Damaged site treatment material comprising nanofiber sheet, method for producing same, and damaged site treatment material kit

Abstract

[Problem] The present invention addresses the problem of providing a nanofiber sheet for treating a damaged site, said nanofiber sheet having favorable adhesion to a biological tissue surface and being capable of preventing air leakage and body fluid leakage without a component derived from biological tissue being used therein. [Solution] A damaged site treatment material that comprises a nanofiber sheet containing: a water-soluble polymer; and a water-insoluble polymer.

Description

Material for treating injured sites comprising a nanofiber sheet, method for manufacturing the same, and kit for treating injured sites

[0001] This invention relates to a material for treating injured sites comprising a nanofiber sheet, a method for producing the same, and a kit for treating injured sites.

[0002] When a portion of living tissue is removed or sutured due to trauma, surgery, or disease, bodily fluids such as blood and tissue fluid leak from the excision site or suture site. In cases of lung diseases such as pneumothorax, it is necessary to prevent air leakage from fragile pleural damage or lung resection stumps. Preventing such fluid and air leakage using tissue occlusive agents contributes to maintaining the patient's life during surgery and suppressing the occurrence of postoperative complications.

[0003] Currently, commonly used tissue occlusive agents are plasma-derived products sometimes called "fibrin glue," and their main components are fibrinogen and thrombin. They are commercially available in liquid and sheet forms. Liquid tissue occlusive agents are applied by spraying an aqueous solution of fibrinogen and thrombin onto the application site. Sheet-type tissue occlusive agents have fibrinogen and thrombin attached to one side (the adhesive side) of a sheet-like support. In both cases, upon contact with the application site, thrombin acts on fibrinogen to form fibrin, which then forms a fibrin membrane that occludes the tissue.

[0004] However, liquid tissue occlusive agents can run off if the surface is sloped, and require separate equipment (applicators) for application, which adds to the cost. On the other hand, while sheet-type tissue occlusive agents do not drip, surgical excision surfaces are not always uniform, and sheet-type agents sometimes fail to adequately conform to the fine irregularities of biological tissue, resulting in gaps. Furthermore, air and fluid leaks often occur from areas that were supposed to be reinforced by applying the sheet. In particular, in the treatment of lung fistulas, the lung tissue of smokers often loses its elasticity, and there have been many reported cases where air leakage cannot be completely prevented even with the application of a sheet.

[0005] In addition, because fibrin glue is a blood product made from blood from numerous donors, there is a risk of contamination by various viruses and thus a risk of infection. Therefore, special management, such as long-term storage of medical records and informed consent, is necessary when using it. Furthermore, because it is expensive, its active use is also a challenge from the perspective of medical costs.

[0006] To address these challenges, much research is currently being conducted. For example, as a method that does not use fibrin glue, a blood product, hydrogels made from polyamines derived from β-1,3-glucan and poly-L-lysine, which are high molecular weight materials derived from food additives (see, for example, Patent Document 1), bio-tissue reinforcing materials consisting of a laminated structure of a fibrous structure, sponge-like body or film made of a bioabsorbable polymer and a film made of etherified cellulose in which the hydroxyl groups of cellulose have been etherified (see, for example, Patent Document 2), and tissue adhesives using derivatives of di or tricarboxylic acids present in the citric acid cycle, esterified and with collagen as adhesive components (see, for example, Patent Document 3).

[0007] International Publication No. 2009 / 057802, Japanese Patent Publication No. 2019-528806, Japanese Patent Publication No. 2004-261222

[0008] However, the adhesive described in Patent Document 1 has inferior gel strength compared to commercially available fibrin glue, raising concerns about insufficient adhesive strength. Patent Document 2 only confirmed pressure resistance in its examples and did not evaluate adhesion under humid conditions that more closely resemble actual surgical environments. Furthermore, the technology described in Patent Document 3 has the drawback of requiring preparation before use due to the instability of the activated esterified derivative, which is time-consuming.

[0009] Therefore, the object of the present invention is to provide a sheet that does not use components derived from biological tissue, has good adhesion to the surface of biological tissue, and can prevent air leakage and bodily fluid leakage.

[0010] The inventors of the present invention have conducted extensive research to solve the above problems and have found that a material for treating injured sites and a kit for treating injured sites comprising a nanofiber sheet containing a water-soluble polymer and a water-insoluble polymer can solve the above problems, thus completing the present invention. More specifically, they have found that a high level of sealing effect can be obtained by using a nanofiber sheet combining a water-soluble polymer and a water-insoluble polymer as the basic structure, and further by laminating this nanofiber sheet with a specific sheet, or by forming a kit combining a specific number of sheets. That is, the present invention has the following configuration: [1] A material for treating injured sites comprising a nanofiber sheet containing a water-soluble polymer and a water-insoluble polymer. [2] The material for treating injured sites according to [1], further comprising an adhesive layer containing tannic acid on the side of the nanofiber sheet that is attached to the injured site. [3] The weight of tannic acid contained per unit area of ​​the adhesive layer is 2 to 350 μg / cm². 2 [2] The injury site treatment material as described in [2]. [4] The injury site treatment material as described in [1], comprising a water-soluble polymer-containing composition sheet laminated on the side of the nanofiber sheet that is attached to the injury site. [5] The injury site treatment material as described in any one of [1] to [4], wherein at least one of the vertical failure resistance score, the side leakage failure resistance score, and the liquid environment resistance score is 3 or higher. [6] The injury site treatment material as described in [5], wherein the total score calculated by the following formula (1) is 21 or higher. [7] The injury treatment material according to [1] or [2], wherein the water-soluble polymer is one or more water-soluble polymers selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, methylcellulose, sodium carboxymethylcellulose, and polyvinyl acetal diethylaminoacetate. [8] The injury treatment material according to [1] or [2], wherein the water-soluble polymer is polyvinyl alcohol and / or sodium carboxymethylcellulose, and the water-insoluble polymer is polycaprolactone. [9] The injury treatment material according to [1] or [2], wherein the nanofiber sheet has a core-shell structure, the core contains a water-insoluble polymer, and the shell contains a water-soluble polymer.

[10] A method for producing an injury treatment material, comprising the step of forming nanofibers by electrospinning using a water-soluble polymer solution containing a water-soluble polymer and a water-insoluble polymer solution containing a water-insoluble polymer.

[11] The method for producing an injury treatment material according to

[10] , comprising the step of spraying a solution containing tannic acid onto at least one surface of the nanofibers obtained by the step of forming the nanofibers.

[12] A method for producing a wound treatment material according to

[10] or

[11] , wherein the water-soluble polymer solution contains 1 to 50% by weight of the water-soluble polymer in the solution, and the water-insoluble polymer solution contains 1 to 50% by weight of the water-insoluble polymer in the solution.

[13] A wound treatment material kit comprising: one or more water-soluble polymer-containing composition sheets placed on the wound site side or used to fill the wound site; and a covering material placed on the sheets and used to cover the wound site, wherein the covering material is a wound treatment material according to any one of [1] to [4], and when the one or more water-soluble polymer-containing composition sheets and the covering material are combined, at least one of the vertical failure resistance score, the side leakage failure resistance score, and the liquid environment resistance score is 3 or higher.

[14] The wound treatment material kit according to

[13] , wherein the total score calculated by the following formula (1) is 21 or higher.

[0011] The injury treatment material and injury treatment material kit comprising the nanofiber sheet of the present invention are highly safe because they do not use components derived from biological tissue. Furthermore, since the raw materials constituting the nanofiber sheet of the present invention are inexpensive, they can be provided at approximately 1 / 10 the price of general fibrin glue, contributing to a reduction in medical costs. In addition, they do not require special devices such as sprayers during use and dissolve and adhere with only a small amount of water on the surface of biological tissue, making them easy to handle and highly versatile. Above all, they conform to even slight irregularities on the surface of biological tissue, thus highly effective in preventing air leakage and bodily fluid leakage.

[0012] A schematic diagram illustrating the reinforcement of a lung injury site using the injury treatment material comprising the nanofiber sheet of the present invention. Scanning electron microscope (SEM) image (10,000x magnification) of the injury treatment material comprising the nanofiber sheet obtained in Example 1.

[0013] This invention relates to a material for treating injury sites comprising a nanofiber sheet containing a water-soluble polymer and a water-insoluble polymer, a method for producing the same, and a kit for treating injury sites. The invention is described in detail below.

[0014] <Forms of the Injury Treatment Material and Injury Treatment Material Kit> The injury treatment material and injury treatment material kit of the present invention can be appropriately selected from the following forms (A) to (D) depending on the shape, depth, and surrounding moist environment of the injury site. The injury treatment material refers to a sheet or patch that can physically cover the injured area of ​​a living organism.

