JP2001017527A - Wound dressing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the possibility of infection by bacteria from the outside and extend the effective life by including a moisture permeable polyurethane film layer, a nonwoven fabric layer made up of hydrophobic fibers and absorp tive fibers, a nonwoven fabric layer consisting of hydrophobic fibers and a hyaluronic acid sponge layer 14. SOLUTION: A wound dressing includes a moisture permeable polyurethane film layer 11, a nonwoven fabric layer 12 made up of hydrophobic fibers and absorptive fibers, a nonwoven fabric layer 13 consisting of hydrophobic fibers and a hyaluronic acid sponge layer 14. The nonwoven fabric layer 12 can absorb a large quantity of wound exudates released from a wound, and has the ability to move moisture contained in the exudates to an exterior surface through the wound dressing within a desirable speed and evaporates into the surrounding environment. In addition, by overlaying with the nonwoven fabric layer 13, fuzzing out of the nonwoven fabric layer 12 can be reduced and the flexibility of the wound covering can be adjusted effectively. Furthermore, the nonwoven fabric layer 12 has good adhesion to the hyaluronic acid sponge layer 14 and can increase the physical strength and durability of the layer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wound dressing. More specifically, it is applied to a wound surface that exudes a large amount of wound fluid during the healing process, and is suitable for use in promoting wound healing.

[0002]

2. Description of the Related Art Conventionally, as a method for treating a wound caused by a burn, pressure sore (bed sore) or other trauma, a method of applying a remedy to a wound, covering the wound with gauze, and fixing with a covering material. Has been taken. In such a case, since the gauze is directly applied to the wound surface, the exudate from the wound surface is directly absorbed by the gauze, but the gauze does not have a high water absorbing ability, and the exudate is stored. This storage, on the contrary, promotes the generation of bacteria and makes early healing difficult. In particular, on a wound surface with a large amount of exudate from the wound, the ointment or cream of the therapeutic agent mixes with the exudate to form a muddy state. Therefore, it is necessary to frequently change the coating material and reapply the ointment or cream. If the dressing is changed frequently, the amount of medicine to be used increases, and the pain of the patient when changing the dressing increases. There is also a problem that the doctor's labor required for changing the covering material cannot be ignored.

[0003] Films of synthetic materials and the like have been used as a part of the covering material in order to prevent invasion of dirt and bacteria from the outside. However, these materials have a poor function of evaporating moisture. However, there is a drawback that exudate tends to accumulate between the wound surface and the dressing material, thereby delaying wound healing.

Further, from the viewpoint of good affinity with the wound surface and promotion of healing, materials derived from living bodies, for example, glucosaminoglycans such as hyaluronic acid, collagen and the like, are used in the medical field such as wound dressing materials. It has come to be taken up by. However, hyaluronic acid easily melts and decomposes when applied to a living body, and is unsuitable as it is for a material for a wound dressing material that requires relatively long-term shape retention. Collagen is abundantly contained in the dermis, tendons, bones, fascia, etc. of animals, and even if it is derived from a heterologous animal, it can be produced in large amounts because it can reduce immunogenicity when it is converted into atelocollagen by enzymatic treatment. Although it is a useful material that can be obtained relatively inexpensively, it re-fibrils under physiological conditions, and thus requires various hydrophilic treatments and cross-linking treatments. Introducing chemical cross-linking with a cross-linking agent improves shape retention, but there is a problem in that biocompatibility, which can be said to be a characteristic of collagen, is significantly impaired.

[0005]

[0003] Wound dressings must have several requirements in order to facilitate wound healing. For example, wound dressings must be highly absorbent and have a high rate of fluid uptake to remove exudate from the wound surface. And it must prevent the absorbed liquid from leaking from the wound dressing and soiling the bedding. The wound dressing must also be breathable so that the wound can breathe and minimize the potential for bacterial infection from the outside to keep the wound as sterile as possible. However, it cannot be said that these requirements have been sufficiently satisfied by the wound dressing materials conventionally used.

[0006] It is therefore an object of the present invention to minimize the possibility of external bacterial infection, to absorb a significant amount of exudate oozing from the wound surface, and to ensure that the Wound dressing that can extend the useful life of the wound dressing by transferring the contained moisture through the wound dressing within the desired rate to the outer surface of the wound dressing and evaporating this moisture into the surrounding environment Is to provide. Further, it is another object of the present invention to provide a wound dressing material having good affinity with a wound surface and having a healing promoting effect on the wound surface.

