Wound scaffolds for inhibiting scarring of biological tissue

Abstract

A technique is provided for inhibiting excessive scarring of biological tissue during the wound healing process. [Solution] An artificial wound scaffold applied to a wound of a living body is mainly composed of a bioabsorbable biomaterial and an anti-fibrotic agent, and the biomaterial contains the anti-fibrotic agent at least during the use of the wound scaffold. The biomaterial functions as an artificial extracellular matrix in the wound, which has a property to which the precursor cells of myofibroblasts of the living body adhere. The wound scaffold is placed in the wound and / or placed in the abdominal cavity so as to make at least one of a first contact locally with an area having a first wound site on the inner surface of the abdominal wall of the living body and a second contact locally with an area having a second wound site on the outer surface of a target organ in the abdominal cavity. As a result, the anti-fibrotic agent is locally administered in the wound, and an anti-scarring treatment is performed during the wound healing process.

Description

[Technical field]

[0001] The present invention relates to a technique for inhibiting excessive scarring of biological tissue during the wound healing process. [Background technology]

[0002] When a living body is locally injured, a wound is formed. Here, the term "wound" has various definitions, but it means, for example, damage to the skin or soft tissue caused by an external force.

[0003] Depending on the cause of their occurrence, wounds can be classified into traumatic injuries caused by accidents and surgical wounds caused by surgery. Surgical wounds include incision wounds (e.g., wounds made during surgery) and organ damage (e.g., wounds made to intraperitoneal organs or the peritoneum during open abdominal surgery).

[0004] In addition, based on the degree of damage, "wounds" are classified into defect wounds involving tissue loss and non-defective wounds without tissue loss, and further classified into shallow skin wounds where damage reaches only the dermis and deep wounds where damage reaches the subcutaneous tissue.

[0005] The body has an innate ability to heal itself. There are various definitions of "natural healing," but for example, it means that damaged biological tissue is repaired over time by regeneration (i.e., scarless healing) or scar healing.

[0006] In the mechanism of wound healing, that is, the process by which wounds naturally heal in the body, soft granulation tissue containing fibroblasts and abundant blood vessels is first formed in the wound. Eventually, the blood vessels in the granulation tissue decrease, and as fibroblasts produce collagen fibers, the tissue is replaced by hard scar tissue. This phenomenon is called fibrosis, and in parallel with this, the epithelium is regenerated.

[0007] Initially, multiple collagen fibers exist in a sparse state within the granulation tissue, but over time, the collagen fibers become dense and homogenous. This type of natural healing accompanied by fibrosis is called scar healing, and the tissue formed by this process is called scar tissue.

[0008] When scar tissue forms within the dermis of the skin of a living body and contracts or thickens, it can cause problems such as restricted movement of the skin, impairing the function of the locomotor organs, pain, and mental distress due to poor appearance, regardless of the severity.

[0009] Additionally, when scar tissue forms within the body's organs (e.g., the eyes, lungs, heart, abdominal organs (liver, kidneys, etc.), and body cavities (peritoneal, thoracic, mediastinum, etc.)), it can cause symptoms such as dysfunction or failure.

[0010] Therefore, although scarring of biological tissue is an unavoidable phenomenon that occurs during the wound repair process for the purpose of natural wound healing, it is desirable to suppress excessive scarring to a level that does not inhibit the body's inherent natural healing function, and therefore it is desirable to develop new technologies for suppressing scarring.

[0011] Patent Document 1 discloses a technique for suppressing scarring in the human eye caused by accidental injury to the eye, surgical incision of the eye, or the like, that is, an anti-scarring treatment method, using the human eye as a target site.

[0012] The document further discloses an anti-scarring treatment method in which an extracellular matrix (hereinafter also referred to as "ECM" or "extracellular matrix") such as decorin is locally administered to the ocular surface of a human patient in the hope that it will act as an anti-fibrotic agent.

[0013] The document also discloses several parameters that should be noted for assessing the occurrence of scarring, namely, several evaluation parameters, such as ECM components that increase with scarring, myofibroblasts or their marker protein α-smooth muscle actin (α-SMA) that increase with scarring, and TGF-β1 as a growth factor that promotes the transformation of fibroblasts that increases with scarring. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Special Publication No. 2022-517510 Summary of the Invention [Problem to be solved by the invention]

[0015] The present inventor has extensively studied treatment methods for inhibiting scarring of biological tissues, and as a result has discovered that in order to inhibit scarring, it is important to administer an anti-fibrotic agent intra-wound or intraperitoneally rather than onto the surface of a wound, locally rather than systemically, and at an early stage of wound development.

[0016] Furthermore, the present inventor has also found that while inhibition of scarring in biological tissues has the advantage of inhibiting, preventing or treating fibrosis or fibrotic diseases, it has the disadvantage of slowing wound healing (e.g., in situations where defective wounds, deep wounds or other wounds are being healed), it is important to develop the treatment method in an individual-adaptive manner (e.g., adapted to the site, extent and characteristics of the wound in each individual, as well as the physiological characteristics such as the immune strength of each individual) so that the advantages more than compensate for the disadvantages.

[0017] Based on these findings, the present invention has been made with the objective of providing a technique for inhibiting excessive scarring of biological tissue during the wound healing process. [Means for solving the problem]

[0018] The present invention provides the following embodiments. Each embodiment is divided into clauses, each clause is numbered, and other clause numbers are cited as necessary. This is to facilitate understanding of some of the technical features that the present invention may employ and their combinations, and should not be construed as limiting the technical features and combinations that the present invention may employ to the following embodiments. In other words, it should be construed that technical features that are not described in the following embodiments but are described in this specification or drawings may be appropriately extracted and employed as technical features of the present invention.

[0019] Furthermore, describing each section in a form that refers to the number of other sections does not necessarily mean that the technical features described in each section are prevented from being separated and made independent from the technical features described in other sections, and it should be interpreted that the technical features described in each section can be made independent as appropriate depending on their nature.

[0020] (Aspect 1) An artificial wound scaffold to be applied to a wound of a living body, comprising: The wound scaffold material is configured to contain a bioabsorbable biomaterial and an anti-fibrotic agent as main components, and the biomaterial contains the anti-fibrotic agent at least during use of the wound scaffold material; the biomaterial is configured to function in the wound during use as an artificial extracellular matrix to which the native myofibroblast precursor cells adhere; The wound scaffold, during use, is placed within the wound and / or within the abdominal cavity so as to make at least one of a first contact in which the scaffold makes localized contact with an area of ​​the inner surface of the abdominal wall of the living body having a first wound site which the abdominal wall has as the wound, and a second contact in which the scaffold makes localized contact with an area of ​​the outer surface of a target organ in the abdominal cavity having a second wound site which the target organ has as the wound, thereby allowing the anti-fibrotic agent to be administered locally within the wound, thereby enabling anti-scarring treatment to be performed during the healing process of the wound.

[0021] Here, the technical matter of "the wound scaffold is placed in the wound" and the technical matter of "the wound scaffold is placed in the abdominal cavity so as to effect at least one of a first contact in which the wound scaffold is locally brought into contact with a region of the inner surface of the abdominal wall of the living body having a first wound site that the abdominal wall has as the wound, and a second contact in which the wound scaffold is locally brought into contact with a region of the outer surface of a target organ in the abdominal cavity having a second wound site that the target organ has as the wound" are common to each other in that, in either case, the anti-fibrotic agent ultimately migrates from the wound scaffold into the wound and is placed there. Therefore, these technical matters can be said to be the same technical feature, or, if not, at least corresponding technical matters.

[0022] (Aspect 2) The wound scaffold according to aspect 1, wherein the biomaterial contains as a main material a protein, a polysaccharide, or a glycoprotein complex having the property of adhering to the precursor cells.

[0023] (Aspect 3) A wound scaffold according to aspect 1 or 2, wherein the biomaterial is in the form of a hydrogel, powder or sponge, or has the form of a film or sheet, and is flexible.

[0024] (Aspect 4) A wound scaffold according to any of Aspects 1 to 3, wherein when the wound scaffold is placed within the living body, the wound scaffold defines a space in the living body isolated from tissue surrounding the wound, into which the progenitor cells can enter, and when the progenitor cells enter the space, allows the invaded progenitor cells to react with the anti-fibrotic agent present in the wound scaffold, thereby inhibiting the transformation of the progenitor cells into myofibroblasts, thereby enabling the anti-scarring treatment to be performed.

[0025] (Aspect 5) A wound scaffold material described in any of Aspects 1 to 4, which has the functions of defining an administration route of the anti-fibrotic agent in the living body, providing a scaffold for the progenitor cells from outside the living body, and replenishing the wound from outside the living body with the artificial extracellular matrix to replace the original extracellular matrix that has been disrupted by the wound.

[0026] (Aspect 6) The wound scaffold according to any one of Aspects 1 to 5, wherein the scaffold is configured to retain the anti-fibrotic agent for at least the period from outside the body until it is placed inside the body.

[0027] (Aspect 7) A wound scaffold according to any of Aspects 1 to 6, wherein during the period in which the wound scaffold is present in the living body, the anti-fibrotic agent remains within the wound scaffold while the progenitor cells from tissues surrounding the wound in the living body permeate into the wound scaffold, thereby causing the progenitor cells to react with the anti-fibrotic agent within the wound scaffold, inhibiting their transformation into myofibroblasts.

[0028] (Aspect 8) A wound scaffold material according to any one of aspects 1 to 7, wherein the precursor cells are a cell population including at least fibroblasts or mesothelial cells among fibroblasts, mesenchymal stem cells, bone marrow-derived stem cells, endothelial cells, vascular endothelial cells, smooth muscle cells and epithelial cells, and which differentiate into the myofibroblasts upon stimulation of the wound.

[0029] (Aspect 9) The wound scaffold according to any one of Aspects 1 to 8, wherein the wound is present in soft tissues of the body surface including the dermis and subcutaneous tissue, in tissues around an implant (e.g., subcutaneous tissue, muscle layer), or in the abdominal cavity of the living body.

[0030] (Aspect 10) The wound scaffold according to any one of Aspects 1 to 9, wherein the wound scaffold is administered immediately after the wound is injured or during the early stage of wound healing.

[0031] (Aspect 11) A wound scaffold according to any of Aspects 1 to 10, wherein the wound scaffold is administered before scar tissue forms in the wound and before or after the wound is sutured, thereby using the wound scaffold to pre-administer the anti-scarring treatment.

[0032] (Aspect 12) A wound scaffold according to any of Aspects 1 to 11, wherein the wound scaffold is administered to the surface of a new wound in the living body after the scar tissue has formed in the wound and the wound has naturally healed, and the new wound in the living body is sutured after the scar tissue has been surgically excised from the living body, thereby allowing the wound scaffold to be used to subsequently perform the anti-scarring treatment.

