JP2001212222A - Wound coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an wound coating material capable of easily and securely fixing a biological material to an wounded part for achieving early and efficient treatment by promoting the growth of tissue cells and new growth of blood vessels with the wounded surface being kept in an appropriate moist condition in the process of treatment, even if the coating material is applied to an wounded part with much effusion, without giving pains to a patient nor damaging the reproduced skin etc., when the coating material is changed. SOLUTION: The wound coating material comprises a polyurethane layer, an adhesive layer made of (meth)acrylate alkyl ester polymer, a non-woven. fabric layer and a sponge layer including hyaluronic acid crosslinked with an epoxy compound, which are layered in order, and includes an antibacterial agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel wound dressing. More specifically, the wound dressing material of the present invention is applied to a wound part that exudes a large amount of wound fluid when stopping or treating a wound part such as a burn, a pressure sore, a skin ulcer, an abrasion, or a cut, thereby protecting the wound part. To allow cells with tissue repair function to enter into it and to quickly and easily fix the biomaterial that promotes the healing of the wound to the wound, and at the same time to easily replace and damage the wound There is no one.

[0002]

2. Description of the Related Art Conventionally, as a method of stopping or treating a wound such as a burn, a pressure sore, a skin ulcer, an abrasion, or a cut, a therapeutic agent is applied to the wound, and then a gauze or cotton wool is applied thereon. There have been proposed many methods for protecting a wound by covering the wound with a wound dressing material.

When gauze is directly applied to a wound, exudate from the wound is directly absorbed by the gauze.
The absorption capacity of the gauze is not very high and exudate accumulation occurs. This storage, on the contrary, promotes the generation of bacteria and makes early healing difficult. In particular, in a wound part where the exudate from the wound is large, the ointment or cream of the therapeutic agent mixes with the exudate to form a muddy state. Therefore, the wound dressing must be replaced frequently and the ointment or cream must be reapplied. Further, if the wound dressing is changed frequently, the amount of medicine to be used increases, and there is a problem that the pain of the patient when changing the wound dressing increases. In addition, these conventional wound dressings have low antibacterial properties and, when protecting the wound for a very short time, even if they can be easily separated from the wound, In the case of peeling after coating for a long time, it is often peeled off integrally with the granulation, and the blood clot is exposed again, causing unpleasant pain and rebleeding, etc. Has disadvantages. Therefore, when the rebleeding wound portion is repeatedly covered with the same wound dressing material again and the final healing is performed, scars easily remain on the wound portion after healing, which is not preferable in cosmetic surgery. There were problems such as.

[0004] As alternatives to these, wound dressing materials made of artificial materials such as silicone gauze and silicone rubber film sheets, and wounds made of biological materials such as freeze-dried pork skin, chitin nonwoven fabric, collagen film, and polyamino acid sponge can be used. Coatings are also known. However, among these, the wound dressing made of an artificial material leaves various problems in terms of adhesion to a wound portion, water vapor permeability, and the like. On the other hand, wound dressings made of biological materials have characteristics such as biocompatibility, but many of them have antigenicity and also have drawbacks such as cell infection and deterioration due to exudate.

Further, from the viewpoint of good affinity with the wound site and promotion of healing, materials derived from living organisms, such as hyaluronic acid and alginic acid, have been taken up in the medical field such as wound dressing. Have been. However, hyaluronic acid is not only highly biocompatible and highly biodegradable, but also can promote the proliferation and angiogenesis of fibroblasts and help heal wounds, When applied, uncrosslinked hyaluronic acid has a short remaining period and is a device for obtaining good retention in the wound, i.e., it is present in the wound for a necessary period, and disappears from the tissue as the defective tissue is healed. It has long been desired to obtain a substance suitable for the purpose of progressing. In addition, since the metal salt of alginic acid extracted from seaweed has a hemostatic effect, an analgesic effect, and a mucosal protective effect, a wound dressing made of alginate has been put to practical use. There is a problem that there is cytotoxicity.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to apply to a wound with a large amount of exudate, to absorb a considerable amount of exudate exuding from the wound and to contain the exudate in the exudate. Proliferation of the tissue cells while maintaining the wound in a moderately moist environment by transferring the moisture to be transferred through the wound dressing to the outer surface of the wound dressing within a desired speed and evaporating this water into the surrounding environment. And quickly and easily hold and fix the biomaterial that promotes angiogenesis to the wound site, thereby realizing early and efficient treatment promotion.
It is an object of the present invention to provide a wound dressing material that does not cause pain when replacing the wound dressing material or damage to the regenerated skin or the like.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. The present invention is as follows. (1) A wound dressing material in which a polyurethane film layer, a pressure-sensitive adhesive layer made of a (meth) acrylic acid alkyl ester-based polymer, a nonwoven fabric layer, and a sponge layer containing hyaluronic acid crosslinked with an epoxy compound are sequentially laminated. (2) 1 to 20 uncrosslinked hyaluronic acid in the sponge layer
2. The wound dressing according to the above 1, which is contained by weight. (3) The wound dressing according to the above (1) or (2), which contains an antibacterial agent.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to a wound with a large amount of exudate, absorbs a large amount of exudate released from the wound, and evaporates water contained therein into the surrounding environment. At the same time, a sponge layer containing hyaluronic acid crosslinked with an epoxy compound is quickly and easily brought into close contact with a wound site, thereby providing a wound dressing material that promotes wound healing and facilitates peeling after healing. Things.

