Collagen-based artificial integrated composite vascular graft, preparation method and application

Abstract

The application belongs to the technical field of medical material preparation, and discloses a collagen-based artificial integrated composite blood vessel graft, a preparation method and application. The composite blood vessel graft is prepared by compounding a collagen tubular support and a polymer tubular framework. The collagen support is formed by electrochemical deposition and directional induction of self-assembly of type I collagen protein, the inner layer is an axial orientation dense structure (simulating the blood vessel endothelium), the middle layer is a ring / axial orientation loose porous structure (porosity 40-80%, interlayer spacing 20-100 mu m), and the thickness and inner diameter are controllable; the polymer framework is prepared by melt electrostatic direct writing, and the graft is given the characteristics of sutured, axial tensile and radial anti-expansion, and is adapted to the mechanical characteristics of the host vessel. The graft can guide the directional growth of endothelial cells / smooth muscle cells, form a layered structure and remodel the regenerated blood vessel, and maintain long-term patency.

Description

Technical Field

[0001] This invention belongs to the field of medical material preparation technology, specifically relating to a collagen-based artificial integrated composite vascular graft, its preparation method, and its application. Background Technology

[0002] Vascular diseases, particularly those affecting small-to-medium diameter (<6 mm) vessels caused by atherosclerosis, trauma, or aneurysms, pose a serious global threat to human health. For long vascular defects that cannot be repaired through direct anastomosis, the standard clinical treatment is autologous vascular transplantation (such as internal mammary artery or great saphenous vein). However, autologous transplantation has inherent drawbacks, including limited donor availability, the need for additional surgery, and the potential for donor site complications. Allogeneic or xenograft transplantation faces risks such as immune rejection, disease transmission, and unsatisfactory long-term patency rates. While synthetic grafts (such as expanded polytetrafluoroethylene or polyester) have been successfully used in large-diameter vascular reconstruction, they are prone to thrombosis, intimal hyperplasia, and restenosis in peripheral arteries with slow blood flow and small diameters due to poor blood compatibility, compliance mismatch, and lack of growth potential. Long-term patency rates are far lower than with autologous vessels.

[0003] Natural blood vessels, especially arteries, are a prime example of tissue engineering with their sophisticated layered structure and mechanical properties. Their walls typically consist of three layers: the intima, a single layer of endothelial cells in direct contact with the blood, attached to a dense, oriented basement membrane, providing anticoagulation and barrier functions; the media, primarily composed of circumferentially arranged smooth muscle cells and spirally or circumferentially arranged collagen and elastic fibers, giving the vessel radial strength, compliance, and contractile-dilate capacity; and the adventitia, mainly composed of longitudinally arranged collagen fibers and fibroblasts, providing axial support and connecting to surrounding tissues. Ideal artificial vascular grafts should mimic this natural structure as much as possible: (1) Structural biomimicry: They should have a dense, smooth, axially guiding inner surface to promote endothelialization, and a middle layer structure with controllable porosity and specific fiber orientation (circumferential / axial) to provide space and physical guidance for the adhesion, migration, orderly arrangement and tissue remodeling of smooth muscle cells; (2) Mechanical adaptation: Their radial resistance to expansion, axial tensile strength, compliance and strain enhancement behavior should match those of the host blood vessel to reduce hemodynamic disturbance and anastomotic hyperplasia; (3) Biofunctionality: The material itself should have good biocompatibility and low immunogenicity, and can be further modified to promote selective adhesion of endothelial cells, inhibit thrombus formation and excessive smooth muscle proliferation.

[0004] Type I collagen, as a major component of the extracellular matrix, is considered an ideal biomaterial for constructing tissue-engineered blood vessels due to its excellent biocompatibility, biodegradability, and ability to promote cell adhesion and migration. However, traditional collagen-based vascular graft preparation techniques (such as freeze-drying, spin coating, and molding) have significant limitations: these methods typically lead to random, disordered aggregation of collagen fibers, forming isotropic porous networks that cannot effectively mimic the ring-shaped orientation of collagen fibers in natural blood vessels. This random structure makes it difficult to provide clear directional guidance for the migration and alignment of endothelial cells and smooth muscle cells at the microscopic level, affecting rapid and orderly endothelialization and the regeneration of the functional middle membrane. More importantly, pure collagen raw materials generally suffer from insufficient mechanical properties—low strength in the wet state, poor flexibility, poor sutureability, and difficulty in maintaining a suitable pore structure while achieving sufficient mechanical strength through simple cross-linking. Furthermore, traditional methods face challenges in precisely controlling the layered structure of the vessel wall (dense inner layer / porous middle layer), inner diameter, porosity, and pore orientation.

[0005] To enhance mechanical properties and biological functions, existing technologies often employ multilayer composite or material composite strategies. However, these methods still have significant limitations in achieving biomimetic structures, controllable fabrication, and cost-effectiveness, as detailed below: 1) Relying on synthetic materials such as polyester and polyurethane, tubular structures are constructed through weaving, electrospinning, or dense coating. For example, patent CN119488382A discloses a double-layer vascular graft consisting of a woven polyester inner layer and a dense polyurethane outer layer. Although such grafts can provide immediate mechanical support, their materials are highly bioinert and lack the ability to actively guide orderly cell growth and tissue remodeling; their structures (such as woven textures and random fiber networks) are far removed from the finely oriented structure of the natural vascular extracellular matrix, making it difficult to effectively achieve the regeneration of functional endothelial and smooth muscle layers.

[0006] 2) Some technologies attempt to combine synthetic fibers with biopolymers (such as bacterial cellulose). For example, patent CN115944786A describes a bilayer graft consisting of electrospun submicron fibers and bacterial cellulose nanofibers interwoven. While this method improves biocompatibility, its structural formation relies on the physical interweaving and penetration of fibers, rather than guiding collagen to perform orderly self-assembly at the molecular level. Therefore, it cannot accurately simulate the specific orientation (axial or circumferential) of collagen fibers in natural blood vessels, and its guiding effect on cells is limited.

