JP2004242705A - Affected part coating material for external application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an affected part coating material for external application, capable of efficiently making a target harmful matter inactive by the photocatalytic reaction without giving the tissue and cells of an affected part serious damage caused by the photocatalytic reaction. <P>SOLUTION: The affected part coating material 20 consists of a protection layer 25, a sterilization layer 24, and a water absorbing layer 22 which are layered one after another. The base material of the sterilization layer 24 is a porous sheet, and typically, a powder photocatalyst 26 is carried in the sterilization layer. The protection layer 25 consists of a porous sheet with gaps of such a size as can receive an exudate etc. from the affected part S. The base material of the absorbing layer 22 is a porous sheet, and an exudate absorbent material such as alginate is included in the absorbent layer. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an externally applied affected area covering material directed to an affected area outside the body, and more particularly to an externally applied affected area covering material containing a photocatalyst and a manufacturing technique thereof.
[0002]
2. Description of the Related Art A lesion such as a tumor formed outside the body (typically, a body surface), or a burned surface or a wounded surface (hereinafter, referred to as an "affected portion") is protected and affected. Various artificial skins and adhesive plasters have been used as a covering material to be attached to the affected part in order to promote recovery and healing of the skin. In addition, there has been proposed an affected part covering material having a function of not only protecting the affected part by physically covering the same, but also at the same time imparting a function of sterilizing and disinfecting the affected part (that is, preventing the occurrence of infection and inflammation). For example, an artificial skin containing an antibacterial agent such as silver sulfadiazine and gentamicin has been disclosed (for example, see Patent Documents 1 and 2).
In general, when an antibacterial drug is used, an excessively small amount thereof is not preferable because it promotes the development of drug-resistant bacteria. On the other hand, if the applied amount is too large, not only harmful substances such as bacteria to be eliminated but also the tissues and cells of the affected area are likely to be considerably damaged. In addition, if the continuous release of the antibacterial agent is continued for a long period of time, the immune mechanism may be weakened. Therefore, the antimicrobial properties of the diseased part covering material are to be achieved so that the cells and tissues of the affected part are not seriously damaged and have a sufficient infection prevention effect, and realize conditions that prevent the occurrence of resistant bacteria and the decline of the immune system. It is necessary to pay attention to the content of the drug and its form.
[0003]
On the other hand, in place of the antibacterial drug having the above-mentioned problems (the emergence of resistant bacteria, a decrease in the immune system, and damage to the affected tissue), there is no danger of the occurrence of drug-resistant bacteria and a decrease in the immune system, and the tissue in the affected area is not affected. It has been considered to include a photocatalyst that does not easily damage cells or cells as a treatment agent in the affected part covering material. For example, a bandage-type affected area covering material in which a photocatalyst such as titanium dioxide is held on a sheet-like substrate has been disclosed (for example, see Patent Documents 3 to 5). By attaching such a photocatalyst-containing covering material to the affected area and irradiating the photocatalyst with light (typically, ultraviolet light of about 400 nm or less, which is also included in sunlight and room light), the surrounding area of the photocatalyst is exposed. A variety of free radicals such as active oxygen and hydroxyl radicals can be generated to cause an oxidation-reduction reaction (hereinafter, the reaction via the photocatalyst is collectively referred to as "photocatalytic reaction"). Then, by such a photocatalytic reaction, bacteria and viruses existing in the affected area and harmful foreign substances (toxins, enzymes, nucleic acids, etc.) produced by them can be inactivated.
[0004]
[Patent Document 1] Japanese Patent No. 2645098
[Patent Document 2] JP-A-10-71199
[Patent Document 3] JP-A-9-322935
[Patent Document 4] JP-A-2000-136129
[Patent Document 5] JP-A-2000-237230
[Patent Document 6] JP-A-11-138017
[Patent Document 7] JP-A-9-276706
[Patent Document 8] JP-A-9-276706
[0005]
However, the conventional photocatalyst-containing affected-part covering material described in each of the above publications is typically obtained by simply holding a powdery photocatalyst on a substrate such as a nonwoven fabric. It's just For this reason, when the photocatalyst contained in such an affected part covering material is irradiated with light, harmful substances such as microorganisms and virus particles that are inactivated (including sterilization, decomposition and detoxification; the same applies hereinafter) by the photocatalytic reaction are eliminated. , And those that are attached to or close to the photocatalyst. Therefore, in order to more efficiently inactivate harmful substances with light irradiation for a certain time or intensity, a large amount of a photocatalyst must be contained in a light-transmittable state. However, if a large excess of the photocatalyst is present in the affected area, the amount of active oxygen and free radicals generated per unit time may be excessive, and there is a concern that the active substances may adversely affect the affected tissues and cells.
[0006]
Accordingly, the present invention has been created to solve the above-mentioned problems relating to the externally-applied affected area covering material including a photocatalyst, and an object of the present invention is to provide a photocatalytic reaction without seriously damaging the affected tissues or cells. An object of the present invention is to provide an externally-applied affected-part covering material that can efficiently inactivate harmful substances present in an affected part based on the above.
[0007]
SUMMARY OF THE INVENTION According to the present invention, there is provided an externally applied affected area covering material for covering an affected area generated outside the body. The external affected area covering material includes a sterilizing layer and a protective layer. The sterilizing layer is held so that the photocatalyst can receive light. On the other hand, the protective layer is laminated on the surface of the sterilizing layer facing the affected part (that is, the inner surface facing the affected part when attached to the affected part; the same applies hereinafter), and exudate from the affected part. And a porous body having voids sized to receive foreign substances mixed in the exudate.
