Scaffold material for wound for suppressing scarring of biological tissue

Abstract

To provide a technique for suppressing excessive scarring of a biological tissue in a wound healing process.SOLUTION: An artificial scaffold material for wound applied to wound of a living body contains a biological absorbing biomaterial and an anti-fibrosis agent as main components, wherein the biomaterial contains the anti-fibrosis agent at least during usage of the scaffold material for wound. The biomaterial functions as an artificial extracellular matrix having properties to bond a precursor cell of a myofibroblast of a living body, in a wound. The scaffold material for wound is placed in an abdominal cavity so that at least one of a first contact in which it is placed in the wound and / or comes in local contact with a region having a first wound part, out of the inner surface of the abdominal wall of the living body, and a second contact in which it comes in local contact with a region having a second wound part, out of the outer surface of a target organ in the abdominal cavity. Thereby, the anti-fibrosis agent is locally administrated into the wound, and anti-scarring treatment is conducted in a wound healing process.SELECTED DRAWING: Figure 2

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 can refer to, for example, damage to the skin or soft tissue caused by an external force.

[0003] Wounds are classified into traumatic injuries caused by accidents and surgical wounds caused by surgery, including incisional wounds (e.g., wounds made during surgery) and organ injuries (e.g., wounds to intraperitoneal organs or the peritoneum caused by abdominal surgery).

[0004] Furthermore, "wounds" are classified based on the degree of damage into defect wounds that involve tissue loss and non-defect wounds that do not involve tissue loss, and further into shallow skin wounds where the damage only reaches the dermis and deep wounds where the damage reaches the subcutaneous tissue.

[0005] The body is born with the ability to heal itself. "Natural healing" has various definitions, but it can mean, for example, that damaged tissues are repaired over time by regeneration (i.e., scarless healing) or scar healing.

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

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

[0008] When scar tissue forms in the dermis of the skin of a living body and contracts or thickens, it can cause problems such as restricted skin movement, impeding the function of motor organs, pain, and mental distress associated with poor appearance, regardless of the severity.

[0009] Furthermore, when scar tissue forms in biological organs (e.g., the eyes, lungs, heart, abdominal organs (liver, kidneys, etc.), body cavities (peritoneal cavity, thoracic cavity, mediastinum, etc.)), it can cause symptoms of dysfunction or failure.

[0010] Therefore, although scarring in biological tissues is an unavoidable phenomenon that occurs during the wound repair process with the aim 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. For this reason, 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 eye damage, surgical incision on the eye, or the like, that is, an anti-scarring treatment method.

[0012] The same 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, 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 inventors have conducted extensive research into treatment methods for inhibiting scarring in biological tissues, and as a result have discovered that 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 in order to inhibit scarring.

[0016] Furthermore, the present inventors have also discovered that while inhibition of scarring in biological tissues has the advantage of inhibiting, preventing, or treating fibrosis or fibrotic diseases, it also has the disadvantage of delaying wound healing (e.g., in situations where the target wound is a defect wound or a deep wound), and that it is important to develop the treatment method in an individual-adaptive manner (e.g., adapted to the location, degree, and characteristics of the wound in each individual, as well as the physiological characteristics of each individual, such as the immune strength) so that the advantages more than compensate for the disadvantages.

[0017] Based on these findings, the present invention aims to provide a technique for inhibiting excessive scarring of biological tissues during the wound healing process. [Means for solving the problem]

[0018] The present invention provides the following aspects. Each aspect is divided into paragraphs, each numbered, and described by citing the numbers of other paragraphs as necessary. This is to facilitate understanding of some of the technical features and combinations thereof that may be employed by the present invention, and should not be construed as limiting the technical features and combinations thereof that may be employed by the present invention to the following aspects. In other words, it should be understood that technical features that are not described in the following aspects 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 paragraph in a format that refers to the number of other paragraphs does not necessarily mean that the technical features described in each paragraph cannot be separated and made independent from the technical features described in other paragraphs, and it should be interpreted that the technical features described in each paragraph can be made independent as appropriate depending on their nature.

[0020] (Aspect 1) An artificial wound scaffold to be applied to a wound in a living body, comprising: a wound scaffold comprising a bioabsorbable biomaterial and an anti-fibrotic agent as main components, and configured so that the biomaterial contains the anti-fibrotic agent at least during use of the wound scaffold; 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 is placed within the wound during use, and / or placed within the abdominal cavity so as to make at least one of a first contact where the scaffold locally contacts an area of ​​the inner surface of the abdominal wall of the living body, the area having a first wound site on the abdominal wall as the wound, and a second contact where the scaffold locally contacts an area of ​​the outer surface of a target organ in the abdominal cavity, the area having a second wound site on the target organ as the wound, thereby allowing the anti-fibrotic agent to be locally administered 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 make at least one of a first contact where the wound scaffold locally comes into contact with an area of ​​the inner surface of the abdominal wall of the living body, the area having a first wound site on the abdominal wall as the wound, and a second contact where the wound scaffold locally comes into contact with an area of ​​the outer surface of a target organ in the abdominal cavity, the area having a second wound site on the target organ as the wound" have in common that 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 ingredient, a protein, a polysaccharide, or a glycoprotein complex to which the progenitor cells have the property of adhering.