[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 comprising a moisture-permeable polyurethane film layer, a nonwoven fabric layer composed of hydrophobic fibers and superabsorbent fibers, a nonwoven fabric layer composed of hydrophobic fibers, and a hyaluronic acid sponge layer. (2) The thickness of the moisture-permeable polyurethane film layer is 5 to 10
The wound dressing according to the above (1), which is 0 μm. (3) The wound dressing according to the above (1) or (2), wherein the basis weight of the nonwoven fabric layer composed of the hydrophobic fiber and the highly absorbent fiber is 30 to 300 g / m ² . (4) The basis weight of the nonwoven fabric layer composed of hydrophobic fibers is 5 to 10
The wound dressing according to any one of the above (1) to (3), which has a weight of 0 g / m ² . (5) The wound dressing according to any one of (1) to (4), wherein the hyaluronic acid sponge layer is formed by crosslinking hyaluronic acid with an epoxy compound.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As one embodiment of the present invention, FIG.
The structure shown in FIG. That is, the nonwoven fabric layer 12 composed of the hydrophobic fiber and the highly absorbent fiber can absorb a large amount of wound exudate released from the wound surface, and can reduce the moisture contained in the exudate at a desired speed. Has the ability to be transferred through the wound dressing to the exterior surface of the wound dressing to allow this moisture to evaporate into the surrounding 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.

As the highly absorbent fiber used in the present invention, wood pulp, natural fiber of cotton, rayon, regenerated fiber of cupra, semi-synthetic fiber such as acetate and the like are used. As the hydrophobic fiber, polyester, nylon, acrylic,
Synthetic fibers such as polypropylene and polyethylene are preferred. 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 fibers constituting the nonwoven fabric layer 12 composed of hydrophobic fibers and superabsorbent fibers is preferably about 0.3 to 5 denier (d), preferably about 0.5 to 3 d. As a method for producing a nonwoven 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 12 can also be made by these known methods or by a combination of these methods. . Since the nonwoven fabric used in the present invention must have elasticity, a nonwoven fabric having a relatively large elongation is used. The elongation is length 60cm width 6c
m when a load of 1500 g is hung on a nonwoven fabric
m is expressed as a percentage of the original length.
The nonwoven fabric used in the present invention is preferably 30 to 200
%, More preferably 40 to 150%.

The thickness of the nonwoven fabric layer 12 is preferably 1 to 20 m in consideration of flexibility, durability, workability, absorbency and the like.
m, more preferably about 1 to 10 mm.

The basis weight of the nonwoven fabric layer 12 is preferably from 30 to 300 g / m ² from the viewpoint of the retention of exudate.
More preferably, those having 50 to 200 g / m ² are suitable.

The nonwoven fabric layer 12 made of hydrophobic fibers and superabsorbent fibers is further provided with a nonwoven fabric layer 13 made of hydrophobic fibers.
Is effective in controlling the fluffing of the nonwoven fabric layer 12 and at the same time adjusting the flexibility of the wound dressing. Furthermore, since the nonwoven fabric layer 13 has good adhesion to the hyaluronic acid sponge layer, there is an advantage that the physical strength and durability of the hyaluronic acid sponge layer can be further improved. Examples of the hydrophobic fiber material used for the nonwoven fabric layer 13 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 the thermoplastic elastomers, polyolefin-based, polyurethane-based, and polyester-based elastomers are particularly preferred because they are soft and rich in 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 13 is preferably about 0.3 to 5 d, more preferably 0.5 to 3 d.
It is desirably about d.

As a method of laminating the nonwoven fabric layer 13 on the nonwoven fabric layer 12, the nonwoven fabric layer 12 and the nonwoven fabric layer 13 are separately formed by the above-mentioned method, and both of the nonwoven fabric layers are formed by using a thermoplastic resin or a bonding fiber. The nonwoven fabric layer 1 is formed by directly spinning the above-mentioned hydrophobic fiber material as a raw material of the nonwoven fabric 13 on one surface of the nonwoven fabric layer 12 into a web shape.
3 is laminated. When the nonwoven fabric layer 13 and the nonwoven fabric layer 12 are bonded via a thermoplastic resin, if the thermoplastic resin is applied to the entire surface, the function of transmitting the exudate from the wound surface is impaired, and the two are easily separated. It is good to make partial adhesion to the extent that it does not.