[0008]
In the external affected part covering material having such a configuration, the photocatalyst and the surface of the affected part are isolated by the interposition of the protective layer. Thereby, direct contact between the photocatalyst and the affected tissue can be prevented. On the other hand, exudate present in the affected area (refers to body fluids such as blood and lymph leached from the affected tissue and the contents thereof; the same applies hereinafter) and foreign substances mixed therein, that is, microscopic harmful substances (harmful microorganisms, viruses) , Toxins, etc.) can enter the voids of the protective layer and reach the sterilizing layer. For this reason, when the externally applied affected area covering material of this configuration is attached to the affected area and the photocatalyst is irradiated with light, harmful substances are efficiently prevented from being damaged by the photocatalytic reaction while avoiding damage to the affected area by the photocatalytic reaction. It can be activated (hereinafter, the treatment of harmful substances based on the photocatalytic reaction is abbreviated as “light treatment”).
[0009]
The preferred externally-affected part covering material having the above-mentioned configuration is formed of a porous body having a size such that the sterilizing layer receives exudate from the affected part and foreign substances mixed in the exudate. The germicidal layer is laminated on the side of the sterilizing layer that does not face the affected part (that is, the outer side that does not face the affected part when attached to the affected part. The same applies hereinafter), and is mixed with the exudate from the affected part and the exudate. It is characterized by having an absorbing layer for absorbing foreign matter.
In the externally applied affected part covering material having such a configuration, exudate present in the affected part and harmful substances (harmful microorganisms, viruses, etc.) mixed therein can enter the voids of the sterilizing layer. Therefore, these exudates and foreign substances mixed in the exudates can be subjected to light treatment from the protective layer to the sterilizing layer, further reach the absorption layer, and be absorbed by the absorption layer. This prevents the exudate from being excessively stored in the affected area, thereby preventing bacterial growth and bacterial infection from outside. Therefore, it is possible to effectively perform light treatment on infection under the covering material while preventing invasion of bacteria from the outside.
It is preferable that the absorption layer is laminated on the sterilization layer in a separable state. When the absorbent layer is separable, the absorbent layer can be separated (typically peeled) after the start of use, and can be replaced with a new absorbent layer. This eliminates the necessity of replacing the sterilizing layer and the protective layer, eliminates peeling of the epidermis formed at the affected part, and promotes treatment.
[0010]
In addition, another preferable example of the externally-applied disease covering material having the above-mentioned configuration is a porous material in which the sterilizing layer has a maximum pore diameter of 1 μm or less (typically 0.5 to 1 μm, preferably 0.6 to 0.8 μm). It is characterized by being composed of a body.
In the externally affected part covering material having such a configuration, bacteria such as staphylococci and Pseudomonas aeruginosa having a size exceeding 1 μm, filamentous fungi and the like can be prevented from entering from outside. Therefore, it is extremely effective in preventing bacterial infection from the outside. In addition, bacterial growth on the affected side can be prevented.
[0011]
The present invention also provides a kit for preparing an externally-used affected-part covering material for covering an affected part outside the body. The kit of the present invention is typically a sheet composed of a porous body having a void size enough to receive exudate from an affected part and a foreign substance mixed in the exudate, and is held in a state where the photocatalyst can receive light. Sterilized sheet, and a sheet laminated or laminated on the surface of the sterilized sheet facing the diseased part, the porous sheet having a size that accepts exudate from the affected part and foreign substances mixed in the exudate. A protective sheet composed of a body, and a sheet laminated or laminated on the side of the sterilizing sheet not facing the diseased part, which is capable of absorbing exudate from the affected part and foreign substances mixed in the exudate And a sheet.
According to the kit having this configuration, the above-mentioned externally affected area covering material according to the present invention can be suitably manufactured.
[0012]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. It should be noted that matters other than matters specifically referred to in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the conventional technology. The present invention can be carried out based on the matters disclosed in the present specification and the drawings and common technical knowledge in the relevant field.
[0013]
The external-use affected-part covering material of the present invention is a therapeutic material that can be widely applied to wound surfaces or lesions such as athlete's foot caused by abrasions or burns. For this reason, as long as the selective light treatment of the harmful substance can be performed by the photocatalytic reaction, the entire size and shape can be appropriately determined according to the intended use.
[0014]
The photocatalyst to be included in the sterilization layer in the externally affected affected area covering material of the present invention is a high photocatalytic active substance that efficiently generates active oxygen and / or free radicals from water present around when irradiated with light, It is preferable that the substance itself does not adversely affect the affected tissue and cells, for example, a substance that is non-toxic and has low irritation to skin tissue. Examples of such a substance include inorganic substances such as titanium dioxide and zinc oxide. Suitable photocatalytically active substances (metal oxides) include titanium dioxide (titania), zinc oxide, iron oxide, tungsten oxide, bismuth oxide, nickel oxide and the like. Particularly, titanium dioxide and zinc oxide, which have high photocatalytic activity and are also used in cosmetics, pharmaceuticals, and the like, are preferable.
[0015]
As the photocatalyst to be contained in the sterilizing layer in the externally-applied diseased dressing material of the present invention, a high-purity purified product of these metal oxides having photocatalytic activity (preferably, a substance consisting essentially of the oxide except for inevitable impurities) ), Or may contain other substances to such an extent that the photocatalytic activity of these metal oxides is not excessively reduced. For example, a metal oxide such as zirconium oxide, aluminum oxide, or magnesium oxide is added to titanium dioxide (titania) or zinc oxide (preferably, about 0.01 to 5 wt% of the total material added to the externally affected affected area as a photocatalyst). ). By adding such a metal oxide, the amount of active oxygen and free radicals generated during light irradiation can be adjusted so as not to be excessive.
