft and smooth, and has moderate viscosity, preferably solution ointment and emulsion ointment.

[0049] The present invention prepares a composite electret film with stronger penetration promotion, antibacterial and waterproof properties through process improvement, and prepares it into an electret medical dressing through a multi-layer bonding method. It can assist various ointments, traditional Chinese medicine iron preparations, and essential oils to achieve stronger characteristics of promoting drug absorption and accelerating wound healing.

[0050] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention. The reagents and materials described in the following embodiments, unless otherwise specified, can be obtained from commercial sources. The biological fiber cloth described mainly utilizes the fiber body made by natural fermentation of Acetobacter xylinum, with a fiber diameter of about 0.05 to 0.08 microns, and presents a 3D staggered structure that allows air to pass through, is soft and has excellent toughness.

[0051] Example 1

[0052] The preparation process and main steps of the composite electret medical auxiliary material include:

[0053] First, two layers of polytetrafluoroethylene film are compounded, with a polytetrafluoroethylene film of 15μm thickness as the lower layer and a polytetrafluoroethylene film of 15μm thickness as the upper layer. The two layers of PTFE are the same and bonded with PUR adhesive to form a composite film. Then, non-woven fabric with good air permeability is selected to be compounded with the composite electret film again to form an overall composite film. Among them, the polytetrafluoroethylene film adopts a high-density and compact structure and has a strong static electricity storage capacity; polyester fiber is used to prepare a hydroentangled non-sensitive breathable and comfortable non-woven fabric with a pore size of 2-3 microns and a thickness of 15-20 microns.

[0054] Secondly, the composite electret film was polarized by using a corona charging device, with a vertical distance of 5 cm between the charging brush and the composite film, a charging voltage of 15 kV, and a charging time of 5 min, so that the surface potential of the electret film carrying a charge was between 1000 V.

[0055] The surface potential of the polarized electret film was measured using an electrometer.

[0056] In addition, another polytetrafluoroethylene film and the skin-friendly layer are bonded and compounded. The polytetrafluoroethylene film is a polytetrafluoroethylene film material that has been stretched and has the sealing property of polytetrafluoroethylene and a thickness of about 25 microns. The skin-friendly layer material is a biological fiber cloth with a water absorption rate of 10-35S / 5cm and a liquid absorption rate of 800-1000%.

[0057] Next, the waterproof and skin-friendly composite film in the above step is further bonded with the composite film after electret polarization; finally, a non-sticky polypropylene film is selected as the anti-sticking layer, and the anti-sticking layer is covered on the surface of the skin-friendly layer of the above composite film to form a complete composite electret medical dressing. The overall thickness of the composite electret medical dressing described in the embodiment of the present invention is about 100 microns, and the density is 3.2g / cm 3 .

[0058] The main steps of using the composite electret medical dressing are as follows: tearing off the anti-adhesive layer when using it, applying the ointment that promotes wound repair on the medical dressing, and then attaching the dressing coated with the ointment to the wound.

[0059] In order to verify the composite strength of the structure of the multi-layer electret medical excipient after compounding and ensure the feasibility of the subsequent process. A tensile testing machine is used to test the composite strength of the composite electret medical excipient (without anti-adhesive layer), and the peel strength measured by the tensile testing machine is used to judge the strength between the layers of the film (one side is on the backing layer, the other side is on the skin-friendly layer, and a tensile test is performed). First, set the tensile testing machine to the initial position of the test, and debug it into standby mode. Place the sample of the overall composite film between the fixtures and fix it. Then start the tensile testing machine and start the test at a speed of 10mm / min, and record the test data during the test of the tensile testing machine.

[0060] The results are shown in Table 1. Three samples were selected based on the test results. Each sample was tested 5 times under the same conditions. The peel strength of the multilayer composite film tested each time was greater than 1 Kgf / cm, proving that the composite strength of this composite film is relatively large and meets the product requirements.