[0007] 3) Some solutions utilize 3D printing, melt spinning, or fiber winding techniques to construct reinforcing layers with oriented fibers. For example, patents CN104921841A and CN106075596A respectively prepare oriented microfiber layers as middle or inner layers, aiming to guide cell orientation growth. However, the "orientation" in these methods usually refers to the arrangement direction of macroscopic fiber bundles, lacking the ability to construct ordered, porous biomimetic structures at the more microscopic level of the extracellular matrix (such as collagen fibers). Cells respond to the directly contacted nano / micro-scale matrix environment; if the gaps or surfaces of macroscopic fibers lack microscopic order, their guiding efficiency will be significantly reduced. Patent CN108452383A's 3D-printed three-layer structure also suffers from similar problems; its hydrogel inner layer and nanofiber septum layer struggle to achieve the inherent orientation self-assembly of collagen fibers.

[0008] 4) In vivo engineering strategy relying on the in vivo environment: Patent CN106730030A proposes a method that uses melt-spun fibers as a framework, implanted subcutaneously in animals as a "bioreactor," relying on the host's own tissue ingrowth and secretion of extracellular matrix (mainly collagen) to construct blood vessels. Essentially, this method entrusts the synthesis and assembly of the collagen matrix to an uncontrollable in vivo environment. Its drawbacks are: high uncontrollability; the fiber arrangement, density, and pore structure of the collagen matrix formed in vivo are greatly affected by individual differences, implantation site, and inflammatory response, resulting in poor repeatability and difficulty in obtaining a consistent and optimized biomimetic structure; high cost and long cycle, requiring two surgeries (implantation and removal of the prefabricated body) and involving live animal culture, making the process complex and incurring extremely high time and economic costs; and inconsistent quality, as the generated collagen tissue may be heterogeneous, and its mechanical properties and degradation behavior are difficult to precisely control.

[0009] In summary, existing technologies share the following common drawbacks: Insufficient structural biomimicry: They generally cannot achieve customizable, ordered orientational arrangements (such as dense axial inner layers and porous circumferential / axial middle layers) at the molecular and fiber levels of collagen, thus failing to effectively simulate the layered and anisotropic structure of natural blood vessels. Poor processing controllability: Especially when collagen is involved, it is either lacking, exists in a random form, or relies on uncontrollable in vivo regeneration processes, making it impossible to manufacture precise, stable, and repeatable biomimetic structures in vitro. Cost and efficiency issues: Relying on complex processes, expensive materials (such as large-scale synthetic polymers), or time-consuming and labor-intensive in vivo engineering processes, it is difficult to achieve economical and efficient large-scale preparation.

[0010] In summary, developing a collagen-based composite vascular graft that can be precisely constructed in vitro with a biomimetic layered and fiber-oriented structure, adapts to the mechanical properties of host blood vessels, and efficiently guides orderly cell regeneration and tissue remodeling has become a core challenge that urgently needs to be overcome in this field.

[0011] Existing technologies are either limited by the materials themselves (such as the bioinertness of synthetic materials), constrained by processing methods (unable to achieve controllable orientation assembly of collagen fibers), or leave the key processes to the uncontrollable in vivo environment. None of them can provide an economical, controllable, and efficient preparation solution that can simultaneously and in one integrated manner solve the above three core problems in vitro. Summary of the Invention

[0012] To address the challenge of accurately constructing artificial vascular grafts with biomimetic structures, adaptive mechanical properties, and efficient guided regeneration capabilities in vitro, the primary objective of this invention is to provide a collagen-based integrated artificial composite vascular graft. This graft is a composite tubular structure, composed of an inner collagen tubular scaffold and an outer synthetic polymer mechanically reinforced tubular framework. The synthetic polymer mechanically reinforced framework is prepared using melt electrostatic writing (MEW) technology, and its fine microfiber tubular network provides the composite graft with essential sutureability, radial resistance to expansion, axial tensile strength, and strain-enhancing characteristics that match the host blood vessel. Collagen tubular scaffolds are fabricated using electrochemical deposition (ECD) technology to guide the self-assembly of type I collagen. Their unique feature lies in the following: the inner wall layer is a dense structure with collagen fibers highly oriented along the graft's axis, mimicking the natural vascular intima basement membrane and providing contact guidance for endothelial cell adhesion and spread; the middle layer (the main body in the thickness direction) is induced to form a loose porous structure with both circumferential and axial orientations through the application of a toroidal electric field, thus mimicking the vascular media and providing physical space and directional cues for smooth muscle cell migration, circumferential alignment, and tissue remodeling. The thickness, inner diameter, porosity (40–80%), and interlayer spacing (20–100 μm) of this collagen scaffold can all be precisely controlled.

[0013] The second objective of this invention is to provide a method for preparing a collagen-based artificial integrated composite vascular graft. This method innovatively employs a process sequence of first constructing a mechanical framework, and then guiding in-situ biomimetic collagen deposition on its inner surface. First, a tubular framework with designable mechanical properties is prepared using molten electrostatic direct writing technology as a support template. Subsequently, this framework is used as part of the working electrode (cathode), and a collagen layer with a biomimetic orientation structure is directly and directionally deposited on the framework surface using electrochemical deposition (ECD) technology to encapsulate it. This combination allows the product to not only meet the mechanical requirements in the initial implantation stage, but also, through its biomimetic structure and biological activity, efficiently guide the directional migration and orderly arrangement of host cells, promoting the regeneration and remodeling of the functional vascular layer, thereby achieving long-term patency.

[0014] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a collagen-based integrated artificial vascular graft, wherein the collagen-based integrated artificial vascular graft is a composite tubular structure, which is formed by interlocking an outer polymer tubular skeleton and an inner collagen tubular scaffold. Includes the following steps: S1. Preparation of the polymer tubular framework: 1) Melt electrostatic direct writing: Melt polymer material and deposit micron-sized fibers under a high-voltage electrostatic field; 2) Skeleton weaving and collection: By programmatically controlling the translation trajectory of the printing needle and the rotation speed of the cylindrical metal receiver, the deposited micron-sized fibers are woven on the surface of the cylindrical metal receiver to form a tubular network skeleton with a preset pattern. The skeleton is then removed from the receiver to obtain the polymer tubular skeleton. S2. Skeleton assembly: The polymer tubular skeleton is tightly fitted onto the outside of the rod-shaped conductive electrode, which serves as the cathode, together forming a composite cathode working electrode. S3. Preparation of collagen tubular scaffolds: 1) Deposition system setup: The composite cathode working electrode and the annular anode are immersed together in an acidic type I collagen solution to form a two-electrode deposition system; 2) Electrochemical directional deposition: By applying a directional electric field, collagen molecules are guided to deposit and self-assemble on the inner surface of the composite cathode working electrode with a polymer tubular framework, directly forming a collagen tubular scaffold that is tightly embedded with the polymer tubular framework. S4. Preparation of composite vascular grafts: 1) Structure induction: By adjusting the electrode configuration and electric field intensity, a circumferentially oriented microstructure is induced in the thickness direction of the collagen tubular scaffold; 2) Crosslinking fixation and post-treatment: The collagen-polymer composite structure with circumferential orientation is taken out from the acidic type I collagen solution, placed in ammonium sulfate solution for physical crosslinking and chemical crosslinking, axial pre-freezing, vacuum freeze-drying, and rod-shaped conductive electrodes are taken out to obtain collagen-based artificial integrated composite vascular grafts.