Alternatively, a composite of a metal oxide having photocatalytic activity as described above and another inorganic substance may be used. For example, a composite (for example, see Patent Documents 6 and 7) of an inorganic substance such as silica, apatite, or zeolite and a metal oxide having photocatalytic activity such as titanium dioxide can be used as the photocatalyst according to the present invention. . Preferable examples of such a composite include metal oxide particles having photocatalytic activity such as titania coated on a porous ceramic film inert as a photocatalyst (for example, see Patent Document 8). According to such coated metal oxide particles, although it is not particularly limited because it depends on the material, a sheet (for example, a sheet made of polyurethane resin) described later can be protected from decomposition and deterioration due to a photocatalytic reaction. Therefore, the externally-used affected-part covering material containing such a photocatalyst (composite of the above-mentioned inorganic substance and a metal oxide having photocatalytic activity) is suitable for use in which it is allowed to adhere to the affected part for a relatively long period of time.
[0016]
A typical example of the shape of the photocatalyst used for constructing the external lesion dressing of the present invention is a powder. In particular, a fine powder having an average particle size of 10 μm or less (more preferably 1 μm or less) is preferable. According to such a finely powdered photocatalyst, it can be uniformly held on the sterilizing layer (typically on the surface or surface layer). Alternatively, a photocatalyst formed in the form of a sheet or a film may be used in place of the photocatalyst in the form of powder (fine particles). For example, an externally applied diseased part covering material having a sterilizing layer formed by applying a paste (ink) containing photocatalyst particles such as titanium dioxide and an appropriate solvent to the surface of a porous body made of a material as described below is also an embodiment of the present invention. Is preferred.
[0017]
Next, the germicidal layer in the externally affected affected area covering material of the present invention may contain a trapping substance in addition to the photocatalyst. The trapping substance is a substance whose main purpose is to selectively collect harmful substances to be light-treated on or near the surface of a substance having a photocatalytic activity (typically, a metal oxide such as titanium dioxide). Examples of a capture substance suitable for such a purpose include an antibody (immunoglobulin such as IgG) having high binding specificity to a specific antigen. For example, a polyclonal antibody or a derivative thereof contained in an antiserum that recognizes a bacterial structure (cell wall, capsule, etc.) or a product (eg, a protein such as a toxin or an enzyme) as an antigen is employed as a capture substance. It does not selectively capture substances (neutrophils, macrophages, etc.) derived from diseased tissues, but specifically binds to foreign substances (bacteria themselves and bacteria-derived substances) that are targets for light treatment, and at or near the surface of the photocatalyst Can be concentrated near the photocatalyst. When an antibody is used as the capture substance, the type and number are not particularly limited, and what kind and how many kinds are used is determined according to the use. For example, when a specific bacterium or virus such as MRSA or HIV is assumed as a target for light treatment, a monoclonal antibody or the like having a high binding specificity only to the specific bacterium or virus can be used. . On the other hand, if the purpose is to prevent general infection of the wound surface, use a globulin fraction of antiserum, polyclonal antibody, etc., which can bind Gram-positive bacteria, Gram-negative bacteria, etc. widely, as capture substances. Is preferred. For example, an antibody group in an antiserum prepared and collected by immunizing a rabbit or the like with several kinds of pathogenic microorganisms or virus particles as antigens may be used without particular classification.
Further, the capture substance that can be used in the externally-applied diseased-part covering material of the present invention is not limited to an antibody. For example, a target cell tissue (receptor) of a virus (such as HIV) that invades a specific cell or tissue or an analog thereof may be used as the capture substance, as long as it does not significantly affect the affected tissue or the physiological condition of the patient. Alternatively, it may be an enzyme utilizing substrate specificity.
[0018]
These trapping substances are arranged in the vicinity of the photocatalytic substance (typically, the above-mentioned metal oxide). Preferably, it is attached to the surface of the photocatalytic substance itself. The binding means is not particularly limited, and a general method of binding a protein such as an antibody molecule to the surface of an inorganic substance such as a metal or a ceramic, which is often used in the field of immunochemistry and the like, can be adopted.
Typically, as shown schematically in FIG. 1, a photocatalyst 1 (typically a metal oxide such as titanium dioxide) and a capture substance 3 (eg, an antibody or its Fragment). For example, using a suitable silane coupling agent having an amino group such as p-aminophenyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, the photocatalyst 1 And the amino group is introduced, and a linker 2 such as glutaraldehyde is bonded to the amino group. Next, a capture substance (protein) 3 such as an antibody molecule may be bound to a terminal functional group (such as an aldehyde group) of the linker 2.
[0019]
Next, a sterilizing layer (sterilizing sheet) constituting the externally-applied affected area covering material of the present invention will be described. The germicidal layer used in the external affected area covering material of the present invention, a function of covering and protecting the site when addressed to the affected area, a function of holding the photocatalyst in a state where light treatment can be performed on the affected area, The material is not particularly limited as long as it can transmit light (typically, ultraviolet light) from the outside. However, it is desirable to be harmless or less irritating to the human body because of indirect contact with the affected area.
