JPH0442019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wound covering and protection material, and more particularly to a protection material preferably used for skin damage such as burns, dermabrasion wounds, abrasion wounds, and traumatic dermabrasion wounds. , relates to a protective material against skin damage made of a nonwoven fabric or fiber sheet made of chitin fibers.

BACKGROUND OF THE INVENTION Conventionally, preferable treatments for skin defects such as burns and skin harvest wounds have been a major issue in the fields of plastic surgery and dermatology, and many materials have been investigated as protective materials for covering these wounds. For example, special fabrics made of synthetic materials such as nylon, polyester, polypropylene, and rayon (single fibers of several hundred microns in diameter protrude from the surface in the form of loops or fluff), and laminations of these fabrics and silicone sheets. body, formanized polyvinyl alcohol sponge, gelatinized block copolymer of ethylene oxide and polyoxypropylene glycol, or "Sofuratul" gauze (Japan Roussel) impregnated with antibiotic-containing ointment. In addition, there are products made from biological materials such as fibrin membranes, plasma membranes, non-woven collagen fibers (product name: Maypack, manufactured by Meiji Seika Sales), and Poshin Skin, which is made by sterilizing and freeze-drying the dermal layer of the pig's back. These are introduced, for example, on page 121 of the Surgical Medical Journal (Showa 50/2).

However, these materials were not necessarily satisfactory as protective materials for skin defects.

In other words, in general, the functions of a wound covering protector are to prevent the loss of biological components from the wound surface until new skin is formed, to prevent infection, and to assist in the generation of granulation and epithelium. sex,
It is necessary to have properties such as water absorption and adsorption of exudates, moisture permeability, tissue compatibility, non-antigenicity, and ability to promote new skin. However, conventional synthetic materials have poor water absorption, exudate adsorption, and moisture permeability, while natural products have poor strength, exudate adsorption, and are particularly susceptible to deep scratches. In this case, the problem was that it would melt into a mush within a few days after treatment. therefore,
When conventional synthetic or natural products were used to protect wounds, granulation and epithelial formation did not occur sufficiently as a result. For example, when it comes to burns,
Depending on the severity of the wound, it can be divided into degree burns, superficial degree burns, deep degree burns, and degree burns, but conventional methods are limited to the treatment of superficial degree burns, that is, mild burns; Treatment of skin harvest wounds also had the drawback of being limited to intermediate-thickness skin grafts.

The present inventors have developed a wound that has good adhesion to the affected area and adsorption of exudate so that exudate does not accumulate, does not dissolve or damage until healing occurs, and in which favorable granulation and epithelial formation occur. As a result of intensive research to develop a wound covering and protective material, we discovered that a nonwoven fabric or fiber sheet using chitin fibers, which has a property of being highly swellable in an acetic acid aqueous solution, is excellent as a wound covering and protective material, leading to the present invention. This is what I did.

That is, the present invention provides a wound covering protection made of a nonwoven fabric or fiber sheet made of chitin fibers that swells in a 2V/V% acetic acid aqueous solution at 25°C with a cross-sectional area of at least 10 times the original cross-sectional area. It is a material.

In the present invention, the chitin fibers that become swollen in a 2V/V% acetic acid aqueous solution at 25°C, the cross-sectional area of which is 10 times or more the original cross-sectional area, can be obtained by, for example, spinning a dope made of chitin to form chitin fibers. After that, it can be prepared by performing appropriate alkali treatment. Here, chitin refers to poly(N-acetyl-D-glycosamine) obtained by treating the exoskeletons of crustaceans and insects with hydrochloric acid and caustic soda to separate and purify the protein and calcium components, or poly(N-acetyl-D-glycosamine) or their derivatives. Refers to derivatives. Examples of chitin derivatives include those in which acetylglycosamine groups are partially deacetylated, etherified products, esterified products, carboxymethylated products, hydroxymethylated products, and 0-ethylated products. Preferred specific examples include poly[ N-acetyl-6-0
-(2'-hydroxyethyl)-D-glycosamine],
Examples include poly[N-acetyl-6-0-(ethyl)-D-glycosamine].

Chitin fibers refer to those produced from chitin as described above by known methods such as wet spinning and dry spinning. For example, purified chitin can be mixed with, for example, a mixture of dimethylacetamide and lithium chloride,
A dope is obtained by dissolving it in a solvent such as a mixture of N-methylpyrrolidone and lithium chloride or a mixture of trichloroacetic acid and a halogenated hydrocarbon, preferably at a concentration of about 0.5 to 15% by weight. The fibers are formed by extrusion into a liquid such as water or an alcohol such as methyl alcohol, ethyl alcohol, propyl alcohol, or butyl alcohol, or a ketone such as acetone through a spinning nozzle having a spinning nozzle, and are coagulated to form fibers. Refers to what has been removed.