[0015] Preferably, in S1, the polymer material includes one or more of polycaprolactone, polylactic acid, polylactic acid-glycolic acid copolymer, polyurethane, and blends thereof.

[0016] Preferably, in step S1, the melting conditions are as follows: placing the polymer material in a 5mL metal heating syringe equipped with a 0.1~0.2mm needle; melting at 120-140℃ for 25~30min to obtain a uniform molten liquid polymer material; setting the printing temperature to 90~120℃ and performing electrostatic direct writing at a voltage of 1 kV; The conditions for the weaving and collection of the skeleton are as follows: a cylindrical metal receiver with a diameter of 1-6 mm is placed 8-10 mm below the needle of a metal heated syringe and rotated at a uniform speed of 50-150 rpm. The speed of the translation of the printing needle and the rotation of the receiver are controlled by the program, and the polymer material is weaved at a specific angle of ±15° to ±60° to form a tubular network skeleton. The preset pattern of the tubular network skeleton is either grid-like or spiral-like; The polymer tubular skeleton prepared has a fiber diameter of 50-60 μm, a pore size of 100-250 μm, and a thickness of 300-500 μm.

[0017] Preferably, in step S3, the preparation of the acidic type I collagen solution involves dissolving type I collagen with a mass concentration of 1-20 mg / mL in an acetic acid solution with a pH of 3-5, and then further processing it using any of the following methods: 1) Add hydrogen peroxide to make the final concentration of hydrogen peroxide 5~200μL / mL; 2) Perform vacuum degassing treatment; This yields an acidic type I collagen solution.

[0018] Preferably, in S3, the annular anode includes any one of a platinum ring mesh, a ruthenium-iridium-titanium mesh barrel, and a graphite cylinder; The radial distance between the composite cathode working electrode and the annular anode is 0.2~3cm; The electrochemical directional deposition was performed in constant current or constant voltage mode, and the deposition time was 1~60 min. The directional electric field condition is: a current density of 1~20 mA / cm². 2 Or the electric field strength is between 1 and 20 V / cm.

[0019] Preferably, in step S4, physical cross-linking is carried out in an ammonium sulfate solution with a molar concentration of 1-3 mol / L for 6-24 hours, followed by rinsing with deionized water or buffer for 5-10 seconds. The chemical cross-linking conditions are any of the following: 1) In 0.2-2% (w / v) genipin ethanol-water solution, adjust the pH to 7.0-8.5, crosslink at 30-37℃ for 6-48 h, and then rinse thoroughly with deionized water or buffer solution; 2) Crosslink in an ethanol-water solution containing 0.1-1% (w / v) glutaraldehyde for 15-120 min at room temperature, then rinse thoroughly with deionized water or buffer solution; 3) In an ethanol-water solution containing 1-3 g / L of ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and an equimolar amount of N-hydroxysuccinimide, the pH was adjusted to 5.5 with MES buffer, and crosslinked at 4°C for 12-24 h, followed by thorough rinsing with deionized water or buffer. 4) In a 1-3% (w / v) ethanol-water solution of tannic acid, adjust the pH to 8.3-8.5, crosslink at 37°C and in the dark for 30-240 min, and then rinse thoroughly with deionized water or buffer solution. 5) In a 1-3% (w / v) ethanol-water solution of proanthocyanidins, adjust the pH to 8.3-8.5, crosslink at 37°C and in the dark for 30-240 min, and then rinse thoroughly with deionized water or buffer solution. The volume fraction of the ethanol-water solution is 80-90% (v / v).

[0020] Preferably, in S4, the axial pre-freezing conditions are as follows: the chemically cross-linked sample is placed vertically with its cross-section facing down on a pre-cooled copper plate at -40°C to -80°C, and wrapped with a polytetrafluoroethylene film to isolate the low-temperature environment around the sample, so that the low temperature is conducted axially from the pre-cooled copper plate along the composite structure, guiding the ice crystals to grow axially for 1 to 4 hours. The conditions for vacuum freeze drying are as follows: the sample, after axial pre-freezing, is transferred to a freeze dryer and dried for 12 to 24 hours under the conditions of cold trap temperature below -45°C, vacuum degree below 0.1 mbar, and shelf temperature between -30°C and -10°C.

[0021] A collagen-based artificial integrated composite vascular graft is obtained by the preparation method described above.

[0022] Preferably, the inner diameter of the collagen-based integrated artificial vascular graft is 1-6 mm.

[0023] Application of a collagen-based artificial integrated composite vascular graft in the preparation of artificial vascular medical devices for repairing or replacing peripheral arteries, for coronary artery bypass grafting, or for constructing arteriovenous fistulas for hemodialysis.

[0024] Compared with the prior art, the present invention has at least the following technical effects: This invention provides a collagen-based artificial integrated composite vascular graft. The graft is a composite tubular structure in which an inner layer of collagen tubular scaffold is deposited in situ and completely encapsulates the inner surface and network pores of an outer layer of polymer (mechanically reinforced) tubular skeleton. The two are interlocked to form an integrated structure with a polymer skeleton as the mechanical support skeleton and a biomimetic collagen coating layer as the bioactive outer scaffold.