[0015] <(1) Nanofiber Sheet (Form (A))> One preferred form of the injury site treatment material of the present invention is a nanofiber sheet consisting of a water-soluble polymer and a water-insoluble polymer. The water-soluble polymer in the nanofiber sheet becomes gelatinous due to the moisture in the affected area and exhibits initial adhesive strength, and the water-insoluble polymer has durability, thus maintaining a physical sealing function to the injury site.

[0016] <(2) Nanofiber sheet with adhesive layer containing tannic acid (Form (B))> As one form of the material for treating injured sites of the present invention, a form is preferred in which an adhesive layer containing tannic acid is provided on the side of the nanofiber sheet that is attached to the injured site. Since tannic acid has many phenolic hydroxyl groups in its molecule, it forms a complex with proteins on the surface of biological tissue (such as collagen) and polymers constituting the nanofiber sheet (especially water-soluble polymers such as polyvinyl alcohol) through hydrogen bonding and hydrophobic interactions.

[0017] More specifically, the multiple phenolic hydroxyl groups of tannic acid bond with carbonyl groups, amino groups, or functional groups of polymers in biological tissues, while simultaneously forming multi-point hydrogen bonds and hydrophobic interactions with hydroxyl groups of water-soluble polymers (especially polyvinyl alcohol) contained in the nanofiber sheet. This results in high adhesion to both biological tissues and nanofiber sheets, improving the nanofiber sheet's ability to seal bleeding and fluid leakage from the damaged area surface.

[0018] Furthermore, due to the inherent astringent properties of tannic acid, it coagulates proteins in minute bleeding points and tissue voids at the site of injury, thereby chemically blocking bleeding and leakage from the surface of the injury site.

[0019] In this invention, from the viewpoint of adhesion, the weight of tannic acid contained per unit area of ​​the adhesive layer is 2 to 350 μg / cm². 2 Preferably, the concentration is 10 to 300 μg / cm³. 2 It is preferable that it be so.

[0020] <(3) Laminate (Form (C))> One form of the material for treating injured sites of the present invention is a form comprising a water-soluble polymer-containing composition sheet laminated on the side of the nanofiber sheet that is attached to the injured site, that is, a laminated form is preferred. Here, the laminated form includes a form in which two sheets are bonded together by heat fusion or adhesive, or a form in which they are laminated and integrated by methods such as continuous spinning in the spinning process.

[0021] The water-soluble polymer-containing composition sheet comes into contact with the damaged area and dissolves with even slight leakage of bodily fluids, making it easy to conform to the unevenness of the affected area. Furthermore, the nanofiber sheet functions as a barrier layer, enabling a high degree of sealing. This is preferable when a stronger sealing ability than that of the nanofiber sheet alone is required.

[0022] <(4) Kit (Form (D))> One form of the injured site treatment material kit of the present invention is a kit that includes one or more water-soluble polymer-containing composition sheets that are placed on the injured site or used to fill the injured site, and a covering material that is placed on the sheets and used to cover the injured site. In this specification, "covering material" means a member used to cover the injured site, and the covering material is preferably one of (A) a nanofiber sheet, (B) a nanofiber sheet having an adhesive layer containing tannic acid, or (C) a laminate. For example, in an area where tissue is irregularly missing, multiple water-soluble polymer-containing composition sheets can be attached and then covered with the covering material to seal the injured site without any gaps.

[0023] Furthermore, if the injury is deep, it is preferable to fill the affected area with a water-soluble polymer-containing composition sheet and then seal it with a covering material. Since the water-soluble polymer-containing composition sheet filled into the affected area is a composition containing a water-soluble polymer, it dissolves with the small amount of moisture on the surface of the biological tissue and has the effect of stuffing the injured area. By applying a nanofiber sheet on top of that, the injured area is sealed, making it possible to more effectively prevent air leakage and bodily fluid leakage.

[0024] <Components of the material for treating injured areas> <(1) Water-soluble polymer> The water-soluble polymer of the present invention refers to a polymer whose solubility in water at 40°C is 75% by mass or more, and either synthetic polymers or natural polymers may be used. It is preferable that the water-soluble polymer is biodegradable. It is preferable to use a biodegradable water-soluble polymer because it is broken down and absorbed in the body, so chronic foreign body reactions do not occur, and there is no need for further surgery to remove the sheet attached to the affected area.

[0025] Examples of synthetic polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyvinyl alcohol / acrylic acid / methyl methacrylate copolymer, polyvinyl alcohol / polyethylene glycol graft copolymer, polyvinyl methyl ether, carboxyvinyl polymer, polymers having N-vinyl cyclic lactam units, poly(meth)acrylic acid or its salts, polyaminoalkyl methacrylate copolymer, ammoniaalkyl methacrylate copolymer, and water-soluble resins such as polyvinyl acetal diethylaminoacetate (AEA). In this specification, (meth)acrylic means acrylic or methacrylic.

[0026] Examples of natural polymers include starch derivatives such as starch, oxidized starch, dextrin, and cation-modified starch; natural proteins such as gelatin, collagen, and casein; cellulose derivatives such as methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose; and natural high molecular weight polysaccharides such as sodium alginate, pectin, sodium pectinate, gum arabic, carrageenan, karaya gum, tragacanth gum, carob gum, quince seed (marmelo), xanthan gum, locust bean gum, guar gum, tamarind gum, and hyaluronic acid.

[0027] In particular, from the viewpoint of ease of handling, the water-soluble polymer is preferably one or more water-soluble polymers selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, methylcellulose, sodium carboxymethylcellulose, and polyvinyl acetal diethylaminoacetate, with polyvinyl alcohol and / or sodium carboxymethylcellulose being more preferred.

[0028] <(2) Water-soluble polymer-containing composition> The water-soluble polymer-containing composition of the present invention preferably contains the water-soluble polymer described above. As long as the water-soluble polymer is included, the other components are not limited, but it is preferable that the water-soluble polymer is the main component in the composition. The main component refers to the component that is present in the largest amount in the water-soluble polymer-containing composition, and it is preferable that the water-soluble polymer is present in an amount of 50 to 100% by weight relative to the total amount of water-soluble polymer and water-insoluble polymer in the solid matter after the solvent has evaporated. It is more preferable to include one or more water-soluble polymers selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, methylcellulose, sodium carboxymethylcellulose, and polyvinyl acetal diethylaminoacetate, and it is even more preferable to include two or more water-soluble polymers. Compositions containing polyvinyl alcohol and / or sodium carboxymethylcellulose are particularly preferred. Note that as long as the water-soluble polymer is the main component of this composition, it may also contain water-insoluble polymers.

[0029] In the case of a composition containing polyvinyl alcohol and sodium carboxymethylcellulose, a ratio of polyvinyl alcohol:sodium carboxymethylcellulose = 99-50% by weight:1-50% by weight is preferred, and a ratio of 95-60% by weight:5-40% by weight is more preferred.

[0030] <(3) Water-soluble polymer solution> The water-soluble polymer solution of the present invention is prepared by dissolving the water-soluble polymer described above in a solvent. Examples of solvents that can be used include water, alcohols (methanol, ethanol, butanol, hexafluoro-2-propanol, etc.), and mixtures thereof. Water is more preferred from the viewpoint of ease of handling and safety.

[0031] The water-soluble polymer solution of the present invention preferably contains 1 to 50% by weight of the water-soluble polymer, and more preferably 5 to 30% by weight.

[0032] <Properties of Polyvinyl Alcohol> When using polyvinyl alcohol as a water-soluble polymer, it is preferable that it has the following properties.

[0033] (Degree of saponification of PVA) The average degree of saponification of polyvinyl alcohol is preferably 70 mol% or more and less than 98 mol%. When the average degree of saponification is within the above range, polyvinyl alcohol exhibits water solubility, which is preferable. The average degree of saponification is determined by the measurement method based on the Japanese Pharmaceutical Additives Standards.

[0034] (Average degree of polymerization of PVA) The average degree of polymerization of polyvinyl alcohol is preferably 200 to 4000, and more preferably 500 to 3800. When the average degree of polymerization is within the above range, it is preferable because the strength of the sheet is improved. All of the above water-soluble polymers are approved as pharmaceutical additives and are preferable because they can be obtained at low cost.

[0035] <(4) Water-insoluble polymers> Water-insoluble polymers are polymers whose solubility in water at 40°C is less than 75% by mass, and in the present invention, water-insoluble polymers that are biodegradable are preferred.