The material constituting the germicidal layer and its configuration differ depending on the use of the externally-applied affected part covering material of the present invention, but it is particularly preferable that the germicidal layer is made of a porous material. By holding the photocatalyst on the porous body, the reaction area of the photocatalyst can be increased, and the photocatalytic activity can be improved. Further, it is preferable that the porous body of the sterilizing layer has voids sized to receive the exudate from the affected area and foreign substances mixed in the exudate. The voids allow the exudate from the affected part and foreign substances mixed in the exudate to be released from the sterilization layer, and prevent the exudate and the like from being excessively stored in the sterilization layer. The sterilization layer has a water vapor transmission rate of approximately 5 to 30 mg / hr · m. ² , Especially 10 to 25 mg / hr · m ² , And 10-15 mg / hr · m, equivalent to normal skin ² (For example, about 13 mg / hr · m ² ) Is preferable. By having such a water vapor transmission rate, a gas such as water vapor, oxygen, carbon dioxide, and the like, and the above-mentioned exudate from the diseased part are appropriately transmitted, so that the condition of the diseased part can be maintained in good and hygienic condition.
[0020]
For example, the material of the porous body serving as the base material holding the photocatalyst in the sterilizing layer may be a natural fiber such as cotton or hemp. Also, silicone, polyurethane, polyacrylate ester, polymethacrylate ester, porous polytetrafluoroethylene (PTFE), polyvinyl alcohol, polyacrylamide, polysaccharide (for example, chitin, chitosan, cellulose, agarose or a derivative thereof), collagen, It may be denatured collagen or the like. In particular, inorganic fibers made of silicon (silicon) are preferable because the fibers are prevented from being oxidized and degraded by a photocatalytic reaction and have high durability. When an organic fiber is used, it is preferable to apply a photocatalytic substance after coating (undercoat) with an inorganic substance such as silica. The undercoat can be carried out by sputtering inorganic particles such as silica, applying a slurry, or using a sol-gel method.
The woven fabric, nonwoven fabric or knitted fabric prepared from the natural fibers or the synthetic fibers as described above is suitable as a porous body having voids sized to receive exudate from the affected part and foreign substances mixed in the exudate. Further, as described above, a porous body having a three-dimensional network structure in which the maximum pore diameter of these porous bodies is 1 μm or less (for example, 0.5 to 1 μm) while holding the photocatalyst is preferable.
[0021]
There is no particular limitation on the means for holding the photocatalytic substance on such a nonwoven fabric or the like. For example, a photocatalyst (typically, a metal oxide powder such as titanium dioxide or zinc oxide) can be attached to the surface of the porous body by a method such as sputtering, slurry coating, a sol-gel method, or a spray. Of these, sputtering is particularly preferred because the photocatalyst can be deposited uniformly and to a desired thickness. Next, the photocatalyst can be fixed to the surface by heating the sterilizing layer to about 30 to 300 ° C (preferably 30 to 180 ° C).
The photocatalytic substance may be held at any part of the sterilizing layer. For example, the photocatalytic substance may be held on the side facing the affected part, or on the side not facing the affected part, or inside the void of the porous body. May be arranged. Furthermore, it may be held on both sides of the side facing the affected part and the side not facing the affected part, or may be uniformly dispersed throughout the sterilizing layer. In the sterilization layer, it is particularly preferable to be held on one surface side facing the affected part, or on both sides (surface layer part) on the side facing the affected part and the side not facing the affected part.
[0022]
The thickness of the sterilizing layer can be appropriately determined according to the permeability and light transmittance of gas and exudate, and is not particularly limited because it depends on the pore diameter of the porous body. (E.g., 50% or more). For example, in the case of a sterilizing layer in which a photocatalyst is held in a porous body made of polyurethane or the like, the thickness is preferably about 5 to 100 μm.
[0023]
Next, the protective layer (protective sheet) constituting the externally-applied affected area covering material of the present invention will be described. The external-use affected-part covering material of the present invention can have improved strength by having a two-layer structure including the sterilizing layer and the protective layer.
The protective layer constituting the externally affected affected area covering material of the present invention is a porous body having voids sized to receive the exudate from the affected area and foreign substances mixed in the exudate. In addition, it is desirable that it is harmless or low irritant to the human body because it comes into direct contact with the affected part. Specific examples of the material of such a porous body include the same organic or inorganic fibers as those listed in the sterilizing layer. That is, silicone, polyurethane, polyacrylate ester, polymethacrylate ester, polytetrafluoroethylene, polyvinyl alcohol, polyacrylamide, polysaccharide (for example, chitin, chitosan, cellulose, agarose or a derivative thereof), collagen, modified collagen and the like. May be. In particular, since it is in contact with the sterilizing layer holding the photocatalyst, it is preferable to be made of an inorganic substance, for example, an inorganic fiber such as a silicon fiber having a high human body affinity. Alternatively, in the case of an organic fiber, it is preferable that an undercoat with an inorganic substance such as silica is applied in order to prevent a decrease in durability due to a photocatalyst as described above. Woven fabrics, nonwoven fabrics or knitted fabrics prepared from these natural fibers or synthetic fibers are suitable as porous bodies having voids sized to receive exudates from affected areas and foreign substances mixed in the exudates.
Further, the thickness of the protective layer may be preferably 5 to 100 μm, particularly preferably 10 to 80 μm in order to prevent contact between the sterilizing layer and the affected part. The average pore diameter of the porous body is preferably from 0.1 μm to 10 mm, particularly preferably from 1 μm to 5 mm.
[0024]
On the other hand, in the case of using the externally applied affected area covering material of the present invention for the purpose of protecting the affected area in which the skin tissue has been extensively lost due to burns or the like for a relatively long period of time (that is, when used as artificial skin), the protective layer is formed of a fibrous material. It is preferably formed from collagen and / or denatured collagen. The protective layer substantially composed of such collagen or denatured collagen (gelatin) constitutes a porous layer (matrix) having pores for receiving fibroblasts involved in regeneration of a dermis-like connective tissue.
