Biocompatible three-dimensional structures for body tube regeneration

Abstract

The present invention relates to a human implant for inducing regeneration of body vessels and a method for treating lymphedema or ischemic diseases using the same. The structure of the present invention not only provides appropriate physical strength and mechanical support to prevent re-injury of body vessels such as lymphatic vessels or blood vessels during regeneration, but also structurally and functionally mimics in vivo body vessel tissue by promoting the flow of body fluids through capillary action using a simple rod structure with irregularities (e.g., H-beams) or lumens (e.g., tubular). Furthermore, the structure of the present invention is implanted into the lesion and decomposes at an appropriate time after the completion of body vessel regeneration, making it useful as an efficient treatment for various pathological conditions caused by blocked lymphatic flow or reduced blood flow.

Description

[Technical Field]

[0001] The present invention relates to a rod-shaped biocompatible structure that promotes the flow of body fluids by capillary action, and a method for inducing the regeneration of body vessels using the same. [Background technology]

[0002] Lymphedema is an intractable chronic disease in which lymphatic fluid accumulates abnormally in the interstitial space of soft tissues due to damage to the lymphatic system. Causes of lymphedema include genetic factors (primary lymphedema), infection, cancer, and traumatic injury (primary lymphedema). Lymph nodes and lymphatic vessels are destroyed during cancer treatment, and lymphedema is frequently observed in cancer patients. When lymphedema becomes severe, the immune response becomes impaired, making even small wounds susceptible to infection, leading to life-threatening complications such as cellulitis and sepsis.

[0003] Symptoms of lymphedema include swelling of the body from localized extremities such as the arms and legs to the entire body, along with accompanying pain, numbness in the hands and feet, and sclerosis. Once symptoms appear, lymphedema is a chronic disease that continues to progress, and is currently an intractable disease for which a fundamental cure is difficult.

[0004] The number of lymphedema patients is increasing every year, with the number of patients in Korea increasing by 62% from 20,999 in 2017 to 34,025 in 2021. The incidence rate is particularly high after breast cancer, with over 74% of all patients being women. While the prevalence of lymphedema in Korea is increasing every year, conservative treatments currently include compression and physical therapy, while surgical treatments include lymphatic venous anastomosis, lymph node metastasis surgery, and lymph node resection. However, even after surgical treatment, only around 50% of patients experience improvement, resulting in limited therapeutic efficacy and a difficult complete cure. Therefore, there is a need for the development of new treatments based on regenerative medicine technology that can efficiently regenerate damaged lymph nodes and lymphatic vessels in order to address the underlying causes of lymphedema.

[0005] Numerous papers and patent documents are referenced throughout this specification, and citations are provided thereto. The disclosures of the cited papers and patent documents are incorporated herein by reference in their entirety, in order to more clearly describe the state of the art and the content of the present invention. Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have conducted extensive research and development to develop a human-inserted structure for tissue regeneration that can efficiently repair body vessels, such as lymphatic or vascular tissue, that have been structurally or functionally damaged due to various causes, including surgery, trauma, cancer, infection, or congenital developmental abnormalities. As a result, the present inventors have discovered that when a rod-shaped biodegradable structure having a cross section with a lumen that serves as a closed passageway through which body fluids, specifically lymph or blood, can flow, or a concave or convex cross section that serves as an open passageway, or a combination thereof, is implanted into the site of a damaged body vessel, it provides mechanical support by acting as a framework in the short term, promotes the smooth flow of body fluids through capillary action, and induces the regeneration of blood vessels, lymph nodes, or lymphatic vessels, thereby efficiently improving and treating various pathological conditions caused by damage to blood vessels or lymphatic vessels, including blood leakage, ischemic disease, and lymphedema. This discovery led to the completion of the present invention.

[0007] Therefore, an object of the present invention is to provide a human body insert for inducing regeneration of body vessels and a composition for treating lymphedema or ischemic disease containing the same.

[0008] Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, the claims and the drawings. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a body insert for inducing regeneration of a body vessel, comprising a rod-shaped biodegradable structure, the cross section of which comprises one or more irregularities, cavities, or a combination thereof that provide a fluid pathway for a body fluid.