[0033] (Aspect 13) The wound scaffold material is a first multi-drug type scaffold material described in any of Aspects 1 to 12, wherein the wound scaffold material is prepared by mixing the biomaterial and the anti-fibrotic agent, at least one of which is in a liquid state, at the site where the anti-scarring treatment is performed.

[0034] (Aspect 14) The biomaterial is a solid agent, The wound scaffold according to aspect 13, wherein the anti-fibrotic agent is a liquid.

[0035] (Aspect 15) The wound scaffold material is a second multi-drug type scaffold material described in any of Aspects 1 to 14, in which the biomaterial and the anti-fibrotic agent are both solid agents, and a liquid is added as a solvent, and the scaffold material is prepared by mixing them at the site where the anti-scarring treatment is performed.

[0036] (Aspect 16) The wound scaffold material according to any one of aspects 1 to 15, comprising a scaffold material in which the biomaterial and the anti-fibrotic agent are premixed to form a single liquid or solid formulation.

[0037] (Aspect 17) A wound scaffold according to any one of Aspects 1 to 16, comprising a scaffold configured as an injectable to be injected into the gap between opposing wound surfaces in the wound.

[0038] (Aspect 18) The injectable agent is injected into the gap of the wound using an injector; The injector includes: a container capable of containing the wound scaffolding material, the container being configured to move in response to an external force such that a required amount of the wound scaffolding material is withdrawn from the container; a discharge section capable of discharging a portion of the wound scaffolding material contained in the storage section that has exited from the storage section; 18. The wound scaffold of embodiment 17, comprising:

[0039] (Aspect 19) The storage section is a first portion capable of housing the biomaterial; A second portion capable of housing the antifibrotic agent; In response to a first external force or a second external force different from the first external force, the biomaterial in the first portion and the anti-fibrotic agent in the second portion are mixed together, thereby creating the wound scaffold. 20. The wound scaffold of embodiment 18, comprising:

[0040] (Aspect 20) The wound scaffold is locally applied to the wound surface or the inner surface of the abdominal wall or the outer surface of the target organ. Applicable Will be Liquids, 20. The wound scaffold of any of embodiments 1 to 19, comprising a scaffold configured as a liniment, patch, or aerosol.

[0041] (Aspect 21) The wound scaffold comprises a scaffold configured as the patch, The wound scaffold of embodiment 20, wherein the patch has the form of a flexible film or sheet and is configured to be inserted into the gap of the wound in a position extending along the wound surface of the wound, or inserted into the abdominal cavity so as to locally cover the inner surface of the abdominal wall and / or the outer surface of the target organ.

[0042] (Aspect 22) The wound scaffold is configured as the patch, The patch is in a flexible sheet form, The patch is used during intraperitoneal surgery on the living body, The intraperitoneal surgery includes: an incision step of incising the abdominal wall, thereby forming a first wound site at the incision; a surgical step of performing a surgical operation on a target organ in the abdominal cavity by introducing a surgical tool from outside the body through the incision into the abdominal cavity, thereby forming a second wound site on the outer surface of the target organ; Including, The patch is inserted into the abdominal cavity from outside the body through the incision in the surgical procedure, 21. The wound scaffold of aspect 20, wherein the patch is placed within the abdominal cavity to make at least one of a first contact where the abdominal wall makes localized contact with an area of ​​the inner surface of the abdominal wall that includes the first wound site and a second contact where the target organ makes localized contact with an area of ​​the outer surface of the target organ that includes the second wound site.

[0043] (Aspect 23) A wound scaffold material as described in Aspect 22, wherein the anti-fibrotic agent contained in the patch migrates to the wound surfaces of the first wound site and the second wound site when the patch is placed in the abdominal cavity, thereby performing anti-scarring treatment on the first and second wound sites.

[0044] (Aspect 24) The wound scaffold material is a wound scaffold material according to any of Aspects 1 to 23, the administration of which is contraindicated when the wound is a defect wound accompanied by tissue defect, reconstruction is not performed on the defect wound, and the wound surface of the wound is exposed.

[0045] (Aspect 25) A wound scaffold as described in any of Aspects 1 to 24, which is prepared by using multiple types of commercially available medicines whose safety and effectiveness for other uses have been established as the biomaterial and the anti-fibrotic agent, respectively, and simply mixing the two. [Brief description of the drawings]

[0046] [Figure 1] FIG. 1 is a cross-sectional and schematic diagram illustrating the basic wound healing process chronologically and conceptually. [Diagram 2] FIG. 2 is a cross-sectional and schematic diagram illustrating, chronologically and conceptually, the wound healing process using a wound scaffold according to some embodiments of the present invention. [Diagram 3] FIG. 3 is a perspective view conceptually illustrating a method of administering a wound scaffold according to some embodiments of the present invention into a wound by liquid injection. [Figure 4] 4(a) and (b) are both diagrams for explaining a method of inserting and leaving a wound scaffold according to some embodiments of the present invention as a sheet agent in a wound gap as a first sheet agent insertion type. Specifically, FIG. 4(a) is a perspective view conceptually showing a first example in which the sheet agent is inserted into a wound gap exposed at the body surface, while FIG. 4(b) is a cross-sectional view conceptually showing a second example in which the sheet agent is inserted into a dissection cavity formed as a wound gap under the muscular layer (or subcutaneously) when leaving an implant in the dissection cavity. Also, FIG. 4(c)- FIG. 1(e) is a diagram for explaining a method of inserting and leaving the sheet agent in the abdominal cavity of a living body as a second sheet agent insertion type. Specifically, FIG. 1(c) is an upper oblique view for explaining the relative positional relationship between the exposed incision wound (an example of a wound) and the sheet agent left in the abdominal cavity when the abdomen is opened, FIG. 1(d) is a cross-sectional view conceptually showing a third example in which the sheet agent is left in the abdominal cavity of a living body when the abdomen is closed, and FIG. 1(e) is a perspective view conceptually showing a fourth example in which the sheet agent is left across two target organs in the abdominal cavity. [Diagram 5] FIG. 5 is a diagram illustrating in tabular form several typologies of two-part wound scaffolds according to some embodiments of the present invention. [Figure 6] FIG. 6 is a partial cross-sectional perspective view illustrating an exemplary timeline of an anti-scarring treatment process using a wound scaffold according to a first embodiment of the present invention. [Figure 7] FIG. 7 is an exemplary timeline of cross-sectional views illustrating an anti-scarring treatment process using a wound scaffold according to the first embodiment. [Figure 8] FIG. 8 is a diagram for explaining, in tabular form, two control groups and two treatment groups (hereinafter referred to as "four groups") in an experiment conducted to evaluate the effectiveness of the wound scaffold according to the first embodiment. [Figure 9] FIG. 9 is a plan view for explaining a number of types of operations performed on mice as experimental animals in an experiment performed to evaluate the effectiveness of the wound scaffold according to the first embodiment. [Figure 10] FIG. 10 shows a number of photographs taken on the third day after skin incision for the four groups in the experiment. [Figure 11] FIG. 11 shows a number of photographs taken on the seventh day after skin incision for the four groups in the experiment. [Figure 12] FIG. 12 is a diagram showing, in table form, the time series of the presence or absence of epithelialization at the wound site in each of the four groups in the experiment. [Figure 13] FIG. 13 shows representative micrographs of scar tissue specimens obtained from the control group 1 on day 7 after skin incision in the experiment. [Figure 14] FIG. 14 shows representative micrographs of scar tissue specimens obtained from the control group 2 on day 7 after skin incision in the experiment. [Figure 15] FIG. 15 shows representative micrographs of scar tissue specimens obtained 7 days after skin incision in the treatment group 1 in the experiment. [Figure 16]FIG. 16 shows representative micrographs of scar tissue specimens obtained 7 days after skin incision in the treatment group 2 in the experiment. [Figure 17] FIG. 17 shows the borders of scar areas in representative photomicrographs from each of the four groups in the experiment. [Figure 18] FIG. 18 is a diagram showing, in tabular form, the scar cross-sectional areas calculated for three individual mice in each of the four groups in the experiment and their average values. [Figure 19] FIG. 19 shows the results of the ANOVA test for the results of the above experiment in tabular form. [Figure 20] FIG. 20 shows the multiple comparison of the results of the above experiment in table form. [Figure 21] FIG. 21 shows, in tabular form, descriptive statistics for several standard statistical values ​​of the results of the experiment. [Figure 22] FIG. 22 is a graph showing the mean and standard deviation of scar cross-sectional area for each of the four groups for the results of the experiment. [Diagram 23] FIG. 23 is a partial cross-sectional side view illustratively showing an injector used for administering into a wound a scaffold according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, some exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] <Overview>

[0049] First, a technical overview common to these embodiments will be provided regarding the wound scaffold material and the anti-scarring treatment method using the same, which is a treatment or therapy method (hereinafter also referred to as "the treatment method") that inhibits scarring of tissue during the wound healing process.

[0050] The purpose of the present inventors in proposing this treatment method is to achieve scarless wound healing (scarless wound healing, scarless healing, wound healing without scarring, scar-free healing, mild scar healing, scarring inhibition therapy, etc.) by suppressing the differentiation (transformation) of fibroblasts, an exemplary precursor cell, into myofibroblasts.

[0051] According to conventional wisdom, in the wound healing process, fibroblasts differentiate into myofibroblasts mainly due to stimulation by TGF-β1 (an example of a growth factor that promotes the transformation of fibroblasts), and these myofibroblasts secrete extracellular matrix (ECM, such as collagen) in excess to form scars. However, conventional anti-scarring treatments (e.g., taping and compression therapy) have limited effectiveness in inhibiting scarring, and scars are inevitable after surgery or trauma.

[0052] Meanwhile, several drugs that suppress differentiation into myofibroblasts have already been approved in Japan under names such as anti-fibrotic agents and ROCK inhibitors (Rho kinase inhibitors), and their effectiveness and safety have been established for the treatment of conditions such as pulmonary fibrosis and glaucoma.

[0053] In response to this, the present inventors believed that a safe and effective anti-scarring treatment method could be realized by combining anti-fibrotic agents, non-exclusively including such approved drugs, with biomaterials and applying them to the medical field of wound healing.

[0054] <General remarks>

[0055] 1. Background

[0056] In humans, as an example of a living organism, when skin is injured after birth, the injured area always heals leaving a scar, and during the wound healing process, unsightly scars such as hypertrophic scars and keloids often occur. Although various efforts have been made in terms of suturing methods and aftercare to make scars less noticeable, the scarring inhibition effect of conventional anti-scarring treatment methods is limited, and new anti-scarring treatment methods are needed. In particular, unsightly scars exposed on the face and hands cause great psychological distress and social stigma, significantly reducing the patient's quality of life (QOL). Many patients who have suffered trauma or surgery wish for "scarless wound healing," and its realization is eagerly awaited.

[0057] As shown conceptually in Figure 1, the basic wound healing process, during wound healing, fibroblasts, an example of precursor cells, differentiate into α-SMA-positive myofibroblasts primarily through stimulation with TGF-β1, and these myofibroblasts then secrete excess ECM to form scars.

