TW200423973A - Wound dressing - Google Patents

Abstract

The present invention provides a wound dressing for wrapping a wound on the surface of a living creature. The wound dressing at least includes more than two layers of a synthetic dressing, which consists of an air-permeable, waterproof, antibiotic upper layer for contacting with the atmosphere, and a liquid-permeable and wound-healing-promoting lower layer for contacting the wound. Each layer construction of the wound dressing further includes a nano metal particle dispersed therein for enhancing the antibacterial power or the regeneration rate of the wound cells.

Description

200423973 V. Description of the invention (1) Technical field to which the invention belongs The present invention relates to a multifunctional wound, and it relates to a multilayer structure t4. This method is especially but impermeable, and has many characteristics that can prevent the invasion of foreign bacteria = have sex and promote wound healing. Reduction of I ^ Scar production in the prior art The industrial skin is an organ of Shida, and its total surface area contract is " ~ 2 square meters A. Skin: In general, it has the function of regulating body temperature and regulating water to avoid dehydration. It is also the body's resistance to foreign pathogens to avoid injury. When it is injured, it may cause physical imbalance. When = cause, death. , Inflammation, cancer ulcer, burns, hands: Ϊ;; Sexual causes of skin deficiency and abnormalities, not only cause the patient. Each stage of treatment often also causes the patient's psychological trauma. According to relevant data, about 3.2 million people from country t are to be transplanted each year. Autogenous skin transplantation is currently used. In the United States, there are approximately one million burns and burns, with an average area of 14%, of which about 23,000 burns must be admitted to 121 burns centers. There are about 2760 patients. ^ Scald 'It is estimated that the average annual hospitalization cost of each burned and burned patient in the United States is ^ 80,000 to 80,000, and the amount of each patient from the beginning of treatment to the wound is 80,000 dollars. It ranges from RMB 6,000 to RMB 117,000. In addition to burns, 200 to 400,000 people in the United States suffer from ulcers in their feet every year due to sugar mills, and about 700,000 people suffer from venous ulcers.

Page 4 200423973 V. Description of the invention (2) U bedsores. These patients were transplanted due to their own regeneration. According to statistics, the patient knew that a skin transplant was needed. In Taiwan, about one-tenth of every 1 + q # of Tumingya burn-injured patients are large noodles; = Qian Guang Er In addition, according to the statistics of the Department of Health, 2Q 02-year spent on the skin. The amount of health insurance is about NT $ 1 billion. On the skin: Normal people usually heal small wounds on their own. The second product: burns a patient, usually from other parts of the patient's body. The skin is pulled by a machine, 0.014 inches. ^: The site is also called multi-layer skin autograft (spllt thlc = ^ s skin has, however, a large area of injury is caused by L blood). Second, the wound regeneration ability is weaker. If you use this method to dig the fruit and replenish the western wall, Yili Dibusce. ^ ^…, /, E add phase. And the wound is deep and the skin can heal, the heart ulcer such as diabetic patients with terminal ulcers, in addition to using chitin = to stop infection, usually need to use a foreign body Skin transplantation. In terms of the source of the skin, people have tried to use moonfrog skin as a source of allogeneic skin transplantation since 1500 AD. Some people used lizard f skin in 1692 and rabbit skin in 1906. The skin of dogs was used in 196, and in 1965 until now, scientists have successively used pig skin to improve it and use it as a material for private planting of heterogeneous skin. Therefore, most of the source of animal skin is artificial skin. Most commonly used As pigskin, and because it is similar to human skin was t pig as artificial skin, the need to remove residual cells after <. ,, springs with radiation sterilization and freeze-dried to reduce their antigenicity while suppressing thin

Page 5 200423973

Artificial skin such as Baker's Chang II is often used as a temporary cover for 2 degree burn wounds. It can be used for up to 10 days. The disadvantage is that radiation treatment and freeze drying are quite expensive. In order to improve this shortcoming, some people have developed the glycerol: storage method, there are not many products on the market, mainly Biocor ’,

Medical Technologies (T0peka, KS, U.S.A)