[0025]
When producing the externally-applied affected area covering material of the present invention, the porous sheet (protective sheet) corresponding to the protective layer may be adhered to the sterilizing sheet corresponding to the sterilizing layer by any means. Typically, a chemical means using a conventionally known adhesive, for example, a solution for forming a silicon film, a solution for forming an organic resin film such as an acrylic resin, or the like, or heat treatment (for example, temperature: 140 to 200 ° C., time : 5 to 20 minutes, pressure: 5 to 300 kgf / cm ² (Approximately 0.5 to 30 MPa)).
[0026]
Further, as the externally applied affected part covering material of the present invention, a material in which an absorbent layer (absorbent sheet) is laminated on one surface of the sterilizing layer (that is, the surface which does not face the affected part when used) is preferable. It is necessary that such an absorbing layer has a high water absorbing ability and is capable of absorbing the exudate from the affected area and foreign substances mixed in the exudate.
As an absorption layer capable of realizing such a water absorbing ability, for example, a layer in which a porous body similar to the above is used as a skeleton and an exudate absorbent is combined is exemplified. Examples of the material of the porous body include silicone, silicone, polyurethane, polyacrylate ester, polymethacrylate ester, polytetrafluoroethylene (PTFE), polyvinyl alcohol, polyacrylamide, and polysaccharides (eg, chitin, chitosan, cellulose, agarose, and the like). And the like). The porous body may have a relatively large pore diameter in order to compound the exudate absorbent. Further, as the exudate absorbent, for example, polyacrylamide agar gel, alginate and the like are suitable.
The pore size of the porous material used in the absorbent layer is preferably from 0.1 μm to 10 mm, particularly preferably from 0.1 μm to 1 mm for the purpose of forming a composite with the exudate absorbent. On the other hand, the thickness of the absorbing layer is preferably from 5 μm to 10 mm, particularly from 5 μm to 1 mm from the viewpoint of light transmission and exudate absorption, but is not particularly limited, and has various pore diameters and thicknesses. Can be used.
[0027]
The absorption layer made of a composite material in which the porous body and the exudate absorbent are composited may be obtained by any means. Typically, it can be produced by impregnating the porous body in a solution or dispersion containing the exudate absorbent and drying. For example, a predetermined porous body is dipped in a solution or dispersion obtained by dissolving an exudate absorbing material, for example, a fiber or a powdery alginate in a solvent such as water (gelling may be used), and dried. Can be obtained.
[0028]
The external affected area covering material having the absorption layer may have a three-layer structure in which the absorption layer is fixed to the sterilization layer. However, the absorption layer is detachable, that is, the absorption layer is separated (separated) from the sterilization layer. Preferably. Since the absorbent layer is separable (peelable), when the exudate from the affected part and foreign substances mixed in the exudate are absorbed, the absorbent layer can be replaced. For this reason, exudate can be obtained by replacing the absorbent layer (typically, the protective layer and the sterilizing layer are not replaced) even if the period until the affected part is completely cured is long (for example, two weeks or more). And the like can be appropriately released to prevent bacterial infection and proliferation from the affected part and the outside, and to maintain the affected part and the externally affected part covering material hygienically. Typically, exudate and the like can be appropriately released by replacing the absorbent layer, so that the protective layer and the sterilizing layer do not need to be replaced until the affected part is cured / recovered (or the number of replacements is reduced). It is possible to prevent the exudation of cells into the layer or the protective layer and the germicidal layer, and to prevent exfoliation of living tissue such as the epidermis formed when the protective layer and the germicidal layer are replaced. For this reason, the water condition of the affected part can be kept good, and the treatment can proceed smoothly in a short period of time.
Any means may be used as a means for detachably adhering the absorbent layer to the sterilizing layer. For example, an acrylic adhesive may be used. Alternatively, a fixing means such as a bandage or a surgical tape may be used.
Moreover, the physical strength of the externally applied affected area covering material of the present invention can be further improved by adopting a three-layer structure including an absorption layer.
[0029]
Next, with reference to the drawings, some preferred forms of the externally-applied affected-part covering material of the present invention and a method for producing the same will be illustrated. FIG. 2 shows one form of the externally applied affected area covering material 10 which is preferable for protecting small-scale wounds and light burns. The externally affected affected area covering material 10 of this embodiment includes a sterilizing sheet 14 forming a sterilizing layer and a protective sheet 15 forming a protective layer. In other words, the sterilizing layer 14 is made of a polyurethane porous sheet as a base material, and a powdery photocatalyst 16 is carried on the surface 13 of the sterilizing layer 14 facing the affected area S, as schematically shown in FIG. . A protective sheet 15 made of a porous sheet made of polyurethane is fixed to a surface 13 of the sterilizing layer 14 facing the affected area S.
[0030]
The externally affected part covering material 10 of such a form can be typically manufactured as follows. That is, as a base material of the protective layer 15 and the sterilizing layer 14, a papermaking sheet (hereinafter, also referred to as a "polyurethane nonwoven sheet") made of polyurethane short fibers having an arbitrary pore size and thickness, respectively, is prepared. The desired pore size and thickness of the polyurethane nonwoven fabric sheet can be obtained by adjusting the amount of polyurethane fibers to be prepared and the conditions of thermocompression bonding. Preferably, a polyurethane nonwoven fabric sheet serving as a base material of the sterilizing layer 14 is coated with a suitable silicon film-forming material by sputtering as an undercoat, and after drying, using a material containing photocatalyst particles, sputtering, a sol-gel method, a slurry. One surface 13 of the sterilizing layer 14 is coated with a photocatalyst (typically, titanium dioxide) by a coating method or the like, and dried.