[0058] Myofibroblasts contract granulation tissue, which can lead to scar contracture. Myofibroblasts are also abundant in the histological images of abnormal scars such as hypertrophic scars and keloids, and recent single-cell analyses have suggested that a subpopulation of fibroblasts with myofibroblast characteristics may contribute to the development of keloids.

[0059] Meanwhile, pirfenidone (which regulates the production of cytokines and growth factors) and nindedanib (a tyrosine kinase inhibitor) have already been approved in Japan as drugs that inhibit the differentiation of fibroblasts into myofibroblasts for the treatment of pulmonary fibrosis, and their efficacy and safety have been established.

[0060] ROCK inhibitors can also suppress differentiation into myofibroblasts through the control of the cytoskeleton, and as ROCK inhibitors, ripasudil for glaucoma and fasudil for cerebral vasospasm have been approved.

[0061] 2. Challenges

[0062] The present inventors considered that these existing drugs that suppress differentiation into myofibroblasts, as well as other existing and subsequent drugs that can be substituted (hereinafter collectively referred to as "anti-fibrotic agents"), could be applied to scar treatment.

[0063] Furthermore, the present inventors believed that by combining an antifibrotic agent with a biomaterial and devising a form of local administration, side effects could be reduced compared to systemic administration of each agent, and thus set the following "objectives".

[0064] (1) What kind of biomaterial is optimal for delivering anti-fibrotic agents to wounds?

[0065] (2) Is it possible to achieve scarless wound healing by administering antifibrotic agents to wounds?

[0066] In order to solve these "problems", the present inventors conducted intensive research prior to completing the present invention.

[0067] 3. Purpose and Effects of This Treatment Method

[0068] The aim of this treatment is to achieve scarless wound healing through a unique approach of suppressing differentiation of fibroblasts into myofibroblasts using an anti-fibrotic agent.

[0069] To this end, the treatment method is characterized by the use of an artificial scaffold, which is designed to provide a dosage form in which an anti-fibrotic agent is administered locally to the wound to be healed, as a suitably constructed biomaterial containing a suitably selected anti-fibrotic agent, thereby inhibiting excessive scarring of tissue during the wound healing process, as conceptually shown in Figure 2.

[0070] This treatment method has the potential not only to achieve scarless wound healing, but also to make a significant contribution to the advancement of wound treatment as a fundamental therapeutic and preventive agent for keloids and hypertrophic scars.

[0071] Furthermore, according to this treatment method, when an existing drug whose safety has already been verified is used as an antifibrotic agent, if the usefulness or efficacy of the existing drug is additionally verified, it is expected that this treatment method will become clinically applicable soon.

[0072] Therefore, this treatment method is expected to provide an artificial scaffold with anti-fibrotic properties that will be useful in preventing adhesions after open surgery and breast implant contracture, and may have broad application in the surgical field.

[0073] 4. How the idea for this treatment method came about

[0074] As a physician, the present inventor encounters many patients in his daily practice in the field of plastic surgery who wish to treat scars complaining of functional disorders, pain, and mental distress caused by trauma or post-surgical scars (e.g., scars triggered by trauma, scars triggered by surgical incisions), and he feels that the realization of scarless wound healing is an important issue in the field of plastic surgery.

[0075] Furthermore, the present inventors feel that since the effectiveness of conventional symptomatic treatments for keloids and hypertrophic scars is limited, novel therapeutic methods based on molecular mechanisms are needed.

[0076] In a preliminary experiment, the inventors used immunohistochemistry (IHC) to observe the distribution of α-SMA-positive myofibroblasts in histological images of mature and immature scars, and found that myofibroblasts were localized deep in immature scars and not present at all in mature scars.

[0077] Based on this finding, the present inventors hypothesized that myofibroblasts appear in the initial wound and secrete ECM, which then forms a scar, and then disappear due to apoptosis or other reasons as the scar matures.

[0078] The present inventors then conceived the idea that if differentiation into myofibroblasts could be suppressed at the early stage of wound healing, excessive ECM production would not occur and scarless wound healing would be possible.

[0079] Furthermore, the inventors observed α-SMA-positive myofibroblasts in keloid tissue by immunostaining and found that myofibroblasts were distributed over a wide area of ​​the keloid lesion (e.g., an area covering more than half of the total area).

[0080] Based on these findings, the inventors considered that keloids are a pathological condition in which differentiation into myofibroblasts occurs constantly due to mechanical stress and continuous stimulation by TGF-β1, and that inhibition of differentiation into myofibroblasts may also be applicable to the treatment of keloids.

[0081] However, since there are reports of side effects caused by systemic administration of anti-fibrotic agents, it is practically difficult to administer them systemically solely for the purpose of cosmetic improvement.

[0082] However, the present inventors thought that it may be possible to use anti-fibrotic agents with as low a risk of side effects as possible by locally administering them to a wound in combination with a biomaterial that functions as an artificial ECM that contributes to the proliferation of the progenitor cells, as conceptually shown in Figure 2.

[0083] 5. Construction of scaffolding material

[0084] (1) Overall structure

[0085] The scaffold material has as its main components a biomaterial that functions as an artificial ECM for the precursor cells and an anti-fibrotic agent, and has a configuration in which the anti-fibrotic agent is contained in the biomaterial.

[0086] The scaffold may contain other components such as auxiliary components or additives, for example, stabilizers, preservatives, solvents, thickeners, etc. The scaffold may be a solid or a liquid having a high viscosity, or a liquid having a low viscosity such as water.

[0087] (2) Structural types

[0088] a.Liquid injection type

[0089] In the liquid injection type, as conceptually shown in Figure 3, the scaffolding material is configured as a liquid (including a gel) that is injected into the gaps on the wound surfaces (each of a pair of surfaces facing each other across a gap in the wound) using an injector.

[0090] Examples of the injector include a syringe in which a pressure piston is pushed into a cylinder to push out a required amount of liquid from the cylinder, and a syringe in which a flexible container that holds the liquid is manually compressed to reduce the volume and push out a required amount of liquid from the container.

[0091] b. Sheet insertion type

[0092] In the sheet-insertion type, the scaffold is configured as a flexible sheet (solid agent including bioabsorbable film, tape, cloth, etc.) that is inserted into the wound gap or other site, for example, into the abdominal cavity, and contains, adheres, coats, or attaches an antifibrotic agent, as conceptually shown in Figure 4. The sheet is configured by containing an antifibrotic agent in a flexible substrate (support base) made of a biomaterial.

[0093] (3) Liquid injection type

[0094] Liquid injection type scaffolding materials can be one-component types or two-component mixed types (an example of multiple-component mixed types).

[0095] In the one-component type, the scaffold is composed of a biomaterial and an anti-fibrotic agent mixed together in one component prior to arriving at the site where the anti-scarring procedure will be performed, and in this case the scaffold can be sold commercially as a finished product.

[0096] In contrast, the two-drug mixed type can take types 1-3 in which at least one of the biomaterial and the antifibrotic agent is a liquid agent, and type 4 in which both are powder agents, as shown in the tabular form in Figure 5. In this case, the scaffold can be commercially sold as a semi-finished product or a kit product, with or without the injector.

[0097] Of the two-agent mixed types, in types 1-3, the biomaterial and the anti-fibrotic agent are mixed together at the site where the anti-scarring treatment is performed to form a single liquid.

[0098] In contrast, in type 4, at the site where the anti-scarring treatment is performed, a liquid (such as physiological saline or purified water) is added to at least one of the biomaterial and the anti-fibrotic agent as a solvent common to both, and the biomaterial and the anti-fibrotic agent are then mixed together to form a single liquid.

[0099] (4) Sheet Insertion Type

[0100] An example of the sheet-insertion type is a first sheet-insertion type in which a sheet-insertion material as a scaffold is inserted and placed in the wound gap of the wound, as conceptually shown in Figures 4(a) and (b). In this type, the scaffold is inserted and placed in the wound gap so that it does not substantially have a protruding portion from the body surface.

[0101] Fig. 1(a) is a perspective view conceptually showing a first example in which the sheet agent is inserted into a wound gap exposed on the body surface, while Fig. 1(b) is a cross-sectional view conceptually showing a second example in which the sheet agent is inserted into a dissection cavity (described in detail later) formed as a wound gap under the muscle layer (or subcutaneously) when placing an implant in the dissection cavity.

[0102] Here, the second example will be described in detail.

[0103] In this example, as shown in the cross-sectional view of FIG. 1(b), the sheet agent is used when inserting and placing the implant subcutaneously or submuscularly in a human body.

[0104] One example of an implant is an artificial breast implant, which is generally partially spherical and is inserted and placed into an artificially created cavity in the human breast (also called an "excision cavity," meaning that the cavity is created between one tissue by excising another tissue) to perform breast reconstruction or augmentation.

[0105] In its breast reconstruction or augmentation application, the implant is a soft, capsule-like medical device filled with a silicone gel or the like.

[0106] An example of the dissection cavity is one formed under a human pectoral muscle (e.g., under the pectoralis major muscle, i.e., between the pectoral muscle and the chest wall) as shown in the figure, and in this example, the implant is inserted under the pectoralis major muscle.

[0107] Another example of a dissection cavity, not shown, is one formed subglandular, in which an implant is inserted subglandularly.

[0108] In either case, the tissue into which the implant is to be placed and into contact with the surface of the implant (hereinafter referred to as the "target tissue") is damaged due to detachment from other tissues, and a wound is formed across the detached surface of the target tissue. Since such wounds can lead to scarring, it is desirable to carry out an anti-scarring treatment.

[0109] Therefore, in this example, the implant is inserted into the dissection cavity with its surface (ideally, the entire surface) covered with the above-mentioned sheet agent and left in place. In this state, the anti-fibrotic agent contained in the sheet agent covering the implant migrates to the surface of the target tissue forming the dissection cavity and is applied over substantially the entire surface (ideally, over the entire surface). As a result, scarring of the dissection cavity is suppressed.

[0110] In this example, covering the surface of the implant with the sheet agent corresponds to an example of inserting the scaffold into a gap in a wound (e.g., the gap between the surface of the pectoralis major muscle damaged by avulsion and the surface of the chest wall damaged by avulsion) in a position extending along the wound surface of the wound (e.g., the surface of the pectoralis major muscle and the surface of the chest wall), and also corresponds to an example of administering the scaffold locally into the wound (e.g., not to the entire breast area).

[0111] The first sheet preparation insertion type has been described in detail above. In contrast to this, as another example, there is a second sheet preparation insertion type in which a sheet preparation as a scaffold is inserted and left in the abdominal cavity, as conceptually shown in Figure 1(c)-(e).

[0112] FIG. 1(c) shows, in a top perspective view, the relative positional relationship between the incision that is exposed at the time of laparotomy and the sheet agent placed in the abdominal cavity.