MedifilTM & SkinTempTM, developed by KollagenTM technology, is a method of reconstituting bovine type 1 collagen in the form of a body or dressing, which is used to promote the healing of superficial wounds. Speed is about 3 weeks faster than traditional methods. In addition, SYNTACOLL AG " (Her 1Sau, Switzerland) uses type 1 collagen extracted from bovine heel bonds to make a collagen film, which can be used to promote foot ulcerative wound healing. The advantages of the / w's and xenogeneic skin transplantation are that the source is not scarce, and the inner layer of the skin is biocompatible collagen; but its disadvantages are: (U xenotransplanted skin needs to be treated in a specific way to remove the animal Antigenic substances may be introduced into the skin, (2) animal-derived skin may carry protein viruses, and (3) treated animal skin cannot obtain blood from the wound. In order to solve the above-mentioned disadvantages of xenogeneic skin transplantation, some people have also proposed It can be used for transplantation. The commonly used allogeneic skin sources include human cadaver or fetal sheep μ, which has the advantages of less complicated processing methods and high compatibility with human skin tissues. The disadvantages are: (Piku (from Yang Jiu Membranes or corpses), ⑺ use of xenograft skin from the human body is also at risk of infection, and (3) allogeneic dermal transplantation is also 200423973

There is a problem of immune rejection. In order to avoid the potential risk of disease infection, artificial skin transplantation has become another option for wound treatment. It is estimated that the market for artificial skin in 2001 was about US $ 430 million. Generally, synthetic dressings are the most commonly used in the treatment of burns and scalds, because they are simple to manufacture and easy to obtain. The materials used must be neutral materials. Synthetic dressings can be attached to the wound, have elasticity, and allow the wound fluid to flow out 'and avoid fine g infections, so there are the most products on the market. The materials used in synthetic dressings are mostly hydrocolloid, polyurethane film, peptides, or chemically synthesized polymers (such as nylon), which are all non-biological Decomposable material. The outer layer is waterproofed with hair spray, and the inner layer contains antibiotics. The wound healing time for human wounds ranges from 7 to 15 days. After the wound heals, it can be removed. In recent years, rapid progress has been applied. It is not convenient, and therefore it has increased its ductility, internal quality, biogenicity, shrinkage, but it is still suitable for many types of A-type skin. Generally, it can not be satisfied. Artificial skin wounds The attachment and enhancement of the storage aperture can be compatible with the material and short wounds. The healing application group is limited to the skin, and its rapid processing also requires the various skins to be still, anti-durable, non-toxic time course of cells, and the epidermal tissue of the skin. And connective tissue, the preparation process is longer, the method is tedious, and the price should be I-2 months to make the wound more necessary for patients with skin defects. There are plenty of room for improvement, including stopping bacteria invasion and growth, increasing bombs, non-immunity, water and gas can be moved every time, using biodegradable materials, easy storage, reducing wound scars and reducing prices.

200423973 V. Description of the invention (5) Summary of the invention The dressing of the present invention is used to prevent foreign bacteria. The degradability of the present invention and the tedious manufacturing process of the present invention The dressing of the present invention is to protect the wound according to the environment in which the gas passes but grows. The layer can be used as a structure, which can promote the separation of cells from the upper layer to the upper layer and the lower layer. It can be prepared on the wound. The purpose of this is to invade another non-toxic and orderly wound system. By using the upper and lower membrane that is impervious to the water, the ring wound on the skin wound can be used to heal in the square layer. The following will be mentioned: Provides a kind of multifunctional synthetic wound that has been promoted to grow. The speed of wound healing and effective prevention of wound infection. ^ Another purpose is to provide a biocompatible and biological wound dressing. The purpose is to provide a cheap and inexpensive material. ^ Several layers of synthetic materials with different characteristics. Purpose of the invention. The indicated wound dressing 'at least contains a layer that can make: f square and-has water absorption and can provide cells as a temporary epidermal replacement I to prevent radon, fluid loss and invasion of bacteria 4 replacement layer, which has three The three-dimensional three-dimensional porous knots, cell regeneration, promote wound healing, and provide a realm and space. In addition, in order to facilitate the easy peeling on the outside without damaging the newly generated tissue, an intermediate layer can be added to separate the upper layer from the lower layer so that the upper layer can be easily peeled and removed. Example of a square layer that can use a hydrophobic polymer ’Contains polyurethane

200423973 V. Description of the invention (6) (polyurethane, PU) and silicone, but not limited to this. In order to make the upper layer have better air permeability, extensibility and elasticity, it can be prepared by using porous polyurethane. As the lower layer mentioned above, a hydrophilic polymer can be used to prepare it. Examples that can be cited here include copolymers of chitin and alginic acid (chi tosan / alginate), and gelatin. , Polylactic acid, polyglycolic acid, copolymers of glycolic acid and lactic acid, copolymerization of lactic acid and aminocaproic acid