[0025] This collagen-based integrated artificial vascular graft has the following advantages: (I) Technological Innovation: Pioneering an integrated manufacturing strategy of "prioritizing the mechanical framework + in-situ collagen deposition", breaking through the bottlenecks of traditional composite processes. 1. Innovative Process Sequence: This invention abandons the existing "collagen first, reinforcement later" or simple blending and compounding approach, and pioneers a process sequence of "first preparing a mechanical framework through melt electrostatic writing (MEW), and then using it as a cathode template for in-situ electrochemical deposition (ECD) of collagen." The rigid / semi-rigid polymer framework provides a stable physical template for subsequent wet collagen deposition, significantly improving process repeatability and structural preparation accuracy, and solving the defects of random arrangement and uncontrollable structure of collagen fibers in traditional processes.

[0026] 2. Enhanced interfacial bonding: Collagen is directly deposited on the surface of the polymer skeleton and within the network pores under the action of an electric field, forming an "embedded / interlocked" integrated bond, rather than a simple physical attachment. This avoids the risk of interlayer separation from the root and ensures the structural stability of the composite graft.

[0027] 3. Independent parameter optimization: Mechanical properties (such as fiber diameter, weaving angle, and porosity controlled by MEW) and bioactivity / structure (such as electric field strength, deposition time, and solution parameters controlled by ECD) can be optimized separately in two independent steps without interference, achieving precise customization of the "mechanical-biological function" of the graft.

[0028] (II) Structural biomimicry: Constructing a dual-oriented collagen biomimetic microstructure to efficiently guide functional angiogenesis. 1. Dual-orientation collagen layer design: Through the induction of a ring-shaped electric field, the collagen layer forms a biomimetic structure of "axially dense inner layer + circumferential / axially composite oriented porous middle layer": The inner layer is a dense structure with collagen fibers highly oriented along the vascular axis, mimicking the natural vascular intima basement membrane, which can effectively guide the axial adhesion and spread of endothelial cells and promote rapid endothelialization; The middle layer is a loose porous structure with a combined circumferential and axial orientation (porosity 40-80%, interlayer spacing of 20-100 μm), which simulates the extracellular matrix of the vascular media. It provides physical space and directional clues for smooth muscle cell migration, circumferential arrangement and functionalization, and is the core basis for realizing functional vascular media regeneration.

[0029] 2. Precise and controllable structural parameters: The thickness, inner diameter, porosity, interlayer spacing and fiber orientation of the collagen layer can all be precisely controlled through ECD process parameters, which solves the technical defects of the existing collagen-based vascular graft structure that are uncontrollable from the nanoscale to the macroscale.

[0030] (III) Mechanical adaptability: The mechanical properties can be designed to balance immediate support and long-term tissue remodeling. 1. Excellent immediate mechanical properties: The outer MEW polymer skeleton can be customized according to the mechanical requirements of the target blood vessel (such as coronary artery, peripheral artery), providing sufficient radial anti-expansion strength (preventing aneurysm), good axial tensile strength (matching vascular pulsation), excellent sutureability, and strain reinforcement behavior can match the host blood vessel, reducing anastomotic intimal hyperplasia caused by mechanical mismatch.

[0031] 2. Controllable and coordinated degradation characteristics: The degradation rate of the collagen layer (6-18 months) can be regulated by cross-linking technology, and the degradation cycle of the polymer skeleton (12-36 months or longer) can be independently designed by material selection; the degradation rates of both are coordinated with the tissue regeneration rate, providing temporary mechanical support while gradually giving way to newly formed autologous tissue, thus achieving long-term vascular patency.

[0032] (iv) Biocompatibility and industrialization: High biosafety and potential for standardized large-scale production. 1. Excellent biocompatibility: Using type I collagen as the core bioactive material, it ensures good cell affinity and low immunogenicity of the graft, reducing the risk of immune rejection after implantation.

[0033] 2. Controllable manufacturing in vitro: The entire preparation process is completed in vitro, avoiding uncontrollable factors such as inflammatory reactions and differences in cell infiltration in in vivo engineering technology, ensuring the consistency of product performance between batches; at the same time, it eliminates the dependence on live animals / in vivo culture, significantly shortens the production cycle, reduces manufacturing costs, and the product can be sterilized and stored and used immediately in clinical practice, which is in line with the application process of conventional medical devices.

[0034] (V) Technological Breakthrough: Systematically Solving Key Bottlenecks in the Field of Small-Diameter Artificial Blood Vessels This invention utilizes a "MEW+ECD" in vitro integrated manufacturing strategy to construct a designable mechanical framework and a biomimetic collagen layer in one integrated manner, achieving the following simultaneously in a single product: ① excellent immediate mechanical properties to meet the clinical needs in the early stages of implantation; ② a biomimetic microenvironment that promotes the regeneration of functional tissues, solving the problem of long-term patency; ③ the potential for standardized mass production, breaking through the core bottleneck of existing technologies where "mechanical and biological functions are difficult to balance and the production process is uncontrollable," providing a feasible solution for the clinical translation of small-diameter artificial blood vessels.

[0035] In summary, the technological innovations include: the "mechanical framework first, then in-situ collagen deposition" sequence, which solves the problems of weak interlayer bonding and uncontrollable structure; the biomimetic structure: the dual-oriented collagen layer accurately simulates the natural blood vessel structure, providing core support for functional regeneration; and the balanced performance: the mechanical properties are designable and the degradation is controllable, and the in vitro manufacturing achieves standardized production, systematically breaking through the technical bottleneck of small-diameter artificial blood vessels. Attached Figure Description

[0036] Figure 1 Here are schematic diagrams and physical images of the electrode device used in Example 3; Figure 2 The images show the PCL skeleton-collagen composite artificial blood vessel prepared in Example 3 after freeze-drying and in a hydrated state. Figure 3 Optical photographs of composite artificial blood vessels cross-linked using different cross-linking methods prepared in Example 4 after being immersed in PBS solution for 12 hours; Figure 4 A schematic diagram of the orientation freezing device constructed in Example 5; Figure 5 Scanning electron microscope (SEM) images of the longitudinal and cross-sectional tube walls of the collagen layer prepared by electrochemical deposition in Example 5, with a scale bar of 100 μm. Figure 6 The image shows a cross-sectional scanning electron microscope image of the PCL skeleton-collagen composite artificial blood vessel prepared in Example 6, with a scale bar of 100 μm. Figure 7 The image shows the carotid artery ultrasound results of the PCL skeleton-collagen composite artificial blood vessel rat transplantation model prepared in Example 6. Detailed Implementation

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0038] All the devices provided in this application can be obtained by existing devices. Although device diagrams are provided, they are only for the purpose of clarifying the explanation of the technology and not for protecting the key points. Therefore, no CAD diagrams are provided.