[0061] Table 1: Peel strength of composite electret medical excipients

[0062]

[0063] Example 2

[0064] First, a non-woven fabric with good air permeability is selected, and its thickness is 25 microns. The non-woven fabric and the composite electret film (composite of polytetrafluoroethylene film and polytetrafluoroethylene film) are bonded and compounded with an adhesive to form a composite film of a composite electret film + a backing layer; wherein the thickness of the polytetrafluoroethylene film is 20 microns, and the thickness of the polytetrafluoroethylene film is 15 microns. The above composite material is polarized by a corona charging device, the vertical distance between the charging brush and the composite material is 5 cm, the charging voltage is 20 kV, the charging time is 5 min, and the surface potential obtained is -1000 V. Secondly, a 15-micron-thick expanded polytetrafluoroethylene film and a biological fiber with strong adsorption capacity are used to make a skin-friendly layer for bonding and compounding, and then the composite material layer after charging is compounded. Finally, an anti-sticking polyethylene film is selected as the anti-sticking layer to cover it, and the preparation of the composite electret medical auxiliary material is completed. The specific use steps are as described in Example 1. The overall thickness of the composite electret medical dressing described in the embodiment of the present invention is 100 microns, and the density is 3.2g / cm 3 .

[0065] Example 3

[0066] (1) Skin wound repair experiment

[0067] 8-week-old Balb / C mice were selected and randomly divided into 2 groups according to body weight, namely, a smear drug group and a composite electret dressing (Example 1) + drug group, wherein the surface initial potential of the electret film was -1000V, and each group had 5 mice. The skin was punched on the back of the mouse using a 1 cm diameter punch to form a surface wound. The smear drug group used 100 μL of repair ointment applied to the wound on a common non-woven fabric, and after tearing the anti-adhesive layer in the composite electret dressing + drug group, 100 μL of repair ointment was applied to the skin-friendly layer and then applied to the wound, and the drugs were administered on the first day (D1), the fifth day (D5) and the seventh day (D7), respectively, and photographed and recorded on the first day (D1) before treatment and the fourteenth day (D14) after treatment.

[0068] Ordinary non-woven fabrics are mainly single-layer, breathable medical non-woven fabrics. The acupuncture patches bought on the market can be used directly; ointments are mainly composed of recombinant human epidermal growth factor, hyaluronic acid, ginseng, angelica and other traditional Chinese medicine extracts.

[0069] Figure 2 The wound healing conditions of mice at different times in the present invention are shown in the figure. Figure 2 The results shown indicate that the wound surface area of ​​the composite electret dressing + drug group is 1 / 2 of the area of ​​the drug application group, indicating that wound healing can be promoted under the action of composite electret medical excipients.

[0070] (2) Skin safety test of composite electret medical excipients

[0071] This test selected 32 volunteers, including 20 males and 12 females, aged 22-36 years old. The composite electret medical auxiliary material patch (after charging, the dressing patch of Example 1) and the common non-woven fabric were used as negative controls and applied to the curved side of the forearm of the subjects, with an area of ​​no more than 30mm 2 After 24 hours, the patches of each group were removed. The grading standards are shown in Table 2.

[0072] As shown in Table 3, the scores of the 32 subjects were all 0 at 0.5h, 24h, and 48h after the removal of the test substance, indicating no adverse reactions.

[0073] Table 2 Skin reaction grading standards for skin occlusive patch test

[0074]

[0075]

[0076] Table 3 Skin occlusive patch test results

[0077]

[0078] (3) Comparative experiment of Chinese medicine patch containing melatonin on pig skin

[0079] This experiment was set up as follows: (1) control group: composite electret medical excipient patch / not charged, plus Chinese medicine containing melatonin for sleeping (the sample contains melatonin, glycerol, water, ethanol, and the useful ingredient is melatonin 0.1-0.15mg / mL); (2) experimental group: electrostatic film + charging (-1000V), plus Chinese medicine containing melatonin for sleeping. The skin of the side of a small boar was selected as the test skin model, and the shape was cut into the size of the receiving pool and placed on the receiving pool. The Chinese medicine containing melatonin for sleeping was evenly applied, and the skin was divided into groups according to the experiment, with 3 replicates in each group. After 3 hours of skin application, the skin was removed from the diffusion pool, and the pig skin of the transdermal area was cut. It was first wiped with an alcohol cotton ball, and the transdermal surface was rinsed with pure water 3 times to remove the drug remaining on the surface. The pig skin was then cut into pieces and placed in a centrifuge tube containing 1mL of methanol. Ultrasonic extraction was performed for 60 minutes, and centrifuged at 13,000 rpm for 15 minutes. The supernatant was taken and detected by HPLC.

