JPS6164256A - Wound covering protective material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to a wound dressing and protection material.

More specifically, the present invention relates to a protective material preferably used for skin damage such as burns, skin extraction wounds, abrasion wounds, traumatic dermabrasion wounds, etc., and relates to a protection material for skin damage made of a porous chitin molded body.

BACKGROUND OF THE INVENTION Conventionally, preferable treatments for skin defects such as burns and skin extraction wounds have been a major issue in the fields of plastic surgery and dermatology, and many materials have been investigated as wound covering and protective materials. For example, nylon and polyester are two synthetic materials.

Special fabrics such as polypropylene and rayon (single fibers with a diameter of several hundred microns protrude from the surface in the form of loops or fluff.) Laminated products of these fabrics and silicone glue, formalized vinyl alcohol sponge, ethylene oxide and polyester fabrics. There are gelatinized block copolymers with oxypropylene glycol and "Sofratinil" gauze (Nippon Lucelle) impregnated with antibiotic-containing ointment, and biomaterials such as fibrin membranes, plasma membranes, and even collagen. There are products such as Chinoku made from non-woven fibers (trade name: Meipanoku (Meiji Seika Sales)) and Poshin Skin, which is made by sterilizing and freeze-drying the dermal layer of the back of pigs.

However, these materials were not necessarily satisfactory +A materials as protective materials for cortical defects. In other words, the general function of a wound covering material is to prevent the loss of biological components from the wound surface until new skin is formed, to prevent angry staining, and to assist in the generation of granulation and epithelial formation. Adhesion, water absorption and leachate adsorption,
Breathable.

It is necessary to have properties such as histocompatibility, non-antigenicity, and ability to promote new skin. However, conventional synthetic materials have poor water absorption, exudate adsorption, moisture permeability, etc., while natural materials have poor strength, exudate adsorption, etc.

Particularly in the case of deep wounds, they had the disadvantage that they would melt into a mush within a few days after treatment. therefore.

When wounds were protected with these conventional synthetic or natural products, granulation, epithelial formation, etc. did not occur sufficiently as a result. For example, regarding burns, depending on the degree of damage, there are first-degree burns, superficial second-degree burns, deep second-degree burns, and second-degree burns.
Conventional burns can be classified into first-degree burns, but conventional methods have the disadvantage of being limited to the treatment of first-degree burns, that is, mild burns, and the treatment of skin harvest wounds after skin grafting is also limited to intermediate-thickness skin grafts. there were.

The present inventors have developed preferable granulation, which has good adsorption of exudate to the affected area, exudate does not accumulate in the affected area, and does not melt or damage until the eruption occurs.

As a result of intensive research aimed at developing a wound covering and protecting material in which epithelium is formed, it was discovered that a porous molded body made of chitin is excellent as a wound covering and protecting material, and the present invention was achieved.

That is, one aspect of the present invention is a wound covering protection forest made of porous chitin molded bodies produced by a wet molding method.

In the present invention, chitin refers to poly(
N-acetyl-D-glucosamine) or derivatives thereof. Examples of chitin derivatives include those in which acetylglucosamine groups are partially deacetylated, etherified products, esterified products, carboxymethylated products, hydroxyethylated products, 0-ethylated products, etc. Preferred specific examples include poly[N -acetyl-6-0-(2''-hydroxyethyl)-D-glucosamine].

Examples include poly[N-acetyl-6-0-(ethyl)-di-glucosamine].

The porous chitin molded body obtained from these chitins has a porosity measured in a dry state (-X100%; B: volume of pores contained in a porous molded body of unit weight).

A: Molded object 1 whose total volume per unit weight of the porous molded object is 90% or more means a wet-formable molded object such as a sheet, rod, or fiber shape.

Such a porous chitin molded article can be produced by the following method, for example.

The purified chitin is mixed with a known chitin solvent 1 such as a mixture of dimethylacetamide and lithium chloride, a mixture of N-methylpyrrolidone and lithium chloride, a mixture of trichloroacetic acid and a halogenated hydrocarbon at a concentration of about 0.5 to 15% by weight. Dissolve in excess to obtain dope. A water-soluble polymer 1 that is solid at room temperature, such as polyvinyl alcohol, polyethylene glycol, or polypropylene glycol, is added to this dope.

Agar, water-soluble starch, protein, etc., preferably polyvinyl alcohol or agar, are uniformly dispersed in the dope.

At that time, the ratio of chitin dope to water-soluble polymer is 115~
It is preferable to select from a range of 5/1 (weight ratio). The chitin dope mixed with a water-soluble polymer is coagulated with a coagulating liquid while maintaining a desired shape by pouring into a form or extruding from a slit die. As the coagulating liquid, for example, water, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol, or ketones such as 7-setone are preferably used. After the solvent has been sufficiently removed and coagulation has been completed, the coagulated product is treated with water or an aqueous solution.

Generally, water-soluble polymers are difficult to remove from the coagulated material at low temperatures, so treatment at a high temperature of 60°C to 125°C is preferred, and 1 hour is preferably 30 minutes or more. The molded product that has been thoroughly washed after processing has a sponge-like appearance with a high moisture content.
To obtain a dried product from this state, a general method of drying at room temperature may be used, but freeze-drying is preferably used. That is, it is preferable to freeze the molded body containing water at a temperature of about -40°C and then freeze-dry it at a temperature of 110°C.