[0039] One specific embodiment of the present invention is as follows: Application of a collagen-based artificial integrated composite vascular graft in the preparation of medical devices for repairing or replacing peripheral arteries, for coronary artery bypass grafting, as a substitute for natural blood vessels, or for constructing arteriovenous fistulas for hemodialysis.

[0040] The application process for non-therapeutic purposes is as follows: the collagen-based artificial integrated composite vascular graft is implanted into the vascular defect or lesion site for bridging, replacement or bypass transplantation.

[0041] Specifically, it includes the following steps: (1) Preoperative preparation: Select a suitable composite vascular graft based on the diameter of the host blood vessel and the length of the defect. Soak the graft in sterile saline or an antibiotic-containing solution for 1-10 minutes to soften it.

[0042] (2) Cutting and trimming: Use sterile surgical scissors to cut the graft to the required length. Check the adhesion between the collagen layer and the polymer skeleton at the port and make gentle trimmings if necessary.

[0043] (3) Anastomosis and implantation: Using standard vascular surgical anastomosis techniques (such as continuous or interrupted sutures) and non-absorbable or absorbable sutures, the two ends of the graft are anastomosed end-to-end or end-to-side to the severed ends of the host blood vessel. During anastomosis, the outer polymer skeleton provides the main suture strength.

[0044] (4) Postoperative recovery: After implantation, the collagen layer inside the graft will guide the migration, proliferation and orderly arrangement of host endothelial cells and smooth muscle cells, gradually forming neovascular tissue. The collagen component gradually degrades within 6 to 18 months, while the polymer skeleton, depending on its material properties, can provide support and slowly degrade within 12 to 36 months or longer, ultimately achieving complete remodeling and regeneration of blood vessels.

[0045] I. The reaction and structural formation principle of this collagen-based integrated artificial vascular graft: 1. Construction Principle of Polymer Mechanical Reinforcement Framework: Melt Electrostatic Writing (MEW) technology utilizes a high-voltage electrostatic field to stretch and refine a polymer melt jet. By programmably controlling the translation of the needle and the rotation of the receiving device, the microfibers formed by the solidified jet can be printed and deposited in a preset pattern (such as a grid or spiral), thereby directly weaving a three-dimensional tubular network framework with specific pore structure, pore size, and fiber orientation. The mechanical properties of this framework (such as modulus, strength, and compliance) can be precisely controlled by the fiber diameter, printing angle, number of layers, spacing, and the polymer material itself.

[0046] 2. Principle of Directional Assembly and Deposition of Collagen Fibers under an Electric Field: During electrochemical deposition (ECD), the applied electric field drives positively charged collagen molecules (in acidic solution) to migrate and accumulate towards the cathode (i.e., the electrode coated with a polymer backbone). At the cathode interface, electrochemical reactions (such as water reduction to produce OH-) occur. - This leads to a local increase in pH, neutralizing the charge on collagen molecules and thus weakening the electrostatic repulsion between molecules. This promotes the directional self-assembly of collagen molecules through supramolecular interactions such as hydrogen bonding and hydrophobic interactions, forming nanofibers that further stack into a macroscopically oriented gel layer. The fiber alignment is influenced by the direction of the electric field lines.

[0047] 3. Principle of Collagen Circumorientation Structure Induced by a Ring-shaped Electric Field: When a ring-shaped anode is used, the resulting electric field is radially distributed around the cathode (rod-shaped electrode), and the electric field lines have a significant circumorientation component. Collagen molecules / fibers deposited in this electric field environment are guided by this circumorientation component during self-assembly, thus exhibiting a preferential circumorientation tendency in a plane perpendicular to the axial direction. Combining deposition kinetics with the directional growth of ice crystals during subsequent freeze-drying, a stable porous layered structure with a combined circumorientation and axial orientation can ultimately be formed along the thickness direction of the collagen layer.

[0048] 4. The composite principle of collagen layer and polymer backbone: During electrodeposition, the polymer backbone acts as an extended surface of the cathode. Collagen molecules not only deposit on its smooth inner surface but also, driven by the electric field, infiltrate into the micron-scale network pores of the backbone for assembly. This "in-situ growth" mode allows collagen gel and polymer fibers to interpenetrate and interlock at the microscale, forming a strong physicochemical bond through subsequent cross-linking reactions, thus achieving an integrated composite structure rather than a simple physical stacking.

[0049] Example 1: Preparation of a polycaprolactone (PCL) tubular mechanically reinforced framework (MEW) (1) Material preparation: The biodegradable polymer polycaprolactone (PCL, Mn=80,000) particles were dried in an oven at 28°C for 4 hours to remove moisture.

[0050] (2) A commercial electrostatic melt-writing system was used. The dried PCL particles were loaded into a metal syringe heated to 120°C and melted for 30 minutes. The printhead temperature was set to 100°C, and the receiver (a stainless steel cylinder, 3 mm in diameter) temperature was set to 25°C. Process parameters were set as follows: applied voltage 1 kV, distance between the syringe needle tip and the receiver surface 10 mm, receiver rotation speed 70 rpm, and needle reciprocating along the collector axis at a speed of 11 mm / s.

[0051] (3) Reinforcement Weaving and Collection: The equipment is started, and the molten PCL fibers are printed under program control at an angle of ±45° to the receiver axis to form a mesh structure. Printing continues for 30 minutes to obtain a uniform tubular fiber network. After printing, the PCL tubular skeleton is carefully removed from the stainless steel receiver after being moistened with 75% ethanol, resulting in a flexible porous tubular skeleton with an inner diameter of approximately 3 mm, a wall thickness of approximately 350 μm, a fiber diameter of approximately 60 ± 3 μm, and a pore size of approximately 200 ± 50 μm. It is then placed in a desiccator for later use.

[0052] Example 2: Preparation of Collagen Solution 2.1 Prepare a 0.05 M glacial acetic acid solution.