Next, an appropriate adhesive (for example, an acrylic adhesive) is applied to one surface 13 side of the sterilizing layer 14 coated with the photocatalyst 16, and a polyurethane non-woven fabric sheet serving as the protective layer 15 is placed thereon. (Preferably 50-80 ° C.). In this way, it is possible to form the two-layer structure of the sterilizing layer 14 and the protective layer 15, and to prepare the externally-used affected-part covering material 10 in which the photocatalyst 16 is held on the affected-part facing surface 13 side of the sterilizing layer 14.
[0031]
According to the external affected part covering material 10 having the form shown in FIG. 2, the surface of the affected part S is isolated from the photocatalyst 16 by the protective layer 15, so that the photocatalyst 16 can be prevented from directly contacting the surface of the affected part S. Therefore, it is possible to prevent the affected tissue from being damaged by active oxygen or free radicals generated by the photocatalytic reaction. Then, foreign substances (typically, biochemical harmful substances such as bacteria, viruses, toxins, etc.) mixed in the exudate on the surface of the affected part S enter into the space of the protective layer 15 together with the exudate and reach the sterilizing layer 14. And reaches the photocatalyst 16. At this time, when natural light or light of a predetermined wavelength (for example, ultraviolet light of about 400 nm when the photocatalyst 16 is titanium dioxide) is applied to the externally affected part covering material 10 from the outside, various active oxygen and Free radicals are generated, and harmful substances (not shown) can be light-treated efficiently.
[0032]
Next, another preferred embodiment of the externally applied affected area covering material of the present invention will be described with reference to FIG. The external affected part covering material 20 of this embodiment has a sterilizing layer 24 and a protective layer 25, similarly to the one shown in FIG. Further, an absorption layer 22 is provided on the surface 21 of the sterilization layer 24 on the side not facing the protection layer 25 in a releasable manner. The absorbent layer 22 is formed by using a porous sheet made of polyurethane or the like having a desired pore diameter and thickness as a base material and compounding an exudate absorbent such as alginate.
[0033]
The external affected part covering material 20 in such a form can be typically manufactured as follows. That is, as the absorbent layer, a polyurethane nonwoven fabric sheet having an arbitrary pore diameter and an arbitrary thickness is prepared in the same manner as described above. Then, the polyurethane nonwoven fabric sheet is dipped in a dispersion liquid (which may be gelled) obtained by dispersing fibers or powder of an exudate absorbent such as alginate in a solution such as water, and then heated and dried. Can be obtained. A two-layer structure of a sterilizing layer 24 and a protective layer 25 is prepared in the same manner as the externally affected area covering material 10 shown in FIG. An acrylic adhesive is applied, the absorbing layer 22 is placed, and dried under appropriate temperature conditions (preferably 50 to 80 ° C.).
In this way, a three-layer structure including the absorption layer 22, the sterilizing layer 24, and the protective layer 25 is formed, and the externally affected affected area covering material 10 in which the photocatalyst 26 is held on the affected area facing surface 23 side of the sterilized layer 24 is manufactured. be able to.
[0034]
According to the external affected part covering material 20 of the form shown in FIG. 3, the same light treatment as that of the external affected part covering material 10 shown in FIG. 2 described above can be performed. On the other hand, the exudate and the like on the affected part surface can be efficiently absorbed once by the absorbing layer 22 and further released. For this reason, the water condition and the hygiene condition of the diseased part S can be favorably maintained, and the treatment can be smoothly reduced. In addition, since the absorbing layer 22 is detachable, the absorbing layer 22 is sterilized when the exudate from the affected area S and foreign substances (various biochemical harmful substances) mixed in the exudate are absorbed. Separate from layer 24, only absorbing layer 22 can be replaced. For this reason, even if the affected part S is healed / recovered for a long time (for example, two weeks or more), exudate can be obtained by exchanging only the absorbent layer 22 without exchanging the protective layer 25 and the sterilizing layer 24. And the like can be appropriately released to prevent bacterial infection and proliferation from the affected area S and the outside, and the externally affected area covering material 20 can be kept more hygienically. Further, since the protective layer 25 and the sterilizing layer 24 do not need to be replaced (or the number of replacements is reduced), it is possible to prevent the peeling of the epidermis and the tissue formed by exuding on the protective layer 25 and the sterilizing layer 24. it can.
[0035]
The external affected area covering materials 10 and 20 can be attached to the affected area S with an adhesive tape or the like having one surface coated with an adhesive. Further, an adhesive tape for affixing / fixing the externally applied affected area covering materials 10 and 20 to the affected area may be provided in advance on the outer surface side of the sterilizing layer or the absorbing layer not facing the affected area S. The adhesive tape to be used is preferably made of a material that can transmit light, and is provided with a large number of holes and slits for securing good air permeability and light transmittance when attached to the affected area S. Is preferred. Typically, it is formed from a synthetic resin film such as a polyolefin.
In addition, these external affected area covering materials 10 and 20 may include the above-described capture substances (antibodies and the like) on or near the surfaces of the photocatalysts 16 and 26, or bind the capture substances to the surfaces of the photocatalysts 16 and 26. You may let it.
[0036]
As described above, the preferred embodiment of the externally applied affected part covering material of the present invention has been described with reference to the drawings, but the externally applied affected part covering material in the form schematically shown in each drawing is an example for embodying the present invention. It is not intended to limit the externally applied affected part covering material of the present invention to those forms.