[0009] The wound dressing directly covers and protects the wound, softens the wound, provides an appropriate moist environment, and prevents bacterial contamination. Furthermore, the wound dressing is made of a cell-infiltrating material, and when applied to the wound site, macrophages, neutrophils and other inflammatory cells infiltrate and fibroblasts infiltrate at an early stage. It is preferable that the dermal-like connective tissue is constructed to promote the healing of the wound, and the material is eventually absorbed by the wound surface and disappears with the healing of the wound. A sponge layer containing hyaluronic acid, which is a biomaterial, is suitable as a material for promoting such cell invasion.

[0010] Hyaluronic acid is a biomaterial, which itself has the effect of promoting wound healing and, at the same time, is degraded and absorbed over time when applied to a wound. Therefore, when the wound dressing of the present invention is applied to a wound, not only can healing be promoted, but also there is no need for peeling or the like at the time of replacement, and there is no possibility that the wound in the healing process will be adversely affected. Hyaluronic acid provides a highly hydrated microenvironment to the wound during the wound healing process. It is known that, in such a microenvironment, adhesion and detachment of a cell membrane and a substrate when various cells move through a wound is controlled, and cell healing is facilitated, so that wound healing is promoted. ing.

Thus, hyaluronic acid is not only highly biocompatible and biodegradable, but also
Although it can promote the proliferation and angiogenesis of fibroblasts and assist wound healing, hyaluronic acid is of biological origin and therefore has a high affinity for cell tissues, but uncrosslinked hyaluronic acid has hyalonase and the like in vivo. Easily decomposed and absorbed by enzymes. When using it there,
It is necessary to introduce cross-links by some means to enhance physical properties. However, the introduction of cross-linking greatly reduces the affinity of hyaluronic acid for cells and tissues before introduction, and tends to prevent cell invasion. That is, it is difficult to achieve both enhancement of physical properties and improvement of biological performance such as affinity for cells and tissues.

As a result of extensive studies, the present inventors have found that a polyurethane film layer, a pressure-sensitive adhesive layer made of an alkyl (meth) acrylate polymer, a nonwoven fabric layer, and a sponge layer containing hyaluronic acid cross-linked with an epoxy compound are sequentially formed. The present invention has found that the wound dressing material formed by laminating can quickly and easily adhere a sponge layer containing hyaluronic acid to a wound site, promotes wound healing and facilitates peeling after healing. Reached. In particular, the wound dressing of the present invention is suitable for application to wounds with high exudate.

[0013] Polyurethane resins suitable for use in making the polyurethane film of the present invention are produced using three components of a diisocyanate, a polyol and a chain extender as basic materials. In the reaction, first, an excess equivalent of diisocyanate is reacted with the polyol at 50 to 120 ° C. to form a urethane prepolymer having an isocyanate group at the terminal, and then the chain is extended with a chain extender at 0 to 100 ° C. in an organic solvent. Good. Here, the equivalent ratio between the diisocyanate and the polyol in the urethane prepolymer is usually 1.5 to 6: 1, but it should be 1.8 to 4.5: 1 in order to combine good physical properties and moisture permeability. Is preferred.

The diisocyanate used in the present invention includes 4,4'-diphenylmethane diisocyanate,
m- and p-phenylene diisocyanate, 2,4-
And aromatic diisocyanates such as 2,6-tolylene diisocyanate, isophorone diisocyanate,
4′-dicyclohexylmethane diisocyanate, 1,
Alicyclic diisocyanates, such as 4-cyclohexylene diisocyanate, and aliphatic diisocyanates, such as hexamethylene diisocyanate. Usually, these compounds are used alone, but two or more kinds may be used in combination.

[0015] The polyol used in the present invention includes:
Polyether polyol, polyester polyol, or polycarbonate polyol is used. And
Examples of the polyether polyol include polypropylene ether glycol and polytetramethylene glycol. Examples of the polyester polyol include polybutylene adipate and polycaprolactone glycol. Moreover, as polycarbonate polyol, 1,
6-hexane polycarbonate diol.
Usually, these compounds are used alone, but two or more kinds may be used in combination.