The thus prepared nonwoven fabric layer 13
Has both water permeability and smoothness, so that the adhesiveness to the wound surface is good, and the exudate from the wound surface passes through the hydrophobic and water-permeable nonwoven fabric layer 13 to form hydrophobic fibers. There is a characteristic that the nonwoven fabric layer 12 made of a highly absorbent fiber is easily absorbed. In particular, when the nonwoven fabric layer 13 is laminated on the nonwoven fabric layer 12 by the spunbond method, the fluffing of the fibers of the nonwoven fabric layer 13 is suppressed as compared with the needle punch method or the spunlace method, and the smoothness is more excellent. Is particularly preferred.

One purpose of the nonwoven fabric layer 13 is to suppress fluffing of the nonwoven fabric layer 12 and at the same time to adjust the flexibility of the wound dressing material. The basis weight of the nonwoven fabric layer 13 is 5 to 100 g / m
² is preferred.

Another object of the present invention is to provide a wound dressing having a healing promoting effect on a wound surface by using hyaluronic acid as a biomaterial.
That is, hyaluronic acid provides a highly hydrated microenvironment to the wound surface during the wound healing process. In such a microenvironment, it is known that adhesion and detachment between a cell membrane and a substrate when various cells move on a wound surface are controlled, and cell migration is facilitated, so that wound healing is promoted. I have. However, hyaluronic acid easily melts and decomposes when applied to a living body, and is unsuitable as it is for a material for a wound dressing material that requires a relatively long-term shape retention. Therefore, by introducing a chemical cross-linking agent into the hyaluronic acid by using a cross-linking agent and forming it into a sponge shape, the shape retention and the adhesion to the wound surface were improved at the same time.

As the hyaluronic acid to be crosslinked, for example, those having a molecular weight of preferably 500,000 to 3,000,000, more preferably about 1.8 to 2.2 million are used. Further, as the crosslinking agent, a water-soluble polyfunctional epoxy compound can be used. As polyfunctional epoxy compounds,
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,
Examples include glycerol triglycidyl ether, trimethylolpropane 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 the reaction solution to ~ 6, a reaction solution obtained by adding the epoxy compound to the hyaluronic acid repeating unit in an amount of 1/20 to 1/2 mol, preferably about 1/10 to 2/10 mol is added. It can be performed using: As the solvent, in addition to the above-mentioned water, an alcohol-water system can be used.

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, the biodegradability, the water content and the hydrolysis rate of the formed hyaluronic acid sponge are determined by the degree of cross-linking. Therefore, the degree of cross-linking should be appropriately selected according to the application site of the wound dressing and the purpose of use. Generally, after being implanted in a living body (for example, subcutaneously of Wistar rats) and allowed to stand for one week, 5
It is preferable to use a hyaluronic acid sponge in which about 30% by weight remains.

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 hyaluronic acid sponge layer is formed by injecting the above-mentioned cross-linked aqueous solution of hyaluronic acid into a forming container,
C. to -100.degree. C., preferably -40 to -80.degree. C., and may be manufactured by quenching and freeze-drying in a freezer, or gradually cooled to -30.degree. C. to -50.degree. C. in a freeze dryer. Then, it may be manufactured by vacuum drying. Examples of the method for forming the sponge layer include the freeze-drying method described above, but the method is not limited thereto, and those skilled in the art can employ an appropriate method. The thickness of the hyaluronic acid sponge layer may be arbitrarily set according to the purpose of use of the wound dressing material or the site to be applied.
It is about 20 mm, more preferably about 2 to 10 mm.

The skin has both a respiratory function such as skin respiration and water vapor transmission, and a barrier function such as prevention of invasion of bacteria and retention of body fluid. Therefore, a wound dressing used for treating wounds caused by burns, pressure sores, and other traumas preferably has both of these functions. Suitable gas and water vapor permeable materials include polyurethane. The wound dressing of the present invention is obtained by laminating a polyurethane film layer 11 having excellent moisture permeability as a surface material on the opposite side (outside) of a nonwoven fabric layer 12 composed of hydrophobic fibers and high-absorbency fibers in contact with the wound surface. . The provision of the moisture-permeable polyurethane film layer 11 protects the outer surface of the nonwoven fabric layer 12 that has absorbed body fluids, thereby preventing contamination due to external contact and having appropriate gas and water vapor permeability.