For example, a light emitting substance capable of emitting light of a wavelength (ultraviolet light) capable of causing a photocatalytic reaction to at least one of the above-described absorption layer, sterilizing layer and protective layer, or an adhesive tape (adhesive sheet for attaching an affected part). May be provided. For example, a fine powder of a spontaneous or phosphorescent luminous ceramic (for example, strontium carbonate containing strontium carbonate, europium, dysprosium, etc.) capable of emitting ultraviolet light of a suitable wavelength is applied in a state where the emitted ultraviolet light can reach the photocatalyst. It is dispersed in a part of the above layer (for example, the outer surface of the sterilizing layer or the inside of the absorbing layer). Thus, a photocatalytic reaction can be caused even when there is no external light irradiation.
[0037]
Further, the externally-applied affected area covering material of the present invention may be provided with a portion (layer position) other than the above-mentioned absorption layer, sterilization layer and protective layer. For example, an anti-reflection film (layer) that can transmit light from the outside and that prevents light reflected on the affected part or a part of the externally applied affected part covering material from diverging from the affected part covering material may be provided. .
[0038]
The present invention will be described in more detail with reference to the following examples, but it is not intended to limit the present invention to those shown in the examples.
[0039]
<Preparation of external affected area covering material>
1. Preparation of sterilization sheet:
According to the following procedure, a papermaking sheet (nonwoven fabric sheet) made of polyurethane short fibers corresponding to the base material of the sterilizing layer was produced.
First, water and a polyurethane short fiber (product of Toray Dupont Co., Ltd .: trade name “T-127C”) are mixed with a propeller stirrer (product of Kumagaya Riki Kogyo Co., Ltd.) in a fiber: water ratio of 1: 200 (weight ratio). , And an appropriate amount of a dispersant (product of Meisei Chemical Co., Ltd .: trade name “Raccoal AL”) and an antifoaming agent (product of Meisei Chemical Co., Ltd .: trade name “Formless P-98”) were added. Then, the mixture was stirred. The stirring liquid thus obtained was put into a material supply section of a general paper forming machine (product of Kumagaya Riki Kogyo Co., Ltd.) and stirred. Then, it was filtered to form a papermaking sheet. Next, the papermaking sheet was dehydrated using a dehydrator (a product of Kumagaya Riki Kogyo Co., Ltd.), and further dried using a rotary dryer (a product of Kumagaya Riki Kogyo Co., Ltd.). Then, with a thermocompression bonding device (product of Kumagai Riki Kogyo Co., Ltd.), the pressure is about 29.4 MPa (300 kgf / cm). ² ), Thermocompression bonding at a temperature of 180 ° C. for 15 minutes, and a polyurethane fiber amount of about 80 g / m 2 ² To produce a porous sheet (sterilized sheet base material) having a thickness of 52 μm.
[0040]
The UV transmittance of the obtained porous sheet was measured using a commercially available spectrophotometer (product of JASCO Corporation: trade name “V-530”). That is, the sample was placed in a sample holder, and the transmittance at 380 nm was measured. As a result, the UV transmittance of this sheet was about 75%.
Further, the maximum pore size of this sheet was determined by Porus Materials Inc. The flow rate was measured using a capillary flow porometer (trade name: CFP-1200-AEL) manufactured by Kabushiki Kaisha and according to a general bubble point method (based on ASTMF 316-86 or JIS K 3832). As a result, the maximum pore size of this sheet was 0.71 μm.
Further, when the water vapor transmission rate of the sheet was measured based on JIS K 7129, the value was about 22.6 mg / hr · m. ² Met.
[0041]
A commercially available material for forming a silicon film (“NRC-300A” manufactured by Nippon Soda Co., Ltd.) was coated (undercoated) on the porous sheet (sterilized sheet substrate) obtained above using a spin coater. Then, it was dried in a drying oven at 60 ° C. for 15 minutes. Further, the surface thereof was coated with a commercially available material for forming a titania film (“NRC-300C” manufactured by Nippon Soda Co., Ltd.) using a spin coater. Then, it was dried in a drying oven at 60 ° C. for 15 minutes.
By the above procedure, a sterilization sheet in which the photocatalyst (titanium dioxide) was uniformly held on the surface layer of the porous sheet was obtained.
[0042]
2. Preparation of protective sheet:
The above 1. A papermaking sheet (nonwoven fabric sheet) made of polyurethane short fibers was produced by the same procedure as that for producing the sterilizing sheet. However, the pressure of the thermocompression bonding is about 0.49 MPa (5 kgf / cm ² ), At a temperature of 130 ° C. for 5 minutes, and the amount of polyurethane fiber is about 30 g / m ² To prepare a porous sheet (protective sheet) having a thickness of 35 μm. The average pore diameter of the present protective sheet measured by the above-described method (bubble point method) was 2,445 μm.
[0043]
3. Preparation of absorbent sheet:
The above 1. A papermaking sheet (nonwoven fabric sheet) made of polyurethane short fibers was produced by the same procedure as that for producing the sterilizing sheet. However, the pressure of the thermocompression bonding is about 0.49 MPa (5 kgf / cm ² ), At a temperature of 130 ° C. for 5 minutes, and the amount of polyurethane fiber is about 60 g / m 2. ² To produce a porous sheet (absorbent sheet substrate) having a thickness of 833 μm. The average pore diameter of the absorbent sheet measured by the above-described method (bubble point method) was 322 μm.
On the other hand, 10 g of alginate ("sodium alginate" manufactured by Wako Pure Chemical Industries, Ltd.) was added to 100 ml of water, and the mixture was stirred while being heated, thereby dissolving the alginate to obtain a partially gelled solution. The porous sheet obtained above was dipped into this solution. Thereafter, the porous sheet was dried at 70 ° C. for 120 minutes.
By the above procedure, an absorbent sheet containing the porous sheet and the exudate absorbent based on alginic acid was obtained.