Polymers, poly (3-hydroxybutyrate) and copolymers of poly (3-hydroxybutyrate) and 3-hydroxyvalerate, but not limited to this. As the above intermediate layer ', a substance such as hydrogel or polyacrylic acid (pAA) can be used. 〃 and 〃 are used to strengthen the antibacterial effect of the upper layer, which can further reduce the number of nano metal particles on the upper layer. In order to obtain a better antibacterial effect, the metal particles may be made of silver, but the example of silver is silver, but it is not only limited to the enhancement of the enhancement of the lower layer. Nr Qikun Mountain The ability to heal from the flail mouth, but a person with a wealthy man added a number of nano in the lower layer of d to improve the effect of d cell growth rate, which promotes the fineness of 40 nanometers. The size of the rainbow described here is preferably

The child is gold, but it is not limited to the examples that He Bei can cite. The present invention will be described with reference to these embodiments and those skilled in the art of the present invention will depart from the scope of the present invention. The following implementations do not limit the ways in which the present invention can be done and the details of the improvements and modification examples disclosed earlier will be described further. ’But still

Page 9 200423973 V. Description of the invention (7) Implementation mode Refer to figure-for a schematic diagram of a wound dressing according to the present invention. In the picture above, the upper layer of the wound Y incision dressing (丨) (:, used to contact with the outside air and resist the invasion of foreign bacteria, replace the layer, as a protective film for the wound ::: acupoint temporary; sexual The invasion of the epidermal generation. The lower layer ，) is used for dyeing, body fluid loss, bacterial fluid permeability, and promoting wound healing, etc .: At the mouth of the altar, it also provides an environment for cell growth and can have It is water-absorbent and capable of stinging the skin. In order to make the wound dressings more gas-permeable, it is said that it has the porosity to allow gas permeability. It was prepared using the < rnrighte > π ρ π material. In order to make the wound dressing more stretchable, it can be used as a joint second dressing. It is preferably formulated from a layer with elasticity and extensibility (11). Regenerating cells-a better growth environment: "Preparation. Λ Wai 'provides space for degree. Stereoporous junction = τ square layer (12) is better-metal particles with three conventional silver have better inhibitory effect. Therefore, in order to make the upper layer (1) υ fruit, especially silver ion bacteriostatic step in the upper layer (11) silver: rob :: the antibacterial effect of the father, can enter-square layer (11) of the antibacterial, ability. Among them; ^ is a particle (13), to strengthen the upper small is preferably Bu 4 0 〇nan, and the size of the upper 7 " metal silver particles is larger than the total amount of dressing in the upper layer 丨 ~ "%. _ The amount of doped silver in the nanometer accounts for the ability to accelerate wound healing. Nano-sized metal particles (⑷: can be further-stepped in the lower layer to strengthen the lower layer (1 2) to promote cells__ 画

ΗΙ

Round 1 10th stomach 200423973 V. Description of the invention (8) Growth ability. Among them, the total amount of nano-gold metal particles is 20%. ~ The lower layer is applied on the other hand, in order to make it easy to peel off above the outer side without hurting it and stretch into the lower part of the reed, it can be advanced later-step on the upper layer ⑵) and below: (layer 2 2 in) :: Health = When weaving, the upper layer (21) and the lower layer (22) can be separated, and the upper layer can be easily peeled and removed after the heart (two) mouth heals. Each, referring to the second figure, is a schematic diagram of another embodiment of a wound dressing having a multi-layer knot according to the present invention. For, Weier can be below the first-lower layer ⑵) as shown in the second figure, and add: ： the first layer (24). As mentioned before, the wound dressing (2) shown in the second figure can further incorporate a plurality of nano metal particles (25) into the upper layer (21) in order to have a good antibacterial effect on the upper layer (21). ). In addition, in order that the two compresses = (_2) can provide better wound healing effects, a plurality of nano metal particles C 2 6) can also be incorporated in the first lower layer (23) (24).