Alkali treatment to provide a swollen chitin fiber with a cross-sectional area of 10 times or more of the original cross-sectional area in a 2V/V% acetic acid aqueous solution at 25°C includes, for example, an alkali such as caustic soda. This can be carried out by immersing chitin fibers as described above in a solution. Preferred conditions for the alkali treatment are: caustic soda 5-60 W/V% aqueous solution, temperature 10-120°C;
For example, when the fibers treated under these conditions are neutralized and dried after the alkali treatment and are immersed in a 2V/V% acetic acid aqueous solution at 25°C, the fibers retain their shape. However, it means that the cross-sectional area is more than 10 times the original cross-sectional area. Therefore, those that lose their shape or dissolve in the acetic acid aqueous solution cannot be used in the present invention.

In addition, normal chitin fiber before alkali treatment is 25
In a 2V/V% acetic acid aqueous solution at .degree. C., its cross-sectional area only increases by about twice the original cross-sectional area at most. The treated fibers are neutralized with acid in an aqueous solution, thoroughly washed and dried.

Non-woven fabric refers to these fibers that are cut or made into a continuous sheet, and generally known methods can be used to manufacture non-woven fabric from alkali-treated chitin fibers. I can do it. For example, a nonwoven fabric can be created by cutting fibers into lengths of 5 to 20 mm and using a general-purpose sheet mat. In this case, the cut fibers are dispersed in water together with a binder such as undrawn fibers of polyvinyl alcohol, water is removed from the bottom through a filter medium, a laminate of fibers is formed on the filter medium, and the fibers are pressurized and dried. A nonwoven fabric can be created by this method, and a continuous sheet mat can also be created using the same principle. The thickness of the nonwoven fabric used as the wound dressing protection material of the present invention is:
It is made according to the case to which it is applied, and generally has a thickness of 0.05 to 1 mm.

In addition, the fiber sheet refers to a sheet made of chitin fibers, such as woven fabric, gauze, velour, etc. These sheets can be made from long or short chitin fibers using generally known fiber processing techniques.

In the present invention, the nonwoven fabric or fibrous sheet can also be used as a wound dressing in a composite laminate, such as in combination with other separate materials.

The wound covering protection material of the present invention exhibits a remarkable effect on the healing of burns, skin harvest wounds after skin grafting, and the like. In other words, when used as a wound dressing for skin injury, it has good adsorption of exudate, reduces accumulation of exudate in the affected area, does not dissolve due to body fluids even after long-term use, and leaves the affected area with a moderate amount of moisture. This is an epoch-making technique in that the new cortical layer is regenerated well because it is maintained in an infiltrated state. Therefore, it is extremely effective as a protective material not only for superficial burns and mid-thickness skin graft wounds, but also for deep burns and thick split-thickness skin graft wounds that cannot be healed with conventional wound dressings. can be used for.

The wound skin protection material of the present invention differs from that made from chitosan fibers in the following points. First, chitosan fibers are generally heated at 25°C.
While it dissolves in 2V/V% acetic acid aqueous solution,
The material of the present invention only swells and does not dissolve, and the material of the present invention is made of chitosan fibers when used as a protective material for deep wounds such as deep burns and deep skin wounds. It is undesirable because it dissolves in a few days due to the influence of leachate, etc.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Chitin powder (manufactured by Kyowa Yushi Co., Ltd.) was ground into 100 meshes, treated with 1N-HCl at 4°C for 1 hour, and further heated at 90 to 100°C for 3 hours in 3% NaOH solution to obtain chitin powder. Calcium and protein contained therein were removed, and then washed with water repeatedly and dried.

The chitin thus obtained was dissolved at room temperature in a mixed solvent of dimethylacetamide and lithium chloride to a concentration of 7% by weight. The resulting highly viscous and transparent liquid was filtered under pressure using a 1480 mesh stainless steel net, and defoamed under reduced pressure while stirring. The resulting solution is placed in a tank;
Transported with a gear pump under pressure, pore diameter 0.07mm
It was discharged from a 20-hole nozzle into isopropyl alcohol at 60°C, taken up with a rotating roll at a speed of 7 m/min, and wound up with a winder.