[0044]
4. Preparation of dressing for external use:
An acrylic adhesive (Nippon Pure Chemical Co., Ltd. product "Julima EM-261 (TM)") was applied to one surface of the sterilizing sheet using a spin coater, and the protective sheet was further laminated thereon. . Thereafter, by drying at 100 ° C. for 3 minutes, a two-layered external affected area covering material (Example 1) composed of a protective sheet (protective layer) and a sterilizing sheet (sterilizing layer) was obtained.
Further, an acrylic adhesive ("Julima EM-261" manufactured by Nippon Pure Chemical Co., Ltd.) was applied to the outer surface of the obtained two-layer structure (Example 1) on the sterilizing layer side (that is, the side not facing the protective layer). (Trademark) "), and the above absorbent sheet was laminated thereon. Thereafter, by drying at 100 ° C. for 3 minutes, an external affected area covering material (Example 2), which is a three-layer structure to which an absorbing sheet (absorbing layer) was peelably adhered, was obtained.
[0045]
<E. Sterilization test for E. coli (stamp test)>
An antibacterial test as schematically shown in FIG. 4 was conducted using the externally affected affected area covering material 10 obtained in Example 1 described above.
That is, the Brain Heart Infusion (BHI) agar medium 30 sterilized by an autoclave is dispensed into a sterilized plate (dish) 31 having a diameter of 100 mm and left at room temperature for 1 hour to solidify the medium 30 in the plate 31. Was. Next, a part of the colonies of Escherichia coli separately cultured for several days on a BHI agar medium was collected and appropriately diluted with sterilized saline to reduce the bacterial concentration to about 3.0 × 10 4. ⁸ A bacterial solution 32 for inoculation was prepared at cfu / ml. Next, 100 μl of the bacterial solution 32 was dropped on the plate 31 and applied to the entire surface of the medium 30 using a conical rod (see FIG. 4).
[0046]
Next, the externally affected affected area covering material 10 (a piece having a size of 10 mm × 10 mm) of Example 1 was placed on the surface of the culture medium 30 of the plate 31 to which the bacterial solution 32 was applied. At this time, the covering material 10 was arranged with the protective layer 15 facing down and the sterilizing layer 14 facing up, as in the case of being applied to a patient. As a comparative control, the culture medium 30 of another plate 31 to which the bacterial solution 32 was coated in the same manner as described above with a coating material of the same shape without a sterilizing layer (that is, a coating material of only the protective layer 15 and having a size of 10 mm × 10 mm). Placed on the surface. Thereafter, these plates 31 were cultured at 37 ° C. for 18 hours while simulating sunlight from a solar simulator 34.
As a result, in the bacterial liquid application plate on which the coating material containing no sterilizing layer was placed as a control, the growth of bacteria was observed on the entire surface of the agar medium. In the plate thus obtained, an area (inhibition spot) in which the growth of bacteria was inhibited in a shape corresponding to a 10 mm × 10 mm piece of the coating material 10 was observed. This indicates that the externally-applied diseased-part dressing material 10 obtained in Example 1 can effectively light-treat (inactivate) harmful substances such as bacteria and their products (toxins and the like) by a photocatalytic reaction. Things.
[0047]
As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and alterations of the specific examples illustrated above.
Further, the technical elements described in the present specification or the drawings exhibit technical utility singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram schematically showing a state of binding between a photocatalyst and a capturing substance via a linker.
FIG. 2 is an explanatory diagram showing a schematic cross-sectional shape of a configuration of an externally applied affected area covering material of the present invention according to one embodiment.
FIG. 3 is an explanatory diagram showing a schematic cross-sectional shape of a configuration of an externally applied affected area covering material according to an embodiment of the present invention.
FIG. 4 is an explanatory diagram schematically showing a method for testing sterilization of Escherichia coli according to one embodiment.
[Explanation of symbols]
1,16,26 Photocatalyst
2 Linker
3 Capture substances
10,20 External affected area covering material
14,24 sterilization layer
15, 25 protective layer
16,26 Photocatalyst
22 Absorbing layer

Claims (5)

An externally applied affected area covering material for covering an affected area outside the body,
A sterilization layer in which the photocatalyst is held in a state capable of receiving light,
A protective layer laminated on a surface of the sterilizing layer facing the affected part, the protective layer being formed of a porous body having a size sized to receive exudate from the affected part and foreign substances mixed in the exudate, . The germicidal layer is composed of a porous body having voids of a size that receives exudate from the affected part and foreign substances mixed in the exudate,
The external affected part covering material according to claim 1, further comprising an absorption layer laminated on a surface of the sterilizing layer that does not face the affected part and absorbing exudate from the affected part and foreign substances mixed in the exudate. The externally applied affected part covering material according to claim 2, wherein the absorbent layer is laminated on the sterilizing layer in a separable state. The external affected part covering material according to any one of claims 1 to 3, wherein the sterilizing layer is formed of a porous body having a maximum pore diameter of 1 µm or less. A kit for producing an external affected part covering material for covering an affected part outside the body,
A sheet composed of a porous body having a void size for receiving exudate from the affected part and a foreign substance mixed in the exudate, and a sterilization sheet held in a state where the photocatalyst can receive light,
A protective sheet comprising a sheet laminated or laminated on the surface of the sterilizing sheet facing the affected part, the porous sheet having voids sized to receive exudate from the affected part and foreign substances mixed in the exudate. Sheet and
A kit comprising: a sheet laminated or laminated on a surface of the sterilizing sheet not facing the affected part, the sheet being capable of absorbing exudate from the affected part and foreign substances mixed in the exudate.

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