[0010] The present inventors have conducted extensive research and development to develop a human-inserted structure for tissue regeneration that can efficiently repair body vessels, such as lymphatic or vascular tissue, that have been structurally or functionally damaged due to various causes, including surgery, trauma, cancer, infection, or congenital developmental abnormalities. As a result, they have discovered that when a rod-shaped biodegradable structure whose cross section has a lumen that serves as a closed passageway through which body fluids, specifically lymph or blood, can flow, or an irregularity that serves as an open passageway, or a combination thereof, is implanted into the site of a damaged body vessel, it provides mechanical support by acting as a framework in the short term, promotes the smooth flow of body fluids through capillary action, and induces the regeneration of blood vessels, lymph nodes, or lymphatic vessels, thereby efficiently improving and treating various pathological conditions caused by damage to blood vessels or lymphatic vessels, including blood leakage, ischemic disease, and lymphedema.

[0011] As used herein, the term "body vessel" refers to any tube-shaped body passage lumen tissue that provides a pathway for the movement of bodily fluids, including, but not limited to, lymphatic vessels, blood vessels, bile ducts, and urethral passages. More specifically, the body vessels that can be regenerated using the implant of the present invention are blood vessels or lymphatic vessels.

[0012] As used herein, the term "structure" refers to a tissue-engineered structure that acts as a temporary mimetic of bodily lumen tissue by placing biological cells, specifically cells derived from a damaged bodily lumen or cells involved in its repair or regeneration (e.g., stem cells), to promote tissue repair and regeneration, while providing mechanical support during the repair period to prevent re-injury of the bodily lumen, and providing a path for fluid flow.

[0013] The term "cell attachment" refers to the direct or indirect attachment of cells to a substrate or to other cells while maintaining their inherent biological activity.

[0014] As used herein, the term "transplantation" refers to the process of transferring living tissue, tissue mimics, cells, active ingredients that aid in tissue regeneration, or artificial structures that house these, from a donor to a recipient with the goal of maintaining the functional integrity of the support, tissue, or cells transplanted to the recipient. Thus, the terms "transplantation" or "implant" have the same meaning as "insertion" or "insertion."

[0015] As used herein, the term "biodegradable" refers to the property of being naturally decomposed when exposed to a physiological solution of pH 6-8, and more specifically, refers to the property of being decomposed over time in vivo by body fluids, decomposing enzymes, microorganisms, etc.

[0016] As used herein, the term "irregularities" refers to a structure in which depressions and / or protrusions intersect regularly or irregularly to form grooves on the surface. These grooves act as open fluid pathways, allowing lymphatic flow through capillary action.

[0017] According to a specific embodiment of the present invention, the cross section including the concave and convex portions is a cross section of an H-beam. In this specification, the term "H-beam" refers to a rod-shaped structure whose cross section is in the shape of the letter H.

[0018] According to a specific embodiment of the present invention, the cross section including the protrusions and recesses is a radial cross section. As used herein, the term "radial" refers to a shape in which a plurality of protrusions extend symmetrically or asymmetrically from a central point to the periphery in a spoke-like manner. Here, spaces formed between adjacent protrusions extending like spokes form grooves that function as open flow paths.

[0019] The rod-shaped biodegradable structure used in the present invention can be applied in a form in which a plurality of structures are twisted together to form a twist or braid.

[0020] In this specification, the term "twist" refers to a shape in which two or more rod-like structures are twisted in the same rotational direction.

[0021] As used herein, the term "braid" refers to a shape in which two or more of three or more rod-like structures are crossed and twisted together.

[0022] More specifically, the plurality of protrusions are in a point-symmetric relationship with respect to the center point.

[0023] According to a specific embodiment of the invention, the cross-sectional shape of the lumen is circular or polygonal.

[0024] When the structure of the present invention has a lumen, the lumen serves as a closed channel through which lymphatic fluid can flow. When the lumen is circular, it does not need to be a perfect circle geometrically, but can have a curved surface similar to a circle. When the lumen is polygonal, it may be, for example, but not limited to, a triangle, a square, a pentagon, or a hexagon. These polygons may also be regular polygons, but are not limited thereto. According to a specific embodiment, the polygonal lumen has a rectangular or square cross-sectional shape.