The obtained yarn was thoroughly washed to remove the coagulation liquid and solvent, dried, and then cut into a length of about 8 mm. This fiber was heated to 100℃ using 10N-NaOH solution.
After treatment for 3 hours, the mixture was neutralized with dilute hydrochloric acid, thoroughly washed and dried. When one filament of this fiber is immersed in a 2V/V% acetic acid aqueous solution at 25℃,
The cross-sectional area became 39 times the original cross-sectional area. 0.5 g of this dry fiber and 0.05 g of undrawn polyvinyl alcohol yarn powder were dispersed in water, and a fiber laminate was created using a No. 177 Tatsupi standard sheet machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.). Compression and drying were performed to obtain a sheet with a thickness of 0.15 mm.

This sheet (length: 100 mm, width: 100 mm) was sterilized and used as a wound dressing for burns.

Specifically, two of the above sheets were applied to the affected area of the thigh of a 38-year-old woman who was determined to have a deep burn after pouring boiling water over it, and the surrounding area was protected with cotton gauze. External findings after one week showed that the seat surface remained in its original condition without any damage.
It was in a moist state, and the exudate from the body was sufficiently adsorbed on the sheet surface, with some of it reaching the gauze surface. Furthermore, the affected area had little accumulation of exudate and was in a moist state. After two weeks, the sheet could be easily peeled off from the affected area, and normal new epidermis was formed on the affected area, indicating that healing had taken place sufficiently.The sheet of this example showed good wound coverage. It turned out to be a protective material.

Example 2 The purified chitin obtained in Example 1 was treated at room temperature.
It was dissolved in a mixed solvent of N-methylpyrrolidone and lithium chloride to a concentration of 6% by weight. The resulting solution was filtered under pressure using a 1480 mesh stainless steel net, and defoamed under reduced pressure. The obtained solution is placed in a tank, transported under pressure by a gear pump, coagulated in methanol at 40℃ through a 40-hole nozzle with a hole diameter of 0.08mmφ, and taken up with a rotating roll at a speed of 10m/min and wound up with a winder. , dry
Chitin long fibers of 60 denier and 40 filaments were obtained. Five of these chitin long fibers were twisted together to create a gauze strip fabric using a gauze loom. This gauze strip fabric was treated with a 10N NaOH solution at 120°C for 1 hour, then neutralized with dilute hydrochloric acid, thoroughly washed and dried. A part of the gauze after treatment was kept at 25℃.
When the cross-sectional area of one filament (approximately 1.5 denier) constituting the gauze was measured by immersing it in a 2V/V% acetic acid aqueous solution, it was found to be 64 times the original cross-sectional area.
This alkali-treated gauze was sterilized and used as a protective material for the skin harvest wound after thick split-thickness skin grafting. The patient was a 43-year-old man.
The upper part was protected with cotton gauze. After 5 days, a large amount of exudate was observed on the gauze surface and the upper cotton gauze surface, and there was little exudate in the affected area, and the formation of granulation was observed. After 13 days, new skin was formed, indicating that the affected area was healing well.

Comparative Example 1 Chitosan powder (Kyowa Yushi (KK) Flownatsuk NA) was dissolved in a 2V/V% acetic acid aqueous solution, and 7
% chitosan dope was obtained. This dope is placed in a tank and transported under pressure using a gear pump.
After discharging into a 1N caustic soda aqueous solution from a 200-hole nozzle with a hole diameter of 0.07 mmφ and coagulating it,
It was taken up with a rotating roll at a speed of m/min and wound up with a winder. After neutralizing and drying the obtained yarn, cut it into a length of about 8 mm, and collect 0.5 g of this dried fiber.
and 0.05g of polyvinyl alcohol unstretched powder and 2
of water, and a sheet was made using a No. 177 Turpee standard sheet machine. This sheet (length: 100 mm, width: 100 mm) was sterilized and used as a wound dressing for burns. Specifically, two stickers were applied to the neck of a 43-year-old man who was diagnosed with deep burns, and the surrounding area was protected with cotton gauze. Healing 2
After a few days, the sheet becomes mushy and dissolved due to the exudate.
It was found that it did not serve as a wound protection material.

Claims (1)

[Claims] 1. A wound covering and protective material made of a nonwoven fabric or fiber sheet made of chitin fibers that swells in a 2V/V% acetic acid aqueous solution at 25°C with a cross-sectional area of at least 10 times the original cross-sectional area.