[0036] Using a water-insoluble polymer that is biodegradable is preferable because it is broken down and absorbed in the body. Specifically, examples include aliphatic polyesters such as polycaprolactone, polylactic acid, polyglycolic acid, and polylactic acid-glycolic acid copolymers, celluloses, and ethylcellulose. Polycaprolactone is preferred due to its extensive track record of use in the medical field. "Biodegradability" refers to a polymer whose degree of biodegradation, as measured in accordance with JIS K6953-1, is 30% or higher.

[0037] Furthermore, if the average degree of saponification of polyvinyl alcohol is 98 mol% or higher, it becomes poorly soluble in cold water; therefore, polyvinyl alcohol with an average degree of saponification of 98 mol% or higher is classified as a water-insoluble polymer.

[0038] <(5) Water-Insoluble Polymer Solution> The water-insoluble polymer solution of the present invention is prepared by dissolving the aforementioned water-insoluble polymer in a solvent. Examples of the solvent that can be used include organic solvents such as alcohols (methanol, ethanol, butanol, hexafluoro-2-propanol, etc.), esters (methyl acetate, ethyl acetate, etc.), DMF (dimethylformamide), chloroform, and dichloromethane, as well as water. When dissolving the polymer in water, it is preferable to dissolve it by heating to 85°C or higher, more preferably 90°C or higher.

[0039] The water-insoluble polymer solution of the present invention preferably contains 1 to 50% by weight of the water-insoluble polymer in the solution, more preferably 1 to 20% by weight.

[0040] <(6) Tannic Acid and Tannic Acid Solution> Tannic acid is an astringent polyphenol contained in leaves and the like of plants. In the present invention, tannic acid obtained from nutgalls, gallnuts and the like is preferable. Specifically, tannic acid described in the Japanese Pharmacopoeia is preferable.

[0041] The tannic acid can be dissolved in a solvent and used as a tannic acid solution. Examples of the solvent include water, alcohols (methanol, ethanol, butanol, hexafluoro-2-propanol, etc.), and mixed solvents thereof. From the viewpoints of biological safety and solubility of tannic acid, it is preferable to use a mixed solution of water and ethanol (aqueous ethanol solution). When an aqueous ethanol solution is used as the solvent, the content of ethanol is preferably 10 to 90% by weight (w / w%) relative to the total weight of the solvent, more preferably 30 to 80% by weight.

[0042] Further, regarding the concentration of tannic acid in the tannic acid solution, it is preferable that tannic acid is contained in an amount of 10 to 60% by weight, more preferably 30 to 55% by weight, based on the total weight of the tannic acid solution, from the viewpoint of ease of application to a nanofiber sheet and spraying.

[0043] <Structure of Nanofiber Sheet, Injury Treatment Material, and Injury Treatment Material Kit> The nanofiber sheet of the present invention contains a water-soluble polymer and a water-insoluble polymer. The nanofiber sheet of the present invention may be used in a single form (form (A) above), or it may be provided with an adhesive layer containing tannic acid (form (B) above) or a water-soluble polymer-containing composition sheet (form (C) above) on the side that adheres to the injury site. Here, "underlayer" refers to a layer or sheet that is positioned on the injury site side of the nanofiber sheet. The aforementioned adhesive layer containing tannic acid or water-soluble polymer-containing composition in sheet form (hereinafter sometimes referred to as "water-soluble polymer-containing composition sheet") corresponds to the underlayer. Furthermore, the water-soluble polymer-containing composition sheet may be laminated on the nanofiber sheet of the present invention, or it may not be physically integrated. Here, the form in which it is not physically integrated corresponds to form (D) above, in which case the water-soluble polymer-containing composition sheet, which is separate from the nanofiber sheet, corresponds to the underlayer.

[0044] When laminated, it is preferable that a laminate is formed in which the nanofiber sheet of the present invention is the upper layer and the water-soluble polymer-containing composition sheet is the lower layer (corresponding to the side that adheres to the damaged area), as shown in the above form (C), and such laminate is referred to as a material for treating damaged areas.

[0045] The amount of water-soluble polymer in the material for treating the injured site is preferably 10 to 90% by weight relative to the total amount of water-soluble polymer and water-insoluble polymer. When a water-soluble polymer-containing composition sheet is laminated onto a nanofiber sheet (the above embodiment (C)), it is preferable that the content of the water-soluble polymer in the nanofiber sheet and the water-soluble polymer-containing composition sheet of the present invention is within the above range.

[0046] Water-soluble polymers contribute to the adhesion of the sheet to the damaged area, while water-insoluble polymers contribute to the durability of the sheet. Therefore, when the proportion of water-soluble polymers is within the above range, it is preferable because the hydrophilicity is not too high, preventing the sheet from dissolving too quickly, and the hydrophobicity is not too high, preventing poor wettability and making it difficult for the sheet to adhere to biological tissue.

[0047] The preferred range for the water-soluble polymer also varies depending on the fiber form and the sheet form. For example, when the nanofiber has a core-shell structure as described later, it is preferable to have a larger amount of water-soluble polymer forming the shell. Specifically, in a nanofiber sheet, it is more preferable that the water-soluble polymer accounts for 60 to 85% by weight relative to the total amount of water-soluble polymer and water-insoluble polymer.

[0048] Furthermore, when a water-soluble polymer-containing composition sheet is laminated on the lower layer (the side that adheres to the damaged area) of the nanofiber sheet of the present invention to form a laminate, it is preferable that the water-soluble polymer content is 10 to 90% by weight relative to the total amount of water-soluble polymers and water-insoluble polymers in the two layers. If a water-soluble polymer-containing composition sheet is included, it is even more preferable that the total amount of water-soluble polymers contained in the water-soluble polymer-containing composition sheet is 60 to 100% by weight relative to the total amount of water-soluble polymers and water-insoluble polymers contained in the water-soluble polymer-containing composition sheet. This is preferable because the adhesion of the sheet is improved when a layer containing a large amount of water-soluble polymer adheres to the damaged area.

[0049] In the case of the above embodiment (D), that is, in the case of a medical material kit for treating an injury site that includes one or more water-soluble polymer-containing composition sheets and a covering material, it is preferable that the content of the water-soluble polymer is 10 to 90% by weight relative to the total amount of water-soluble polymers and water-insoluble polymers when the one or more water-soluble polymer-containing composition sheets and the covering material are combined.

[0050] <Method for Manufacturing Nanofiber Sheets> The nanofiber sheets of the present invention are preferably manufactured using a water-soluble polymer solution containing the water-soluble polymer and a water-insoluble polymer solution containing the water-insoluble polymer. Conventional known methods such as electrospinning, meltblowing, needle punching, spunbonding, flash spinning, water entanglement, airlaid, thermal bonding, resin bonding, and wet methods can be used as manufacturing methods. Among these, electrospinning and meltblowing are preferred, and electrospinning is more preferred. Fibers can be formed by these methods, and the fibers can be deposited to obtain a sheet.

[0051] <(1) Method for producing nanofibers having a core-shell (coaxial) structure> As one form of the nanofiber sheet of the present invention, a nanofiber sheet having a single-core (core-shell (coaxial)) structure is preferred, wherein the core contains a water-insoluble polymer and the shell contains a water-soluble polymer. A water-insoluble polymer solution containing the water-insoluble polymer is used as the core material solution, and a water-soluble polymer solution containing the water-soluble polymer is used as the sheath material solution, and this is applied to the electrospinning method.

[0052] The configuration of the electrospinning apparatus is shown. The electrospinning apparatus of the present invention comprises coaxial needles with different inner diameters (an outer layer needle for supplying sheath material solution and an inner layer needle for supplying core material solution), a syringe for containing core material solution and a syringe for containing sheath material solution, a collector, and a high-voltage power supply for applying a high voltage between the coaxial needle and the collector.

[0053] Specifically, the outer layer needle of the coaxial needle is supplied with a sheath material solution, and the inner layer needle is supplied with a core material solution. The distance between the coaxial needle and the collector is 10 to 20 cm, and a voltage of +1 to 30 kV is applied to the needle side and a voltage of -5 to -1 kV is applied to the collector side, causing the core material solution and sheath material solution to be discharged from the spinning nozzle at the tip of the coaxial needle.

[0054] As a result, the core material solution is covered with the sheath material solution, and as the solvent evaporates, it becomes fibrous. Core-sheath fibers covered with fibrous sheath material fibers are produced and collected by the collector.

[0055] <(2) Method for producing nanofibers having a sea-island structure> As one form of the nanofiber sheet of the present invention, a nanofiber sheet having a sea-island structure is preferred. It can be obtained by applying the prepared spinning solution to the electrospinning method or the melt-blown method. The electrospinning method using a spinning needle is preferred.