It is necessary to determine how much water vapor permeable material should be used for the polyurethane film layer 11 on the basis of the amount of water dissipated from the wound surface. The amount of water dispersion of the skin is about 200 gH ₂ O / m ² · 2 for healthy skin.
4 hrs, about 300 g H ₂ O / m ² · 2 for degree I burn wound
4 hrs, about 4,300 gH ₂ O / m ^{2 for} II degree burn wound
・ 24 hrs, 3,400 g H ₂ O /
m ² · 24 hrs, about 5,100 g H ₂ O from granulation wound
/ M ² · 24 hrs, about 3,600 gH ₂ from skin wound
O / m ² · 24 hrs.

If the moisture permeability of the moisture-permeable polyurethane film layer 11 is too low, the wound part becomes humid, causing maceration around the wound part. On the other hand, even if the moisture permeability is too high, the wound part is dried and hardly healed.

Therefore, considering the above water dispersion loss as a preferable moisture permeability, 300 to 6,000 gH ₂ O /
m ² · 24 hrs.

Considering that the wound dressing of the present invention is applied to a wound surface with a large amount of exudation, the moisture permeability of the wound dressing is 3,000 to 3,000.
It can be said that 6,000 gH ₂ O / m ² · 24 hrs is preferable.

The moisture-permeable polyurethane film layer 1 of the present invention
Polyurethane resins suitable for use in (1) are produced using three components of diisocyanate, polyol and chain extender as basic raw 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.

The polyol used in the present invention includes:
Examples include a polyether polyol, a polyester polyol, and a polycarbonate polyol. And
Examples of the polyether polyol include polypropylene ether glycol and polytetramethylene glycol. Examples of the polyester polyol include polybutylene adipate and polycaprolactone glycol. Also, as the 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 a 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 film 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, a solvent having a strong dissolving power such as dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like 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.

In the present invention, in order to provide the polyurethane film layer 11 on one side (outside) of the nonwoven fabric layer 12,
For example, a solvent coating method, a hot melt coating method, a lamination method, or the like is used.

In the case of the solvent coating method, after the polyurethane resin is uniformly dissolved in the solvent, the solution is applied onto the nonwoven fabric layer 12 and the solvent is dried to obtain the polyurethane film layer 1.
1 is obtained.

In the case of the hot melt coating method, the polyurethane resin is dissolved by heating and stirring at a temperature of 100 to 220 ° C. under a nitrogen atmosphere, and then applied onto the nonwoven fabric layer 12 using a hot melt coater. By drying, the polyurethane film layer 11 is obtained.

In the laminating method, first, polyurethane is first applied on a support by a solvent coating method or a hot melt coating method and then dried or semi-dried by a dry method, or a polyurethane resin solution is applied on the support and solidified. After extracting the solvent and other soluble substances in the bath, the polyurethane film layer is formed by a wet method of drying or semi-drying. Next, the polyurethane film layer 11 formed by the above method is bonded to the nonwoven fabric layer 12. As a method of laminating, a method of laminating the semi-dried polyurethane film layer 11 with the nonwoven fabric layer 12 and then drying, or an organic solvent which moderately swells the surface of the dried polyurethane layer, for example, an alcohol such as methanol And after swelling with a non-woven fabric layer 12 and other solvents. Further, a method of laminating both with an adhesive is adopted. When the nonwoven fabric layer 12 and the polyurethane film layer 11 are laminated via an adhesive, if the adhesive is applied to the entire surface, the function of the moisture-permeable polyurethane film layer 11 is impaired, and the two are not easily separated. It is preferred to have a degree of partial adhesion.

The support used for forming the polyurethane film layer 11 by the above-mentioned dry method or wet method is not particularly limited, but a release paper coated with a release agent of polyethylene, polypropylene, fluorine or silicone is used. Alternatively, a cloth or the like is used.

The thickness of the polyurethane film layer 11 can be adjusted by, for example, the concentration of the polyurethane solution or the amount of the solution to be applied. The thickness of the polyurethane film layer 11 is not particularly limited, but is usually 5 to 100 μm, preferably 8 to 50 μm. When the thickness is 5 μm or less, pinholes are easily formed during coating, and the polyurethane film 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 film layer becomes hard, and the adhesion to the skin tends to be impaired.

The polyurethane film layer obtained by the above method has practically sufficient strength, elongation and durability.