As the chain extender used in the present invention, a low molecular weight diol or diamine is used. Representative examples of the low molecular weight diol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexamethylene glycol and the like. Representative examples of low molecular weight diamines include aliphatic diamines such as ethylenediamine, 1,2-propanediamine, tetramethylenediamine, and hexamethylenediamine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 1,4-cyclohexylene. Alicyclic diamines such as diamines; Of these, isophoronediamine is preferable from the balance of various physical properties of the polyurethane layer, and can be used alone or in combination of two or more.

As the organic solvent used for synthesizing the polyurethane of the present invention, solvents having a strong dissolving power such as dimethylformamide, dimethylacetamide and dimethylsulfoxide are suitable. These solvents are used alone or in an aromatic solvent such as toluene and xylene, methyl ethyl ketone, and the like. One or more selected from ketone solvents such as acetone and cyclohexanone, ether solvents such as tetrahydrofuran and dioxane, acetate solvents such as ethyl acetate and butyl acetate, and alcohol solvents such as methanol, ethanol and isopropanol. It can be used as a mixture with two or more kinds.
The concentration of the polyurethane solution is 2 to 30% by weight, preferably 3 to 25% by weight.

The polyurethane film layer used in the present invention can be prepared by, for example, a dry method or a wet method. That is, in the case of the dry method, it is obtained by applying a polyurethane resin solution onto release paper and drying the solvent. In the case of the wet method, it is obtained by applying a urethane solution on a release paper, extracting a solvent or other soluble substances in a coagulation bath, and then drying, but is not limited to the above method. .

The thickness of the polyurethane film layer can be adjusted by, for example, the concentration of the polyurethane solution or the amount of the applied solution. The thickness of the polyurethane film layer is not particularly limited, but is usually 5 to 100 μm, preferably 8 to 5 μm.
0 μm. When the thickness is 5 μm or less, pinholes are easily formed during coating, and the polyurethane layer is easily blocked and is difficult to handle. If it is 50 μm or more, it tends to be difficult to obtain sufficient moisture permeability. Further, the polyurethane layer becomes hard, and the adhesion to the skin tends to be impaired.

The polyurethane film obtained by the above method has sufficient strength, elongation and durability for practical use, and at the same time, does not allow water and bacteria to pass therethrough. In addition, because of its good moisture permeability, it prevents stuffiness at the wound site.

The release paper used when preparing a polyurethane film by the above-mentioned dry method or wet method is as follows.
Although not particularly limited, polyester, polyethylene-coated high-quality paper, polyolefin-coated glassine paper, polypropylene film, or the like having one surface coated with a fluorine or silicone release agent is used.

After the release paper used in the preparation of the polyurethane film is removed, the release paper may be laminated on the pressure-sensitive adhesive layer, the nonwoven fabric layer and the sponge layer, or the pressure-sensitive adhesive layer, the nonwoven fabric layer and the sponge layer with the release paper attached. May be removed after attaching to the wound.

The pressure-sensitive adhesive layer used in the present invention comprises (meth)
It is composed of an alkyl acrylate polymer. As the monomer capable of forming the (meth) acrylic acid alkyl ester polymer, for example, (meth) acrylic acid alkyl ester and a polymerizable monomer copolymerizable therewith are preferably used. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and dodecyl (meth) acrylate. And the like. Further, as the polymerizable monomer copolymerizable, (meth) acrylic acid,
Examples thereof include vinylpyrrolidone, diacetone acrylamide, (poly) ethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, vinyl acetate, and styrene.

The above (meth) acrylic acid alkyl ester-based polymer can be synthesized by a method such as solution polymerization or bulk polymerization.

These polymers are usually formed in a pressure-sensitive adhesive layer after being dissolved in a solvent. The solvent used to dissolve the polymer is not particularly limited as long as it is a solvent that dissolves the above-mentioned polymer, but, for example, methyl ethyl ketone, acetone, ketone solvents such as cyclohexanone, tetrahydrofuran, dioxane and the like One or two or more selected from ether solvents, acetic ester solvents such as ethyl acetate and butyl acetate, and alcohol solvents such as methanol, ethanol and isopropanol can be used. The concentration of the polymer in the solvent is appropriately selected depending on the thickness of the pressure-sensitive adhesive layer, but is preferably in the range of 2 to 50% by weight, and 5 to 30% by weight.
Is more preferable.

There is no particular limitation on the method of laminating the pressure-sensitive adhesive layer on the polyurethane film layer. For example, the pressure-sensitive adhesive layer obtained by applying the above-mentioned polymer solution on release paper and drying the solvent is removed. It may be prepared by laminating with a polyurethane film layer, or by directly applying the above-mentioned polymer solution on the polyurethane film layer and evaporating the solvent.