[0056] The spinning solution is preferably an emulsion. It may be prepared by mixing the water-soluble polymer and the water-insoluble polymer in a solvent, or by preparing separate solutions (the water-soluble polymer solution and the water-insoluble polymer solution) and mixing them together. The mixing method is not particularly limited as long as it is a method that can form an emulsion in the spinning solution, and known dispersion devices such as homogenizers, ball mills, and dissolvers can be used.

[0057] <(3) Method for producing nanofibers having a single structure> As one form of the nanofiber sheet of the present invention, a nanofiber sheet having a single structure in which a water-soluble polymer and a water-insoluble polymer are uniformly dispersed in the fiber, without having a core-shell structure or a sea-island structure, is preferred. It can be obtained by applying a mixed solution containing a water-soluble polymer and a water-insoluble polymer as a spinning solution to an electrospinning method or a melt-blown method. An electrospinning method using a spinning needle is preferred.

[0058] <Method for manufacturing the material for treating injured sites> The material for treating injured sites of the present invention can be manufactured by the following method.

[0059] <(1) Manufacturing method of form (A)> Form (A) is a form consisting of a single nanofiber sheet. It can be manufactured by the nanofiber sheet manufacturing method described above.

[0060] <(2) Method for manufacturing form (B)> Form (B) is a nanofiber sheet having an adhesive layer containing tannic acid on the side of the nanofiber sheet that adheres to the damaged area. An adhesive layer is formed by spraying a solution containing tannic acid onto at least one surface of the aforementioned nanofiber. Preferably, the tannic acid solution used is one in which tannic acid is dissolved in the aforementioned solvent and the tannic acid concentration is adjusted to 10 to 60% by weight. Preferably, the tannic acid is sprayed using the electrospinning method, with a spraying rate of 0.5 to 1.0 mL / h, and spraying is performed for a predetermined time. The spraying time can be appropriately adjusted in the range of 5 seconds to 30 minutes depending on the desired adhesive strength and tannic acid content. If the spraying time is excessively long, for example, if spraying is performed for more than 1 hour, the tannic acid layer may thicken, reducing the flexibility of the sheet and potentially impairing its ability to conform to biological tissue. Therefore, in order to impart excellent adhesion while maintaining the inherent flexibility of the nanofiber sheet, it is preferable to control the spraying within the above time range and the amount of tannic acid deposited per unit area, as described later.

[0061] Furthermore, in this invention, as mentioned above, the weight of tannic acid contained per unit area of ​​the adhesive layer is 2 to 350 μg / cm². 2 Preferably, the concentration is 10 to 300 μg / cm³. 2It is more preferable that the weight percentage (wt%) of tannic acid in the nanofiber sheet is 0.3 to 10% by weight. By uniformly spraying a small amount of tannic acid in this way, it is possible to impart excellent adhesion to biological tissue while maintaining the inherent flexibility of the nanofiber sheet. The characteristic of form (B) is that it has a two-layer structure consisting of a nanofiber sheet and a tannic acid layer. For example, when polyvinyl alcohol, a water-soluble polymer that constitutes the nanofiber sheet, and tannic acid are mixed in the same solution, the viscosity of the solution increases significantly due to the strong hydrogen bonding between the two, and gelation proceeds. Therefore, it is virtually impossible to form it as a nanofiber sheet, as it can lead to nozzle clogging and other problems in various spinning processes, including electrospinning. The inventors have solved the manufacturing problem by adopting a configuration in which a tannic acid solution is sprayed onto the surface of a pre-formed nanofiber sheet. In other words, form (B) is based on a mechanism in which polyvinyl alcohol and tannic acid dissolve and mix only with the small amount of moisture on the surface of the biological tissue, exhibiting strong adhesive force.

[0062] <(3) Method for manufacturing form (C)> Form (C) is a form comprising a water-soluble polymer-containing composition sheet laminated on the lower layer (the side on which the damaged area is adhered) of the nanofiber sheet.

[0063] The manufacturing method is not particularly limited. The water-soluble polymer-containing composition sheet can be prepared by known methods, but it may also be prepared by the nanofiber manufacturing method described above.

[0064] Two sheets may be manufactured separately and then bonded together by methods such as pressure bonding, heat fusion, or adhesive bonding. Alternatively, a water-soluble polymer-containing composition may be filled into an electrospinning apparatus and sprayed onto one side of a nanofiber sheet to form a layer. When the two sheets are laminated, handling is improved, and it is preferable because a layer of the water-soluble polymer-containing composition sheet can be applied to the damaged area, dissolved by the small amount of moisture in the biological tissue to conform to the unevenness of the tissue, and then the nanofiber sheet can be applied as the top layer to seal the damaged area.

[0065] <(4) Method for manufacturing form (D)> Form (D) is a material kit for treating injured sites. The covering material included in the kit is preferably manufactured by any of the methods (1) to (3) described above. In addition, one or more water-soluble polymer-containing composition sheets included in the kit can be made by known methods, but may also be made by the nanofiber manufacturing method described above.

[0066] <Nanofiber Characteristics> Nanofibers manufactured by either method preferably have an average fiber diameter of 1 nm to 10 μm, more preferably 5 nm to 2,000 nm, and even more preferably 10 nm to 1,000 nm. Within the above range, they are easy to form into sheets and exhibit sufficient sheet strength, resulting in good handling during use. They also have high conformability to the fine irregularities of biological tissue. The average fiber diameter of nanofibers refers to the average of the fiber diameters measured by randomly observing 10 locations on a piece of fabric cut from the center using an electron microscope.

[0067] The average fiber length of the manufactured nanofibers is not particularly limited, but from the viewpoint of ease of handling, it is preferably 10 times or more the diameter, more preferably 100 times or more, and even more preferably 1000 times or more. Furthermore, it is more preferable that the nanofibers are continuous fibers.

[0068] The obtained nanofibers are deposited in a randomly overlapping manner to produce a nanofiber sheet. The collecting body for deposition is not particularly limited and can be, for example, a drum, nonwoven fabric, flat plate, or belt shape, and can be a conductive material made of metal or carbon, or a non-conductive material made of organic polymer. The collecting body does not need to be a conductive material as described above, and a counter electrode can be placed behind the collecting body. In this case, the collecting body and the counter electrode may be in contact or separated.

[0069] <Characteristics of the Injury Treatment Material and Injury Treatment Material Kit> The injury treatment material (forms (A) to (C)) and injury treatment material kit (form (D)) of the present invention have good adhesion to the surface of biological tissue and can adequately conform to the fine irregularities of biological tissue, thereby preventing air leakage and bodily fluid leakage. Specifically, it is preferable that the injury treatment material or injury treatment material kit of the present invention has at least one of the following scores: vertical failure resistance score, lateral leakage failure resistance score, and liquid environment resistance score, which are 3 or higher. Each score will be explained in detail below.

[0070] The scoring criteria include all forms (A) to (D) mentioned above. Forms (A) to (C) will be evaluated using the respective materials, while the kit for form (D) will be evaluated in a state where one or more water-soluble polymer-containing composition sheets and the coating material are combined.

[0071] (Vertical Failure Resistance Score) The vertical failure resistance score is a numerical representation of the pressure resistance performance, indicating whether a hole will form in the center of the injury site treatment material or injury site treatment material kit of the present invention (hereinafter, these may be collectively referred to as "specimen") under pressure load. It is evaluated using a large animal lung fistula model in which air leakage from the lung can be confirmed with the naked eye using a leak test with physiological saline. The lung fistula in this case should be one in which leakage can be confirmed with the naked eye at an airway pressure of 15 cmH2O set on the ventilator while physiological saline is being dripped into it. Specifically, a small hole is made in the lung of a beagle dog. If the small hole is made with an electrosurgical unit, it should be approximately 3 mm x 3 mm, and if an 18G needle is used, it should be approximately 1.26 mm in diameter. The specimen (3.8 cm x 2.6 cm) is attached to the fistula site to close the lung fistula. If the specimen is the aforementioned injury site treatment material kit (form D), one or more water-soluble polymer-containing composition sheets are placed or filled into the injury site depending on the depth and shape of the injury site, and then a covering material (3.8 cm x 2.6 cm) is applied on top to close the lung fistula. Subsequently, the set airway pressure of the ventilator is gradually increased from 15 cmH2O to 30 cmH2O, and the pressure load condition at which the center of the specimen ruptures is measured and scored as follows. In this process, no bio-derived adhesive is used, and the performance is measured.

[0072] 1 point: Rupture occurs at peak airway pressure < 20 cmH2O 2 points: Rupture occurs at 20 cmH2O ≤ peak airway pressure < 25 cmH2O 3 points: Rupture occurs at 25 cmH2O ≤ peak airway pressure < 30 cmH2O 4 points: Rupture occurs at 30 cmH2O ≤ peak airway pressure 5 points: Withstands 30 cmH2O ≤ peak airway pressure A score of 3 or higher is preferable because the sample is less likely to vertically rupture even under the 30 cmH2O pressure standard used in leak tests during lung surgery.