[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 in the form of a film or sheet, and is flexible.

[0024] (Aspect 4) A wound scaffold according to any one of Aspects 1 to 3, wherein when the wound scaffold is placed in the living body, the wound scaffold defines a space in the living body that is isolated from the tissue surrounding the wound, into which the progenitor cells can invade, and when the progenitor cells invade the space, the invaded progenitor cells are allowed 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 carried out.

[0025] (Aspect 5) A wound scaffold according to any one of aspects 1 to 4, wherein the scaffold has the functions of defining an administration route for the antifibrotic agent in the living body, providing a scaffold for the progenitor cells from outside the body, and replenishing the wound from outside the 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 the time outside the body until the time when the scaffold is placed inside the body.

[0027] (Aspect 7) A wound scaffold according to any one 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 and 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 from 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 on the surface of the body, 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 in the early stage of wound healing.

[0031] (Aspect 11) A wound scaffold according to any one 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-treat the anti-scarring treatment.

[0032] (Aspect 12) A wound scaffold according to any one of Aspects 1 to 11, wherein the wound scaffold is administered to the surface of a new wound formed by the scar tissue excised from the living body by surgical operation after the wound has naturally healed with the formation of scar tissue, and the new wound is then sutured, 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 wound scaffold material described in any of Aspects 1 to 12, in which at least one of the biomaterial and the anti-fibrotic agent is in a liquid state and is prepared by mixing them at the site where the anti-scarring treatment is performed.

[0034] (Aspect 14) The biomaterial is a solid agent, 14. 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 wound 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 two are prepared by mixing them at the site where the anti-scarring treatment is performed.

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

[0037] (Embodiment 17) A wound scaffold according to any one of embodiments 1 to 16, comprising a scaffold configured as an injection 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 a storage section capable of storing the wound scaffold material, which responds to an external force and causes a required amount of the wound scaffold material to exit the storage section; a discharge section capable of discharging a portion of the wound scaffolding material contained in the container section that has exited the container section; and 18. The wound scaffold of embodiment 17, comprising:

[0039] (Aspect 19) The storage section is a first portion capable of containing the biomaterial; a second portion capable of containing the anti-fibrotic agent; and a function of reacting to a first external force that is the same as the external force or a second external force different therefrom, mixing the biomaterial in the first portion and the anti-fibrotic agent in the second portion, thereby creating the wound scaffold. 20. The wound scaffold of embodiment 18, comprising:

[0040] (Aspect 20) A wound scaffold according to any one of Aspects 1 to 19, comprising a scaffold configured as a liniment, patch or aerosol to be locally applied to the wound surface, the inner surface of the abdominal wall or the outer surface of the target organ.

[0041] (Aspect 21) The wound scaffold includes the scaffold configured as the patch, 21. The wound scaffold of aspect 20, 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, 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 an incision step of incising the abdominal wall, thereby forming a first wound site at the incision; a surgical step in which a surgical instrument is introduced from outside the body through the incision into the abdominal cavity to perform a surgical operation on a target organ in 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 during the surgical procedure, 21. The wound scaffold of aspect 20, wherein the patch is placed in the abdominal cavity so as to make at least one of a first contact where the abdominal wall locally contacts an area of ​​the inner surface of the abdominal wall that includes the first wound site, and a second contact where the target organ locally contacts an area of ​​the outer surface of the target organ that includes the second wound site.

[0043] (Aspect 23) A wound scaffolding material according to 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 according to any one of Aspects 1 to 23, wherein administration of the wound scaffold is contraindicated when the wound is a defect wound accompanied by a tissue defect, reconstruction of the defect wound is not performed, and the wound surface of the wound is exposed.

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

[0046] [Figure 1] Figure 1 is a cross-sectional and schematic diagram that chronologically and conceptually depicts the basic wound healing process. [Figure 2] FIG. 2 is a cross-sectional view and schematic diagram illustrating, chronologically and conceptually, the wound healing process using a wound scaffold according to some embodiments of the present invention. [Figure 3] FIG. 3 is a perspective view conceptually illustrating a method for administering a wound scaffold according to some embodiments of the present invention into a wound by liquid injection. [Figure 4] 4(a) and 4(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 into 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 muscle layer (or subcutaneously) when leaving an implant in the dissection cavity. 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 a top perspective 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. [Figure 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 a cross-sectional view showing an exemplary timeline of 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 conducted 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 from Treatment Group 1 on day 7 after skin incision in the experiment. [Figure 16]FIG. 16 shows representative micrographs of scar tissue specimens obtained 7 days after skin incision for treatment group 2 in the experiment. [Figure 17] FIG. 17 shows the borders of the scar area 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 is a diagram showing the multiple comparisons of the results of the above experiment in a table format. [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 the scar cross-sectional area for each of the four groups for the results of the experiment. [Figure 23] FIG. 23 is a partial cross-sectional side view exemplarily showing an injector used for administering into a wound a scaffold according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] Hereinafter, several exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] <Overview>

[0049] First, we will provide a technical overview common to these embodiments of the wound scaffold 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 suppresses 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 leaving a scar, scar-free healing, healing with minimal scarring, scar formation inhibition therapy, etc.) by suppressing the differentiation (transformation) of fibroblasts, which are exemplary precursor cells, into myofibroblasts.