[0053] 2.2 Type I collagen (derived from bovine Achilles tendon, purchased from a biotechnology company) was dissolved in the above acetic acid solution at a concentration of 15 mg / mL and magnetically stirred overnight at 4°C to ensure complete dissolution. The pH of the collagen solution was slowly adjusted to 3.6 using 1 M NaOH solution. Subsequently, the solution was centrifuged at 8000 rpm for 10 min at 4°C to remove air bubbles. To reduce the side reaction of air bubbles during electrodeposition, 30% hydrogen peroxide solution was added to the solution to a final concentration of 100 μL / mL, mixed well, and then placed in an ice-water bath for later use.

[0054] Example 3: In-situ electrochemical deposition and cross-linking of collagen layers within a PCL framework (composite graft preparation) like Figure 1 The figures shown are schematic diagrams and actual images of the electrode setup used. Among them, (a) is an actual image of a PCL tubular framework tightly fitted onto a titanium rod as a composite working electrode, (b) is a schematic diagram of the electrochemical deposition system, and (c) is an actual image of the electrochemical deposition system.

[0055] The results show that (1) electrode assembly: the PCL tubular skeleton prepared in Example 1 is tightly fitted onto a titanium rod with a diameter of 3 mm and a smooth surface, ensuring that the two are in close contact, and this serves as the composite working electrode (cathode). Figure 1 As shown in Figure a, the scale bar is 1 cm.

[0056] (2) Deposition system setup: A two-electrode system is used. For example... Figure 1 In diagram b, the electrochemical deposition system is shown below. Figure 1 Figure c shows a physical diagram of the electrochemical deposition system. Using the aforementioned composite electrode as the cathode, a spring-shaped platinum wire with an inner diameter of 20 mm and a single-turn pitch of 10 mm is used as the anode, coaxially sleeved outside the composite cathode. The two electrodes are vertically fixed in the electrodeposition tank, and the radial distance between the anode and the outer surface of the composite cathode is adjusted to approximately 10 mm.

[0057] (3) Electrochemical deposition: The assembled electrode system was immersed in the cooled collagen solution prepared in Example 2. A constant current power supply was connected, and the current density was 6 mA / cm². 2 Electrochemical deposition was performed for 15 minutes under conditions (calculated based on the effective deposition surface area of ​​the titanium rod). During the deposition process, a transparent gel layer was observed to gradually form on the cathode surface.

[0058] (4) Crosslinking and fixation: After deposition, the composite electrode structure with the collagen gel layer was removed from the solution and gently rinsed with deionized water. Then, it was physically crosslinked by immersing it in a 3 mol / L ammonium sulfate solution for 12 h. Then, it was crosslinked by immersing it in a 90% ethanol aqueous solution of 1% (w / v) tannic acid in a constant temperature shaker at 37°C in the dark for 2 hours.

[0059] (5) Cleaning and post-treatment: After cross-linking, rinse the sample with plenty of deionized water to remove residual tannic acid. Then, place the entire sample in an ultra-low temperature freezer at -80℃ for 4 hours for pre-freezing.

[0060] (6) Freeze-drying and demolding: The pre-frozen sample was transferred to a freeze dryer and dried for 12 hours at a cold trap temperature of -50°C and a vacuum degree of <0.1 mbar. After drying, the titanium rod inside was carefully rotated out of the PCL-collagen composite tube to obtain the final composite vascular graft.

[0061] like Figure 2 The images shown are of the prepared PCL skeleton-collagen composite artificial blood vessel after freeze-drying and in a hydrated state. (a) shows the freeze-dried state of the vessel wall layer, and (b) shows the hydrated state of the vessel wall layer. The scale bar is 1 cm.

[0062] Example 4: Comparison of different crosslinking methods A PCL composite electrode with a deposited collagen gel layer was prepared according to steps (1)-(3) of Example 3. The electrode was then treated using the following three crosslinking methods: (1) Glutaraldehyde crosslinking group (GA): The sample was immersed in 0.625% (w / v) glutaraldehyde in 90% ethanol-water solution and crosslinked at room temperature for 2 hours. Then it was rinsed 3 times with 70% ethanol solution for 10 min each time, and then immersed in PBS buffer for 24 hours to remove residual crosslinking agent.

[0063] (2) EDC / NHS crosslinking group: The sample was immersed in 50 mM MES buffer (pH 5.5) containing 50 mM EDC and 10 mM NHS and crosslinked at 4°C for 24 hours. The reaction was then terminated with 0.1 M Na2HPO4 solution (pH 9.0) for 2 hours and then rinsed thoroughly with deionized water.

[0064] (3) Proanthocyanidins (PAs): The sample was immersed in 1% (w / v) proanthocyanidins in 90% (v / v) ethanol-water solution, the pH was adjusted to 8.3-8.5, crosslinked at 37°C for 12 hours, and then rinsed thoroughly with deionized water or PBS.

[0065] All groups subsequently underwent the same freeze-drying and demolding process.

[0066] The effects of different cross-linking methods on the cross-linking strength of composite grafts were compared by a swelling test conducted after immersion in PBS solution for 12 hours.

[0067] like Figure 3 The image shown is an optical photograph of composite artificial blood vessels cross-linked using different cross-linking methods after being immersed in PBS solution for 12 hours.

[0068] Results combined Figure 3 It is known that cross-linking of GA or PAs can significantly improve the mechanical strength and morphological retention of composite grafts compared to cross-linking of EDC / NHS.

[0069] Example 5: Collagen layer regulation with circumferential / axially oriented porous structure This embodiment aims to demonstrate how to induce circumferential structures by altering the deposition electric field and subsequent treatment.

[0070] (1) Repeat steps (1)-(3) of Example 3, but in the electrodeposition step, replace the anode with a more precise platinum ring (20 mm inner diameter) that is highly coaxial with the cathode, and apply an additional, slowly rotating cathode assembly (e.g., 5 rpm) motion to enhance the uniformity of the ring electric field.