The thickness of the pressure-sensitive adhesive layer is not particularly limited as long as the sponge layer can be adhered to and retained on the polyurethane film layer without impairing the moisture permeability, and the present wound dressing can be adhered and retained on the skin of a human body. ５０50 μm, preferably 5-30 μm. One object of the wound dressing of the present invention is to absorb a large amount of exudate released from a wound when applied to a wound with a large amount of exudate, and to remove water contained in the exudate. Within the desired rate, transfer through the wound dressing to the outer surface of the wound dressing, allowing this moisture to evaporate into the surrounding environment and keeping the wound in a reasonably moist environment. In order to achieve this object, it is preferable to use a nonwoven fabric composed of hydrophobic fibers and superabsorbent fibers.

As the hydrophobic fiber used in the present invention, synthetic fibers such as polyester, nylon, acryl, polypropylene and polyethylene are preferable. As the highly absorbent fiber, wood pulp, natural fiber of cotton, rayon, regenerated fiber of cupra, semi-synthetic fiber such as acetate, and the like are used. Particularly, the hydrophobic fiber and the superabsorbent fiber are 6: 4 by weight.
When used in a ratio of 8: 2, the hydrophobic fibers receive water from the highly absorbent fibers that have absorbed the exudate, and serve to evaporate the water in the outer air layer, which is particularly preferable. The thickness of the fiber constituting the nonwoven fabric layer composed of the hydrophobic fiber and the highly absorbent fiber is about 0.3 to 5 denier (d), preferably 0.5 to 3 denier (d).
It is desirably about d.

As a method for producing a non-woven fabric, it can be produced by a known method, for example, the following method. A wet process in which a short fiber layer (web) is made with water, impregnated with resin, and dried and hardened, just as paper is made. A dry method in which a web is made mechanically without using water and bonded with resin or adhesive fibers. A needle punch method in which a web of the same type as the dry type is pierced with a pierced needle to mechanically entangle the fibers. Spunlace method in which fibers are entangled with a high-pressure water stream on a web of the same type as the dry type. A web with a uniform thickness by arranging a large number of continuous yarns in all directions like a spider web while simultaneously blowing out the melted raw resin from many small holes (nozzles) before forming fibers Spunbonding method, where yarns are naturally and mechanically attached to each other.

The above-mentioned nonwoven fabric layer can also be formed by any of these known methods,
Alternatively, these methods can be used in combination, but depending on the production method, a direction in which the fiber is easily stretched and a direction in which the nonwoven fabric is difficult to stretch can be formed. Since the nonwoven fabric used in the present invention must have elasticity, a nonwoven fabric having a relatively large elongation is used. The degree of elongation is a percentage of the original length of a nonwoven fabric having a length of 60 cm and a width of 6 cm when a load of 1500 g is hung. The nonwoven fabric used in the present invention is preferably 30 to 200%. And more preferably, 40 to 150%.

The thickness of the nonwoven fabric layer is preferably 1 to 20 mm in consideration of flexibility, durability, workability, absorbency and the like.
And more preferably about 1 to 10 mm. The basis weight of the nonwoven fabric layer, from the viewpoint of the retention of exudate,
Preferably, the basis weight is 30 to 300 g / m ² , more preferably 50 to 200 g / m ² .

When a nonwoven fabric layer composed of only the hydrophobic fibers is further laminated on one or both sides of the nonwoven fabric layer composed of the above-mentioned hydrophobic fibers and superabsorbent fibers, the nonwoven fabric layer composed of the above hydrophobic fibers and the superabsorbent fibers is formed. There is an advantage that, at the same time as suppressing fluffing, the adhesiveness of the nonwoven fabric layer composed of the hydrophobic fiber and the highly absorbent fiber can be further improved.

Examples of the fiber material composed of only hydrophobic fibers include polyester, polypropylene, polyethylene, nylon, and thermoplastic elastomer. Among these hydrophobic fiber materials, a thermoplastic elastomer is a preferable material as a wound dressing material because it exhibits rubber elasticity at room temperature and is highly elastic. Among thermoplastic elastomers,
Polyolefin-based, polyurethane-based, and polyester-based elastomers are particularly preferred because they are soft and have high elasticity. As these hydrophobic fiber materials, commercially available products or improved products thereof can be used.

The thickness of the fibers constituting the nonwoven fabric layer composed of only hydrophobic fibers is preferably about 0.3 to 5 d, more preferably about 0.5 to 3 d.

The basis weight of the nonwoven fabric layer composed of only hydrophobic fibers is preferably 5 to 100 g / m ² .

The method for laminating the nonwoven fabric layer on the pressure-sensitive adhesive layer laminated on the polyurethane film is not particularly limited, but the area of the nonwoven fabric layer is made smaller than the area of the pressure-sensitive adhesive layer to be laminated, and It is necessary to keep the pressure-sensitive adhesive layer exposed at the periphery.