[0051] According to conventional wisdom, during the wound healing process, fibroblasts differentiate into myofibroblasts, primarily due to stimulation by TGF-β1 (a growth factor that promotes fibroblast transformation), and these myofibroblasts then secrete extracellular matrix (ECM) (such as collagen) in excess, resulting in scar formation. However, conventional anti-scarring treatments (such as taping and compression therapy) have limited effectiveness in inhibiting scar formation, making it inevitable that scars will remain after surgery or trauma.

[0052] On the other hand, 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, for example, pulmonary fibrosis and glaucoma.

[0053] In response to this, the present inventors have considered that a safe and effective anti-scarring treatment method can be realized by combining anti-fibrotic agents, including but not limited to such approved drugs, with biomaterials and applying them to the field of medical treatment related to wound healing.

[0054] <General Overview>

[0055] 1. Background

[0056] In humans, as an example of a living organism, skin injury after birth always leaves a scar at the site of injury, and the wound healing process often results in unsightly scars such as hypertrophic scars and keloids. Although various suturing techniques and aftercare methods have been developed to make scars less noticeable, the effectiveness of conventional anti-scarring treatments in inhibiting scarring is limited, and new anti-scarring treatments are needed. In particular, unsightly scars on the face or hands cause significant psychological distress and social stigma, significantly reducing patients' quality of life (QOL). Scarless wound healing is the wish of many patients who have undergone trauma or surgery, and its realization is eagerly awaited.

[0057] As shown conceptually in Figure 1, the basic wound healing process involves fibroblasts, an example of progenitor cells, which differentiate into α-SMA-positive myofibroblasts primarily through stimulation with TGF-β1. These myofibroblasts then secrete excess ECM, resulting in scar formation.

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

[0059] On the other hand, 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 generic drugs that can be substituted (hereinafter also collectively referred to as "anti-fibrotic agents"), could be applied to scar treatment.

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

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

[0065] (2) Is scarless wound healing possible by using anti-fibrotic agents on wounds?

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

[0067] 3. Purpose and effects of this treatment

[0068] The goal of this treatment is to achieve scarless wound healing through a unique approach that uses anti-fibrotic agents to inhibit the differentiation of fibroblasts into myofibroblasts.

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

[0070] This treatment method not only realizes scarless wound healing, but also has the potential to significantly contribute to the advancement of wound treatment as a fundamental treatment and preventative agent for keloids and hypertrophic scars.

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

[0072] Therefore, this treatment method is expected to produce an artificial scaffold with anti-fibrotic properties that will be useful in preventing adhesions after abdominal 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 sees many patients in his daily practice in the field of plastic surgery who wish to receive treatment for scars complaining of functional disorders, pain, and mental distress caused by trauma or post-surgical scars (e.g., scars triggered by trauma or scars triggered by surgical incisions), and he feels that realizing 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, new treatments based on molecular mechanisms are needed.

[0076] Therefore, in a preliminary experiment, the inventors used immunohistochemistry (IHC) to examine the distribution of α-SMA-positive myofibroblasts in histological images of mature and immature scars, and found that myofibroblasts were localized deep within immature scars and completely absent in mature scars.

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

[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 immunohistochemistry 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 this finding, the inventors considered that keloids are a pathological condition in which differentiation into myofibroblasts occurs constantly due to mechanical stress and sustained stimulation by TGF-β1, and that inhibition of differentiation into myofibroblasts could also be applied to the treatment of keloids.

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

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

[0083] 5. Scaffolding Material Composition

[0084] (1) Overall structure

[0085] The scaffold material has as its main components a biomaterial that functions as an artificial ECM for the progenitor cells and an anti-fibrotic agent, and 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 between 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 extrude a required amount of liquid from the cylinder, and a syringe in which a flexible container that contains the liquid is manually compressed to reduce the volume and extrude 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 (a solid agent including a bioabsorbable film, tape, cloth, etc.) inserted into the wound gap or other site, for example, into the abdominal cavity, and is impregnated, adhered, coated, or attached with an antifibrotic agent, as conceptually shown in Figure 4. The sheet is configured by impregnating an antifibrotic agent into a flexible substrate (support base) made of a biomaterial.

[0093] (3) Liquid injection type

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

[0095] In the one-component type, the scaffold is prepared by mixing the biomaterial and anti-fibrotic agent into a one-component scaffold before arriving at the site where the anti-scarring treatment will be performed, and in this case the scaffold can be sold commercially as a finished product.

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

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

[0098] In contrast, in Type 4, at the site where the anti-scarring treatment is performed, a liquid (such as 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 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 as a scaffold is inserted into the wound gap and left therein, as conceptually shown in Figures 4(a) and 4(b). In this type, the scaffold is inserted into the wound gap and left therein so that it does not substantially have any protrusions 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 below) 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 such an implant is an artificial breast implant, which is generally partially spherical and is inserted and placed in an artificial cavity (also called an "excision cavity," meaning a cavity formed between one tissue by exfoliating another) within the human breast to perform breast reconstruction or augmentation.