[0113] Fig. 1(d) conceptually shows a cross-sectional view of a third example in which the sheet agent is placed in the abdominal cavity of a living body when the abdomen is closed, and Fig. 1(e) conceptually shows a perspective view of a fourth example in which the sheet agent is placed across two target organs in the abdominal cavity.

[0114] In a third example shown in Figure 1(d) and a fourth example shown in Figure 1(e), intraperitoneal laparotomy surgery is configured to include an incision process in which the patient's abdominal wall is incised, thereby forming a first wound site (e.g., a skin-side wound site) at the incision (incision wound), and a surgical process in which a surgical instrument is introduced from outside the body through the incision in the abdominal wall into the abdominal cavity to perform a surgical operation on a target organ, thereby forming a second wound site (e.g., an intraperitoneal organ-side wound site) on the outer surface of the target organ.

[0115] In addition, in the same figure (d), the term "second wound site" is not indicated because this is not essential to explain the specific functions of the scaffold in this example, such as the anti-scarring function and anti-adhesion function described below.

[0116] The sheet agent is inserted into the abdominal cavity from outside the body through an incision during the surgical procedure.

[0117] In a third example shown in FIG. (d), the sheet agent is placed in the abdominal cavity so as to make a first contact, that is, a localized contact (e.g., surface contact) with an area of ​​the peritoneum including the first wound site.

[0118] In this example, when the sheet is placed in the abdominal cavity and the surface of the sheet is in contact with the peritoneum, the anti-fibrosis agent contained in the sheet migrates from the sheet to the wound surface of the first wound site and performs an anti-scarring treatment on the first wound site.

[0119] In a fourth example shown in Figure (e) of the same figure, the sheet is placed in the abdominal cavity so as to make both a first contact (e.g., surface contact) in which the sheet makes localized contact with an area of ​​the peritoneum that includes the first wound site, and a second contact (e.g., surface contact) in which the sheet makes localized contact with an area of ​​the outer surface of the target organ that includes the second wound site.

[0120] When the sheet is placed in the abdominal cavity and the surface of the sheet is in contact with the peritoneum, the anti-fibrosis agent contained in the sheet migrates from the sheet to the wound surface of a first wound site to perform an anti-scarring treatment on the first wound site, whereas when the back surface of the sheet is in contact with the outer surface of a target organ, the anti-fibrosis agent migrates from the sheet to the wound surface of a second wound site to perform an anti-scarring treatment on the second wound site.

[0121] More specifically, as shown in Fig. 1(e), the sheet agent is placed across two target organs in the abdominal cavity on the two surfaces of the target organs. Fig. 1(e) shows a perspective view of the scaffold being placed across two target organs in the abdominal cavity on the surfaces of the organs.

[0122] In this example, when the sheet is configured as a single sheet member, the sheet is configured to comprehensively perform the first contact for anti-scarring treatment on an incision (surgical wound) in the abdominal wall, i.e., a first wound site, the second contact for anti-scarring treatment on the outer surface of a first target organ within the abdominal cavity, and the second contact for anti-scarring treatment on the outer surface of a second target organ within the abdominal cavity.

[0123] In addition, FIG. 1(e) shows the state in which two target organs are sutured together. Examples of the two organs for which this is performed include the stomach and small intestine, and the liver and intestinal tract.

[0124] Furthermore, in some of the above examples, intraperitoneal local administration using the sheet agent is performed at least at the first wound site for anti-scarring treatment, but in addition to this, for example, for the first wound site, the above-mentioned liquid injection type may be additionally adopted and a liquid agent as a scaffold material may be locally administered into the first wound site using an injector.

[0125] In summary, the sheet agent shown in FIG. 1(e) constitutes an example of a concentrated anti-scarring treatment type patch in which both the first contact and the second contact are performed using a single sheet member.

[0126] Incidentally, in the third and fourth examples, since the sheet agent is composed of at least a biomaterial, one might imagine that the biomaterial may promote adhesion between the abdominal wall and intraperitoneal organs.

[0127] However, what is noteworthy is that rather than having such a healing effect, the sheet agent acts as a physical spacer that physically separates the abdominal wall and the intraperitoneal organs, and also acts as a routing (pathway definition) that guides the anti-fibrotic agent to the target site (the opening on the abdominal cavity side of the first wound site in the abdominal wall, and the opening on the abdominal cavity side of the second wound site in the intraperitoneal organs).

[0128] Therefore, by placing the sheet material in the abdominal cavity, particularly in a position between the abdominal wall and the intraperitoneal organs, not only can it be effective in inhibiting scarring of the abdominal wall and the intraperitoneal organs, but it can also be effective in preventing adhesion between the abdominal wall and the intraperitoneal organs after surgery.

[0129] In this specification, the "target organ" may be defined as an intraperitoneal organ on which a surgical procedure is performed, or an intraperitoneal organ on which a surgical procedure is not performed but which comes into contact with a scaffold.

[0130] Other examples of the second sheet material insertion type will be described below.

[0131] In one example, although not shown, the sheet agent has a first sheet member and a second sheet member that are independent of each other. The first sheet member is configured to locally contact an area including a first wound site in the abdominal wall on its front surface. The second sheet member is configured to locally contact an area including a second wound site in a target organ in the abdominal cavity on its back surface.

[0132] In this example, when the sheet is placed in the intraperitoneal cavity and the surface of the first sheet member is in contact with the inner surface of the abdominal wall, the anti-fibrosis agent contained in the sheet migrates from the first sheet member to the wound surface of the first wound site to perform anti-scarring treatment on the first wound site, whereas when the back surface of the second sheet member is in contact with the outer surface of the target organ, the anti-fibrosis agent migrates from the second sheet member to the wound surface of the second wound site to perform anti-scarring treatment on the second wound site.

[0133] In summary, in this example, the sheet agent constitutes an example of a distributed anti-scarring treatment type patch in which the first contact and the second contact are performed at discrete locations using separate sheet members (multiple sheet members that are independent of each other).

[0134] Incidentally, in the several examples described above regarding the first and second sheet agent insertion types, all of the sheet agents are flexible but have shape-retaining properties (the property of not changing shape without an external force), and therefore can be left in a state of surface contact with curved anti-scarring treatment surfaces such as the inner surface (inner surface) of the abdominal wall and the outer surface (outer surface) of an organ.

[0135] Thus, an advantage of using a sheet for anti-scarring treatment is that the sheet's shape has the ability to easily conform to the surface of the area where it is to be placed, allowing it to be placed in surface contact with a curved anti-scarring treatment surface.

[0136] Generally, when localized damage, such as a surgical wound, occurs on the surface of an organ in the abdominal cavity, scarring begins at that site in the organ, and the scarring has the characteristic of spreading in a planar manner on the surface of the organ.

[0137] Therefore, an advantage of using a sheet for anti-scarring treatment is that the sheet can be applied locally to the surface of the organ so as to cover not only the damaged area but also the surrounding area, making it easier to effectively suppress the spread of scarring on the surface of the organ.

[0138] (5) Materials that can be used as components of biomaterials

[0139] The biomaterials mainly contain proteins (e.g., collagen, elastin, gelatin), polysaccharides (e.g., hyaluronic acid, chondroitin sulfate, cellulose), or glycoprotein complexes (e.g., aggrecan, versican). The biomaterials are in the form of hydrogels, powders, sponges, or sheets, and have flexibility and shape retention.

[0140] There are no particular limitations on the materials that make up the biomaterials, so long as they are materials that can be dissolved, decomposed, metabolized, or absorbed by cells, microorganisms, or living organisms through their inherent life activities.

[0141] Furthermore, examples of commercially available drugs (medical products, etc.) that constitute the biomaterial include collagen sponges (e.g., Pelnac (registered trademark), Terdermis (registered trademark)), collagen sheets (e.g., Integra (registered trademark)), gelatin hydrogels (e.g., Genocel (registered trademark)), gelatin sponges (e.g., Spongel (registered trademark)), etc.

[0142] (6) Drugs that can be used as antifibrotic agents

[0143] As the antifibrotic agent, low molecular weight agents such as fasudil, ripasudil, pirfenidone, nindedanib, etc. can be used. The antifibrotic agent can be liquid, powder or particulate. The concentration of the antifibrotic agent can vary depending on the type of antifibrotic agent, the type of wound, the extent of wound, and the characteristics of the individual (organism, human) to be administered, etc.

[0144] 6. Basic guidelines for experimental methods

[0145] (1) Purpose

[0146] In order to confirm the efficacy of an anti-fibrotic agent, which has been commercially available and whose efficacy and safety as a treatment method for living organisms, e.g., human subjects, has been established in relation to other uses (e.g., treatment of other diseases), when applied together with a biomaterial to the skin of a living organism for anti-scarring treatment in this treatment method (its safety is naturally confirmed without the need to conduct experiments, since it is commercially available), in vivo animal experiments are conducted using the scaffold material of the invention, thereby confirming the anti-scarring effect of the anti-fibrotic agent.

[0147] (2) Experimental Overview

[0148] Mouse wound model treatment experiment

[0149] An incision is made on the back of a mouse from the epidermis to the fascia, and the incision is sutured and fixed. Then, a mouse wound model is prepared in such a state that an antifibrotic agent-containing scaffold is locally administered and retained in the intrawound gap (in the gap between a pair of wound surfaces facing each other across a gap in the incision, in the dermal gap, etc.) of the incision.

[0150] Therefore, it is expected that myofibroblasts will be formed in the region between the boundary layer between the epidermis and dermis and the fascia at the wound surface.

[0151] (3) Setting up a control group

[0152] As two types of control groups, Control group 1: The wound was simply sutured without administration of biomaterials or antifibrotic agents. Control group 2: A biomaterial containing no antifibrotic agent and purified water was administered into the wound as a gel scaffold (without antifibrotic agent). In each control group, three mice are used.

[0153] Here, the significance of each control group will be explained. Control group 2 is significant in that, by comparing it with control group 1, it is possible to confirm the advantages and disadvantages that can be obtained solely from the biomaterial in the scaffold material when the scaffold material of the present invention is applied to a wound.

[0154] (4) Treatment group selection

[0155] There are two treatment groups: Treatment group 1: A biomaterial containing a first antifibrotic agent (e.g., fasudil) at a predetermined concentration was administered into the wound as a gel scaffold (with antifibrotic agent); Treatment group 2: The biomaterial was administered into the wound as a gel scaffold (with antifibrotic agent) containing a second antifibrotic agent (e.g., Ripasudil) at a predetermined concentration. Set the following: In each treatment group, 3 mice are used.

[0156] It should be noted here that the scaffold of the invention contains an antifibrotic agent, whereas the scaffold used in the experiment does not contain an antifibrotic agent for the control group, but contains an antifibrotic agent only for the treatment group.