[0073] (Axillary Leakage and Rupture Resistance Score) The axillary leakage and rupture resistance score is a numerical representation of the adhesive performance of the injury site treatment material or injury site treatment material kit of the present invention, indicating its durability until it peels off from the biological tissue adhesion portion under pressure load. The measurement method is the same as that used for the vertical rupture resistance score evaluation. Specifically, the evaluation is performed using a large animal lung fistula model, similar to the vertical rupture resistance score evaluation, and the pressure load conditions under which the sample peels off from the biological tissue are measured, and a score is assigned as follows. In this case, no biological tissue-derived adhesive is used, and the performance is measured without it.

[0074] 1 point: Failure occurs at peak airway pressure < 20 cmH2O 2 points: Failure occurs at 20 cmH2O ≤ peak airway pressure < 25 cmH2O 3 points: Failure occurs at 25 cmH2O ≤ peak airway pressure < 30 cmH2O 4 points: Failure occurs at 30 cmH2O ≤ peak airway pressure 5 points: Withstands 30 cmH2O ≤ peak airway pressure A score of 3 or higher is preferable because the specimen is less likely to detach from the adhesive area even under the 30 cmH2O pressure standard used in leak tests during lung surgery.

[0075] (Liquid Environment Resistance Score) The liquid environment resistance score is a numerical representation of the ability of the injury site treatment material or injury site treatment material kit of the present invention to withstand a liquid environment of body fluids or physiological saline. First, a fistula is created in which leakage can be visually confirmed at a set airway pressure of 15 cmH2O on a ventilator while physiological saline is dripped onto it. Specifically, a small hole is made in the lung of a beagle dog (approximately 3 mm x 3 mm if the hole is made with an electrosurgical unit, or approximately 1.26 mm in diameter if an 18G needle is used) in the same manner as when evaluating the vertical rupture resistance score described above. A specimen (3.8 cm x 2.6 cm) is attached to the fistula site to close the lung fistula. Physiological saline is dripped onto the sheet under ventilation from a ventilator, and the time until the sheet ruptures is measured. A score is assigned based on the time until rupture, as follows. At this time, no biological tissue-derived adhesive is used to measure performance.

[0076] 1 point: Breaks down with body fluids alone. 2 points: Breaks down immediately upon addition of saline solution. 3 points: Breaks down within 30 minutes after addition of saline solution. 4 points: Breaks down within 60 minutes after addition of saline solution. 5 points: Withstands for more than 60 minutes after addition of saline solution. The body contains a lot of water, and if a sample is placed in such a humid environment, there is a risk that the sample will absorb water and break down. A score of 3 or higher is preferable because it is less likely to break down even in a humid environment within the body.

[0077] (Overall Score) The injury treatment material or injury treatment material kit of the present invention preferably has an overall score of 21 or higher calculated by the following formula (1).

[0078] The balance score indicates whether the three scores—vertical failure resistance score, lateral leakage failure resistance score, and liquid environment resistance score—are well-balanced. It is scored according to the table below, based on the average score calculated using the formula (2) below.

[0079] A total score of 21 or higher is preferable because it makes the material less prone to vertical failure and side leakage, and also less prone to failure in humid environments, thus preventing air and bodily fluid leakage.

[0080] <Drugs> The injury treatment material or injury treatment material kit of the present invention may contain drugs. The drugs are drugs that are suitable for adhesion to biological tissue, and poorly membrane-permeable drugs, easily water-soluble drugs, polymer drugs, etc. are preferred.

[0081] Specifically, examples include macromolecular drugs such as peptide drugs and protein drugs, and nucleic acid drugs. Examples of macromolecular drugs include oxytocin, desmopressin, leuprolide, goserelin, octreotide, as well as peptides, proteins, fusion proteins, antigens, growth factors, proliferation factors, cytokines, interferons, hormones, blood coagulation and fibrinolytic factors, enzymes, conjugate proteins, protein vaccines, antibody-like proteins, cells, and nucleic acids. Examples of nucleic acid drugs include vaccines, decoy nucleic acids, antisense nucleic acids, siRNA, miRNA, ribozymes, and aptamers.

[0082] The drug content in the injury site treatment material and injury site treatment material kit of the present invention varies depending on the physical properties of the drug, but 1 to 100% by weight is preferred.

[0083] <Method of Using the Injury Treatment Material and Injury Treatment Material Kit> The method of using the injury treatment material and injury treatment material kit of the present invention can be appropriately selected as follows, depending on the condition of the injury site (depth, size, shape of the wound, etc.). Basically, by using a nanofiber sheet (form (A)) that combines a water-soluble polymer and a water-insoluble polymer, it is possible to seal the injury site simply and quickly. If a higher level of adhesion is required, it is preferable to select as follows: ・When the injury site is relatively shallow and flat: Form (A) is used as the base, and if higher adhesion is desired, it is preferable to select form (B) or form (C). ・When the injury site is very uneven: In order to improve conformability to the tissue, it is preferable to select form (B) which has an adhesive layer or form (C) which is a laminate. ・When the injury site is deep: It is preferable to use the kit of form (D) to fill the gaps.

[0084] <Applications of the Injury Treatment Material and Injury Treatment Material Kit of the Present Invention> The injury treatment material and injury treatment material kit of the present invention can be used for injury treatment to close defects or cut surfaces of organs and biological tissues such as the pleura, pericardium, and serosa. In particular, they are suitably used for tissue closure in the field of respiratory surgery, such as closing air leaks from lung pleural delamination surfaces, lung cut surfaces, or bronchial stumps.

[0085] While the injury site treatment material and injury site treatment material kit of the present invention are effective even when used as nanofiber sheets alone, depending on the size of the defect or cut surface of the organ or biological tissue, tissue occlusion can be more effectively achieved by first filling the defect with the aforementioned water-soluble polymer-containing composition or attaching it to the cut surface, and then applying the nanofiber sheet or injury site treatment material of the present invention.

[0086] The embodiments of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0087] <Raw materials used> (Water-soluble polymers) ・EG-40P: Polyvinyl alcohol manufactured by Mitsubishi Chemical Corporation (product name: Gosenol EG), degree of saponification (mol%): 86.5-89.0, viscosity of 4% aqueous solution (mPa・s): 36.6-49.4 ・CMC-Na: Sodium carboxymethylcellulose manufactured by Wako Pure Chemical Industries, Ltd. (product code: 039-01335) ・Eudragit S100: Methacrylic acid copolymer manufactured by EVONIK INDUSTRIES

[0088] (Water-insoluble polymers) ・PCL: Polycaprolactone manufactured by SIGMA-ALDRICH (product number: 440744-250G) ・NH-26: Polyvinyl alcohol manufactured by Mitsubishi Chemical Corporation, degree of saponification (mol%): 99.0 or higher, viscosity of 4% aqueous solution (mPa・s): 60-70 ・N-300: Polyvinyl alcohol manufactured by Mitsubishi Chemical Corporation (product name: N-type Gosenol), degree of saponification (mol%): 98.0-99.0, viscosity of 4% aqueous solution (mPa・s): 25.0-30.0 Tannic acid: Fujifilm Wako Pure Chemical Industries

[0089] (Solvents) ・Ethanol: Ethanol (99.5%) reagent grade manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. ・Ethyl acetate: Ethyl acetate reagent grade manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. ・Chloroform: Chloroform reagent grade manufactured by Nacalai Tesque (CAS No. 67-66-3) ・DMF: N,N-dimethylformamide reagent grade manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0090] (Other) ・Coumarin-6: COUMARIN 6 LASER GRADE (CAT No. 190347) manufactured by MP Biomedicals ・NeoVeil Sheet: manufactured by Gunze Medical Co., Ltd. ・Beriplast P Combi-Set Tissue adhesion (biological tissue-derived adhesive): manufactured by CSL Behring

[0091] <Method for Manufacturing the Nanofiber Sheet of the Present Invention> The nanofiber sheet, injury site treatment material, and injury site treatment material kit of the present invention were manufactured by the following manufacturing method. In Tables 1 to 4, the main sheet corresponds to the nanofiber sheet. Bilayer refers to a water-soluble polymer-containing composition sheet laminated on the nanofiber sheet. The "underlayer sheet" refers to a water-soluble polymer-containing composition sheet manufactured separately from the nanofiber sheet. The injury site treatment material kit was constructed by combining multiple of these underlayer sheets or by filling the injury site.