[0105] In its use for breast reconstruction or augmentation, 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 the human pectoral muscle (e.g., under the pectoralis major muscle, i.e., between the pectoral muscle and the chest wall), as shown in the same 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 under the mammary gland, and in this example, an implant is inserted under the mammary gland.

[0108] In either case, the tissue into which the implant is 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 this wound can cause scarring, it is desirable to perform 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 and left there. In this state, the antifibrotic agent contained in the sheet covering the implant migrates to the surface of the target tissue that forms the dissection cavity and is applied over substantially the entire surface (ideally, over the entire surface). As a result, scarring in the dissection cavity is suppressed.

[0110] In this example, coating the surface of the implant with a sheet material corresponds to an example of inserting the scaffold material 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 material 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, but as another example, there is a second sheet preparation insertion type in which a sheet preparation as a scaffold is inserted and retained in the abdominal cavity, as conceptually shown in Figure 1(c)-(e).

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

[0113] Fig. 1(d) is a cross-sectional view conceptually showing a third example in which the sheet preparation is placed 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 preparation is placed across two target organs in the abdominal cavity.

[0114] In the third example shown in Figure 1(d) and the 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, thereby performing 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] Note that the term "second wound site" is not used in Figure (d) because it is not essential to explaining the specific functions of the scaffold in this example, such as the anti-scarring and anti-adhesion functions 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 Figure (d) of the same figure, the sheet agent is placed in the abdominal cavity so as to make a first contact, that is, a local contact (e.g., a surface contact) with the area of ​​the peritoneum that includes the first wound site.

[0118] In this example, when the sheet is placed in the abdominal cavity and the surface of the sheet comes into contact with the peritoneum, the anti-fibrotic 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 the fourth example shown in Figure (e), the sheet is placed in the abdominal cavity so as to make both a first contact (e.g., surface contact) with the area of ​​the peritoneum that includes the first wound site, and a second contact (e.g., surface contact) with 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 contacts the peritoneum, the anti-fibrotic agent contained in the sheet migrates from the sheet to the wound surface of the first wound site to perform anti-scarring treatment on the first wound site, while when the back surface of the sheet contacts the outer surface of the target organ, the anti-fibrotic agent migrates from the sheet to the wound surface of the second wound site to perform anti-scarring treatment on the second wound site.

[0121] More specifically, as shown in Fig. 1(e), the sheet is placed across two target organs in the abdominal cavity and on the two surfaces of the target organs, which is a perspective view showing the state in which the scaffold is placed across two target organs in the abdominal cavity and 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, Figure 1(e) shows how two target organs are sutured together. Examples of two organs that can be sutured together 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 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 aforementioned liquid injection type may be additionally adopted and the liquid as a scaffold material may be locally administered into the wound at the first wound site using an injector.

[0125] In summary, the sheet agent shown in Figure (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] In the third and fourth examples, the sheet agent is made of at least a biomaterial, which may suggest the possibility that the biomaterial may promote adhesion between the abdominal wall and the intraperitoneal organs.

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

[0128] Therefore, by placing the sheet in the abdominal cavity, particularly in a position between the abdominal wall and the intraperitoneal organs, not only is it possible to inhibit scarring of the abdominal wall and the intraperitoneal organs, but it is also possible to prevent 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 as an intraperitoneal organ on which a surgical procedure is not performed but which comes into contact with a scaffold.

[0130] Hereinafter, some other examples of the second sheet material insertion type will be described.

[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, on its front surface, an area in the abdominal wall that includes a first wound site. The second sheet member is configured to locally contact, on its back surface, an area in the abdominal cavity that includes a second wound site.

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

[0133] In summary, in this example, the sheet agent constitutes an example of a dispersed 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] In the multiple examples described above for the first and second sheet insertion types, the sheets are all flexible but have shape-retaining properties (they do not change shape without external force), and therefore can be left in 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] In this way, an advantage of using a sheet for anti-scarring treatment is that its shape has the property of easily conforming to the surface of the place where it is to be placed, and so it can be placed in a state of surface contact with the 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 in the organ from that location, and the scarring has the characteristic of spreading in a planar fashion 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] Biomaterials contain proteins (e.g., collagen, elastin, gelatin), polysaccharides (e.g., hyaluronic acid, chondroitin sulfate, cellulose), or glycoprotein complexes (e.g., aggrecan, versican) as their main components. Biomaterials are in the form of hydrogels, powders, sponges, or sheets, and are flexible and shape-retaining.

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

[0141] Furthermore, commercially available drugs (medical products, etc.) that constitute biomaterials include, for example, 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] The antifibrotic agent may be a low molecular weight agent such as fasudil, ripasudil, pirfenidone, or nindedanib. The antifibrotic agent may be in liquid, powder, or particulate form. The concentration of the antifibrotic agent may vary depending on the type of antifibrotic agent, the type of wound, the severity of the wound, and the characteristics of the individual (organism, human) to be administered.