[0071] (2) After deposition and cross-linking, the sample is not directly freeze-dried, but is placed in a specially designed directional freezing device (e.g., Figure 4 The diagram shows a schematic of the constructed orientation freezing device. This device brings the sample into radial (i.e., the tube wall thickness direction) contact with a -20°C cold stage, while the sample interior (tube cavity) is exposed to room temperature air, thus establishing a radial temperature gradient within the tube wall. Pre-freezing under these conditions for 2 hours induces the radial (i.e., circumferential) growth of ice crystals.

[0072] (3) Then vacuum freeze drying is performed.

[0073] like Figure 5 The image shows scanning electron microscope (SEM) images of the longitudinal and cross-sectional sections of the collagen layer prepared by electrochemical deposition. The scale bar is 100 μm.

[0074] Results combined Figure 5 It can be seen that the longitudinal section of the collagen layer of the final product (SEM) was examined using a scanning electron microscope (SEM). Figure 5 a) and cross section ( Figure 5 Observation in b) clearly shows a layered porous structure with alternating light and dark areas, which is different from simple axial deposition. The pores also show a certain orientation in the circumferential direction, confirming the formation of a circumferential / axial composite orientation structure.

[0075] Example 6: Performance Characterization and In Vivo Functional Evaluation of Composite Vascular Grafts The composite vascular grafts prepared according to the method described in Example 1 were systematically characterized and their in vivo functional evaluation in animals was performed as follows: 1. Morphological and structural characterization The surface and cross-sectional morphology of the freeze-dried samples were observed using scanning electron microscopy (SEM).

[0076] like Figure 6 The image shown is a cross-sectional scanning electron microscope image of the prepared PCL skeleton-collagen composite artificial blood vessel. The scale bar is 100 μm.

[0077] Results combined Figure 6 As can be seen from the macroscopic structure, the graft exhibits a complete and continuous tubular morphology with uniform tube walls.

[0078] Microscopic composite structure: Cross-sectional SEM images clearly show that the outer layer is a grid-like support framework woven from regular polycaprolactone (PCL) microfibers with uniform fiber diameter and interconnected pores; the inner layer is a collagen layer that not only completely covers the PCL fiber framework but also densely fills its grid pores, forming a tight physical interlocking.

[0079] Fine structure of the collagen layer: The inner surface of the collagen layer in contact with the lumen is dense and smooth, with visible fibrous textures arranged along the axial direction. The cross-section of the collagen layer exhibits a porous structure with obvious layered characteristics, with interconnected pores and uniform interlayer spacing, confirming the circumferential / axial composite orientation biomimetic structure induced by a ring electric field.

[0080] 2. Animal in vivo experimental evaluation 2.1 Animal Model Establishment and Surgical Implantation Healthy male Sprague-Dawley (SD) rats (n=6) weighing 250-300g were selected. After anesthesia, a 2cm long common carotid artery was dissected from one side. The autologous blood vessel was passed through a polyethylene (PE) catheter (approximately 1.2mm outer diameter), and the end was everted and fixed to the catheter. A composite blood vessel with an inner diameter of 1.5mm was cut to a length of 1cm and placed over the outer layer of the PE catheter, then knotted and fixed to ensure that the intima of the autologous blood vessel adhered to the inner wall of the composite blood vessel. SD rats were allowed free movement and feeding 12 hours after surgery and were given standard care.

[0081] 2.2 Patency rate and hemodynamic monitoring Postoperative monitoring was performed regularly using a high-frequency small animal ultrasound imaging system.

[0082] like Figure 7 The image shows the carotid artery ultrasound results of a rat model transplanted with a PCL skeleton-collagen composite artificial blood vessel. (a) shows the result 1 month post-transplantation; (b) shows the result 3 months post-transplantation; and (c) shows the result 6 months post-transplantation.

[0083] Results combined Figure 7 It can be seen that 1 month postoperatively (a): all implanted grafts (6 / 6) remained patent, ultrasound showed unobstructed blood flow in the lumen, smooth anastomosis, and no significant stenosis or aneurysm formation.

[0084] Three months post-operation (b): The graft patency rate was 83.3% (5 / 6), with one case of occlusion due to local thrombosis at the anastomosis site. Continuous and uniform blood flow signals were observed within patent grafts, and the vessel walls pulsated well with the cardiac cycle.

[0085] Six months post-operation (c): patency rate remained at 83.3% (5 / 6). Ultrasound imaging showed that the graft lumen diameter remained stable, matched well with adjacent autologous vessels, and no progressive stenosis or dilation was observed. The blood flow spectrum was similar to that of normal arteries.

[0086] 2.3 Organizational Remodeling and Regeneration Analysis Graft specimens were obtained at 1, 3, and 6 months post-surgery for histological (H&E, Masson trichrome staining) and immunofluorescence staining analysis.

[0087] One month post-surgery: H&E staining showed a monolayer of cells covering the inner wall of the tube. Masson staining revealed the initial deposition of blue, newly formed collagen within the graft wall. Immunofluorescence (CD31 / α-SMA) showed endothelial cells (CD31... + ) form localized adhesions on the vessel wall, smooth muscle cells (α-SMA) + The infiltration begins at both ends of the anastomosis and progresses towards the middle of the graft.

[0088] Three months post-surgery: The vessel wall thickens, and the cells and matrix become more abundant. CD31-positive cells form a continuous and complete endothelial layer on the inner surface of the lumen. The number of α-SMA-positive cells increases significantly, and they show a clear circumferential arrangement trend in the middle layer of the vessel wall, beginning to mimic the structure of the natural vascular media.

[0089] Six months post-surgery: The graft has largely completed host remodeling. Histological examination revealed a clear layered structure: an inner layer of dense endothelium, a middle layer of neomembranous media rich in circularly arranged smooth muscle cells, and an outer layer of connective tissue integrated with surrounding tissues. Immunofluorescence further confirmed that α-SMA-positive cells exhibited a highly ordered circular arrangement. Simultaneously, some PCL fibers remained, undergoing slow degradation, without significant chronic inflammation or pathological calcification.