[0025] According to the present invention, the structure of the present invention may have a cross section in which the above-mentioned irregularities or lumens are applied selectively, or may have a cross section in which both irregularities and lumens are applied. When both irregularities and lumens are applied, the radial centers of the protrusions forming the irregularities and the center of the lumens may or may not coincide. More specifically, the radial centers of the protrusions and the lumens have the same center.

[0026] According to a specific embodiment of the present invention, the cross section of the rod-shaped biodegradable structure of the present invention has a major axis of 0.1-3.0 mm and a minor axis of 0.1-3.0 mm. If the major axis or minor axis is less than 0.1 mm, the size of the grooves caused by the unevenness is not suitable for the formation of vascular endothelial cells or lymphatic endothelial cells, and if it exceeds 3.0 mm, the high rigidity of the structure will induce severe pain in the patient. More specifically, the cross section has a major axis of 0.5-1.5 mm and a minor axis of 0.5-1.5 mm, and most specifically, a major axis of 0.8-1.2 mm and a minor axis of 0.6-0.8 mm.

[0027] According to a specific embodiment of the present invention, the area of ​​the lumen is 0.0025-6.25 mm 2 More specifically, 0.01-4.0 mm 2 and even more specifically, 0.1-0.5 mm 2 and even more specifically, 0.1-0.3 mm 2 and most specifically, 0.1-0.2 mm 2 is.

[0028] According to a specific embodiment of the present invention, the biodegradable structure of the present invention comprises a biodegradable polymer.

[0029] As used herein, the term "polymer" refers to a synthetic or natural polymeric compound in which the same or different types of monomers are sequentially linked. Therefore, polymers include homopolymers (polymers polymerized from one type of monomer) and hybrid polymers made by polymerizing at least two different types of monomers, and hybrid polymers include both copolymers (polymers made from two different types of monomers) and polymers made from more than two different types of monomers. According to the present invention, the biodegradable structure of the present invention can be a structure made from a biodegradable or biocompatible polymer.

[0030] As used herein, the term "biocompatibility" refers to the property of not causing short-term or long-term side effects when administered into a living body and comes into contact with cells, tissues, or body fluids of an organ. Specifically, this term includes not only tissue compatibility and anticoagulant compatibility, which prevent tissue necrosis or blood coagulation upon contact with living tissue or blood, but also biodegradability, which disappears after a certain period of time has passed after administration to the body.

[0031] Biodegradable or biocompatible polymers that can be used as raw materials for the biodegradable structure of the present invention include PCL [poly(caprolactone)], HEMA [poly(2-hydroxyethyl metacrylate)], PVA (polyvinyl alcohol, PEO (Polyethylene oxide), phospholipid, collagen, aliphatic polyether, PLA [poly(lactide)], PGA [poly(glycolide)], PDO [poly(dioxanone)]), PBL [poly(butyrolactone)], PVL [poly(valerolactone)], PLGA [poly(lactide-co-glycolide)], PU (polyurethane), fibronectin, vitronectin, poly(L-lysin), poly(L-glutamic acid), Poly(aspartic acid), carboxymethyl cellulose, cellulose sulfate, agarose, alginate, carrangeenan, hyaluronic acid, dextran, chitosan, poly(hydroxybutyric acid), poly(alkylene succinate), polyamide, poly(anhydride), poly(ortho-ester), poly(cyano acrylates), polyphosphazene, poly(hydroxyethyl metacrylate), poly(methyl metacrylate), poly(tetrafluoroethylene), poly(dimethylsiloxane), poly(ethyleneoxide-β-propyleneoxide), Poly(vinylmethylether), Poly(N-alkylacrylamide), decelluarized matrix (dECM), and combinations thereof.More specifically, the biodegradable polymer used in the present invention is one or more selected from the group consisting of PCL [poly(caprolactone)], PLA [poly(lactide)], PGA [poly(glycolide)], PDO [poly(dioxanone)], PBL [poly(butyrolactone)], PVL [poly(valerolactone)], and PLGA [poly(lactide-co-glycolide)].