[0092] (Upper layer of Example 1) Example 1 consists only of the upper layer and corresponds to form (A). The water-soluble polymer solution was prepared by dissolving 0.75 g of EG-40P in 3.75 g of distilled water with stirring at 85°C to obtain a 16.67% EG-40P aqueous solution. In addition, 0.1 g of CMC-Na was dissolved in 3.9 g of distilled water with stirring at room temperature to obtain a 2.5% CMC-Na aqueous solution. Then, 4.5 g of the 16.67% EG-40P aqueous solution and 3.33 g of the 2.5% CMC-Na aqueous solution were mixed to prepare the water-soluble polymer solution. In addition, 1.2 g of PCL was dissolved with stirring in 10 g of chloroform / DMF (4 / 1) mixture to prepare a 10.7% PCL solution, which was used as the water-insoluble polymer solution. Coaxial spinning was performed using an electrospinning apparatus (Bioinicia LE-50) with the water-insoluble polymer solution on the inside and the water-soluble polymer solution on the outside. The spinning conditions were: needle-side voltage 22kV, collector-side voltage -2kV, distance (from needle to collector) 16cm, and flow rate 0.12mL / h inside and 0.6mL / h outside.

[0093] Table 2, Example 1, lists the proportions of each polymer contained in the sheet. In Example 1, a water-soluble polymer solution was prepared by mixing 4.5 g of a 16.67% EG-40P aqueous solution and 3.33 g of a 2.5% CMC-Na aqueous solution. Therefore, the concentration of EG-40P in the water-soluble polymer solution is 16.67% × 4.5 g / (4.5 g + 3.33 g) = 9.58 wt%. Similarly, the concentration of CMC-Na in the water-soluble polymer solution is 1.06 wt%. On the other hand, a 10.7 wt% PCL solution was used as the water-insoluble polymer solution. Since the flow rate under spinning conditions is related to the spinning ratio, in Example 1, spinning was performed with a mixing ratio of water-soluble polymer solution:water-insoluble polymer solution = 5:1. Therefore, the amount of polymer contained in the sheet is EG-40P = 9.58, CMC-Na = 1.06, and PCL = 10.7 / 5 = 2.14. If we consider the sum of these (12.78) as 100%, then the sheet contains EG-40P = 75.0% by weight, CMC-Na = 8.3% by weight, and PCL = 16.7% by weight. Therefore, the ratio of water-soluble polymer to (water-soluble polymer + water-insoluble polymer) in the upper layer is (75.0 + 8.3) = 83.3% by weight. The above values ​​are shown in Table 2. The same applies to the following examples and comparative examples.

[0094] The nanofiber sheet obtained in Example 1 was observed using a scanning electron microscope (SEM) at a magnification of 10,000x. The SEM image is shown in Figure 2.

[0095] (Example 2) Example 2 consists of "one lower sheet + one upper sheet" attached together, and therefore corresponds to form (D).

[0096] (Upper layer of Example 2) 1.6 g of EG-40P was dissolved in 18.4 g of distilled water at 85°C with stirring to prepare an 8% EG-40P aqueous solution, which was used as a water-soluble polymer solution. In addition, 1.2 g of PCL was dissolved in 10 g of a chloroform / DMF (4 / 1) mixture with stirring to prepare a 10.7% PCL solution, which was used as a water-insoluble polymer solution. The water-insoluble polymer solution was placed on the inside and the water-soluble polymer solution on the outside, and coaxial spinning was performed using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 9.5 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 17.5 cm, and a flow rate of 0.16 mL / h on the inside and 1 mL / h on the outside.

[0097] (Lower layer of Example 2) 2 g of N-300 was added to 18 g of distilled water and stirred to dissolve while heating to over 90°C to prepare a 10% N-300 aqueous solution, which was then used as a water-insoluble polymer solution. A water-soluble polymer solution made from 5 g of 8% EG-40P aqueous solution and a water-insoluble polymer solution made from 2 g of 10% N-300 aqueous solution were mixed to prepare a mixture. The mixture was uniaxially spun using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 13 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 15 cm, and a flow rate of 0.7 mL / h.

[0098] (Upper layer of Example 3) 1.2 g of EG-40P was dissolved in 18.8 g of distilled water with stirring at 85°C to prepare a 6% EG-40P aqueous solution, which was a water-soluble polymer solution. Also, 1.2 g of PCL was dissolved in 8.8 g of ethyl acetate with stirring to prepare a 12% PCL (ethyl acetate) solution, which was a water-insoluble polymer solution. 5 g of the 12% PCL (ethyl acetate) solution and 5 g of the 6% EG-40P aqueous solution were measured out, mixed by hand for 30 seconds, and then homogenized in a water bath at 8000 rpm for 5 minutes. After a 3-minute rest, homogenization was performed again at 8000 rpm for 5 minutes to obtain an emulsion solution with a PCL:EG-40P ratio of 2:1. The emulsion solution was uniaxially spun using the above electrospinning apparatus. The spinning conditions were a needle-side voltage of 6 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 11 cm, and a flow rate of 0.8 mL / h. Immediately after spinning the above sheet at a flow rate of 0.8 mL / h for 120 minutes, a solution containing a water-soluble polymer composition was added on top to form a second layer. Specifically, 2 g of EG-40P was dissolved in 18 g of distilled water at 85°C with stirring to obtain a 10% EG-40P aqueous solution. 0.1 g of CMC-Na was dissolved in 3.9 g of distilled water at room temperature with stirring to obtain a 2.5% CMC-Na aqueous solution. 2 g of the 10% EG-40P aqueous solution and 4.5 g of the 2.5% CMC-Na aqueous solution were mixed to prepare a water-soluble polymer solution. This solution was then added on top of the upper sheet immediately after spinning, and the solution containing the water-soluble polymer composition was uniaxially spun. The spinning conditions were a needle-side voltage of 6 kV, a collector-side voltage of -2 kV, a distance of 11 cm (from needle to collector), and a flow rate of 0.8 mL / h for 120 minutes. The spinning conditions for each layer of the above two-layer sheet (the first layer being a sheet using an emulsion solution, and the second layer being a sheet containing a water-soluble polymer composition) were the same: a flow rate of 0.8 mL / h and a spinning time of 120 minutes, so the amount of solution dispensed was 1.6 mL. The concentration of the water-soluble polymer in the water-soluble polymer solution of the first layer was (6% × 5 g) / (5 g + 5 g) = 3%, so the amount of water-soluble polymer contained in the dispensed volume of 1.6 mL was 3% × 1.6 mL = 0.048 g.On the other hand, the concentration of water-soluble polymer in the second layer of water-soluble polymer solution is (10% × 2g + 2.5% × 4.5) / (2g + 4.5g) = 4.8%, so the amount of water-soluble polymer contained in the 1.6mL discharge volume is 4.8% × 1.6mL = 0.077g. The total amount of water-soluble polymer in both layers is 0.048 + 0.077 = 0.125g, and the total amount of water-soluble polymer and water-insoluble polymer in both layers is 0.048 + 0.077 + (12% × 5g / (5g + 5g) × 1.6) = 0.221g, so the content of water-soluble polymer in both layers is 0.125 / 0.221 × 100 ≈ 57% by weight.

[0099] (Lower layer of Example 3) A mixture similar to that of the lower layer of Example 2 was prepared. The mixture was uniaxially spun using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 15kV, a collector-side voltage of -2kV, a distance (from needle to collector) of 13cm, and a flow rate of 0.4mL / h.

[0100] (Upper layer of Example 4) This was prepared in the same manner as the upper layer of Example 1.

[0101] (Lower layer of Example 4) A water-soluble polymer solution prepared in the same manner as the water-soluble polymer solution used in the upper layer of Example 1 was uniaxially spun using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 17kV, a collector-side voltage of -2kV, a distance of 15cm (from the needle to the collector), and a flow rate of 0.3mL / h.

[0102] (Upper layer of Example 5) The water-soluble polymer solution was prepared in the same manner as the water-soluble polymer solution used in the upper layer of Example 1, and the water-insoluble polymer solution was prepared by adding 20 mg of Coumarin-6 to the water-insoluble polymer solution of Example 1. The water-insoluble polymer solution was placed inside and the water-soluble polymer solution outside, and coaxial spinning was performed using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 20 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 14 cm, and a flow rate of 0.11 mL / h inside and 0.55 mL / h outside.

[0103] (Lower layer of Example 5) Prepared in the same manner as the lower layer of Example 4.