[0144] 6. Basic guidelines for experimental methods

[0145] (1) Purpose

[0146] In order to confirm the efficacy of an anti-fibrotic agent, which is commercially available and whose efficacy and safety as a treatment method for living organisms, for example, 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 for further experiments, as 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) Experiment Overview

[0148] Treatment experiments in a mouse wound model

[0149] An incision is made on the back of a mouse, reaching from the epidermis to the fascia, and the incision is sutured. A mouse wound model is then created in such a state that an antifibrotic agent-containing scaffold is locally administered and placed in the intrawound gap (e.g., in the gap between a pair of opposing wound surfaces in the incision, or in the dermal gap).

[0150] Therefore, it is expected that myofibroblasts will be formed in the region from the boundary layer between the epidermis and dermis to 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 is explained as follows: Control group 2 has the significance 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 when the scaffold of the invention is applied to a wound.

[0154] (4) Treatment group selection

[0155] There were 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 (containing the antifibrotic agent); Treatment group 2: The biomaterial was administered into the wound as a gel scaffold containing a second antifibrotic agent (e.g., Ripasudil) at a predetermined concentration. Set the following: Three mice are used in each treatment group.

[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 following significance: by comparing it with control group 1, it makes it possible to confirm the effects of a scaffold material as an invention having a biomaterial and a first antifibrotic agent; by comparing it with control group 2, it makes it possible to confirm the advantages and disadvantages obtained by the first antifibrotic agent alone in the scaffold material as an invention; and by comparing it with treatment group 2, it makes it possible to confirm the advantages and disadvantages obtained by the first antifibrotic agent alone in the scaffold material as an invention relative to the advantages and disadvantages obtained by the second antifibrotic agent alone in the scaffold material as an invention.

[0158] Furthermore, treatment group 2 has the significance of making it possible to confirm, by comparison with control group 1, the effects of the scaffold material of the invention having a biomaterial and a second antifibrotic agent; making it possible to confirm, by comparison with control group 2, the advantages and disadvantages obtained solely by the second antifibrotic agent in the scaffold material of the invention; and making it possible, by comparison with treatment group 1, to confirm, relative to the advantages and disadvantages obtained solely by the second antifibrotic agent in the scaffold material of the invention, the advantages and disadvantages obtained solely by the first antifibrotic agent in the scaffold material of the invention.

[0159] (5) Incision and suture

[0160] Two skin incisions were made per mouse. Specifically, two 10 mm incisions were made on the shaved back of each mouse, each at full skin depth. Each incision was then sutured with two stitches (e.g., 6-0 nylon) in the epidermis only.

[0161] (6) Local administration of scaffolds

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

[0163] (7) Appearance evaluation and scar tissue collection

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

[0165] (8) Specimen collection and scar tissue evaluation

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

[0167] The evaluation method involved 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). "Wound" also includes open and closed wounds. Tissues that may be wounded include the skin and subcutaneous tissue, muscle tissue, peritoneum, digestive organs, and 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 infiltrate 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 regress during the subsequent tissue remodeling phase, and are ultimately replaced by scar tissue primarily composed of collagen. It is known that excessive collagen deposition during this 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 to any bodily 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 tissue, scars of the peritoneum, abdominal cavity, and intra-abdominal 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 areas 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., scar 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 proliferation 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 administered to a patient after the onset of the target disease, but also to curing, ameliorating, or at least partially ameliorating the disorder, and also to preventive treatment administered 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 cellular organization in living organisms. The ECM provides structural scaffolding for cells and is a major component of physical support in the formation of tissues, organs, and tissues. The ECM is primarily composed of three major classes of biomolecules, including fibrous proteins such as collagen (e.g., types I and 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 "anti-fibrotic," "fibrosis suppression," and "fibrosis inhibition" refer to the suppression of the progression of fibrosis in tissue.

[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 that has a preventive or therapeutic effect against fibrosis in tissue. For example, an antifibrotic agent prevents or treats fibrosis by suppressing the differentiation of fibroblasts into myofibroblasts.

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

[0192] 9. Biomaterials

[0193] In this specification, the term "biomaterial" refers to a product with a specific use and a specific function, as opposed to the broader 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 are suitable for introduction into living tissue.

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

[0196] The biocompatible material can be of the indwelling type, which is left in the body after being introduced into biological tissue, or the biodegradable type, which is decomposed and absorbed in the body after being introduced into biological tissue. In this embodiment, the "biomaterial" is made using a biodegradable biocompatible material. Therefore, the "biomaterial" is of the in vivo degradable type, and is replaced by the body's own tissue over time, resulting in its disappearance in the body.

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

[0198] As used herein, the term "scaffold" is defined as a material that fulfills the functions of, for example, securing space for tissue regeneration and assisting the regeneration of damaged tissue while maintaining the shape of the regenerated tissue. The term may also be defined as a material that fulfills the functions of, for example, providing space for the regeneration of target cells while distributing them three-dimensionally and imparting a specific shape to them.

[0199] The actual object or substance administered into the body to realize this “scaffold” function is an artificial “scaffolding material.” Therefore, in this embodiment, the “scaffolding material” has, for example, good adhesiveness to target cells (e.g., the progenitor 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 implanted in the body and is no longer needed, and has sufficient strength to withstand damage even when the body moves.