In order to make the spirit and technical characteristics of the present invention 'a clearer understanding of the technical skills of the present invention, the upper layer (21) is prepared by porous polyamino acid I, and the chitosan domain and The lower layer (22) is prepared by using oscillating acid or a copolymer obtained by copolymerizing two f, and an intermediate layer (2 3) is prepared by using polyacrylic acid "2", and an example is given to further explain the specific technology of the present invention. The above-mentioned wound dressing with multi-layer structure, in which polyacrylic acid can be obtained by

Page 11 200423973 V. Description of the invention (9) 7-ray (7-ray) irradiation is graft polymerization to make it adhere to the surface of the square, porous polyurethane. Then chitosan and / or alginic acid or a copolymer obtained by copolymerizing them with 1-ethyl- 3- (3-dimethylaminopropyl) carbodiimide (1-ethyl- 3- (3_dimethyamino propyl) carbodiimide (EDC) is connected to a porous polyurethane with polyacrylic acid on its surface to form a multilayer wound dressing. Example 1 Preparation of Multilayer Structure Wound Dressing An appropriate amount of polyurethane (pel lethane 2363-80A) was dissolved in tetrahydrofuran (THF) to prepare a 10% (w / v) polyurethane solution, and added 〇 · 5 ～ 8 times relative to the weight ratio of polyurethane to sodium chloride particles (< 25. After that, take this solution and pour it into a Teflon dish, under 60 ～ 65, and evacuate until the bath is completely evacuated. Dry until the dried polyurethane film is washed with deionized water at 80 C for 24 hours to remove sodium gas. Finally, it is dried to cast into a porous polyurethane Ester film: The above porous polyurethane film was placed in a different acrylic acid (aa) (10 ~ 40 wt%) solution, and the graft polymerization reaction was performed with 60C0 gamma rays ff. . After the completion of the graft polymerization reaction, the 忒 4 film was washed with deionized water for 24 hours to remove the reaction polymer. ^ ^ Dissolve chitosan in a 1% acetic acid solution to prepare 丨% chitosan m In addition, ‘dissolve seaweed gum salt in deionized water to prepare a 1% solution. These two solutions were mixed and then poured into

Page 12 200423973 V. Description of the invention (10) ^ = ¼ formic acid film, add ethyl ethyl 3_ (3-dimethylaminopropyl) rabbit diimide (EDC), chitin Chemically fixed to propylene

^ &Amp;, C… ^ &Jun; this sample was freeze-dried at -20 ° C. After the moxibustion and moxibustion, P was added with a vaporized 4 bow (C a C 1 2) solution for cross-linking reaction. In order to prepare a wound dressing having a multilayer structure. Example 2 Preparation of Multilayer Structure Wound Dressing Containing Nanogold Particles An appropriate amount of polyurethane (PeUethane 2363_80A) was prepared with tetrahydrofuran (THF) and glutamate to form a 10% (w / v) polyamine group. Formate solution, and add ^ 0.5 to 8 times + sodium gasified particles (< 25 #m) relative to the weight ratio of polyurethane. Then take three times to pour this solution into a Teflon dish, at 60 ~ 65 ° C, and evacuate until the bath is completely dried. The dried polyurethane thin film was washed with deionized water at 80 C for 24 hours to remove sodium chloride. Finally, it is dried to cast a porous polyurethane film. The above porous polyurethane film was put into different acrylic acid (AA) (10 ~ 40 wt%) solution, and the graft polymerization reaction was performed by irradiation with 60Cor rays. After the completion of the graft polymerization reaction, the film was washed with deionized water for 24 hours to remove unreacted monomers or homopolymers. Chitin is dissolved in 1% acetic acid solution to prepare 1% chitosan. In addition, the seaweed gum salt was dissolved in deionized water to prepare a 丨% solution. These two solutions were mixed, and then a water solution of 丨% (w / v) nano-gold particles was added so that the concentration of nano-particles in the mixed solution was 0.1% (w / v).