It should be noted that the adhesive layer exposed on the periphery of the polyurethane film should be pasted with a release paper which can be easily peeled off before application to the wound in order to prevent adhesion to unnecessary parts. Is preferred. The release paper is removed just before applying the wound dressing to the wound.

When hyaluronic acid crosslinked with an epoxy compound is used for the sponge layer of the wound dressing of the present invention, it is possible to achieve both enhancement of the physical properties of hyaluronic acid and improvement of biological performance. That is, when the carboxyl groups of hyaluronic acid are cross-linked with an epoxy compound, a cross-linked hyaluronic acid that is strong and has high enzyme decomposability can be obtained without affecting the basic structure of hyaluronic acid. When the cross-linked hyaluronic acid is decomposed by the enzyme again, the hyaluronic acid is regenerated and effectively acts on the wound healing, so that a highly safe wound dressing material having a long-lasting healing effect can be obtained.

Further, the uncrosslinked hyaluronic acid is added in an amount of 1 to 20.
It is particularly preferable to add the amount by weight so that the effect of hyaluronic acid is exerted immediately after the wound dressing is applied to the wound.

As the hyaluronic acid to be crosslinked, for example, those having a molecular weight of preferably 500,000 to 3,000,000, more preferably 1.8 to 2.2 million are used. As the crosslinking agent, a water-soluble polyfunctional epoxy compound can be used. As the polyfunctional epoxy compound, for example,
Ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylol Examples thereof include propane triglycidyl ether, sorbitol polyglycidyl ether, diglycidyl succinate, and diglycidyl adipate.

The crosslinking reaction is generally carried out at 0.2 to 2.0% by weight of hyaluronic acid, preferably at 0.5 to 1% by weight.
An aqueous solution is prepared and the pH of the solution is 4-7, preferably about 5
After adjusting to ~ 6, a reaction in which the epoxy compound is added so as to be about 1 / 5,000 to 1 mol, preferably about 5 / 5,000 to 1/5 mol with respect to the repeating unit of hyaluronic acid. It can be performed using a liquid. As the solvent, in addition to the above-mentioned water, an alcohol-water system can be used.

The reaction temperature may be, for example, about 20 to 80 ° C., preferably about 40 to 60 ° C., and the reaction time is preferably 2 to 10 hours, more preferably 4 to 6 hours.

The degree of cross-linking of hyaluronic acid is determined by the type, proportion and reaction conditions of the epoxy compound used in the cross-linking reaction. The degree of cross-linking determines the biodegradability, water content and hydrolysis rate of hyaluronic acid after molding. Therefore, the degree of cross-linking should be appropriately selected according to the application site of the wound dressing and the purpose of use.

In general, after being implanted in a living body (for example, subcutaneously of Wistar rats) and allowed to stand for one week, 5 to 30
It is preferable that about weight% of hyaluronic acid or hyaluronic acid crosslinked with an epoxy group remains.

The cross-linked hyaluronic acid used in the present invention needs to have good contact with the wound.
For this reason, a sponge-like material is particularly preferable. The sponge layer containing cross-linked hyaluronic acid may be a sponge layer composed of only cross-linked hyaluronic acid, a mixed sponge layer composed of cross-linked hyaluronic acid and uncrosslinked hyaluronic acid, or a sponge layer of cross-linked hyaluronic acid and uncrosslinked hyaluronic acid. It may be a laminate of sponge layers.

As a method for forming the sponge layer of the present invention,
Generally, a solution comprising hyaluronic acid and / or cross-linked hyaluronic acid is treated at -20 ° C to -100 ° C, preferably at -4 ° C.
Freeze-freeze in a freezer at 0 to -80 ° C and vacuum dry,
Alternatively, it is obtained by gradually freezing at −30 to −50 ° C. in a freeze dryer and then vacuum drying. For example,
When preparing a mixed sponge layer containing hyaluronic acid and cross-linked hyaluronic acid, after mixing an aqueous solution of hyaluronic acid and an aqueous solution of cross-linked hyaluronic acid, −20 ° C. to −100 ° C.,
Preferably, it may be produced by quenching and freeze-drying in a freezer at −40 to −80 ° C., or gradually drying at −30 to −50 ° C. in a freeze dryer, followed by vacuum drying. May be manufactured.

When a sponge layer containing hyaluronic acid and a sponge layer containing cross-linked hyaluronic acid are laminated, first, a solution of hyaluronic acid is poured into a molding container, and then a solution of cross-linked hyaluronic acid is poured onto the container. -20 ° C to -10
It may be manufactured by quenching and freeze-drying in a freezer at 0 ° C., preferably −40 to −80 ° C., or gradually freeze to −30 to −50 ° C. in a freeze dryer, It may be manufactured by drying.

As a method for forming the sponge layer, the freeze-drying method as described above can be exemplified, but the method is not limited thereto, and those skilled in the art can employ an appropriate method.