[0032] According to a specific embodiment of the invention, the body fluid is lymph and the body vessel is a lymphatic vessel.

[0033] According to a specific embodiment of the invention, the body fluid is blood and the body vessel is a blood vessel.

[0034] According to another aspect of the present invention, there is provided a composition for treating lymphedema, which comprises the above-described human body insert of the present invention as an active ingredient.

[0035] According to yet another aspect of the present invention, there is provided a method for treating lymphedema, comprising inserting the above-described human body insert of the present invention into the body of a subject.

[0036] As used herein, the term "lymphedema" refers to a disease in which lymphatic tissue is damaged due to various causes, such as surgery, trauma, cancer, infection, or congenital developmental abnormality, causing the movement of lymphatic fluid to become impeded, resulting in excessive accumulation of lymphatic fluid in the interstitium of soft tissues such as the skin and subcutaneous tissue, resulting in abnormal expansion of the volume of an arm or leg.

[0037] As used herein, the term "treatment" means (a) inhibiting the development of a disease, disorder, or symptom; (b) alleviating a disease, disorder, or symptom; or (c) eliminating a disease, disorder, or symptom. When the composition of the present invention is implanted into an affected area of ​​a subject's body, it promotes the smooth flow of lymphatic fluid that has accumulated in specific soft tissues due to lack of circulation and induces the regeneration of damaged lymphatic vessels and lymph nodes, thereby inhibiting, eliminating, or alleviating the development of a series of symptoms caused by damage and dysfunction of lymphatic tissue. Therefore, the composition of the present invention may be used by itself to treat these diseases, or may be implanted together with other pharmacological components (e.g., stem cells capable of differentiating into lymphatic tissue) and used as an adjunct to the treatment of lymphedema. Therefore, as used herein, the terms "treatment" or "therapeutic agent" encompass the meaning of "adjunct treatment" or "adjunct treatment agent."

[0038] As used herein, the term "subject" includes, without limitation, a human, mouse, rat, guinea pig, dog, rabbit, cat, horse, cow, pig, monkey, chimpanzee, baboon, or rhesus monkey. Specifically, the subject of the present invention is a human.

[0039] In yet another aspect, the present invention provides a composition for treating ischemic diseases caused by vascular leakage or vascular damage, which comprises the above-described human body insert of the present invention as an active ingredient.

[0040] According to yet another aspect of the present invention, there is provided a method for treating ischemic diseases caused by vascular leakage or vascular damage, comprising the step of inserting the above-described human body insert of the present invention into the body of a subject.

[0041] According to the present invention, when the composition of the present invention is implanted into a damaged vascular lesion, it stabilizes the vascular wall, prevents blood leakage, and promotes the regeneration and growth of normal blood vessels, thereby effectively treating various pathological conditions caused by reduced blood flow, including ischemic tissue edema, local anemia, and ischemic tissue necrosis. [Effects of the Invention]

[0042] The features and advantages of the present invention can be summarized as follows:

[0043] (a) The present invention provides a human body implant for inducing regeneration of body vessels and a method for treating lymphedema or ischemic diseases using the same.

[0044] (b) The structure of the present invention not only provides adequate physical strength and mechanical support to prevent re-injury of body vessels such as lymphatic vessels or blood vessels during regeneration, but also mimics in structure and function body vessel tissues in vivo by promoting the flow of body fluids through capillary action using a simple rod structure with irregularities (e.g., H-shaped steel) or lumens (e.g., tubular).

[0045] (c) The structure of the present invention can be transplanted into the affected area and decomposed at an appropriate time after the completion of vascular regeneration, and can be useful as an efficient treatment for various pathological conditions caused by blockage of lymphatic flow or reduced blood flow. [Brief explanation of the drawings]