200423973

The mixed solution was poured into a container with a two-layer private film on the upper surface, and ethyl lambda-3_n-dicarbamate urethane thin imine (EDC) was added to polymerize chitin with monomethyl After carbonizing propyl), this sample was applied to -20: = acrylic acid hydrogel. The popular solution of CaCi2 is used for drying. Wound the dressing immediately after drying. Order the response. To prepare a multi-layered junction Example 3 Cell compatibility and growth rate test The multi-layered wound dressing prepared in Example-and Example 2 was sterilized with a 70% ethanol aqueous solution, and then a phosphate buffer solution ( PBS, pH = 7.4) Wash several times until ethanol is completely removed. The sterilized wound dressing was then placed in a 24-well (wel 1) cell culture box to complete the thin addition of the piglet chondrocytes (2nd generation) with 0.25% trypsin (trypsi η). Punch in the culture box to form a cell suspension. Centrifuge the cell suspension at 200 Or pm, remove the supernatant, and then add Dulbecco's Modified Eagle Media to 1 04. ce 1 1 s / m 1 cell suspension. Add 1 ml of each of the above cell suspensions to each well, and then place them in an environment of 5% CO2 and 37 ° C for cultivation. After 72 hours, remove the cells for cell attachment and growth tests. Refer to the third figure for the effect of nano metal particles on cell growth promotion of wound dressing. It can be seen from the third figure that after 72 hours of incubation 4

200423973 V. Description of the invention (12) Cells can proliferate to about 4 to 5 times. Among them, the number of cells attached to the nano-metal particle group is significantly larger than that of the non-metal nano-particle group. The indicated wound dressings containing nano metal particles have better cell adhesion and promote cell growth effects. It is speculated that the addition of nano gold particles may cause the surface to form a nano surface (nano roughness), giving cell physics Stimulation on cells, thus promoting cell growth. Φ

Page 15 200423973 Brief description of the drawings The first-the diagram is a schematic diagram of a wound t 7 dressing with a multilayer structure according to the present invention. The second diagram is a wound t 7 with a multilayer structure according to the present invention. Schematic diagram of an embodiment. The first figure: L is the effect of adding nano metal particles on the wound dressing to promote cell growth. O Element representative symbol 1 wound π dressing 11 upper layer 12 lower layer 13 middle layer 14 nano metal particles 15 nano Metal particles 2 Wound dressing 21 Upper layer 22 Intermediate layer 23 First lower layer 24 Second lower layer 25 Nano metal particles 26 Nano metal particles

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Claims (1)

