JPH04300362A - Chitin molding and production thereof - Google Patents

Abstract

PURPOSE:To obtain a molding of yarn aggregate having chitin surface and production thereof. CONSTITUTION:A chitin molding wherein constituent fibers of molded and processed yarn aggregate are entangled with mycelia of mold fungi and a chitin layer is exposed to the surface of the mycelia. The chitin molding is obtained by dispersing spores of the chitin-containing mycelia into a liquid medium to give a spore suspension, attaching the spore suspension to constituent fibers of the molded and processed yarn aggregate, culturing the mycelia on the surface of the constituent fibers and treating the constituent fibers with an alkali expose the chitin layer to the surface of the mycelia.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded fiber aggregate having chitin or its derivative chitosan on its surface, and a method for producing the same.

0002

BACKGROUND OF THE INVENTION Chitin is a type of aminopolysaccharide that is widely found in nature, such as in the shells of crustaceans such as shrimp and crabs, and in the cell walls of filamentous fungi, and chitosan is a deacetylated product of chitin. These materials are known to have a high affinity with living organisms, have antibacterial properties, and have the effect of promoting wound healing, and are used as wound covering and protective materials. In recent years, with the aim of effectively utilizing these excellent properties, studies have been made to form chitin into a sheet, and furthermore to obtain molded products that can fit into the uneven parts of the body.

For example, Japanese Patent Application Laid-Open No. 61-240963 discloses that chitin fibers made of chitin separated and purified from crustaceans, insects, etc., or chitosan, a derivative thereof, and a fibrous binder such as polyvinyl alcohol are used. It has been proposed to create a nonwoven fabric from this material and use it as a wound dressing. This has a fineness of 1 as a chitin fiber.
It has been shown that by using a nonwoven fabric with less than denier, it is possible to obtain a nonwoven fabric with flexibility and good adhesion to the wound surface, but when used on uneven parts of the body, was not sufficient, and a molded product that could fit over the uneven parts was desired.

However, the above-mentioned Japanese Patent Application Laid-Open No. 61-240
Chitin fibers with a small fineness, especially fibers made of chitin with a low degree of deacetylation, which constitute the nonwoven fabric as shown in Publication No. 963, are very brittle. It has been extremely difficult to mold nonwoven fabrics. Molding processing is also possible by increasing the amount of fibrous binder, but if the amount of binder is increased, the chitin fibers will be covered with the binder, which will inhibit the excellent properties of chitin as described above. However, there were problems in that the system could be damaged or its flexibility could be lost.

[0005] Furthermore, it is preferable to use chitin with a low degree of deacetylation as it is less likely to be dissolved by body fluids, etc. as the chitin used in the wound dressing protection material. Chitin obtained from the shells of crustaceans, insects, etc., is treated with dilute hydrochloric acid and hot dilute sodium hydroxide to remove protein and calcium from the shells, resulting in depolymerization or depolymerization of chitin. The problem of acetylation was unavoidable.

On the other hand, a chitin solution prepared by dissolving chitin in a suitable solvent was applied directly to a sheet base material such as a nonwoven fabric without making it into fibers, and the chitin solution was made insolubilized by chemical treatment such as crosslinking. something is known. However, it is very difficult to apply the coating uniformly to a molded product with an uneven surface.In particular, in order to obtain the flexibility required for wound dressing protection materials, fineness is applied to the constituent fibers of the sheet base material. If a material with a small pore diameter is used, the pore diameter becomes small, resulting in clogging of the base material upon application, and when used as a wound dressing, there is a problem that it becomes difficult for the skin to breathe.

[0007]

[Problems to be Solved by the Invention] The present invention provides a molded chitin product that can effectively utilize the excellent properties of chitin as described above, and that does not impede the flexibility and breathability required for wound dressings, etc. The purpose is to provide.

[0008]

[Means for Solving the Problems] The present invention provides a chitin molded article characterized in that the constituent fibers of a fiber aggregate are entangled with hyphae of a filamentous fungus, and a chitin layer is exposed from the hyphae.
A spore suspension in which filamentous fungal spores are dispersed in a liquid medium is attached to the constituent fibers of the fiber aggregate, the filamentous fungi are cultured on the surface of the constituent fibers, and hyphae are grown, followed by treatment with alkali. This is a method for producing a chitin molded article, which is characterized by exposing the chitin layer from the hyphae.

[0009]

[Function] In the present invention, chitin refers to poly-N-acetyl-D-glucosamine or its deacetylated product (
chitosan), and filamentous fungi that contain these substances in their cell walls are used as chitin sources. The chitin layer can be exposed on the surface of the hyphae by treating the hyphae of these filamentous fungi with alkali to dissolve and remove soluble S-glucans, proteins, and lipids present in the cell walls along with chitin. In addition, the hyphae after alkali treatment are
In addition to the chitin layer, it also contains an alkali-insoluble R-glucan layer.