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

[0201] First Embodiment

[0202] 1. Scaffolding material composition

[0203] (1) Selection of antifibrotic agents

[0204] Two antifibrotic options were selected: ripasudil hydrochloride hydrate (Ripasudil) and fasudil hydrochloride hydrate (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 biomaterial scaffold material. Genocel® is manufactured by Kyoto Medical Design Co., Ltd. and is a cell culture scaffold material using gelatin with a nonwoven structure.

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

[0208] 2. Manufacturing method of scaffold 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 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 with two chambers and a nozzle located at the tip of the main body. The injector also has a switching function that normally keeps the two chambers isolated but switches them to a connected 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 to mix the scaffold material at the site where the anti-scarring treatment is performed, the two chambers are brought into communication with each other, thereby initiating mixing. When the same first external force as the external force or a different second external force is then applied to mix the scaffold material, the scaffold material moves from the container to the nozzle, and the required amount of scaffold material is discharged from the nozzle.

[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, 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 on-site or at a different location, and then fill the injector with the mixed liquid thus prepared.

[0217] 3. Scaffold administration method

[0218] liquid injection mold

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

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

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

[0222] After suturing, the scaffold is locally administered 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 needleless device, a syringe, a bottle, a dropper, a pipette, etc.

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

[0224] For ease of explanation, the scaffold material is injected into the wound gap, as shown in an exaggerated manner in Figure 7. Because the scaffold material is bioabsorbable, it will eventually be replaced by the body's own tissue and disappear.

[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 suppressed, thereby inhibiting excessive scarring of biological tissue during the wound healing process. 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 invade. Once the progenitor cells invade the space, they react with the anti-fibrotic agent present in the scaffold, thereby inhibiting the transformation of the progenitor cells into myofibroblasts and thereby providing an anti-scarring treatment.

[0229] Furthermore, the scaffold material has the functions of defining the administration route of antifibrotic 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 in living skin.

[0232] The purpose of this experiment was to evaluate the effectiveness of the scaffold using an animal model. Specifically, an 8-week-old mouse incision wound model was used to evaluate its effect of inhibiting scar formation during the wound healing process.

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

[0234] Twelve C57BL / 6JJcl mice (male, 8 weeks old, CLEA Japan, Inc.) were used as experimental animals. Mice were housed in clean S cages and mouse M2 cages, with three mice per cage, in a standard environment (temperature: 20-26°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 as tabulated in Figure 8: Control group 1 (n=3), Control group 2 (n=3), Treatment group 1 (n=3), and The animals were divided into four groups: treatment group 2 (n=3);

[0237] 5-3. Treatment of mice

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

[0239] Furthermore, two separate longitudinal incisions were made in each mouse, each approximately 10 mm long and reaching the full skin thickness, and then each incision was closed with two epidermal sutures (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 postoperative day 3, and the other wound site is harvested for scar tissue on postoperative day 7.

[0241] 5-4. Setting up a control group

[0242] As shown in the table in Figure 8, two types of control groups were used: 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 three mice in control group 1 are designated as individual numbers 101, 102, and 103, and the three mice in control group 2 are designated as individual numbers 201, 202, and 203.

[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 the mixture was suspended by pipetting or inversion. The drug was administered immediately after preparation.

[0246] 5-5. Treatment group setting

[0247] The two treatment groups are shown in table format in Figure 8: Treatment group 1: A biomaterial containing fasudil was administered into the wound as a gel scaffold, 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, identified as individual numbers 301, 302, and 303, and the three mice in treatment group 2, identified as individual numbers 401, 402, and 403, are shown in the figure.

[0249] More specifically, for treatment groups 1 and 2, the following applies:

[0250] Treatment group: Treatment group 1 Antifibrotic agent administration concentration: 30 mg / mL Scaffold volume administered: 20 μL / wound site (20 μL was administered to each of two wound sites on each mouse.) Scaffold dosage: Approximately 53.1 mg / kg (weight of scaffold administered to each mouse per 1 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 solution was administered immediately after preparation.

[0251] Treatment group: Treatment group 2 Antifibrotic agent administration concentration: 4 mg / mL Scaffold volume: 20 μL / wound site (20 μL each for two wound sites on each mouse) Scaffold dosage: Approximately 7.1 mg / kg (weight of scaffold administered to each mouse per 1 kg of each mouse) Preparation method: Using a 200 μL pipette tip, 200 μL of Ripasudil (Glanatec® eye drops 0.4%) was added to 800 μg of Genocel® powder, and the mixture was suspended by pipetting or inversion. The solution was administered immediately after preparation.

[0252] In treatment group 1, the concentration of fasudil was 30 mg / mL, but 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 the 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.Administration method

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

[0256] Specifically, as shown in Figure 9, after the suture procedure, mice in control group 2, treatment group 1, and treatment group 2 were anesthetized and 20 μL of scaffold material was evenly administered into the wound 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 consume an analgesic (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 site of each mouse was photographed with a scale on Day 0, Day 3, and Day 7. Of the photographed images, those on Day 3 are shown in Figure 10, and those on Day 7 are shown in Figure 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 staining"), and the label "α-SMA" indicates that the photograph is of a specimen stained immunohistochemically using anti-α-SMA antibody (or referred to as "α-SMA immunostaining").