[0046] [Figure 1] FIG. 1 is a schematic diagram showing the process of lymphatic vessel normalization by applying the lymphatic vessel repair-inducing biocompatible structure of the present invention. [Figure 2a] FIG. 2a is a front view of a biocompatible structure of the present invention. [Figure 2b] FIG. 2b is a front view of the biocompatible structure of the present invention. [Figure 3a] FIG. 3a is an image obtained by ICG (indocyanine green) fluorescent staining to confirm lymphatic flow 6 weeks after implantation of the biocompatible structure of the present invention into a rabbit model. [Figure 3b] FIG. 3b shows an image obtained by ICG (indocyanine green) fluorescent staining to confirm lymphatic flow 6 weeks after implantation of the biocompatible structure of the present invention into a rabbit model. [Figure 4a]Figure 4a shows the results of tissue transplanted with the structure of the present invention extracted from an experimental animal, sectioned transversely, and then stained with H&E (hematoxylin & eosin) and MT (Masson's trichrome). [Figure 4b] Figure 4b shows the results of tissue extracted from an experimental animal into which the structure of the present invention was transplanted, sectioned longitudinally, and then stained with H&E (hematoxylin & eosin) and MT (Masson's trichrome). [Figure 5] FIG. 5 shows the results of immunofluorescence staining targeting LYVE-1 and CD31 at the site where the construct was transplanted in each experimental animal. DETAILED DESCRIPTION OF THE INVENTION

[0047] The present invention will be described in more detail with reference to the following examples. It will be obvious to those skilled in the art that these examples are merely for the purpose of explaining the present invention in more detail, and that the scope of the present invention is not limited to these examples according to the gist of the present invention.

[0048] (Example) [Manufacturing Example 1: Manufacturing of a biocompatible structure for lymphatic vessel repair] We used a 3D printer (RAISE 3D, USA) to fabricate three-dimensional polymer structures. The 3D printing method allows for easy adjustment of the size of the three-dimensional structure depending on conditions such as nozzle diameter, temperature, discharge pressure, and nozzle movement speed. We fabricated a structure with a three-dimensional structure similar to that of a lymphatic vessel by stacking strands with a height of 0.2 mm and a diameter of 0.4 mm into an H-beam and a tubular structure, respectively, as shown in Figure 2a. Polycaprolactone (PCL, Polycaprolactone, Sigma-Aldrich, USA) was used as the raw polymer. For fabrication, the nozzle diameter was set to 0.4 mm, the nozzle temperature to 130 °C, the output speed to 6 mm / s, and the nozzle movement speed to 6 mm / s. After the setup was complete, the H-beam and tubular structures were fabricated with diameters of 0.8 mm and 1 mm, and heights to 0.6 mm and 0.8 mm, respectively. They were sterilized using an e-beam before use in subsequent experiments.

[0049] [Experimental Example 1: Tensile strength evaluation] The inventors performed a tensile strength evaluation to confirm the physical properties of the lymphatic vessel-like biocompatible structure of the present invention. A universal testing machine (UNITEST M1, Korea) was used to measure the tensile strength, setting the grip distance to 65 mm and the tensile speed to 50 mm / min. Table 1 shows the tensile strength evaluation results for the H-beam biocompatible structure. Table 2 shows the tensile strength evaluation results for the tubular biocompatible structure.

[0050] [Table 1]

[0051] [Table 2]

[0052] The tensile strength evaluation results showed that the tensile strength of the H-beam biocompatible structure was 15.39 MPa and that of the tubular biocompatible structure was 15.92 MPa, indicating that the tubular biocompatible structure had a higher tensile strength.The elastic modulus of the H-beam biocompatible structure was 4.90 MPa and that of the tubular biocompatible structure was 4.19 MPa, indicating that the H-beam biocompatible structure had a higher rigidity.

[0053] [Experimental Example 2: Rabbit model animal experiment] The present inventors attempted to evaluate whether the transplantation of the lymphatic vessel-like biocompatible structure of the present invention would induce lymphatic vessel regeneration. Experiments were conducted in New Zealand white rabbits (10-week-old, female) divided into four groups: a group in which a 2cm lymphatic vessel located in the groin was resected and the remaining lymphatic vessel was sutured to the lymph node, a group in which the H-beam-shaped structure of the present invention was sutured to the lymph node and lymphatic vessel, a group in which the tubular structure of the present invention was sutured to the lymph node and lymphatic vessel, and a group with normal lymphatic vessels.