The thickness of the sponge layer may be arbitrarily set depending on the purpose of use of the wound dressing material and the site to be applied. Preferably, the thickness of the sponge layer is 1 to 20 mm, more preferably about 2 to 10 mm. . When a sponge layer of hyaluronic acid and a sponge layer of cross-linked hyaluronic acid are laminated, the sum of the thicknesses is 1 to 20 mm, more preferably 2 to 10 mm.
It is about.

The thickness of the sponge layer of hyaluronic acid and / or cross-linked hyaluronic acid can be arbitrarily set by changing the concentration and ratio of the hyaluronic acid and / or cross-linked hyaluronic acid solution to be injected into the molding container.

As a method of laminating the above-mentioned sponge layer and nonwoven fabric layer, any known method may be used. When a sponge layer containing hyaluronic acid and / or cross-linked hyaluronic acid is prepared, a polyurethane film layer and an adhesive layer are used. And a non-woven fabric layer. That is, first, a laminate comprising a polyurethane film layer, a pressure-sensitive adhesive layer, and a nonwoven fabric layer is prepared, a mold having the same shape as the nonwoven fabric layer is placed on the pressure-sensitive adhesive layer, and hyaluronic acid and / or
Preferably, a solution containing cross-linked hyaluronic acid is added and freeze-dried. In this case, since the pressure-sensitive adhesive is exposed at the periphery of the polyurethane film layer, the pressure-sensitive adhesive layer can be stuck so as to be in contact with healthy skin around the wound. In this case, the pressure-sensitive adhesive layer at the peripheral portion of the wound dressing has a strong adhesive force and thus is not easily peeled off. In addition, since the skin irritation is extremely small, there is an advantage that skin irritation hardly occurs even when applied to the skin for a long time. . On the other hand, since only the sponge layer containing the crosslinked hyaluronic acid of the biomaterial comes into contact with the wound site, it not only promotes the healing of the wound site but also damages the wound site when removing the wound dressing of the present invention. Absent. Furthermore, when applied to a wound part with a large amount of exudate, a large amount of exudate released from the wound part can be absorbed, and the moisture contained in the exudate can be absorbed at a desired rate within a wound dressing material. Through the skin to the exterior surface of the wound dressing, allowing this moisture to evaporate into the surrounding environment and keeping the wound in a moderately moist environment. in this way,
By allowing the water vapor from the absorbed liquid to escape into the atmosphere, the frequency of replacement of the wound dressing can be reduced.

The wound dressing material has a problem that the antibacterial effect is not exerted at the wound site. Therefore, the wound dressing material may be any of the constituent members of the polyurethane film layer, the adhesive layer, the nonwoven fabric layer and the sponge layer. Alternatively, it is preferable to mix an antibacterial agent in all the constituent members. Antibacterial agents include sulfa drugs, penicillin, nalidixin,
Although any antibacterial agent such as silver sulfadiazine, polymyxin sulfate, and gentamicin sulfate can be used, the most preferable is to use silver sulfadiazine having a broad antibacterial spectrum and resistant bacteria from appearing. The content of the antibacterial agent may be determined according to the type of the drug, the purpose of use of the wound dressing, and the application site. When silver sulfadiazine is used, the content or the amount of the wound dressing is 20 to 500 μg / cm ² , preferably 30-400
μg / cm ² . With such a content, the growth of bacteria on the wound surface can be suppressed, and at the same time, the growth of cells inside the wound dressing that has absorbed the exudate can be effectively suppressed.

The present wound dressing can be formed into an arbitrary shape such as a bandage shape or a pad shape of several cm square to several tens cm square, and is appropriately selected according to the degree and depth of the wound, the area of the wound surface, and the like. Can be used.

[0054]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the effects of the present invention will be specifically described. However, the present invention is not limited to the following Examples.