[0090] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a collagen-based integrated artificial vascular graft, characterized in that, The collagen-based artificial integrated composite vascular graft is a composite tubular structure, which is formed by the interlocking of an outer polymer tubular skeleton and an inner collagen tubular scaffold. Includes the following steps: S1. Preparation of the polymer tubular framework: 1) Melt electrostatic direct writing: Melt polymer material and deposit micron-sized fibers under a high-voltage electrostatic field; 2) Skeleton weaving and collection: By programmatically controlling the translation trajectory of the printing needle and the rotation speed of the cylindrical metal receiver, the deposited micron-sized fibers are woven on the surface of the cylindrical metal receiver to form a tubular network skeleton with a preset pattern. The skeleton is then removed from the receiver to obtain the polymer tubular skeleton. S2. Skeleton assembly: The polymer tubular skeleton is tightly fitted onto the outside of the rod-shaped conductive electrode, which serves as the cathode, together forming a composite cathode working electrode. S3. Preparation of collagen tubular scaffolds: 1) Deposition system setup: The composite cathode working electrode and the annular anode are immersed together in an acidic type I collagen solution to form a two-electrode deposition system; 2) Electrochemical directional deposition: By applying a directional electric field, collagen molecules are guided to deposit and self-assemble on the inner surface of the composite cathode working electrode with a polymer tubular framework, directly forming a collagen tubular scaffold that is tightly embedded with the polymer tubular framework. S4. Preparation of composite vascular grafts: 1) Structure induction: By adjusting the electrode configuration and electric field intensity, a circumferentially oriented microstructure is induced in the thickness direction of the collagen tubular scaffold; 2) Crosslinking fixation and post-treatment: The collagen-polymer composite structure with circumferential orientation is taken out from the acidic type I collagen solution, placed in ammonium sulfate solution for physical crosslinking and chemical crosslinking, axial pre-freezing, vacuum freeze-drying, and rod-shaped conductive electrodes are taken out to obtain collagen-based artificial integrated composite vascular grafts.

2. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In S1, the polymer material includes one or more of polycaprolactone, polylactic acid, polylactic acid-glycolic acid copolymer, polyurethane and its blends.

3. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In step S1, the melting conditions are as follows: placing the polymer material in a 5mL metal heating syringe equipped with a 0.1~0.2mm needle; melting at 120-140℃ for 25~30min to obtain a uniform molten liquid polymer material; setting the printing temperature to 90~120℃ and performing electrostatic direct writing at a voltage of 1 kV; The conditions for the weaving and collection of the skeleton are as follows: a cylindrical metal receiver with a diameter of 1-6 mm is placed 8-10 mm below the needle of a metal heated syringe and rotated at a uniform speed of 50-150 rpm. The speed of the translation of the printing needle and the rotation of the receiver are controlled by the program, and the polymer material is weaved at a specific angle of ±15° to ±60° to form a tubular network skeleton. The preset pattern of the tubular network skeleton is either grid-like or spiral-like; The polymer tubular skeleton prepared has a fiber diameter of 50-60 μm, a pore size of 100-250 μm, and a thickness of 300-500 μm.

4. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In step S3, the preparation of the acidic type I collagen solution involves dissolving type I collagen with a mass concentration of 1-20 mg / mL in an acetic acid solution with a pH of 3-5, and then further processing it using any of the following methods: 1) Add hydrogen peroxide to make the final concentration of hydrogen peroxide 5~200μL / mL; 2) Perform vacuum degassing treatment; This yields an acidic type I collagen solution.

5. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In S3, the annular anode includes any one of a platinum ring mesh, a ruthenium-iridium-titanium mesh barrel, and a graphite cylinder; The radial distance between the composite cathode working electrode and the annular anode is 0.2~3cm; The electrochemical directional deposition was performed in constant current or constant voltage mode, and the deposition time was 1~60 min. The directional electric field condition is: a current density of 1~20 mA / cm². 2 Or the electric field strength is between 1 and 20 V / cm.

6. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In step S4, physical cross-linking is carried out in an ammonium sulfate solution with a molar concentration of 1-3 mol / L for 6-24 h, followed by rinsing with deionized water or buffer for 5-10 s; The chemical cross-linking conditions are any of the following: 1) In 0.2-2% (w / v) genipin ethanol-water solution, adjust the pH to 7.0-8.5, crosslink at 30-37℃ for 6-48 h, and then rinse thoroughly with deionized water or buffer solution; 2) Crosslink in an ethanol-water solution containing 0.1-1% (w / v) glutaraldehyde for 15-120 min at room temperature, then rinse thoroughly with deionized water or buffer solution; 3) In an ethanol-water solution containing 1-3 g / L of ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and an equimolar amount of N-hydroxysuccinimide, the pH was adjusted to 5.5 with MES buffer, and crosslinked at 4°C for 12-24 h, followed by thorough rinsing with deionized water or buffer. 4) In a 1-3% (w / v) ethanol-water solution of tannic acid, adjust the pH to 8.3-8.5, crosslink at 37°C and in the dark for 30-240 min, and then rinse thoroughly with deionized water or buffer solution. 5) In a 1-3% (w / v) ethanol-water solution of proanthocyanidins, adjust the pH to 8.3-8.5, crosslink at 37°C and in the dark for 30-240 min, and then rinse thoroughly with deionized water or buffer solution. The volume fraction of the ethanol-water solution is 80-90% (v / v).

7. The method for preparing a collagen-based integrated artificial vascular graft according to claim 1, characterized in that, In S4, the axial pre-freezing conditions are as follows: the chemically cross-linked sample is placed vertically with its cross-section facing down on a pre-cooled copper plate at -40°C to -80°C, and wrapped with a polytetrafluoroethylene film to isolate the low-temperature environment around the sample, so that the low temperature is conducted axially from the pre-cooled copper plate along the composite structure, guiding the ice crystals to grow axially for 1 to 4 hours. The conditions for vacuum freeze drying are as follows: the sample, after axial pre-freezing, is transferred to a freeze dryer and dried for 12 to 24 hours under the conditions of cold trap temperature below -45°C, vacuum degree below 0.1 mbar, and shelf temperature between -30°C and -10°C.

8. A collagen-based integrated artificial composite vascular graft, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 7.

9. The collagen-based integrated artificial composite vascular graft according to claim 8, characterized in that, The inner diameter of the collagen-based artificial integrated composite vascular graft is 1-6 mm.

10. The use of a collagen-based artificial integrated composite vascular graft as described in claim 8 or 9 in the preparation of artificial vascular medical devices for repairing or replacing peripheral arteries, for coronary artery bypass grafting, or for constructing arteriovenous fistulas for hemodialysis.

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