[0010] The hyphae of filamentous fungi have the characteristic of forming mycelium while branching or merging, so when filamentous fungi are cultured on the surface of the constituent fibers of a fiber aggregate, the hyphae will separate from the constituent fibers. They grow while being intricately intertwined. In the present invention, the term "entanglement between mycelia and fiber aggregates" refers to what is obtained by the complex branching structure of the hyphae of this filamentous fungus, and chitin molded products refer to molded fiber aggregates (hereinafter referred to as "fiber aggregates"). The mycelia with exposed chitin layer are intertwined with the constituent fibers of the molded body.

[0011] The filamentous fungi used in the present invention include Aspergillus spp.
icillium genus, Mucor genus, Neurospora genus, P.
Genus hycomyces, Choan
ephora) genus, Zygorhyn
There are no particular restrictions on mycelia, as long as they contain chitin in their cell walls, such as those of the genus P. chus and genus Rhizopus, but when used as a wound covering, sufficient flexibility is required. Thin ones are preferable, and since those with a high degree of deacetylation have the disadvantage of being easily dissolved by body fluids, Aspergillus aspergillus, Aspergillus mold, Arachnoid mold, etc. containing only chitin are more preferable.

[0012] As the fiber aggregate of the present invention, woven fabrics, knitted fabrics, non-woven fabrics, etc. can be used. Among these, non-woven fabrics are preferred because the constituent fibers can be entangled in the thickness direction and the pore diameter can be easily designed. used.

The fibers constituting the fiber aggregate are selected from those having resistance to the above-mentioned alkali treatment and heat resistance to sterilization treatment such as autoclaving. When the fiber aggregate is sterilized by autoclaving, it is preferable to use a material having a melting point at least 10°C higher than the processing temperature, which is usually set at 121°C. Such fibers include polyester fibers, nylon fibers, polyvinyl chloride fibers, acrylic fibers,
There are polypropylene fibers, polyurethane fibers, etc.

[0014] Furthermore, it is preferable to blend the above-mentioned fibers with heat-fusible fibers, because it can be easily molded using a mold and moldability can also be improved. The mixing ratio of the heat-fusible fibers to the total constituent fibers may be 30% or more, but it is more preferable that it is 60% or more because excellent moldability can be obtained, and composite types such as core-sheath type and parallel type. Heat-fusible fibers can also be used. Furthermore, when used as a wound dressing, hydrophobic fibers such as olefin fibers are desirable because they can prevent adhesion to the epidermis.

[0015] The method for producing the chitin molded article of the present invention will be described in detail below.

[0016] The fiber aggregate is molded into a desired shape by a known method to produce a fiber molded body. This fiber molded body is placed in a container such as a beaker and sterilized using an autoclave or the like.

[0017] As a liquid medium for growing filamentous fungi, known ones can be used. After sterilizing this medium in an autoclave, spores of filamentous fungi are suspended therein at a concentration of 10 6 to 10 7 spores/ml to prepare a spore suspension. The above-mentioned sterilized fiber molded body is immersed in this spore suspension, and after the spore suspension adheres to the constituent fibers of the fiber molded body, the fiber molded body is taken out from the spore suspension and sterilized. The cells are placed in a pre-treated beaker or the like and cultured for 1 to 2 days in saturated steam at 30°C. All of the above operations are performed aseptically.

The hyphae of the filamentous fungi grow onto the surface or inside of the molded fiber body while intricately intertwining with the constituent fibers of the molded fiber body, so that they are firmly fixed. In particular, the surface of the fiber molded body has a high density of hyphae, so that it is almost completely covered with hyphae.

When mycelium is to be grown on both surfaces of the fiber molded body, it may be cultured by, for example, standing it upright in a sterilized beaker or the like so that both surfaces do not come into contact with other objects. In addition, when growing mycelium on only one surface of the fiber molding, culture by superimposing a support of the same type as the fiber molding on the surface on which hyphae are not allowed to grow, or place a film such as polyester on the surface. All you have to do is mold it on top of the surface and culture it.

After culturing, the culture medium is removed by washing with water, and immersed in a strong alkaline solution such as about 1N sodium hydroxide solution for about 2 hours to remove the water-soluble glucans and intermediates present in the outer layer of the cell wall of the hyphae. The alkali-soluble S-glucan in the layer and the proteins present together with chitin in the inner layer are removed to expose the chitin layer.

[0021] The cell wall of the hyphae of filamentous fungi generally has 80
~90% is polysaccharide, the rest is protein and lipid, and does not contain inorganic salts mainly composed of calcium carbonate, unlike the shells of crustaceans and insects, so treatment with dilute hydrochloric acid is not necessary. It is. Therefore, there is little risk of depolymerization of chitin due to acid. Furthermore, since the proportion of protein is lower than that of crustaceans, insects, etc., alkali treatment can be carried out at room temperature, so deacetylation is less likely to occur.