Example 1 Production of Wound Dressing Material Production of Polyurethane Film Layer 700 parts by weight of polytetramethylene glycol having a number average molecular weight of 2,000 and 180.6 parts by weight of 4,4'-dicyclohexylmethane diisocyanate were placed in a flask under dry nitrogen. After reacting at 75 ° C. for 5 hours in the mixture to obtain a urethane prepolymer having an isocyanate group at the terminal, a chain extending reaction is carried out for 2 hours while maintaining the temperature at 20 ° C. using isophoronediamine as a chain extender in a dimethylacetamide solvent. This gave a colorless, transparent and viscous polyurethane solution having a polyurethane solid concentration of 25% by weight. Methyl ethyl ketone was added to this solution to prepare a 15% by weight polyurethane solution, which was applied to release paper having a silicon-based film formed on the surface so that the thickness of the polyurethane layer upon drying was 40 μm. Next, it was placed in a hot air dryer and dried at 100 ° C. for 3 minutes to remove the solvent. Manufacture of pressure-sensitive adhesive layer 50 parts by weight of acrylic acid, 100 parts by weight of vinylpyrrolidone, 250 parts by weight of isooctyl acrylate, 100 parts by weight of ethyl acetate in an inert gas atmosphere in a reactor equipped with a thermometer, a stirrer and a reflux condenser Parts and 2 parts by weight of azobisisobutyronitrile were charged and polymerized at 60 ° C. for 30 hours. After taking out the polymer, ethyl acetate was further added so that the polymer concentration became 25% by weight, and the mixture was uniformly mixed to prepare a pressure-sensitive adhesive layer solution. This solution was applied onto release paper having a thickness of 40 μm and treated with silicone treated polyethylene terephthalate so as to have a thickness of 20 μm after drying, and dried at 60 ° C. for 30 minutes to produce an adhesive layer. Manufacture of non-woven fabric layer The non-woven fabric layer composed of the hydrophobic fiber and the high-absorbency fiber is formed by mixing a polyester fiber having an average fineness of 1.5d and a rayon fiber having a average density of 2.0d at a weight ratio of 70:30, and then forming an extremely thin fiber After making a layer (web) of the above and laminating the web so that the basis weight is 100 g / m ² , the web layer is stuck with a pierced needle and the fibers are mechanically entangled with each other. (Needle punch method). Next, a hydrophobic polyester-based thermoplastic elastomer (trade name: Perprene, manufactured by Toyobo Co., Ltd.) was bonded to both surfaces of the nonwoven fabric layer by a spun bond method so that the total weight of the nonwoven fabric layer was 140 g / m ² . . Manufacture of cross-linked hyaluronic acid One of the 2 million molecular weight hyaluronic acid produced by fermentation
Ethylene glycol diglycidyl ether as a crosslinking agent was added to a 1% by weight aqueous solution (pH = 6) so as to be 1/10 mol of the molecular weight of the repeating unit of hyaluronic acid. Next, the mixture was allowed to stand in a dryer set at 50 ° C. for 5 hours to perform an intermolecular crosslinking reaction. The pressure-sensitive adhesive layer manufactured in the step of manufacturing the wound dressing was bonded to the manufactured polyurethane film having a thickness of 40 μm to prepare a laminate having the pressure-sensitive adhesive layer and the polyurethane film layer. Next, the above laminate was cut into a circular shape having a diameter of 100 mm, and the inner release paper was removed, leaving a peripheral portion of the adhesive layer 25 mm around the release paper. The nonwoven fabric thus obtained was placed on the nonwoven fabric and bonded via an adhesive.
Next, a circular polystyrene mold having an inner diameter of 50 mm (20 cm ² ) and a height of 20 mm is placed on the nonwoven fabric, and 16 cc of a cross-linked hyaluronic acid aqueous solution adjusted with 4 cc of a 1% by weight aqueous solution of uncross-linked hyaluronic acid is placed therein. Then, 1 mg of silver sulfadiazine was sufficiently mixed and added, frozen at −40 ° C., and dried under vacuum to produce a spongy wound dressing containing crosslinked hyaluronic acid.

Example 2 Preparation of Wound Dressing Preparation of Cross-Linked Hyaluronic Acid 1 of 2,000,000 molecular weight hyaluronic acid produced by fermentation
Ethylene glycol diglycidyl ether as a cross-linking agent was added to a 1% by weight aqueous solution (pH = 6) so as to be 1/100 mol based on the molecular weight of the repeating unit of hyaluronic acid. Next, the mixture was allowed to stand in a dryer set at 50 ° C. for 5 hours to perform an intermolecular crosslinking reaction. Production of Wound Dressing Material The laminate composed of the pressure-sensitive adhesive layer and the polyurethane film layer produced in Example 1 was cut so as to have a circular shape having a diameter of 100 mm, leaving 25 mm of the peripheral part of the release paper of the pressure-sensitive adhesive layer. Then, the inner release paper was removed, and the nonwoven fabric having a straight diameter of 50 mm produced in Example 1 was placed thereon and bonded through an adhesive. Then, the inner diameter of 50 mm (2
0 cm ² ), put a circular polystyrene mold having a height of 20 mm, put 20 cc of the prepared cross-linked aqueous solution of hyaluronic acid, then put 1 mg of silver sulfadiazine, freeze at -40 ° C., and dry in vacuum. Thus, a wound dressing containing a sponge-like crosslinked hyaluronic acid was produced.

Comparative Example 1 A wound dressing material for a control experiment A circular polystyrene container having an inner diameter of 50 mm and a height of 20 mm was poured with 20 cc of a 1% by weight aqueous solution of hyaluronic acid having a molecular weight of 2,000,000 prepared by fermentation. Example 1
The produced polyurethane film was cut into a circular shape having a diameter of 50 mm and mounted. Next, the polystyrene container was put into a freeze dryer, frozen at -40 ° C, and dried under vacuum to produce a sponge-like wound covering material containing hyaluronic acid.