[0263] Figure 12 shows in tabular form for each group whether the wound site had epithelialized on days 3 and 7. Here, "epithelialization" means that the epithelium at the wound site had become completely continuous and the wound had 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 (e.g., a plate-like portion that is generally circular or oval in plan view) with a long diameter of approximately 15 mm was cut out from the skin of each mouse for each wound site, with each wound site positioned approximately in the center. The cut-out portion was then trimmed into a rectangular shape to prepare a scar specimen.

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

[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 immunohistochemically stained using 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 were observed and photographed under an optical microscope on day 7. In each photomicrograph, the boundary between the scarred and non-scarred areas was drawn using NDP.view2 software (Hamamatsu Photonics Co., Ltd.), 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, areas with a higher cell count, denser collagen fibers, and randomly arranged collagen fiber bundles compared to the surrounding areas were distinguished from other areas and determined to be areas where scarring had occurred.

[0279] For ease of illustration, lines have been added to 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 lined up in a horizontal row.

[0281] The calculated scar cross-sectional area for each group and for each mouse for the corresponding scar area 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 analysis of variance (ANOVA) was performed using GraphPad Prism 9 (GraphPad Software, LLC), followed by a Tukey's test. The experimental data were statistically analyzed based on the results of these tests. 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 multiple comparisons (labeled "Multiple Comparisons (Tukey test results)") in a table format.

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

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

[0288] In these figures, the definitions of the main symbols are 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 established for the difference between experimental data groups, the difference between the groups was considered to be statistically significant, and the contrasted groups were considered to have a significant difference.

[0291] (3) Evaluation of myofibroblast quantity

[0292] The α-SMA immunostained sections on days 3 and 7 were observed under a microscope and photographed, and the presence or absence of myofibroblasts was visually evaluated from the images of each micrograph. The micrographs of each section on day 3 are shown in Figure 10, and the micrographs of each section on day 7 are shown in Figure 11.

[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 had epithelialized, whereas on day 7, the wound sites of the mice in all groups had 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 showed a decrease in scar cross-sectional area compared to control group 2, and there was a statistically significant difference between the two (p=0.03).

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

[0300] b. Fasudil's potential 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, there was no statistically significant difference between the two, but it was considered that fasudil, one of the scaffold materials according to this embodiment, may have an anti-scarring effect by itself.

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

[0304] Furthermore, if the same concentration and dosage of fasudil as 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 concluded 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 allowed the biomaterial to function as a space where myofibroblasts could adhere, and collagen production by the myofibroblasts was vigorously carried out within this space, resulting in a larger cross-sectional scar area than in control group 1.

[0309] On the other hand, the scar cross-sectional area was not larger in treatment groups 1 and 2 compared to control group 1, which indicates 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 antifibrotic agents, have anti-scarring effects.

[0314] (4) Visual inspection of 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 wound.

[0316] Furthermore, as shown in the figure, the treatment groups 1 and 2 had fewer α-SMA-positive myofibroblasts than the 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 discussion of the above-described experiment demonstrate that the scaffold according to the present embodiment has a scarring inhibitory effect. Although this experiment was conducted on mouse skin, common technical knowledge and experience suggest that similar experiments conducted on human skin would have a similar mechanism of action and effect.

[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 suppressed 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 impairment, pain, and mental distress caused by scarring.

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

[0324] Therefore, according to this embodiment, unless early wound healing is particularly desired due to tissue loss, it is expected that epithelialization will not be prolonged due to delayed healing caused by the inhibition of scarring. This was verified by the experimental results showing that epithelialization was achieved in all treatment groups by Day 7 (see Figure 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 be attenuated not only by adjusting the concentration (concentration and dilution) and / or the dose (increase and decrease) of the antifibrotic agent, but also by adjusting the concentration and / or the dose of the biomaterial instead, and in addition to the above adjustments, by adjusting the concentration and / or the dose 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 these multiple options in an individualized manner to suit the characteristics of the patient and the wound.

[0328] (2) Simplifying the 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 converted into biomaterials and anti-fibrotic agents as the main components of the scaffold, 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 this embodiment uses an antifibrotic agent with a relatively low molecular weight, such as one with a molecular weight of 400 or less. Therefore, such low-molecular-weight antifibrotic agents are cheaper and easier to chemically synthesize than high-molecular-weight antifibrotic agents, such as those with a molecular weight of 10,000 or more, and in addition to having a stable structure, such low-molecular-weight antifibrotic agents act intracellularly, making it possible to directly and effectively inhibit the signaling pathway that differentiates the precursor cells into myofibroblasts.

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

[0334] According to this embodiment, the biomaterial and anti-fibrotic agent are stored as solid agents rather than liquid agents, for example, in a storage location or in an injector, prior to administering the scaffold into the wound 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 very stage when the treatment is about to be performed, so even if there is a risk of some kind of denaturation occurring in 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) Possible application in the field of cosmetic medicine

[0339] The wound scaffold according to this embodiment can suppress or prevent the occurrence of scars and marks, 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 (liquid mixture) 100, i.e., before mixing a biomaterial (powder) 102 and an anti-fibrotic agent (liquid) 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 chamber 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 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, movement resistance may be reduced when moving it in its longitudinal direction through a narrow wound gap, which may improve convenience. An outlet for discharging the scaffold material 100 (mixed liquid) is opened at the tip of the nozzle 40.