[0157] In addition, to explain the significance of each treatment group, treatment group 1 has the significance of making it possible to confirm, by comparing it with control group 1, the effect of a scaffold material as an invention having a biomaterial and a first anti-fibrotic agent, the significance of making it possible to confirm, by comparing it with control group 2, the advantages and disadvantages obtained by the first anti-fibrotic agent alone in the scaffold material as a product of the invention, and the significance of making it possible to confirm, by comparing it with treatment group 2, the advantages and disadvantages obtained by the first anti-fibrotic agent alone in the scaffold material as a product of the invention relative to the advantages and disadvantages obtained by the second anti-fibrotic agent alone in the scaffold material as a product of the invention.

[0158] In addition, treatment group 2 has the significance of making it possible to confirm, by comparison with control group 1, the effects of a scaffold material as an invention having a biomaterial and a second anti-fibrotic agent, by comparison with control group 2, making it possible to confirm the advantages and disadvantages obtained by the second anti-fibrotic agent alone in the scaffold material as a product of the invention, and by comparison with treatment group 1, making it possible to confirm the advantages and disadvantages obtained by the second anti-fibrotic agent alone in the scaffold material as a product of the invention relative to the advantages and disadvantages obtained by the first anti-fibrotic agent alone in the scaffold material as a product of the invention.

[0159] (5) Incision and suture

[0160] For the skin incision, two wounds are made per mouse. Specifically, two incisions are made per mouse on the shaved back, 10 mm long and at full skin depth. Then, two sutures (e.g., 6-0 nylon thread) are used to suture the epidermis only.

[0161] (6) Local administration of scaffolds

[0162] Immediately after suturing, a single administration is performed into the wound using a gel scaffold material, for example, using the injector, for each of control group 2, treatment group 1, and treatment group 2. This completes one treatment for each mouse.

[0163] (7) Appearance assessment and scar tissue sampling

[0164] After surgery, the appearance of the incision surface (exposed surface) was evaluated and scar tissue was harvested from each mouse. The caudal wound was harvested on day 3 after the procedure, and the cranial wound was harvested on day 7 after the procedure.

[0165] (8) Sampling and scar tissue evaluation

[0166] For each group, one tissue specimen per scar tissue was taken, formalin fixed and paraffin embedded, and the scar tissue was evaluated for each tissue specimen.

[0167] The evaluation method consisted of measuring the cross-sectional area of ​​the scar for each tissue specimen and performing immunohistochemical staining using myofibroblast markers such as α-SMA and SM22 to confirm the presence or absence of myofibroblasts.

[0168] <Specifics>

[0169] Definition of Terms

[0170] 1. “Wound”

[0171] As used herein, the term "wound" refers to any tissue injury (e.g., acute, subacute, delayed, or difficult-to-heal wounds, and chronic wounds). In addition, "wound" may also include open wounds and closed wounds. Tissues in which wounds occur may include the skin and subcutaneous tissue, muscle tissue, peritoneum, digestive tract, and the digestive tract.

[0172] The wound healing process is generally divided into four steps: hemostasis, inflammation, proliferation, and tissue remodeling. During the proliferation phase, myofibroblasts and capillaries invade the wound site, promoting myofibroblast proliferation and collagen production. As a result, granulation tissue is formed at the wound site during the proliferation phase. The abundant blood vessels in the granulation tissue formed during the proliferation phase eventually retract during the subsequent tissue remodeling phase, and are eventually replaced by scar tissue whose main component is collagen. It is known that excessive deposition of collagen during the wound healing process can lead to the formation of hypertrophic scars and keloids.

[0173] 2. "Scarring," "inhibition of scarring," etc.

[0174] As used herein, the term "scar" refers to fibrous connective tissue that forms at the site of injury in any body tissue. Scar tissue is typically composed of the same proteins (i.e., collagen) as the tissue it replaces. However, the fibrous composition of scar tissue differs significantly from the fibrous composition of non-scar tissue. Types of scars may include, but are not limited to, atrophic scars, skin graft scars, hypertrophic scars, keloids, and the like. Scar sites may also include, but are not limited to, scars of the skin and subcutaneous tissues, scars of the peritoneum, abdominal cavity and intraperitoneal organs, scars of muscles, tendons, or joints, and the like.

[0175] As used herein, the term "hypertrophic scar" refers to a raised scar formed by excessive production of ECM in an attempt to repair a wound (hereinafter sometimes referred to as "wound site") after trauma. Hypertrophic scars that spread to normal skin are specifically called "keloids."

[0176] As used herein, "scarring (also referred to as "scar formation")" refers to the replacement of damaged sites of biological tissue with ECM (mainly collagen).

[0177] In the case of wounds on the human body surface, with a few exceptions such as fingertips, injuries that do not reach deeper than the outer layer of the skin (papillary dermis) result in little or no scarring (i.e., regeneration). However, injuries that reach the reticular dermis result in scarring and tissue remodeling, resulting in healing (i.e., cicatricial healing).

[0178] As used herein, the terms "inhibition of scarring," "inhibition of scar formation," "anti-scarring" and "inhibition of scar formation" refer to the inhibition of excessive proliferation of granulation tissue or excessive production of collagen during the proliferative and tissue remodeling phases of the wound healing process.

[0179] 3. “Treatment”

[0180] As used herein, the term "treatment" refers not only to treatment in the usual sense performed on a patient after the onset of the target disease, but also to curing, ameliorating or at least partially ameliorating a disorder, and also to preventive measures performed in advance to prevent the occurrence and recurrence of hypertrophic scars and / or keloids.

[0181] 4. "Extracellular matrix (ECM)"

[0182] As used herein, the term "extracellular matrix (ECM)" refers to a substance that plays a role in the organization of cells in living organisms. ECM provides structural scaffolding for cells and is a major part of the physical support in the formation of tissues, organs, and organs. ECM is mainly composed of three major classes of biomolecules, including fibrous proteins such as collagen (e.g., type I, type III) and elastin, glycoproteins such as fibrillin, fibronectin, and laminin, and glycoprotein complexes such as aggrecan and versican.

[0183] 5. Collagen

[0184] As used herein, the term "collagen" refers to an abundant protein found in the ECM.

[0185] 6. "Fibrosis"

[0186] As used herein, the term "fibrosis" refers to the deposition of ECM proteins (mainly collagen) in biological tissues.

[0187] 7. "Anti-fibrosis" etc.

[0188] As used herein, the terms "antifibrotic," "fibrosis suppression," and "fibrosis inhibition" refer to suppressing the progression of fibrosis in tissues.

[0189] 8. "Anti-fibrotic agents" etc.

[0190] As used herein, the terms "antifibrotic agent," "fibrosis suppressing agent," or "fibrosis inhibitor" refer to a pharmaceutical agent having a preventive or therapeutic effect against fibrosis in tissues. For example, an antifibrotic agent prevents or treats fibrosis by suppressing differentiation of fibroblasts into myofibroblasts.

[0191] Anti-fibrotic agents are also classified according to their molecular weight, such as those with low molecular weight (molecular weight of about 300 to about 400, e.g., pirfenidone) and those with high molecular weight (molecular weight of about 36,000 to about 40,000, e.g., decorin).

[0192] 9. Biomaterials

[0193] In this specification, the term "biomaterial" refers to a product having a specific use and a specific function, unlike the broad term "biomaterial" which simply means a specific material.

[0194] Specifically, in this embodiment, the "biomaterial" is made using natural or synthetic biocompatible materials that maintain selected biologically active cells in a viable state and that are suitable for introduction into living tissue.

[0195] Furthermore, in this embodiment, the "biomaterial" is prepared using a material among the biocompatible materials that is suitable for functioning as an artificial ECM that functions as a scaffold for the progenitor cells and supporting the proliferation of the progenitor cells.

[0196] Incidentally, the biocompatible material may be of the indwelling type, which is left in the body after being introduced into biological tissue, or of the biodegradable type, which is decomposed and absorbed in the body after being introduced into biological tissue. In this embodiment, the "biomaterial" is prepared using a biocompatible material of the in vivo degradable type. Therefore, the "biomaterial" is of the in vivo degradable type, and is replaced by the body's own tissue over time, and as a result, disappears in the body.

[0197] 10. "Scaffolding" and "Scaffolding Materials"

[0198] In the present specification, the term "scaffold" is defined as a function of, for example, securing space for tissue regeneration and assisting the regeneration of damaged tissue while maintaining the shape of regenerated tissue. The term may also be defined as a function of, for example, distributing target cells three-dimensionally, imparting a specific shape, and providing a space for the regeneration of target cells.

[0199] The actual object or substance administered into the body to realize the function of the "scaffold" is an artificial "scaffold material." Thus, in this embodiment, the "scaffold material" has, for example, good adhesiveness to target cells (e.g., the precursor cells), bioaffinity or biocompatibility as a property that does not adversely affect the living body, low immunogenicity, is easily absorbed by the living body after being embedded in the body and becoming unnecessary, and has sufficient strength so that it will not be damaged even when the body is moved.

[0200] Next, the above-mentioned several embodiments will be described individually.

[0201] First Embodiment

[0202] 1. Composition of scaffolding material

[0203] (1) Selection of antifibrotic agents

[0204] The two antifibrotic options chosen were Ripasudil and Fasudil, both of which are commercially available drugs. Both Ripasudil and Fasudil are classified as ROCK inhibitors. Both antifibrotic agents are liquid formulations.

[0205] (2) Selection of biomaterials

[0206] Gelatin hydrogel (Genocel®) was selected as the bioscaffold material for the biomaterial. The agent named Genocel® is manufactured by Kyoto Medical Design Co., Ltd. and is a cell culture scaffold material using gelatin with a nonwoven structure.

[0207] The gelatin hydrogel is available in a sheet type, a block type, and a powder type. The biomaterial used in the scaffold according to the present embodiment is a powder type and is configured as a powder. Therefore, the biomaterial is a solid agent.

[0208] 2. Manufacturing method of scaffolding material

[0209] (1) Two-drug combination

[0210] The scaffold according to this embodiment is Type 1 in FIG. 5, and is produced by mixing a powdered biomaterial with a liquid anti-fibrotic agent.

[0211] (2) On-site manufacturing type

[0212] To manufacture the scaffold, the biomaterial and the anti-fibrotic agent are mixed at the site where the anti-scarring procedure will be performed (eg, in the operating room).

[0213] The mixing process is carried out in a two-component injector as shown in FIG.

[0214] Specifically, the injector has a main body having two chambers and a nozzle located at the tip of the main body. The injector further has a switching function that normally keeps the two chambers isolated from each other, but switches the two chambers to a communicating state when an external force is applied. Before mixing, the biomaterial and the antifibrotic agent are contained separately and isolated in the two chambers.

[0215] When the external force is applied for mixing at the site where the anti-scarring treatment is performed, the two chambers are made to communicate with each other, thereby starting mixing. Then, when a first external force the same as the external force or a second external force different from the first external force is applied for mixing, the scaffold material moves from the storage section to the nozzle, and the scaffold material is discharged from the nozzle in a required amount.