It is preferable that an antibacterial agent is added to any or all of the polyurethane film layer, the nonwoven fabric layer, and the hyaluronic acid sponge layer, which are the respective components of the wound dressing of the present invention. Antibacterial agents include sulfa drugs, penicillin, nalidixin, silver sulfadiazine,
Although any antibacterial agent such as polymyxin sulfate or 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 agent, the purpose of use and the application site of the wound dressing, but when silver sulfadiazine is used,
The content or application amount of the wound dressing is 20 to 500 μg /
cm ² , preferably 50 to 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 wound dressing of the present invention is used so that the hyaluronic acid side is in contact with the wound surface.
It can be used in any shape such as a pad shape of several cm square to several tens cm square. It can be appropriately selected and used depending on the degree and depth of the wound, the area of the wound surface, and the like.

[0045]

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 Preparation of Polyurethane Solution 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 at 75 ° C. for 5 hours. After reacting for a period of time to obtain a urethane prepolymer having an isocyanate group at the end, a chain extension reaction was carried out for 2 hours while maintaining the temperature at 20 ° C. using isophoronediamine as a chain extender in a dimethylacetamide solvent, and a polyurethane solid concentration of 25 wt. % Of a clear and viscous polyurethane solution.

Example 2 A composite nonwoven fabric layer (nonwoven fabric layer 12,
Preparation of 13) The nonwoven fabric layer 12 composed of the hydrophobic fiber and the high-absorbency fiber is formed by mixing a polyester fiber having an average fineness of 1.5 d and a rayon fiber having a average size of 2.0 d at a weight ratio of 70 to 30 and then extremely thin. A fiber layer (web) is formed, and the web is overlaid so that the basis weight is 100 g / m ^{2. Then} , the web layer is pierced with a piercing needle to mechanically entangle the fibers with each other. They were made together (needle punch method). Next, a hydrophobic polyester-based thermoplastic elastomer (trade name: Perprene, manufactured by Toyobo Co., Ltd.) is bonded to one surface of the nonwoven fabric layer 12 by a spun bond method.
Was adjusted to 30 g / m ² . This nonwoven fabric layer contains 50 μg / cm of silver sulfadiazine as an antibacterial agent.
² was applied.

Example 3 Production of Composite Polyurethane Film Layer (Wound Covering Material for Control Experiment) Methyl ethyl ketone was added to the dimethylacetamide solution containing 25% by weight of the polyurethane resin obtained in Example 1 to prepare a 15% by weight polyurethane solution. . When this solution is dried, the thickness of the polyurethane film layer is 10 μm.
Was applied to release paper having a silicon-based film formed on the surface. Next, it was placed in a hot air dryer and dried at 100 ° C. for 3 minutes to remove the solvent. Nonwoven fabric layer 1 of the composite nonwoven fabric layer prepared in Example 2 using the obtained polyurethane film layer
Part 2 was partially adhered via an adhesive. Next, the release paper was peeled from the polyurethane film layer to obtain a wound dressing material on which the hyaluronic acid sponge layer was not laminated.

The moisture permeability of this wound dressing material was measured according to JIS-Z-0.
Under the conditions of 40 ° C. and 90% RH according to
It was determined by weight measurement using a pump. Its value is 4,600
gH _TwoO / m^Two-It was 24 hrs.

In order to measure the absorbency of the wound dressing thus prepared, the measured wound dressing is immersed in water,
After taking it out and letting it drip for 30 seconds, it was weighed again to measure the water absorption. This wound dressing is 17 g /
g was found to have an extremely high absorption capacity. Therefore, it is suitable for a wound dressing in the case of a large amount of exudate from the wound surface.

Example 4 Preparation of Wound Dressing Material Hyaluronic acid having a molecular weight of 2,000,000 produced by fermentation method
% Aqueous solution (pH = 6), ethylene glycol diglycidyl ether as a cross-linking agent was added so as to be 1/10 mol of the molecular weight of the repeating unit of hyaluronic acid.
100 ml of this mixture was poured into a 200 ml polystyrene container (length 10 cm, width 10 cm, height 2 cm). Next, the composite polyurethane film layer produced in Example 3 was cut so as to have a size of 10 cm × 10 cm, and the nonwoven fabric layer 12 made of a hydrophobic fiber was placed so as to be in contact with the hyaluronic acid solution. This polystyrene container was allowed to stand in a dryer set at 50 ° C. for 5 hours to perform an intermolecular crosslinking reaction of hyaluronic acid. Then, at -80 ° C
And then vacuum-dried to form a hyaluronic acid sponge layer.