[0104] (Upper layer of Example 6) 1.6 g of EG-40P was dissolved in 18.4 g of distilled water with stirring at 85°C to prepare an 8% EG-40P aqueous solution, which was a water-soluble polymer solution. 1.2 g of PCL was dissolved in 8.8 g of ethyl acetate with stirring to prepare a 12% PCL (ethyl acetate) solution, which was a water-insoluble polymer solution. 4 g of the 12% PCL (ethyl acetate) solution and 6 g of the 8% EG-40P aqueous solution were measured out, mixed by hand for 30 seconds, and then homogenized in a water bath at 8000 rpm for 5 minutes. After a 3-minute rest, homogenization was performed again at 8000 rpm for 5 minutes to obtain an emulsion solution with a PCL:EG-40P ratio of 1:1. The emulsion solution was uniaxially spun using the above electrospinning apparatus. The spinning conditions were a needle-side voltage of 6.7 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 15 cm, and a flow rate of 0.6 mL / h.

[0105] (Lower layer of Example 6) The same 8% EG-40P aqueous solution as the upper layer of water-soluble polymer solution in Example 2 was used as the water-soluble polymer solution. The water-soluble polymer solution was uniaxially spun using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 10kV, a collector-side voltage of -2kV, a distance of 15cm (from the needle to the collector), and a flow rate of 0.5mL / h.

[0106] (Upper layer of Example 7) This was prepared in the same manner as the upper layer of Example 2.

[0107] (Upper layer of Example 8) Prepared in the same manner as the upper layer of Example 5.

[0108] (Upper layer of Example 9) The water-soluble polymer solution was prepared in the same manner as the water-soluble polymer solution used in the upper layer of Example 1. For the water-insoluble polymer solution, 2 g of PCL was dissolved by stirring in 8 g of chloroform / DMF (4 / 1) mixture to prepare a 20% PCL solution. The water-insoluble polymer solution was placed inside and the water-soluble polymer solution outside, and coaxial spinning was performed using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 22 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 15 cm, and a flow rate of 0.11 mL / h inside and 0.55 mL / h outside.

[0109] (Upper layer of Example 10) 1.6 g of EG-40P was dissolved in 18.4 g of distilled water with stirring at 85°C to prepare an 8% EG-40P aqueous solution, obtaining a water-soluble polymer solution. 1.6 g of NH-26 was added to 18.4 g of distilled water and dissolved with stirring while heating to 90°C to prepare an 8% NH-26 aqueous solution, obtaining a water-insoluble polymer solution. 5 g of the water-soluble polymer solution from the 8% EG-40P aqueous solution and 5 g of the water-insoluble polymer solution from the 8% NH-26 aqueous solution were mixed to prepare a mixture. The mixture was uniaxially spun using the above electrospinning apparatus. The spinning conditions were needle-side voltage 15 kV, collector-side voltage -2 kV, distance (from needle to collector) 14 cm, and flow rate 1 mL / h.

[0110] (Upper layer of Example 11) The water-soluble polymer solution was prepared using the same 8% EG-40P aqueous solution as in Example 10. The water-insoluble polymer solution was also prepared using the same 8% NH-26 aqueous solution as in Example 10. A mixture was prepared by mixing 1 g of the water-soluble polymer solution with 5 g of the water-insoluble polymer solution with the 8% NH-26 aqueous solution. The water-soluble polymer solution was uniaxially spun using the above electrospinning apparatus. The spinning conditions were a needle-side voltage of 17 kV, a collector-side voltage of -2 kV, a distance (from needle to collector) of 14 cm, and a flow rate of 1 mL / h.

[0111] (Upper layer of Example 12) This was prepared in the same manner as the upper layer of Example 11.

[0112] (Lower layer of Example 12) Prepared in the same manner as the lower layer of Example 4.

[0113] (Upper layer of Example 13) The water-insoluble polymer solution was prepared in the same manner as the upper layer water-insoluble polymer solution of Example 1. The water-insoluble polymer solution was uniaxially spun using the electrospinning apparatus described above. The spinning conditions were a needle-side voltage of 16.5kV, a collector-side voltage of -2kV, a distance of 15cm (from the needle to the collector), and a flow rate of 0.3mL / h. Immediately after spinning the sheet at a flow rate of 0.3mL / h for 200 minutes, a water-soluble polymer-containing composition was added on top to form a second layer. Specifically, immediately after spinning the upper layer sheet, a water-soluble polymer solution prepared in the same manner as the upper layer water-soluble polymer solution of Example 1 was added on top and uniaxially spun. The spinning conditions were a needle-side voltage of 5.5kV, a collector-side voltage of -2kV, a distance of 13cm (from the needle to the collector), and a flow rate of 0.5mL / h for 24 minutes. Of the two layers described above, if the sheet using the water-insoluble polymer solution is designated as the first layer and the sheet containing the water-soluble polymer composition is designated as the second layer, the amount of liquid dispensed from the first layer is 1 mL, and the amount of solution dispensed from the second layer is 0.2 mL. Since the concentration of water-soluble polymer in the water-insoluble polymer solution of the first layer is 0%, the amount of water-soluble polymer contained in 1 mL of dispensed volume is 0 g. On the other hand, the concentration of water-soluble polymer in the water-soluble polymer solution of the second layer is (9.58 + 1.06 =) 10.6%, so the amount of water-soluble polymer contained in 0.2 mL of dispensed volume is 10.6% × 0.2 mL = 0.021 g. The total amount of water-soluble polymer in both layers is 0.021 g, and the total amount of water-soluble polymer and water-insoluble polymer in both layers is 0.021 + (10.7% × 1 mL) = 0.128 g. Therefore, the content of water-soluble polymer in both layers is 0.021 / 0.128 × 100 ≈ 17% by weight.

[0114] (Upper layer of Example 14) This was prepared in the same manner as the upper layer of Example 1.

[0115] (Lower layer of Example 14) Prepared in the same manner as the lower layer of Example 4.

[0116] (Upper layer of Example 15) A two-layer sheet (laminated structure) was prepared in the same manner as the upper layer of Example 13.

[0117] (Lower layer of Example 15) Prepared in the same manner as the lower layer of Example 4.

[0118] (Upper layer of Example 16) This was prepared in the same manner as the upper layer of Example 9.

[0119] (Lower layer of Example 16) Prepared in the same manner as the lower layer of Example 4.

[0120] (Upper layer of Example 17) This was prepared in the same manner as the upper layer of Example 2.

[0121] (Example 18) Using the same electrospinning apparatus as used to manufacture the upper layer sheet, tannic acid was sprayed onto one side of the upper layer of Example 1. Specifically, a 45 w / w% tannic acid solution (solvent: 62.5 w / w% ethanol aqueous solution) was prepared and filled into a syringe pump, and a 2.5 cm square nanofiber sheet (6.25 cm) attached to the collector was sprayed. 2 The liquid was sprayed towards the target area at a delivery rate of 0.75 ml / h for 10 seconds. Under these conditions, assuming no scattering or loss of the delivered liquid, the amount of liquid per sheet (6.25 cm) 2 The amount of tannic acid per square centimeter is approximately 19.8 μg, and the amount of tannic acid per unit area is 3.17 μg / cm². 2 This is the result.

[0122] (Example 19) The same procedure as in Example 18 was followed, except that the spraying time of the tannic acid solution was changed to 1 minute.

[0123] (Example 20) The same procedure as in Example 18 was followed, except that the spraying time of the tannic acid solution was changed to 5 minutes.

[0124] (Example 21) The same procedure as in Example 18 was followed, except that the spraying time of the tannic acid solution was changed to 15 minutes.

[0125] (Comparative Examples 1 and 5) Commercially available NeoVeil sheets were used.

[0126] (Comparative Examples 2 and 6) Commercially available NeoVeil sheets and Beriplast P Combi-Set Tissue adhesive were used.

[0127] (Comparative Example 3) Prepared in the same manner as the lower layer in Example 4.

[0128] (Upper layer of Comparative Example 4) 1.2 g of the water-soluble polymer solution Eudragit S100 was dissolved in 8.8 g of ethanol at room temperature with stirring to prepare a 12% Eudragit S100 solution. The 12% Eudragit S100 solution was uniaxially spun using the above electrospinning apparatus. The spinning conditions were a needle-side voltage of 6 kV, a collector-side voltage of -3 kV, a distance (from needle to collector) of 12 cm, and a flow rate of 0.8 mL / h.

[0129] (Lower layer of Comparative Example 4) Prepared in the same manner as the lower layer of Example 4.

[0130] (Comparative Example 7) A commercially available NeoVeil sheet was prepared in the same manner as in Example 21, except that tannic acid was sprayed onto one side.