[0054] Six weeks after suturing, approximately 1 cc of 10% ICG (indocyanine green) fluorescent material was injected subcutaneously between the toes, and the lymphatic vessels and lymph nodes along the resection path were imaged to examine their flow (Figures 3a and 3b). Each animal was sacrificed, and tissue from the implanted area was extracted and sectioned transversely and longitudinally. H&E (hematoxylin and eosin) staining and Masson's trichrome (MN) staining were then performed (Figures 4a and 4b). Immunofluorescence staining was also performed for LYVE-1 (lymphatic vessel endothelial hyaluronic acid receptor 1) and CD31 (cluster of differentiation 31) antigens (Figure 5).

[0055] It was observed that the ICG used in the lymphatic flow test was well visualized from the injection site in the foot to the femoral lymphatic vessels where the resection was performed, confirming that the fluorescent reagent circulated well through each structure. This confirmed that both the H-beam structure and the tubular structure of the present invention can generally function as lymphatic vessels.

[0056] Using H&E and MT staining, it was observed that when the H-beam-shaped structure was transplanted, muscle grew around the H-beam structure, and when the tubular structure was transplanted, collagen filled the area around the structure. In the case of lymphatic vessels, the area that abuts the internal space through which lymph flows is composed of lymphatic endothelial cells, and these endothelial cells are surrounded by smooth muscle, while lymphatic capillaries are composed of lymphatic endothelial cells surrounded by collagen fibers. These aspects confirmed that the H-beam-shaped structure of the present invention mimics the shape of lymphatic vessels, and the tubular structure of the present invention mimics the shape of lymphatic capillaries, thereby efficiently inducing regeneration of lymphatic vessels and lymphatic capillaries.

[0057] Lymphatic vessel formation and regeneration are initiated by lymphatic endothelial cells, making lymphatic endothelial cells an important indicator of lymphatic vessel regeneration. LYVE-1 is a receptor present on lymphatic endothelial cells, and LYVE-1 staining can confirm the presence of lymphatic endothelial cells. Furthermore, CD31 is an adhesion molecule present primarily on platelets, leukocytes, and endothelial cells. It aids in the attachment and growth of endothelial cells and is therefore an important indicator of blood vessel formation and regeneration. Immunofluorescent staining targeting LYVE-1 and CD31 confirmed significant lymphatic endothelial cell formation around the transplanted H-beam and tubular structures, and CD31, which is involved in blood vessel formation, was also observed (Figure 5). These findings confirm that lymphatic vessel regeneration is efficiently induced in both the H-beam and tubular structures of the present invention.

[0058] Although certain parts of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the present invention. Therefore, the true scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A human body insert for inducing regeneration of a body vessel, comprising a rod-shaped biodegradable structure, the cross section of which includes one or more irregularities, cavities, or a combination thereof that provide a fluid pathway for a body fluid.

2. 2. The body insert of claim 1, wherein the cross section including the concave and convex portions is an H-beam.

3. 2. The body insert of claim 1, wherein the cross section including the concaves and convexes is radial.

4. The body insert of claim 1, wherein the lumen is circular or polygonal.

5. 2. The body insert of claim 1, wherein the cross-section has a major axis of 0.1-3.0 mm and a minor axis of 0.1-3.0 mm.

6. The body insert of claim 1, wherein the area of ​​the lumen is 0.0025-6.25 mm2.

7. 2. The human body insert according to claim 1, wherein the biodegradable structure comprises one or more biodegradable polymers selected from the group consisting of PCL [poly(caprolactone)], PLA [poly(lactide)], PGA [poly(glycolide)], PDO [poly(dioxanone)], PBL [poly(butyrolactone)], PVL [poly(valerolactone)], and PLGA [poly(lactide-co-glycolide)].

8. 2. The body insert according to claim 1, wherein the body fluid is lymphatic fluid and the body vessel is a lymphatic vessel.

9. 2. The body insert of claim 1, wherein the body fluid is blood and the body vessel is a blood vessel.

10. A composition for treating lymphedema, comprising the human body insert of claim 8 as an active ingredient.

11. A composition for treating ischemic diseases caused by vascular leakage or vascular damage, comprising the human body insert of claim 9 as an active ingredient.

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