Example 5 Animal experiment The wound dressings obtained in Examples 3 and 4 were sterilized with ethylene oxide gas, and then subjected to the following experiment.
That is, under anesthesia, both backs of a Japanese white rabbit (3 months old) were shaved, disinfected with isodine, and a circular full-thickness skin defect wound with a diameter of 55 mm was created on both backs of the rabbit, and the right back The wound dressing material laminated with the hyaluronic acid sponge layer produced in Example 4 was applied to the same, and the wound dressing material not laminated with the hyaluronic acid sponge layer produced in Example 3 was applied to the left back as a control experiment. Gauze was put on the top and fixed with elastic adhesive tape. One week later, the dressing was removed under anesthesia, the condition of the wound surface was observed, and the wound area was disinfected with isodine.
A wound dressing laminated with a hyaluronic acid sponge layer and a control dressing were applied, and gauze was applied thereto and fixed with an elastic adhesive tape. Thereafter, a new wound dressing material was replaced every week, and the state of the wound was observed over time.

When a wound dressing material in which a hyaluronic acid sponge layer was laminated was applied, almost all of the hyaluronic acid was decomposed and absorbed when it was removed in one week. Further, the exudate was sucked up by the nonwoven fabric layer, and no accumulation of exudate occurred under the coating material.

The formation of granulation tissue and shrinkage from around the wound were promoted on the right back to which the wound dressing layer with the hyaluronic acid sponge layer was applied.
The diameter of the skin defect wound became about 10 mm.

On the other hand, in the left back part to which the coating material containing no hyaluronic acid was applied, the exudate did not accumulate under the coating material at the third week of application of the coating material, but the diameter of the skin defect wound was smaller than that of the skin material. It was about 20 mm.

Judging comprehensively, the wound dressing on which the hyaluronic acid sponge layer is laminated can appropriately absorb the exudate due to the presence of the nonwoven fabric layer. The effect of promoting healing by hyaluronic acid was observed.

[0057]

As described above, the wound dressing according to the present invention has the following effects. Since the moisture-permeable polyurethane film layer 11 is provided on the outer surface of the wound dressing, it prevents dirt and bacteria from entering the wound surface from the outside, and at the same time, absorbed body fluid leaks from the wound dressing and soils the bedding. There is nothing. Since the nonwoven fabric layer 12 is composed of hydrophobic fibers and high-absorbency fibers, it can absorb a large amount of wound exudate released from the wound surface, and can remove water contained in the exudate as desired. The exudate is stored between the wound and the wound dressing because it has the ability to evaporate this moisture into the surrounding environment by passing through the wound dressing at a rate to the outer surface of the wound dressing. Nothing. Therefore, the frequency of changing the wound dressing can be reduced, so that the complexity of the operation is reduced, and the labor of the healer can be greatly reduced. By incorporating the hyaluronic acid sponge layer, which is a biomaterial, into the wound dressing, wound healing can be promoted. By cross-linking hyaluronic acid, the effect of hyaluronic acid on promoting wound healing can be maintained.

[Brief description of the drawings]

FIG. 1 shows one embodiment of a wound dressing according to the present invention.

Continued on the front page F-term (reference) 4C081 AA02 AA12 BA14 BB01 BB02 BB07 BB08 BB09 BC02 CA021 CA091 CA161 CA211 CA231 CB042 CC05 CC09 CD022 CD082 CE01 CE08 DA02 DA04 DA05 DA12 DC04 DC06 EA02 EA03 BA10 BA10 BA10 BA10 BA05 BA10 BA10 BA10 BA05 BA10 BA10 BA10 BA10 BA10 BAJ DG01B DG15B DG15C DJ01D EC09 EC092 EJ05D GB66 JB06B JB06C JB16 JD02 JD04A JD15 JD15B YY00A YY00B YY00C

Claims (5)

[Claims] 1. A wound dressing comprising a moisture-permeable polyurethane film layer, a nonwoven fabric layer composed of hydrophobic fibers and superabsorbent fibers, a nonwoven fabric layer composed of hydrophobic fibers, and a hyaluronic acid sponge layer. 2. The wound dressing according to claim 1, wherein the thickness of the moisture-permeable polyurethane film layer is 5 to 100 μm. 3. The wound dressing according to claim 1, wherein the basis weight of the nonwoven fabric layer composed of the hydrophobic fiber and the superabsorbent fiber is 30 to 300 g / m ² . 4. The wound dressing according to claim 1, wherein the basis weight of the nonwoven fabric layer made of hydrophobic fibers is 5 to 100 g / m ² . 5. The wound dressing according to claim 1, wherein the hyaluronic acid sponge layer has crosslinked hyaluronic acid with an epoxy compound.