[0080] The results are shown in Table 4. Compared with the control group, the composite electret medical excipient can effectively improve the permeation of melatonin in the sleeping Chinese medicine patch on pig skin, and the permeation enhancement effect reaches 180%, indicating that the composite electret medical excipient has a strong permeation enhancement effect.

[0081] Table 4: Comparative experiment of Chinese medicine patch containing melatonin on pig skin

[0082]

[0083] It can be seen from the above embodiments that the embodiments of the present invention utilize the composite electret film to promote the growth and migration of fibroblasts, promote wound healing and antibacterial characteristics. The product prepared by the multi-layer composite process can be used as a new type of composite electret medical dressing and used together with a variety of drugs and essential oils to achieve better biocompatibility, absorbability, antibacterial, and efficacy-promoting advantages.

[0084] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A composite electret medical dressing, characterized in that: It includes a backing layer, an electret layer, a waterproof layer, a skin-friendly layer and an anti-sticking layer which are compounded in sequence; The backing layer is a breathable fiber layer; the electret layer is a polarized organic polymer material film layer; the waterproof layer is a fluorine-containing hydrophobic layer; the skin-friendly layer is a biocompatible fiber cloth layer, and forms a closed structure with the backing layer to wrap the electret layer; the anti-sticking layer is an anti-sticking polyolefin layer.

2. The composite electret medical dressing according to claim 1, characterized in that: The backing layer is a breathable non-woven fabric layer or a breathable biological fiber fabric layer.

3. The composite electret medical dressing according to claim 1, characterized in that: The electret layer is a film layer of polytetrafluoroethylene or its isomers that has been subjected to polarization treatment, or a film layer of polyperfluoroethylene-propylene or its isomers that has been subjected to polarization treatment.

4. The composite electret medical dressing according to claim 3, characterized in that: The electret layer has a thickness between 15 micrometers and 45 micrometers, and a surface potential between 1000V and 2000V.

5. The composite electret medical dressing according to claim 1, characterized in that: The waterproof layer is a polytetrafluoroethylene hydrophobic layer, preferably with a thickness of 10-25 microns.

6. The composite electret medical dressing according to claim 1, characterized in that: The skin-friendly layer is a biological fiber cloth layer, a foamed polymer film or a collagen sponge.

7. The composite electret medical dressing according to claim 6, characterized in that: The water absorption rate of the skin-friendly layer is 10-35S / 5cm, and the liquid absorption rate is 800-1000%.

8. The composite electret medical dressing according to any one of claims 1 to 7, characterized in that: The anti-adhesive layer is an anti-adhesive polypropylene layer or an anti-adhesive polyethylene layer; the anti-adhesive layer is removed during use and the medicine is coated on the medical dressing.

9. A method for preparing the composite electret medical dressing according to any one of claims 1 to 8, comprising the following steps: Compounding the air-permeable fiber layer with the organic polymer polarized material film, wherein the compounding method includes adhesive bonding, hot-melt film hot-pressing bonding or ultrasonic integral bonding; The non-composite surface of the organic polymer polar material film is subjected to polarization treatment by using a corona charging device to form an electret layer; The fluorine-containing hydrophobic layer and the biocompatible fiber cloth layer are compounded in sequence and wrapped with the electret layer, and finally an anti-sticking polyolefin layer is selected as the anti-sticking layer covering the entire film layer to obtain the composite electret medical dressing.

10. The preparation method according to claim 9, characterized in that: The vertical distance between the charging brush in the corona charging device and the non-composite surface of the organic polymer material film is 5-10 cm, the charging voltage is 10-20 kV, and the charging time is 5-10 min; The fluorine-containing hydrophobic layer and the biocompatible fiber cloth layer are sequentially compounded in a manner including adhesive bonding, hot melt film hot pressing bonding or ultrasonic integral bonding.

Images