As a porous chitin molded article in the present invention.

A porous chitin molded article obtained as described above treated in an alkaline solution is preferably used. Preferred conditions for carrying out the alkali treatment are 2. For example, using a 5-60 W/V% aqueous solution of sodium hydroxide at a temperature of 10-12
The treatment is carried out at 0°C for 1 minute or more. In the present invention, a particularly preferably used porous chitin molded body is one that does not dissolve when the neutralized molded body is immersed in a 2V% acetic acid aqueous solution at 25°C after treatment.

The porous chitin molded article of the present invention is used as a wound dressing after sterilization, but it is particularly preferable to have a wet strength of 1 g/mm or more. It is preferred as a wound dressing and protectant, and is particularly effective in treating burns, skin-grafted wounds after skin grafting, etc. In other words, when used as a wound dressing for skin-deficient injuries, it is effective in adsorbing exudate. This is a breakthrough in that the accumulation of exudate in the affected area is reduced, dissolution by body fluids does not occur even after long-term use, and the affected area is kept in a moderately moist state, resulting in good regeneration of new skin. It has a certain effect.

The wound dressing protection material of the present invention can be used not only for superficial burns of the first grade and for intermediate-thickness skin grafts, but also for deep burns of the first grade and thick partial thickness, which cannot be treated with conventional wound dressings. It can be used extremely effectively as a protective material for skin graft wounds.

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 mesoyu pieces,
It was treated with IN-HCl at 4°C for 1 hour, then heated in a 3% NaOH solution for 3 hours at 90-100°C, washed with water repeatedly, and dried. The obtained chitin was dissolved at room temperature in a dimethylacetamide solvent containing 8% by weight of lithium chloride to a concentration of 2% by weight to obtain a clear liquid, which was then filtered under pressure using a 1480 mesh stainless steel net. Then, defoaming was performed under reduced pressure while stirring to obtain a chitin dope.

Add Poval 0F-170GS to 100g of this chitin dope.
(manufactured by Unitika Chemical Co., Ltd.; degree of polymerization 170, degree of saponification 95% or more) was added and stirred for 1 hour in a beaker equipped with a stirring blade to prepare a uniform dispersion.

This dispersion was cast onto a glass plate to a thickness of 1 mm.

Thereafter, the sheet was immersed in water at about 25° C. to sufficiently solidify and wash the sheet. Next, this sheet was immersed in water and then treated in a boiling state for 5 hours to obtain a sheet-like chitin molded article. After freezing this molded body at -40°C,
Freeze-drying was performed at °C to obtain a porous chitin molded body. The porosity of this molded body was 99.2%, and the wet strength was 4.
5 g: 7 mm2.

This sheet (length 120mm, width 120mm, thickness 0
．． 8 mm) was sterilized and used as a wound dressing.

Specifically, two of these porous sheets were applied to the affected area of a 30-year-old man who had sustained extensive burns on his back and were judged to be deep burns, and the skin was covered with cotton gauze. Protected the top.

After 6 days, the sheet remained undamaged and remained in its initial state, adsorbed exudates from the body, and became moist.
Some of it had reached the cotton gauze layered on top of the sheet. Furthermore, the affected area had little accumulation of exudate and maintained an appropriate moist state. After 12 days of continued treatment, the sheet became dry and could be easily peeled off from the affected area, and normal new epidermis was formed on the affected area, indicating that the treatment had been sufficiently performed.

Example 2 The chitin powder obtained in Example 1 was mixed with dimethylacetamide containing 8% by weight of lithium chloride. Yong? (It was dissolved at 1% by weight in lt and filtered and defoamed to obtain a transparent chitin dope.

A mixed solution was prepared by adding 100 g of agar powder to 100 g of this dope. Pour this liquid to a height of 15 cm.

The mixture was poured into a mold having a width of 15 cm and a depth of 11, and was coagulated with methanol to remove the solvent contained therein to obtain a sheet. This sheet was immersed in water and treated in an autoclave at 121'C for 1 hour, then further autoclaved with 40% strength soda solution at 121°C for 1 hour, neutralized and Wash thoroughly with water.

After freezing at -40°C while still containing water.

When freeze-dried at 10'C, the wet strength was 6.5 g.
A porous chitin root with a thickness of 0.8 mm and a porosity of /mm2+99.2% was obtained.

This porous chitin sheet was sterilized and used as a protective material for skin harvest wounds after thick split-thickness skin grafting. That is, the patient is 37
Two 12 mm strips were applied to the skin harvest wound on the back of a female patient, and the upper part was protected with cotton gauze. 6 days later,
A large amount of exudate was observed on the surface of the protective material, and less exudate was observed in the affected area, and granulation was observed. After 14 days, new skin was formed, indicating that the affected area had healed well.

Claims (3)

[Claims] (1) A wound covering protection material consisting of a porous chitin molded body produced by a wet molding method. (2) The porous chitin molded body has a wet strength of 1 g/mm^
The wound covering protection material according to claim 1, which is two or more. (3) The wound covering protection material according to claim 1, wherein the porous chitin molded body is subjected to alkali treatment after wet molding.