200423973 1. A wound dressing with a strengthening function, comprising at least: an upper reed dressing for contacting with the outside air and blocking the invasion of foreign bacteria; s, contact with human skin wounds and providing a regenerative cell growth space and a lower dressing for the environment Layer; wherein the wound D dressing is doped with a plurality of nano metal particles. The wound dressing described in item 2.2 of the patent application scope, wherein the plurality of nano metal particles are dispersed in the upper layer dressing. 3. The wound dressing according to item 2 of the scope of the patent application, wherein the material of the plurality of nano metal particles is selected from the group consisting of 'silver. 4. The wound dressing according to item 2 of the patent claim, wherein the plurality of nano metal particles have a size of 1 to 400 nanometers. 5. The wound dressing according to item 2 of the scope of the patent application, wherein the doped amount of the plurality of nano metal particles accounts for 20% of the total dressing of the upper layer. 6. The wound dressing according to item 2 of the scope of patent application, wherein the plurality of nano metal particles can strengthen the antibacterial property of the upper layer dressing. 7. The wound dressing according to item 1 of the patent application scope, wherein the plurality of nano metal particles are dispersed in the lower layer dressing. 8. The wound dressing according to item 7 of the scope of patent application, wherein the material of the plurality of nano metal particles is selected from gold. 9. The wound dressing according to item 7 in the scope of the patent application, wherein the size of the plurality of nano metal particles is 400 nanometers. 10 · The wound material according to item 7 in the scope of the patent application, wherein the doped amount of the plurality of nano metal particles accounts for 20% of the total dressing of the lower layer. 200423973 The scope of application for patents 1 and 2 is the patented wound σ dressing described in item 7 above, wherein the plurality of metallic particles can strengthen the rate of the lower layer dressing to promote the growth of regenerative cells to accelerate wound healing. ,, 1 2 · = The wound dressing described in item 1 of the scope of patent application, wherein the upper layer dressing is porous, which allows gas to pass through but is impervious to water. 〃 1 3 · The wound dressing as described in item 1 of the patent application scope, wherein the upper acoustic dressing is elastic and extensible. / Said the wound dressing according to item 12 or 13 of the scope of the patent application, wherein the square-layer dressing is selected from the group consisting of porous polyurethane or Shi Xiyu 15 16. 17. 18. The lower layer provides cells with the wound dressing as described in item 1 of the scope of the patent application. The wound dressing has a three-dimensional spatial three-dimensional porous structure, and uses the environment and space. ί Γί The wound dressing according to item 1 of the scope, wherein the lower layer of Fang Wen 枓 is biocompatible, biodegradable, and non-toxic. The wound dressing according to item 15 or 16 of the scope of the applied patent may not be j 1: the side is selected from the copolymer of chitosan and alginic acid: coagulation; Pui Shui Li, Polyglycolic Acid, Glycolic Acid, Lactic Acid and Lactic Acid, Copolymer of F and Aminocaproic Acid, Poly (3-Hydroxybutyrate ') Dimer (3_ Sodium Butyrate) and 3— Copolymer of valproate. A wound dressing having a strengthening function, comprising at least: an upper dressing for contacting with outside air and blocking invasion of foreign bacteria; and a wound dressing for contacting the skin wound and providing regeneration cell growth space 200423973 VI. Scope of patent application " ----- ^ ___ and the lower dressing layer under the environment;--^ 2 / Eight middle layers that make the upper dressing and the lower dressing easy to peel off; and 19 • Such as a plurality of nano metal particles in a two-D dressing. The wound dressing according to item 18 of Gan Taigan Wai, wherein the plurality? Η = Meng_ particles are dispersed in the upper layer dressing. It is called the wound dressing described in item 19 of the patent fan garden, and the material of the plurality of 21 1 solid ^ metal particles is selected from silver. Eight Φ • The wound dressing according to item 19 of the scope of patent application, wherein the plurality of nano metal particles have a size of 400 nanometers. ', 2 2 · The wound dressing according to item 19 of the patent claim, wherein the plurality of metal particles can strengthen the antibacterial property of the upper layer dressing. The wound material according to item 19 of the patent application scope, wherein the doped amount of the plurality of nano metal particles accounts for 1 to 20% of the upper layer dressing 纟 Φ and the amount. "2 4 · The wound material according to item 18 of the scope of patent application, wherein the plurality of nano metal particles are dispersed in the lower layer material. 25. The wound material according to item 24 of the patent application, wherein the material of the plurality of nano metal particles is selected from gold. 26. The wound material according to item 24 of the scope of the patent application, wherein the size of the plurality of nano metal particles is about 400 nanometers. 2 7 · The mouth dressing of item 24 in the scope of the patent application, wherein the doped plutonium of the plurality of nano metal particles accounts for 1 to 20% of the total dressing of the lower layer.乂 ’ 200423973 6. Scope of patent application-28. The number of wounds as described in item 24 of the scope of patent application, wherein the plurality of nano metal particles can strengthen the rate of the lower layer dressing to promote the growth of regenerative cells to accelerate wound healing. 29. The wound material according to item 18 of the scope of the patent application, wherein the upper layer dressing has porosity, which allows gas to pass through but is impervious to water. 30. The wound dressing as described in item 18 of the patent claim, wherein the upper layer dressing is elastic and extensible. 31. The wound dressing as described in claim 29 or 30, wherein the The top dressing is selected from porous polyurethane or silicone. 3 2 · The wound dressing according to item 18 of the scope of patent application, wherein the lower layer dressing has a three-dimensional spatial three-dimensional porous structure to provide an environment and space for cell regeneration. 3 3 · The wound dressing according to item 8 in the scope of the patent application, wherein the lower layer dressing is biocompatible, bio V-cleavable and non-toxic. 3 4 · The wound dressing according to item 3 2 or 33 of the scope of the patent application, wherein the lower layer dressing is selected from the group consisting of a copolymer of chitosan and citric acid, gelatin, polylactic acid, polyglycolic acid , A copolymer of ethanol, lactic acid and lactic acid, a copolymer of lactic acid and aminocaproic acid, and a copolymer of poly (3-butanoate) or poly (3-hydroxybutyrate) and 3-hydroxyvalerate. 35. The wound dressing according to item 18 of the scope of the patent application, wherein the intermediate layer dressing is selected from hydrogel or polyacry1ic acid (PAA). 3 6 · The wound dressing according to item 丨 8 of the patent application scope, wherein the intermediate Page 20 200423973 VI. Scope of patent application The layer dressing is attached to the surface of the upper layer dressing by graft copolymerization. 37. The wound dressing according to item 18 of the scope of the patent application, wherein the wound dressing further comprises a plurality of lower layer dressings according to different needs. Page 21