Comparative Example 2 A wound dressing material for a control experiment A circular polystyrene container having an inner diameter of 50 mm and a height of 20 mm was charged with 10 cc of a 2% by weight aqueous solution of commercially available sodium alginate (Wako Pure Chemical Industries, Ltd.). 50 m straight through the polyurethane film produced in Example 1.
m was cut and placed. Next, the polystyrene container was placed in a freeze dryer, frozen at -40 ° C, and then dried under vacuum to produce a sponge-like wound dressing material containing alginic acid.

Example 3 Animal Experiment The wound dressings obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were sterilized with ethylene oxide gas, and then subjected to the following experiment. That is, under anesthesia, the backs of Japanese white rabbits (3 months old) were shaved, disinfected with isodine,
A 0 mm circular full-thickness skin defect wound was created on both backs of a rabbit, the right back was applied with the wound dressing according to the present invention manufactured in Example 1 or 2, and the left back was used as a comparative example as a control experiment. The control wound dressings prepared in 1 or 2 were applied.

When the wound dressing prepared in Examples 1 and 2 is applied, the pressure-sensitive adhesive layer from which the sponge layer covers the wound portion and the release paper is peeled comes into contact with healthy skin around the wound portion. I stuck it. The release paper on the polyurethane film was removed after the wound dressing was applied.

When applying the wound dressing for control experiments produced in Comparative Examples 1 and 2, since the wound dressing is easy to move since there is no pressure-sensitive adhesive layer on the periphery, the polyurethane film from which the release paper was removed was used. A few pieces of gauze were placed on the top, and the top was fixed with adhesive tape.

After one week, the covering material was removed under anesthesia, the condition of the wound surface was observed, and the wound periphery was disinfected with isodine.
The wound dressing according to the present invention and a wound dressing for control experiments were applied. Thereafter, a new wound dressing material was replaced every week, and the state of the wound was observed over time.

When the wound dressing according to the present invention was applied, almost all of the hyaluronic acid and / or cross-linked hyaluronic acid was decomposed and absorbed when removed in one week.

On the right back to which the wound dressing according to the present invention is applied, the wound surface is maintained in an appropriate moist environment, the formation of granulation tissue and the shrinkage from the wound periphery are promoted, and the wound dressing is applied.
At the week, the diameter of the skin defect wound was about 10 mm. On the other hand, on the left back to which the wound dressing for control experiment consisting of only the hyaluronic acid or alginic acid sponge layer was applied, the diameter of the skin defect wound was about 20 mm at 3 weeks after the application of the wound dressing.

As described above, the wound dressing according to the present invention exhibited a healing promoting effect as compared with the wound dressing for control experiments using only hyaluronic acid or alginic acid.

When the wound dressing according to the present invention having an adhesive layer was applied to a wound, the sponge layer and the polyurethane film layer were held on the wound without slipping. In addition, the wound dressing was easily replaced, and the wound was not damaged at all.

On the other hand, when a wound dressing for a control experiment having no pressure-sensitive adhesive layer on the periphery is applied to the wound, the wound dressing is easy to move, and in this case, the movement of the wound dressing from the wound is difficult. Admitted.

[0068]

As described above, the wound dressing according to the present invention has the following effects. Since the wound dressing material is laminated with a nonwoven fabric layer composed of a hydrophobic fiber and a highly absorbent fiber, even when a large amount of exudate is released from the wound, the exudate is absorbed and contained therein. The wound can be constantly kept in a moderately moist environment because the moisture that has been evaporated can be evaporated into the surrounding environment. By cross-linking hyaluronic acid with an epoxy compound, the effect of promoting wound healing can be maintained for a long period of time. Therefore, it is not necessary to replace the hyaluronic acid for a long period of time. By providing the pressure-sensitive adhesive layer around the polyurethane film layer, the sponge layer can be easily and reliably fixed to the wound portion, and can be easily replaced without damaging the wound portion. By adding an antibacterial agent, the proliferation of bacteria is suppressed, and a further excellent healing promoting effect can be obtained.

Claims (3)

[Claims] 1. A wound dressing material comprising a polyurethane film layer, a pressure-sensitive adhesive layer comprising an alkyl (meth) acrylate polymer, a nonwoven fabric layer, and a sponge layer containing hyaluronic acid crosslinked with an epoxy compound. 2. The non-crosslinked hyaluronic acid in the sponge layer contains 1 to
The wound dressing according to claim 1, which is contained in an amount of 20% by weight. 3. The method according to claim 1, further comprising an antimicrobial agent.
A wound dressing according to claim 1.