[0216] The injector has a mixing function for mixing the two components in addition to an injection function for injecting the mixed liquid, but instead of this, an injector having an injection function but no mixing function may be used. In this case, prior to using the injector, an operator may mix the two components at the site or a different location, and further fill the injector with the mixed liquid thus prepared.

[0217] 3. Method of administration of scaffold material

[0218] liquid injection mold

[0219] The scaffold is configured as a liquid injectable that is injected into the gap between opposing wound surfaces in a wound.

[0220] The scaffold is administered locally, e.g., intradermally, to the wound at the site of the anti-scarring procedure. The scaffold is administered to the wound early in the wound healing process, e.g., immediately after suturing, within 5 minutes of suturing, etc. Administration may be after suturing of the entire wound or in parallel with the suturing process.

[0221] As shown in Figures 6 and 7, the incised wound is sutured with sutures or staples, or in some cases closed without sutures (wound closure). Incised wounds are sutured with dermal and / or epidermal sutures. Dermal sutures are a suture method in which a needle is inserted into the second layer of the dermis without penetrating the first layer of the epidermis. Epidermal sutures are a general term for various suture methods that penetrate the first layer of the epidermis.

[0222] After suturing, the scaffold is administered locally into the wound. As shown in Figures 6 and 7, the scaffold is injected into the wound using the injector with its nozzle inserted into the wound gap. Alternatively, the scaffold can be injected into the wound using, for example, a needle or a needle-free device, a syringe, a bottle, a dropper, a pipette, etc.

[0223] The scaffold material is injected into at least one of a number of regions separated by a number of sutures along the axial direction of the wound opening after suturing, and the scaffold material can be injected into the regions one after the other in the juxtaposed direction, or every other region or regions.

[0224] For ease of explanation, the scaffold is injected into the wound gap, as shown in an exaggerated manner in Figure 7. Since the scaffold is bioabsorbable, it will be replaced by autologous tissue and disappear in time.

[0225] 4. Mechanism of anti-scarring using scaffolds containing anti-fibrotic agents

[0226] As shown in Figure 2, when the scaffold is administered into the wound, fibroblasts in the living tissue migrate into the scaffold.

[0227] The fibroblasts adhere to the scaffold and react with the anti-fibrotic agent in the scaffold, which inhibits the differentiation of fibroblasts into myofibroblasts and the proliferation of myofibroblasts. As a result, collagen production from myofibroblasts is inhibited, which inhibits excessive scarring of biological tissue during wound healing. The biomaterial then degrades and disappears.

[0228] Specifically, when the scaffold is placed in the body, it defines a space in the body that is isolated from the tissue surrounding the wound and into which the progenitor cells can enter, whereupon the progenitor cells react with the anti-fibrotic agent present in the scaffold, thereby inhibiting the transformation of the progenitor cells into myofibroblasts, thereby providing an anti-scarring treatment.

[0229] Furthermore, the scaffold material has the functions of defining the administration route of anti-fibrotic agents in the body, of providing a scaffold for progenitor cells from outside the body, and of replenishing the wound from outside the body as the artificial ECM to replace the original ECM that has been disrupted by the wound.

[0230] 5. Experimental Method

[0231] Based on the above basic principles, experiments were conducted to confirm the effectiveness of the scaffold according to this embodiment in relation to anti-scarring treatment in the wound healing process of skin in a living body.

[0232] The purpose of this study was to evaluate the effectiveness of the scaffold using an animal model. Specifically, an incisional wound model was used in 8-week-old mice to evaluate its scarring inhibition effect during the wound healing process.

[0233] 5-1.Animals used in the experiment

[0234] Twelve C57BL / 6JJcl mice (male, 8 weeks old, Japan CLEA Co., Ltd.) were used as experimental animals. The mice were housed in clean S cages and mouse M2 cages, with three mice per cage, in a standard environment (temperature: 20°C-26°C, humidity: 40%-70%, 12-hour light-dark cycle). Food and water were available ad libitum. After the treatment described below, mice were housed one per cage to avoid the risk of other mice damaging the wound.

[0235] 5-2. Grouping of multiple mice

[0236] Twelve mice were randomly assigned to the following groups: Control group 1 (n=3), Control group 2 (n=3), Treatment group 1 (n=3), and The animals were divided into four treatment groups: treatment group 2 (n=3).

[0237] 5-3. Treatment of mice

[0238] Each mouse was anesthetized by inhaling an anesthetic (e.g., isoflurane inhalation anesthetic "VTRS" (Viatris Pharmaceutical Co., Ltd.)). Furthermore, the back of each mouse was shaved. Furthermore, the skin at the incision site on the back of each mouse was disinfected with a disinfectant (e.g., povidone iodine gel).

[0239] Furthermore, for each mouse, two separate incisions were made in the longitudinal direction (body length direction) at a length of about 10 mm and at a depth of the entire skin layer, and then each incision was sutured with two stitches using suture thread (e.g., 6-0 nylon thread) for each mouse.

[0240] Two wound sites are created in each mouse, one wound site is harvested for scar tissue on post-op day 3 and the other wound site is harvested for scar tissue on post-op day 7.

[0241] 5-4. Setting the control group

[0242] As two types of control groups, as shown in the table format in Figure 8, Control group 1: The wound was simply sutured without administration of biomaterials or antifibrotic agents. Control group 2: A biomaterial containing no antifibrotic agent and purified water was administered into the wound as a gel scaffold. was set.

[0243] Three mice were used in each control group. The individual numbers 101, 102, and 103 of the three mice in control group 1 and the individual numbers 201, 202, and 203 of the three mice in control group 2 are shown in the figure.

[0244] More specifically, the control groups 1 and 2 are as follows.

[0245] Treatment group: Control group 1 Antifibrotic agent dose: 0 Scaffold dosage: 0 Treatment group: Control group 2 Antifibrotic agent dose: 0 Scaffold administration volume: 20 μL / wound site (20 μL was administered to each of the two wound sites of each mouse.) (That is, a total of 20 μL of the scaffold was administered to each wound site so that it was distributed approximately evenly among the three areas, i.e., administration positions, described below. This was the same for the other groups.) Preparation method: Using a 200 μL pipette tip, 800 μg of Genocel® powder was added to 200 μL of purified water, and suspended by pipetting or inversion. The drug was administered immediately after preparation.

[0246] 5-5. Setting of treatment groups

[0247] The two treatment groups are shown in table format in Figure 8. Treatment group 1: Fasudil was administered into the wound as a gel scaffold containing biomaterial. Treatment group 2: A biomaterial containing Ripasudil was administered into the wound as a gel scaffold. was set.

[0248] Three mice were used in each treatment group. The three mice in treatment group 1 are labeled with individual numbers 301, 302, and 303, and the three mice in treatment group 2 are labeled with individual numbers 401, 402, and 403.

[0249] More specifically, for treatment groups 1 and 2, the treatments are as follows:

[0250] Treatment group: Treatment group 1 Antifibrotic agent concentration: 30mg / mL Scaffold volume administered: 20 μL / wound site (20 μL was administered to each of the two wound sites of each mouse.) Scaffold dosage: Approximately 53.1 mg / kg (weight of scaffold administered to each mouse per kg of each mouse) Preparation method: Using a 200 μL pipette tip, 200 μL of fasudil (30 mg of Eril® intravenous infusion solution) was added to 800 μg of Genocel® powder, and the mixture was suspended by pipetting or inversion. The mixture was administered immediately after preparation.

[0251] Treatment group: Treatment group 2 Antifibrotic agent concentration: 4mg / mL Scaffold volume administered: 20 μL / wound site (20 μL administered to each of the two wound sites of each mouse) Scaffold dosage: Approximately 7.1 mg / kg (weight of scaffold administered to each mouse per kg of each mouse) Preparation method: Using a 200 μL pipette tip, 200 μL of Ripasudil (Granatec (registered trademark) eye drops 0.4%) was added to 800 μg of Genocel (registered trademark) powder, and suspended by pipetting or mixing by inversion. The drug was administered immediately after preparation.

[0252] In treatment group 1, the concentration of fasudil was 30 mg / mL, whereas in the scaffold according to this embodiment, the concentration of fasudil can be, for example, within the range of about 28 mg / mL to about 32 mg / mL, within the range of about 25 mg / mL to about 35 mg / mL, or within the range of about 20 mg / mL to about 40 mg / mL.

[0253] Similarly, in treatment group 2, the concentration of Ripasudil was 4 mg / mL, but in a scaffold according to this embodiment, the concentration of Ripasudil can be, for example, within the range of about 3.5 mg / mL to about 4.5 mg / mL, or within the range of about 3 mg / mL to about 5 mg / mL, or within the range of about 2.5 mg / mL to about 5.5 mg / mL.

[0254] 5-6. Method of administration

[0255] For control group 2, the scaffold (without antifibrotic agent) was administered to each mouse immediately after preparation, and for treatment groups 1 and 2, the scaffold (with antifibrotic agent) was administered to each mouse immediately after preparation.

[0256] Specifically, as shown in Figure 9, after suturing, mice in control group 2, treatment group 1, and treatment group 2 were anesthetized and 20 μL of scaffolding material was evenly administered into the wounds using a 200 μL pipette tip into three areas created by suturing each incision (each wound site) in two places.

[0257] Therefore, a total of 20 μL of scaffold material was administered per wound site. After administration, each mouse was kept warm on a heat-retaining mat. After confirming that each mouse had woken up from anesthesia, the mouse was allowed to freely take a painkiller (carprofen).

[0258] 6. Experimental Results

[0259] 6-1. Observation of the wound site

[0260] The day of surgery (wound creation) was designated as day 0, and the wound sites of each mouse were photographed with a scale on days 0, 3, and 7. Among the photographs, the images on day 3 (Day 3) are shown in FIG. 10, and those on day 7 (Day 7) are shown in FIG. 11.

[0261] In each figure, the label "Sham" refers to control group 1, the label "Genocel®" refers to control group 2, the label "Genocel® + Fasudil" refers to treatment group 1, and the label "Genocel® + Ripasudil" refers to treatment group 2.

[0262] Furthermore, in each figure, the label "HE" indicates that the photograph is of a specimen stained with hematoxylin and eosin (hereinafter referred to as "HE stained"), and the label "α-SMA" indicates that the photograph is of a specimen stained with immunohistochemical staining using anti-α-SMA antibody (or referred to as "α-SMA immunostaining").

[0263] 12 shows in tabular form whether the wound site was epithelialized or not for each group on days 3 and 7. Here, "epithelialization" means that the epithelium at the wound site was completely continuous and the wound was healed.

[0264] 6-2. Dyeing

[0265] On days 3 and 7, scar tissue was excised from each wound site from each mouse and subjected to HE staining and α-SMA immunostaining.