[0022] After the alkali treatment, the target chitin molded product can be obtained by washing with water until it becomes neutral, sterilizing it again in an autoclave or the like to kill filamentous fungi, and then drying it naturally.

[0023]

[Example] Example 1 Polyester fiber (fineness 3 denier, fiber length 64 mm)
70% by weight, core-sheath type heat-fusible polyester fiber (fineness 4 denier, fiber length 51 mm, melting point of sheath part 200°C) 3
The web containing 0% by weight was needle punched to obtain a fiber aggregate with a basis weight of 200 g/m2. Next, a polyester film was placed on the concave surface of a shoulder-shaped thermoforming mold, the obtained fiber aggregate was placed on top of the polyester film, and a clearance of 1.5
mm, and was molded for 50 seconds at 240°C to obtain a shoulder-shaped fiber molded body. This fiber molded article was placed in a beaker with a polyester film attached, and sterilized in an autoclave at 121° C. for 15 minutes.

Next, 30g of glucose, 9g of yeast extract
, 9g of malt extract, 15g of peptone in 1000ml of distilled water
A medium for mycelial growth was prepared by dissolving the mixture in 100 mL of water and sterilizing it in an autoclave in the same manner. Spores of Rhizopus niveus (Rhizopus niveus IAM6035 strain) were suspended in this medium at a concentration of 106 to 107 spores/ml to obtain a spore suspension.

[0025] After immersing the above-mentioned sterilized fiber molded body in this spore suspension for 5 minutes, it was taken out, placed in a beaker that had been dry heat sterilized in advance, and immersed in saturated steam at 30°C.
Cultured for 24-48 hours. Note that all these operations were performed aseptically.

[0026] After culturing, the fiber molded body was taken out, the polyester film was removed, it was thoroughly washed with water, and it was immersed in a 1N sodium hydroxide solution for 2 hours.

After thoroughly washing with water, the product was sterilized again in an autoclave and air-dried to obtain the desired chitin molded product.

The surface of the obtained chitin molded product was completely covered with mycelia with exposed chitin, and no mycelia were peeled off from the fiber molded product. The diameter of the hyphae was about 10 μm, and the pore size of the surface covered by the hyphae was about 10 μm.

When this chitin molded product was used as a wound dressing, it was possible to completely cover the shoulder with mycelia with exposed chitin, and the surface had sufficient flexibility.

Example 2 Neurospora crassa (Neuros) as a filamentous fungus
A chitin molded product was obtained in the same manner as in Example 1 except that Pora crassa IFO6178 strain was used. The surface of the obtained chitin molded product was completely covered with mycelia with exposed chitin, and there was no peeling. The diameter of the hyphae was about 5 μm, and the pore size of the surface covered by the hyphae was about 5 μm.

Example 3 Aspergillus niger (Aspergillus niger) was used as a filamentous fungus.
A chitin molded product was obtained in the same manner as in Example 1, except that S. illus niger IAM2094 strain was used. The surface of the obtained chitin molded product was completely covered with mycelia with exposed chitin, and there was no peeling. The diameter of the hyphae was about 8 μm, and the pore size of the surface covered by the hyphae was about 5 μm.

[0032]

[Effects of the invention] ■The surface of the chitin molded product of the present invention is completely covered with hyphae with chitin exposed from the cell wall, so chitin has excellent properties such as biocompatibility, promotion of wound healing, and antibacterial properties. Show characteristics. ■According to the manufacturing method of the present invention, a uniform chitin surface can be formed on a fiber molded body of any complicated shape. As a result, the above-mentioned excellent properties of chitin can be effectively utilized as a wound covering and protective material that fits well to the irregularities of the body, or as a freshness-preserving material by forming a chitin surface on molded containers for fruits and vegetables. ■Since the hyphae are minute, the surface has sufficient flexibility, and when used as a wound dressing, there is little irritation to the wound area, and the inside is also composed of fiber aggregates. Therefore, it is also breathable. ■Mycelia and fiber aggregates are strongly connected by the complex branching structure of hyphae, and since no binders are used, the binders are not dissolved by body fluids, making it extremely safe.

Claims (2)

[Claims] 1. A chitin molded article characterized in that the constituent fibers of the fiber aggregate are entangled with hyphae of a filamentous fungus, and a chitin layer is exposed from the hyphae. 2. A spore suspension in which filamentous fungal spores are dispersed in a liquid medium is attached to the constituent fibers of the fiber aggregate, and the filamentous fungi are cultured on the surface of the constituent fibers to grow hyphae. ,
A method for producing a chitin molded article, which comprises exposing the chitin layer from the hyphae by treating with an alkali.