[0131] <Evaluation of Vertical Rupture Resistance> Small holes were made in the lungs of beagle dogs. When using an electrosurgical unit, holes of approximately 3 mm x 3 mm were made, and when using an 18G needle, small holes of approximately 1.26 mm in diameter were made. The nanofiber sheet of the present invention (3.8 cm x 2.6 cm) was attached to each fistula site to close the lung fistula, and the set airway pressure of the ventilator was gradually increased from 15 cmH2O to 30 cmH2O, and the pressure load conditions at which the center of the sheet ruptured were measured. The score was calculated according to the above description. When a water-soluble polymer-containing composition sheet was used as the lower layer (the side attached to the damaged area) of the nanofiber sheet, it was attached in a size of 3.8 cm x 2.6 cm.

[0132] <Evaluation of side leakage rupture resistance> This was evaluated using the same method as for vertical rupture resistance evaluation. The score was calculated using the method described above.

[0133] <Evaluation of Liquid Environment Resistance> Small holes were made in the lungs of beagle dogs. When using an electrosurgical unit, holes of approximately 3 mm x 3 mm were made, and when using an 18G needle, small holes of approximately 1.26 mm in diameter were made. The nanofiber sheet of the present invention (3.8 cm x 2.6 cm) was attached to each fistula site to close the lung fistula, and physiological saline solution was dripped onto the sheet under ventilation from a ventilator. The time until the sheet ruptured was measured. The time until rupture was measured and evaluated. The score was calculated according to the above description.

[0134] Table 2 shows the results of attaching to small holes using an electrosurgical unit, and Tables 3 and 4 show the results of attaching to small holes using an 18G needle.

[0135] The "Usage Method" column in each table indicates how to apply the sheet prepared in the example to the damaged area. For example, in Example 2, it means that one lower sheet was applied to the damaged area, and then one upper sheet was applied on top of that.

[0136]

[0137] Because the nanofiber sheet of the present invention contains both water-soluble and water-insoluble polymers, it has an overall score of 21 or higher and exhibits excellent air and liquid leakage prevention effects. Furthermore, it is noteworthy that even relatively large holes of approximately 3 mm x 3 mm, which would require suturing in actual clinical settings, could be prevented from leaking air and liquid by simply applying the sheet, and that this effect was achieved without using bio-tissue-derived adhesives such as fibrin glue.

[0138] Comparative Example 1 uses a commercially available NeoVeil sheet, but the NeoVeil sheet does not adhere to the damaged area unless a bio-tissue-derived adhesive is used. As a result, the overall score is very low at 3 points, making it unsuitable as a tissue occlusive agent. Comparative Example 2 shows the results when using a NeoVeil sheet and Beriplast P Combi-Set Tissue adhesive (bio-tissue-derived adhesive). The overall score was 30 points, similar to that of Example 1, but it is expensive because it uses bio-tissue-derived components, and safety is also a concern.

[0139] As is clear from the comparison between Example 1 and Examples 2, 4, and 5, when one or more sheets of a water-soluble polymer-containing composition were applied to the damaged area, and the nanofiber sheet of the present invention was applied as the top layer, the overall score was higher, and air leakage and bodily fluid leakage were prevented.

[0140]

[0141]

[0142] Because the nanofiber sheet of the present invention contains both water-soluble and water-insoluble polymers, it has an overall score of 21 or higher, demonstrating excellent air and liquid leakage prevention effects. A particularly noteworthy effect is that air and liquid leakage could be prevented without the use of bio-derived adhesives such as fibrin glue.

[0143] For example, comparing Example 14 with Comparative Example 4, although there are differences in the fiber morphology of the upper layer, Example 14, which contains both a water-soluble polymer and a water-insoluble polymer in the upper layer, has a higher overall score than Comparative Example 4, which does not contain a water-insoluble polymer, indicating that it was able to effectively prevent air and liquid leakage.

[0144] In Examples 13 and 15, although the upper layer contained only water-insoluble polymers, the water-soluble polymer-containing composition sheet laminated on top of it contained water-soluble polymers, which is presumed to be the reason for the high overall score.

[0145] Furthermore, commercially available NeoVeil sheets alone did not function as a tissue occlusive agent (Comparative Example 5). When used in combination with a bio-derived adhesive, the overall score was 30 points, but the cost was high and safety was a concern (Comparative Example 6).

[0146] In Examples 5 and 8, a nanofiber sheet was prepared by adding Coumarin-6, an organic luminescent material, to a water-insoluble polymer solution and spinning the resulting material. After one hour of attaching the sheet to a pore, the attachment site was illuminated with excitation light and observed. Green fluorescence was observed at the attachment site, confirming the presence of Coumarin-6. Since the biological environment is humid, the nanofiber sheet attached to the damaged area needs to be water-resistant. The fact that Coumarin-6 could still be detected one hour after attachment demonstrated that the nanofiber sheet of the present invention has sufficient water resistance to withstand the humid environment of the biological system (data not shown).

[0147] Table 5 shows the results for nanofiber sheets with an adhesive layer containing tannic acid (results of attachment to small holes using an electrosurgical unit).

[0148]

[0149] As is clear from a comparison between Example 1 shown in Table 5 and Examples 18 to 21, by providing an adhesive layer containing tannic acid on the surface of the nanofiber sheet that is on the adhesive side of the damaged site, maintenance or improvement was observed in all three scores. In particular, when the weight of tannic acid contained in the adhesive layer is 2 to 350 μg / cm 2 , a significant improvement was confirmed in all three scores, and the overall score showed an extremely high value of 44 points or more. This is considered to be because the multipoint hydrogen bonds and hydrophobic interactions of tannic acid, as well as its astringent effect on proteins, firmly sealed the adhesive interface between the wet biological tissue surface and the nanofiber sheet.

[0150] On the other hand, as in Comparative Example 7, even when tannic acid was sprayed onto a commercially available Neoveil sheet, all scores remained at the minimum value of 1 point, and no sealing function was observed at all. It was confirmed that the excellent effect of tannic acid is achieved by the synergistic effect between the nanofiber sheet of the present invention and the adhesive layer containing tannic acid.

Claims

1. A material for treating injured sites, comprising a nanofiber sheet containing a water-soluble polymer and a water-insoluble polymer.

2. The material for treating a damaged area according to claim 1, wherein the surface of the nanofiber sheet that is attached to the damaged area is provided with an adhesive layer containing tannic acid.

3. The weight of tannic acid contained per unit area of ​​the adhesive layer is 2 to 350 μg / cm². 2 The material for treating a damaged site according to claim 2.

4. The material for treating a damaged site according to claim 1, comprising a water-soluble polymer-containing composition sheet laminated on the side of the nanofiber sheet that is attached to the damaged site.

5. A wound treatment material according to any one of claims 1 to 4, wherein at least one of the vertical failure resistance score, the lateral leakage failure resistance score, and the liquid environment resistance score is 3 or higher.

6. The injury treatment material according to claim 5, wherein the total score calculated using the following formula (1) is 21 or higher.

7. The material for treating injured sites according to claim 1 or 2, wherein the water-soluble polymer is one or more water-soluble polymers selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, methylcellulose, sodium carboxymethylcellulose, and polyvinyl acetal diethylaminoacetate.

8. The material for treating a wound site according to claim 1 or 2, wherein the water-soluble polymer is polyvinyl alcohol and / or sodium carboxymethylcellulose, and the water-insoluble polymer is polycaprolactone.

9. The material for treating a damaged site according to claim 1 or 2, wherein the nanofiber sheet has a core-shell structure, the core comprises a water-insoluble polymer, and the shell comprises a water-soluble polymer.

10. A method for producing a material for treating a damaged site, comprising the step of forming nanofibers by electrospinning using a water-soluble polymer solution containing a water-soluble polymer and a water-insoluble polymer solution containing a water-insoluble polymer.

11. A method for producing a material for treating an injured site according to claim 10, comprising the step of spraying a solution containing tannic acid onto at least one surface of the nanofibers obtained by the step of forming the nanofibers.

12. A method for producing a material for treating an injured site according to claim 10 or 11, wherein the water-soluble polymer solution contains 1 to 50% by weight of the water-soluble polymer in the solution, and the water-insoluble polymer solution contains 1 to 50% by weight of the water-insoluble polymer in the solution.

13. A wound treatment material kit comprising: one or more water-soluble polymer-containing composition sheets placed on the wound site or used to fill the wound site; and a covering material placed on the sheets and used to cover the wound site, wherein the covering material is a wound treatment material according to any one of claims 1 to 4, and when the one or more water-soluble polymer-containing composition sheets and the covering material are combined, at least one of the vertical failure resistance score, the side leakage failure resistance score, and the liquid environment resistance score is 3 or higher.

14. The injury site treatment material kit according to claim 13, wherein the overall score calculated by the following formula (1) is 21 or higher.

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