[0266] Specifically, the following tasks were carried out in sequence:

[0267] (1) On the third and seventh days, after observation of each wound site was completed, each mouse was anesthetized by inhaling the isoflurane inhalation anesthetic "VTRS" (Viatris Pharmaceutical Co., Ltd.).

[0268] (2) After the sutures were removed from each mouse, a teardrop-shaped portion measuring approximately 15 mm in long diameter (e.g., a plate-shaped portion roughly circular or elliptical in plan view) was cut out from the skin of each mouse for each wound site, with each wound site positioned approximately in the center, and the cut-out portion was trimmed into a rectangular shape to prepare a scar specimen.

[0269] (3) After removing scar specimens from each wound site from each mouse in this manner, the skin of each mouse was sutured at each wound site, and each mouse was given an analgesic (carprofen) ad libitum in drinking water.

[0270] (4) Each excised scar specimen was fixed in formalin and then embedded in paraffin.

[0271] (5) Multiple sections were cut from each paraffin-embedded scar specimen, and each section was prepared as a paraffin section.

[0272] (6) A first subset of the paraffin sections was stained with HE, and a second subset was stained with immunohistochemistry using an anti-α-SMA antibody (M0858, 1:300, Dako) (hereinafter referred to as “α-SAM immunostaining”).

[0273] For each paraffin-embedded scar specimen, one HE-stained specimen and one α-SMA immunostained specimen were prepared as histological staining samples.

[0274] 6-3. Evaluation of scarring

[0275] (1) Measurement of scar cross-sectional area

[0276] For each group, three HE-stained specimens on day 7 were observed and photographed under an optical microscope. In each micrograph, the boundary between the scarred area and the non-scarred area was drawn using NDP.view2 software (Hamamatsu Photonics K.K.), and the area of ​​the enclosed scarred area was quantified as the cross-sectional area of ​​the scar.

[0277] 13-16 show photomicrographs of one HE stained specimen on day 7 for control groups 1 and 2 and treatment groups 1 and 2, respectively.

[0278] In the micrographs shown in each figure, the boundary between the scarred area and the other areas was extracted as a single closed line, focusing on the difference in collagen fiber properties. Specifically, in the dermis layer, the area with a higher number of cells, denser collagen fibers, and randomly arranged collagen fiber bundles compared to the surrounding area was distinguished from the other areas and determined to be the scarred area.

[0279] For ease of illustration, lines have been added to each of the micrographs shown in each figure to highlight the boundaries of the scar regions extracted as described above.

[0280] In FIG. 17, the four boundary lines extracted as described above for the four groups are shown aligned in a horizontal row.

[0281] The calculated scar cross-sectional area for each group and for each mouse is tabulated in Figure 18. The figure also tabulates the mean scar cross-sectional area for each group.

[0282] (2) Significance of experimental data

[0283] To evaluate the statistical reliability and significance of the multiple scar cross-sectional areas as experimental data, one-way ANOVA was performed using GraphPad Prism 9 (GraphPad Software, LLC), followed by Tukey's test, and the experimental data was statistically analyzed based on the test results. The results are shown in tables in Figures 19-22.

[0284] Specifically, FIG. 19 shows the ANOVA test results (labeled "ANOVA Results") in a tabular format.

[0285] FIG. 20 also shows the multiple comparisons (labeled "Multiple Comparisons (Tukey test results)") in table format.

[0286] FIG. 21 also shows in tabular form descriptive statistics (labeled "Descriptive Statistics") for several standard statistics about the experimental data used for ANOVA tests and multiple comparisons.

[0287] FIG. 22 also graphically depicts the mean and standard deviation of the scar cross-sectional area for each group, and further illustrates that there is a significant difference in scar cross-sectional area between control group 2 and treatment group 2 (P=0.03).

[0288] In these drawings, the main symbols are defined as follows:

[0289] A: Control group 1 B: Control group 2 C: Treatment group 1 D: Treatment group 2 ns: no significant difference *: Significant difference SS: sum of squares, variation DF: degrees of freedom MS:mean square, mean square SD: standard deviation F: F value Cl: confidence interval P-value: P value

[0290] When P<0.05 was satisfied for the difference between groups in the experimental data, the difference between the groups was considered to be statistically significant, and the contrasted groups were considered to have a significant difference.

[0291] (3) Assessment of myofibroblast mass

[0292] The sections stained with α-SMA on days 3 and 7 were observed under a microscope and photographed, and the presence or absence of myofibroblasts was evaluated with the naked eye from the images of each micrograph. The micrographs of each section on day 3 are shown in FIG. 10, and the micrographs of each section on day 7 are shown in FIG.

[0293] 6-4. Results and Discussion

[0294] (1) Visual inspection of the wound area

[0295] On day 3, the wound sites of the mice in none of the groups were epithelialized, whereas on day 7, the wound sites of the mice in all of the groups were epithelialized.

[0296] (2) Statistical analysis

[0297] a. Effectiveness of Ripasudil as an antifibrotic agent

[0298] As shown in Figures 20 and 22, treatment group 2 had a reduction in scar cross-sectional area compared to control group 2, with a statistically significant difference between the two (p=0.03).

[0299] From this, it was considered that Ripasudil alone, which is one of the scaffold materials according to this embodiment, has an anti-scarring effect.

[0300] b. Fasudil as an anti-fibrotic agent

[0301] As shown in Figures 20 and 22, treatment group 1 had a reduction in scar cross-sectional area relative to control group 2.

[0302] In this case, although there was no statistically significant difference between the two, it was considered that Fasudil, one of the scaffold materials according to this embodiment, may have an anti-scarring effect by itself.

[0303] Furthermore, it is speculated that if the concentration and / or dosage of fasudil in treatment group 1 had been set higher than the experimental values ​​in this study, the anti-scarring effect in treatment group 1 would have been greater than that shown in Figure 22.

[0304] In addition, if the same concentration and dosage of fasudil as used in this experiment were used in treatment group 1 and more individuals were treated, it is possible that the scar area would be significantly reduced compared to control group 2.

[0305] Therefore, it is believed that not only ripasudil but also fasudil are anti-fibrotic agents that can exert anti-scarring effects in the presence of biomaterials.

[0306] c. The significance of biomaterials

[0307] As shown in Figures 20 and 22, Control Group 2 was larger than Control Group 1 in terms of scar cross-sectional area.

[0308] The reason for this is thought to be that in control group 2, a biomaterial that did not contain an antifibrotic agent was placed in the gap between the sutured wounds, which meant that the biomaterial functioned as a space where myofibroblasts could adhere, and collagen was actively produced by the myofibroblasts within this space, resulting in a larger scar cross-sectional area than in control group 1.

[0309] On the other hand, since the scar cross-sectional area was not larger in treatment groups 1 and 2 compared to control group 1, it can be determined that the anti-fibrotic agent was functioning sufficiently to suppress collagen production.

[0310] (3) Visual inspection of micrographs of HE-stained specimens

[0311] Macroscopic observation of HE-stained micrographs revealed scar tissue at the wound site in mice of all groups on day 7, as shown in Figures 13-16.

[0312] Additionally, as shown in FIG. 17, treatment groups 1 and 2 were smaller in terms of scar cross-sectional area relative to control groups 1 and 2.

[0313] From these findings, it was considered that ripasudil and fasudil, as anti-fibrotic agents, have anti-scarring effects.

[0314] (4) Macroscopic observation of the micrographs of α-SMA immunostained specimens

[0315] As shown in FIG. 11, macroscopic observation of the α-SMA immunostained specimens confirmed that scar tissue containing myofibroblasts had formed in the wounds.

[0316] Furthermore, as shown in the figure, treatment groups 1 and 2 had fewer α-SMA-positive myofibroblasts than control groups 1 and 2.

[0317] The number of myofibroblasts in control group 2 was higher than that in control group 1. The reason for this has been explained above.

[0318] 6-5. Supplementary Information

[0319] The results and considerations of the above-mentioned experiment show that the scaffold according to the present embodiment has a scar formation inhibitory effect. Although this experiment was performed on mouse skin, it is considered that the same mechanism of action and effect would be obtained if the same experiment were performed on human skin, based on technical common sense and experience.

[0320] 7.Effects

[0321] (1) Measures to prevent delayed wound healing as a side effect of scar inhibition

[0322] According to this embodiment, tissue scarring is inhibited during the natural healing process of deep wounds (e.g., surgical wounds) whose wound surface reaches the subcutaneous tissue without causing tissue loss, making it easier to relieve patients from inconveniences such as functional disorders, pain, and mental distress caused by scarring.

[0323] In the present embodiment, scarring of tissues is suppressed during the wound healing process, which may delay wound healing. However, the biomaterial in the scaffold has a function of supporting the migration and adhesion of the precursor cells, such as fibroblasts, in the living body.

[0324] Therefore, according to this embodiment, unless early wound healing is particularly strongly desired due to tissue loss, it is expected that epithelialization will not be delayed due to delayed healing caused by scarring inhibition. This was verified by the fact that epithelialization was obtained in all treatment groups on Day 7 of the experimental results (see FIG. 12).

[0325] In other words, according to this embodiment, the scaffold material can be considered to have two bases with antagonistic effects: an anti-fibrotic agent that suppresses tissue scarring in the wound healing process and, as a secondary effect, delays wound healing, and a biomaterial that attenuates the wound healing delay effect by assisting the migration and adhesion of the progenitor cells.

[0326] Therefore, according to this embodiment, the delayed wound healing can of course be attenuated by adjusting the concentration (concentration and dilution) and / or dosage (increase and decrease) of the antifibrotic agent, but alternatively, it can also be attenuated by adjusting the concentration and / or dosage of the biomaterial, and in addition to the above adjustments, it can also be attenuated by adjusting the concentration and / or dosage of the biomaterial.

[0327] As a result, according to this embodiment, the operator has multiple prescription options to choose from in order to attenuate the side effect of delaying wound healing, making it easier to select and optimize the multiple options in an individual-adaptive manner in accordance with the characteristics of the patient and the wound.

[0328] (2) Simplifying procurement of scaffolding materials

[0329] According to this embodiment, several types of commercially available medicines whose safety and efficacy have been established for other uses can be repurposed as biomaterials and anti-fibrotic agents as the main components of the scaffold material, respectively, and can be obtained by simply mixing the two.

[0330] Therefore, according to this embodiment, it becomes easy to procure a scaffold material for performing anti-scarring treatment during the wound healing process simply, at low cost and safely.

[0331] (3) High permeability due to low molecular weight anti-fibrotic agents

[0332] The wound scaffold according to the present embodiment uses an antifibrotic agent with a relatively low molecular weight, such as one with a molecular weight of 400 or less. Thus, such low molecular weight antifibrotic agents are cheaper and easier to chemically synthesize than high molecular weight antifibrotic agents, such as one with a molecular weight of 10,000 or more, and furthermore, have a stable structure. In addition, such low molecular weight antifibrotic agents act intracellularly, and therefore can directly and effectively suppress the signal transduction pathway that differentiates the precursor cells into myofibroblasts.