[0346] The main body 30 is divided into two parts: a tip side part 60 that forms the first chamber 20 and a rear side part 62 that 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 includes a selective communication mechanism 72 that does not normally break a diaphragm functioning portion 70 that 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 functioning portion 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 portion 60 and the rear end side portion 62, causing them to rotate relative to each other.

[0348] The 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 engaging 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 engaging protrusion.

[0349] An example of the diaphragm function portion 70 is a portion of the wall of the glass ampoule. When the wall portion engages with the engaging protrusion (a rigid body such as metal), it breaks, and the broken portion 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] When the first and second chambers 20, 22 are in communication, for example, the antifibrotic agent in the second chamber 22 flows into the first chamber 20, and the antifibrotic agent that has flowed in and the powdered biomaterial that is already present in the first chamber 20 are mixed together to form 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 the two agents.

[0352] During the mixing and stirring process (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 portion 60 is at least partially flexible, when a scaffolding material is present as a mixed liquid in the first chamber 20, the operator can press the tip side portion 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 the nozzle 40, when the operator injects the scaffolding material into the wound, for example, when the nozzle 40 is inserted into the wound gap, if the nozzle 40 tends to tilt relative to the wound surface, the operator can easily maintain a state in which the nozzle 40 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 it may instead be in a hydrogel or sponge form, and instead of being in a dispersion form, it may be in the form of a continuous body, for example, a film or a sheet.

[0358] In some of the preceding embodiments, the scaffold is configured to retain the antifibrotic agent at least until it is placed in the body from outside the body (e.g., until it is moved from outside the body to inside the body), but it may also be configured to retain the antifibrotic 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 the preceding embodiments, fibroblasts have been considered as the precursor cells, but mesothelial cells may alternatively or additionally be considered.

[0360] Furthermore, in addition to fibroblasts or mesothelial cells, cell populations including at least one of mesenchymal stem cells, bone marrow-derived stem cells, endothelial cells, vascular endothelial cells, smooth muscle cells, and epithelial cells may also be considered as precursor cells.

[0361] In some of the preceding embodiments, the scaffold is administered into the wound immediately after wound injury (e.g., when scarring begins in the tissue) or during the early stages of wound healing, but alternatively or additionally, the scaffold may be administered into the wound at a later time and stage.

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

[0363] In contrast, a scaffold material may be administered to the surface of a new wound formed by the excision after the wound has healed naturally with scar tissue formed in the wound being surgically excised from the living body and the new wound formed by the excision is sutured, thereby allowing the scaffold material to be used to perform the anti-scarring treatment after the fact.

[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-described embodiments or examples are provided for the purpose of interpreting 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 text in the above description, those skilled in the art will readily understand that many variations exist in those specific examples without substantially departing from the novel teachings and advantages of the present invention. For example, multiple features described in connection with one specific example may be incorporated, in whole or in part, into any other specific example of the present invention.

[0367] Therefore, all such modifications are intended to be encompassed within the scope of the present invention, which is defined in the following claims and all equivalents thereto. Furthermore, it is contemplated that many embodiments will 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 in question is not within the scope of the present invention. Because various modifications can be made within the foregoing scope without departing from the scope of the present invention, all matter contained in the detailed description of the invention should be interpreted as interpreting the scope of the claims, and not as limiting them.

Claims

1. An artificial wound scaffold to be applied to a wound of a living body, comprising: a wound scaffold comprising a bioabsorbable biomaterial and an anti-fibrotic agent as main components, and configured so that the biomaterial contains the anti-fibrotic agent at least during use of the wound scaffold; 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 is placed within the wound during use, and / or placed within the abdominal cavity so as to make at least one of a first contact where the scaffold locally contacts an area of ​​the inner surface of the abdominal wall of the living body, the area having a first wound site on the abdominal wall as the wound, and a second contact where the scaffold locally contacts an area of ​​the outer surface of a target organ in the abdominal cavity, the area having a second wound site on the target organ as the wound, thereby allowing the anti-fibrotic agent to be locally administered within the wound, thereby enabling anti-scarring treatment to be performed during the healing process of the wound.

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 that is isolated from tissue surrounding the wound, into which the progenitor cells can invade, and upon invading the space, the progenitor cells are allowed 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 take place.

3. The wound scaffold material according to claim 1, which has the functions of defining an administration route for the anti-fibrotic agent in the living body, providing a scaffold for the progenitor cells from outside the body, and replenishing the wound from outside the 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 mixture 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 to be performed.

5. The wound scaffold of claim 1 , comprising a scaffold configured as an injectable agent 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 liniment, patch or aerosol to be topically applied to the wound surface, the inner surface of the abdominal wall or the outer surface of the target organ.

7. The wound scaffold includes the scaffold configured as the patch, The wound scaffold according to claim 6, 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, or to be 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.

8. The wound scaffold according to claim 1, wherein administration of the wound scaffold is contraindicated when the wound is a defect wound accompanied by a tissue defect, the defect wound is not reconstructed, and the wound surface of the wound is exposed.

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