[0333] (4) Long-term storage stability of drugs

[0334] According to this embodiment, the biomaterial and the antifibrotic agent are stored as solid agents rather than liquid agents, for example, in a storage location or in an injector, prior to intrawound administration of the scaffold material using the injector shown in Fig. 3. Therefore, according to this embodiment, deterioration of the agent is suppressed compared to when the biomaterial is a liquid agent, and long-term storage of the agent is facilitated.

[0335] (5) Improved quality stability of scaffolding materials

[0336] According to this embodiment, at the site where anti-scarring treatment is being performed, an operator or assistant can use an injector to mix the biomaterial and the anti-fibrotic agent to prepare a scaffold at the stage when the treatment is about to be performed, so that even if there is a risk of some denaturation of the mixed solution after mixing, the period during which such risk occurs is short.

[0337] As a result, according to this embodiment, it becomes easier to use the scaffolding material with the desired performance, and the quality stability of the scaffolding material is improved.

[0338] (6) Potential applications in the field of cosmetic medicine

[0339] The wound scaffold according to the present embodiment can suppress or prevent the occurrence of scars and scars, and therefore can be applied not only in the medical field associated with disease treatment but also in the field of cosmetic surgery.

[0340] <Second embodiment>

[0341] In this embodiment, an injector 10 shown in FIG. 23 is used as a specific example of the two-component mixing injector shown in FIG.

[0342] 1. Configuration

[0343] As shown in the figure, this injector 10 has a front end and a rear end, and a main body 30 having a first chamber 20 on the front end side and a second chamber 22 on the rear end side. Before preparing a scaffold material (mixed liquid) 100, i.e., before mixing a biomaterial (powder agent) 102 and an anti-fibrotic agent (liquid agent) 104, the biomaterial 102 and the anti-fibrotic agent 104 are separately contained as drugs in the first and second chambers 20, 22, respectively. The biomaterial 102 and the anti-fibrotic agent 104 may be contained in either of the chambers 20, 22.

[0344] In the example shown in the figure, a powdered biomaterial 102 is contained in the presence of air in the first chamber 20. In the example shown in the figure, the second chamber 22 is formed in a glass ampoule, and a liquid or gel-like anti-fibrotic agent 104 is enclosed in the ampoule.

[0345] The nozzle 40 extends from the tip of the tip side portion 60. The tip side portion 60 has a characteristic of being at least partially flexible. The nozzle 40 also has a characteristic of being at least partially flexible. The cross-sectional shape of the nozzle 40 may be circular or flat. If the nozzle 40 has a flattened cross-sectional shape, the resistance to movement may be reduced when moving the nozzle 40 in its longitudinal direction through a narrow wound gap, improving convenience. At the tip of the nozzle 40, an outlet for the scaffold material 100 (mixed liquid) is opened.

[0346] The main body 30 is divided into two parts, a tip side part 60 which forms the first chamber 20 and a rear side part 62 which forms the second chamber 22, and the two parts are connected at their opposing ends so that they can rotate relative to each other.

[0347] The injector 10 further has a selective communication mechanism 72 that does not break a diaphragm function part 70 that normally functions as a diaphragm (or partition) between the first and second chambers 20, 22 and keeps the first and second chambers 20, 22 isolated from each other, but breaks the diaphragm function part 70 and connects the first and second chambers 20, 22 to each other when a relative rotational force is applied to the front end side part 60 and the rear end side part 62 and they rotate relative to each other.

[0348] This selective communication mechanism 72 can be configured to include, for example, a screw mechanism that converts the relative rotational force into an axial force acting in the axial direction of the injector 10, and an engagement protrusion that is moved in the axial direction by the axial force, and to break the diaphragm function part 70, which has a portion extending in a direction intersecting the axial direction, by engaging with the engagement protrusion.

[0349] An example of the diaphragm function portion 70 is a part of the wall of the glass ampoule. When the part of the wall engages with the engagement protrusion (a rigid body such as metal), it breaks, and the broken part then functions as a passage that allows the antifibrotic agent 104 to move from the second chamber 22 to the first chamber 20.

[0350] 2. Effect

[0351] With the first and second chambers 20, 22 in communication, for example, the anti-fibrotic agent in the second chamber 22 flows into the first chamber 20, and the anti-fibrotic agent that has flowed in and the powdered biomaterial that is present from the beginning are mixed into a single liquid agent in the first chamber 20. In this state, the operator agitates the mixed liquid by, for example, shaking the injector 10, and uniformly mixes both agents.

[0352] In the process of mixing and stirring (e.g., in a standby state), a locking member 80 may be used that can selectively block at least locally the nozzle 40 so that the scaffolding material in the injector 10 does not leak out of the nozzle 40 against the operator's will. The locking member 80 is, for example, an elastic clip formed by a pair of arms elastically connected to each other at a hinge.

[0353] 3.Effects

[0354] Thanks to the property that the tip side 60 is at least partially flexible, when the scaffolding material is present as a mixed liquid in the first chamber 20, the operator can press the tip side 60 to reduce the volume of the first chamber 20, thereby ejecting the scaffolding material from the nozzle 40 in the required amount according to the pressing force.

[0355] Thanks to the at least partially flexible nature of nozzle 40, when the operator injects the scaffolding material into the wound, for example when nozzle 40 is inserted into the wound gap, if nozzle 40 tends to tilt relative to the wound surface, the operator can easily maintain a state in which nozzle 40 closely conforms to the wound surface without applying excessive force to the wound surface.

[0356] <Some other embodiments>

[0357] In some of the preceding embodiments, the biomaterial has a powder form, but may instead be in a hydrogel or sponge form, and may also have a continuous form, such as a film or sheet, instead of a dispersion form.

[0358] In some of the preceding embodiments, the scaffold is configured to retain the anti-fibrotic agent at least for the period from outside the body until it is placed in the body (e.g., until it is moved from outside the body to inside the body), but may be configured to retain the anti-fibrotic agent for a longer period, for example, while it is placed in the body (until the scaffold is absorbed and decomposed and disappears).

[0359] In some of the preceding embodiments, fibroblasts are considered to be the precursor cells, but mesothelial cells may alternatively or additionally be considered.

[0360] Furthermore, in addition to fibroblasts or mesothelial cells, the precursor cells may also be a cell population that includes at least one of mesenchymal stem cells, bone marrow-derived stem cells, endothelial cells, vascular endothelial cells, smooth muscle cells, and epithelial cells.

[0361] In some of the preceding embodiments, the scaffold is administered into the wound immediately following wound injury (e.g., when tissue begins to scar) or during the early stages of wound healing, but may alternatively or additionally be administered into the wound at later times and stages.

[0362] In some of the preceding embodiments, a scaffold is administered to the wound surface before scar tissue forms in the wound and after the wound is sutured (or may be before it is sutured), thereby using the scaffold to pre-treat the anti-scarring treatment.

[0363] In contrast, a scaffold may be administered to a wound formed by scar tissue that has been surgically excised from a living body after the wound has naturally healed, and then the new wound formed by the excision is sutured, so that the scaffold can be used to perform the anti-scarring treatment retrospectively.

[0364] In some of the preceding embodiments, the scaffold is configured as a single liquid formulation in which the biomaterial and the anti-fibrotic agent are premixed, but may alternatively be configured as a single solid formulation.

[0365] In some previous embodiments, the scaffold is configured as an injectable or patch that is injected into the wound space, but may alternatively be configured as a paint or aerosol.

[0366] The details of some of the above embodiments or examples are provided for the purpose of explaining the scope of the claims, and should not be construed as limiting the scope of the present invention. Although only a few specific examples of the present invention have been described in detail in the text above, those skilled in the art can easily understand that there are many variations in the specific examples without substantially departing from the novel teachings and advantages of the present invention. For example, multiple features described in relation to one specific example may be incorporated in any other specific example of the present invention, whether in whole or in part.

[0367] Therefore, all such modifications are intended to be included within the scope of the present invention, which is defined in the following claims and all equivalents thereto. Furthermore, it is envisioned that many embodiments do not achieve all of the advantages of some embodiments, particularly the preferred embodiments described above, and the absence of a particular advantage does not necessarily mean that the embodiment is not within the scope of the present invention. Since various modifications can be made within the scope described above without departing from the scope of the present invention, all matters contained in the detailed description of the invention are to be interpreted as interpreting the scope of the claims and not as limiting them.

Claims

1. An artificial wound scaffold for application to a wound in a living body, comprising: The wound scaffold material is configured to contain a bioabsorbable biomaterial and an anti-fibrotic agent as main components, and the biomaterial contains the anti-fibrotic agent at least during use of the wound scaffold material; the biomaterial is configured to function in the living body during the use as a body that retains the antifibrotic agent and as an artificial extracellular matrix having properties to which myofibroblast precursor cells of the living body adhere and support the proliferation of the precursor cells; During the use, the wound scaffold is placed in an incision formed in the skin as the wound, thereby allowing the anti-fibrotic agent and the biomaterial to be administered locally into the wound, thereby allowing an anti-scarring treatment to be performed in a wound healing process while inhibiting the retardation of wound healing; The wound scaffold further comprises: The wound does not include a wound formed by an eye surgery in the living body; The wound is characterized in that it does not include a defect wound. Including, the wound scaffold is placed within the wound such that the anti-fibrotic agent is administered locally to a location isolated from the epithelium of the skin; The wound scaffold is placed within the wound during the early stages of the wound healing process.

2. 2. The wound scaffold of claim 1, wherein when the wound scaffold is placed in the living body, the wound scaffold defines a space in the living body isolated from tissue surrounding the wound, into which the progenitor cells can enter, and upon entry of the progenitor cells into the space, the progenitor cells are allowed to react with the anti-fibrotic agent present in the wound scaffold, thereby inhibiting transformation of the progenitor cells into myofibroblasts, thereby allowing the anti-scarring treatment to take place.

3. The wound scaffold material as described in claim 1, which has the functions of defining an administration route of the anti-fibrotic agent in the living body, providing a scaffold for the progenitor cells from outside the living body, and replenishing the wound from outside the living body with the artificial extracellular matrix to replace the original extracellular matrix that has been disrupted by the wound.

4. The wound scaffold material according to claim 1, wherein the wound scaffold material is a multi-drug type prepared by mixing the biomaterial and the anti-fibrotic agent, at least one of which is in a liquid state, at the site where the anti-scarring treatment is performed.

5. 10. The wound scaffold of claim 1, comprising a scaffold configured as an injectable that is injected into a gap between opposing wound surfaces in the wound.

6. 2. The wound scaffold of claim 1, comprising a scaffold configured as a liquid, liniment, patch or aerosol to be applied topically to the wound surface.

7. The wound scaffold comprises a scaffold configured as the patch, The wound scaffold according to claim 6, wherein the patch is in the form of a flexible film or sheet and is configured to be inserted into the gap of the wound in a position extending along the wound surface of the wound.

Images