A Degradable Hydrogel-Coated Spring Coil Based on Zinc-Iron-Copper Alloy and Its Preparation Method

Abstract

The present invention discloses a degradable hydrogel-coated coil based on a zinc-iron-copper alloy and a preparation method thereof. The degradable hydrogel-coated coil includes a coil body. Among them, a hydrogel drug-loading coating is coated on the surface of the coil body, and an anti-unwinding wire is arranged inside the coil body. The material of the coil body contains the following components by mass percentage: 58.5% - 90.25% of zinc element; 1.9% - 7.6% of iron element; 0.65% - 1.9% of copper element; 5% - 35% of platinum-tungsten powder. The degradable hydrogel-coated coil based on a zinc-iron-copper alloy and the preparation method thereof provided by the present invention have completely degradable performance, good biocompatibility, dense packing property, good imaging performance and are safe and reliable.

Description

Technical Field

[0001] The present invention relates to a minimally invasive interventional medical device and a preparation method thereof, and particularly relates to a degradable hydrogel-coated coil based on a zinc-iron-copper alloy and a preparation method thereof. Background Art

[0002] Aneurysms, gastrointestinal bleeding, tumors, hypervascular tumors, etc. are common hemorrhagic diseases of arteries. Taking aneurysms as an example, if the aneurysm ruptures, the patient's life may be endangered. In the past, the treatment of such diseases often required surgical methods, which had relatively high risks and traumas, especially for elderly patients. With the progress and development of medical technology, endovascular interventional treatment has become the preferred treatment option for such diseases. Among many treatment options, coil embolization treatment stands out due to its advantages such as safety, reliable implantation, convenient delivery, etc., and is favored by doctors and researchers.

[0003] Currently, coil embolization devices can be divided into bare metal coils and surface-modified coils according to materials and structures. Bare metal coils are the coils with the longest development history and the most commonly used in clinics. The coil body material is platinum-tungsten alloy, which has a self-metal imaging function and good biocompatibility. After being implanted into the lesion, it occludes the lesion site through the thrombus mechanism to achieve the treatment effect. Surface-modified coils are further divided into bioactive surface-coated coils, hydrogel coils, and coils with fiber tufts. Bioactive surface-coated coils refer to coating the surface of bare metal coils with drug coatings having a thrombus-promoting effect, such as prothrombin complex, vitamin K, reptilase, and protamine sulfate, etc.; hydrogel coils refer to having a hydrogel filament core in the coil or a hydrogel coating on the coil surface. After contacting with blood, it expands, increasing the packing property of the device. At the same time, the additional expansion of the hydrogel volume increases the filling rate of the lesion, and the implantation amount of the coil can be reduced; coils with fiber tufts refer to having high-molecular materials such as nylon, polypropylene, polytetrafluoroethylene, and poly(glycolide-co-lactide) (PGLA) embedded outside the coil body. Through the mechanical overlap of microfibers, a dense network is built at the lesion site to change the hemodynamics and achieve the effect of rapid and stable thrombosis. Currently, the coil body materials of all coils used clinically are 100% platinum-tungsten alloy and do not have degradable properties. After the implant reaches the lesion, although blood supply is inhibited due to mechanical occlusion or thrombus mechanism, the implant will remain in the body permanently. For aneurysms, the implantation of metal coils cannot shrink the aneurysm body, so it will continuously compress the nerve tissue outside the aneurysm, and the mass effect cannot be eliminated. The long-term implantation of metal materials may also produce metal toxicity, causing certain damage to the human body, and its long-term safety still needs to be investigated. In addition, the metal artifacts will also affect the image quality during postoperative follow-up, bringing some inconvenience to clinicians.

[0004] At present, there are patent documents mentioning the use of magnesium-based alloys to prepare degradable coils, but the degradation rate of magnesium alloys in the body is too fast, and they may have been completely degraded before the embolization treatment effect is achieved at the lesion site. There are also patent documents mentioning the use of poly-L-lactic acid (PLLA) sutures to wind and prepare degradable coils, but the physical strength of this kind of coil needs to be investigated and whether it has good imaging effect is still unknown.

[0005] Therefore, to solve the above problems, it is of great significance to develop a medical coil with degradable performance, good biocompatibility, dense packing property, good imaging performance and safety and reliability. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a degradable hydrogel-coated coil based on zinc-iron-copper alloy and its preparation method, which has degradable performance, good biocompatibility, dense packing property, good imaging performance and safety and reliability.

[0007] The technical solution adopted by the present invention to solve the above technical problems is to provide a degradable hydrogel-coated coil based on zinc-iron-copper alloy, including a coil body. Among them, a hydrogel drug-loading coating is coated on the surface of the coil body, an anti-unwinding wire is arranged inside the coil body, and the material of the coil body contains the following components by mass percentage:

[0008] Zinc element: 58.5%-90.25%;

[0009] Iron element: 1.9%-7.6%;

[0010] Copper element: 0.65%-1.9%;

[0011] Platinum-tungsten powder: 5%-35%.

[0012] Further, the material of the coil body contains the following components by mass percentage:

[0013] Zinc element: 68.5%-85%;

[0014] Iron element: 3%-5.8%;

[0015] Copper element: 0.8%-1.55%;

[0016] Platinum-tungsten powder: 10%-25%.

[0017] Further, in the platinum-tungsten powder, platinum accounts for 92% of the total mass percentage and tungsten accounts for 8%.

[0018] Further, the wire diameter range of the coil body is between 0.02-0.2 mm, the diameter of the first-level coil is between 0.05-1 mm, and the diameter of the second-level spiral coil is between 0.2-5 mm.

[0019] Furthermore, the material of the anti-unwinding wire is any one of polypropylene, polyethylene, polyisoprene, nitinol alloy, magnesium alloy, and poly(p-dioxanone).

[0020] Furthermore, the thickness of the hydrogel drug-loading coating is 0.01 - 1 mm; the hydrogel drug-loading coating is any one of polyacrylic acid gel coatings, polyacrylamide gel coatings, polycarbonate gel coatings, polyurethane gel coatings, amphiphilic block copolymer gel coatings, transparent acetate gel coatings, chitosan gel coatings, alginate gel coatings, polyethylene glycol gel coatings, polyvinyl alcohol gel coatings, and carrageenan gel coatings.

[0021] The present invention also provides a preparation method of the above-mentioned degradable hydrogel-coated coil based on zinc-iron-copper alloy to solve the above technical problems. The method includes the following steps: Step S1: Melt the zinc-iron-copper raw materials, add platinum-tungsten powder and mix evenly, stretch them into filamentous materials by a machine, then wind the metal wire into the initial shape of a coil by a winding machine or a mandrel die, and finally perform high-temperature shaping by a heat treatment device. After annealing, a degradable coil can be obtained; Step S2: Place the head and tail ends of the anti-unwinding wire into the degradable coil, and connect them with the head and tail ends of the coil by a welding process or an adhesive method to form an integral body; Step S3: Prepare a hydrogel drug-loading solution, coat the hydrogel drug-loading solution on the surface of the coil body, dry it to form a film, and form a hydrogel drug-loading coating on the surface of the coil body.

[0022] Furthermore, in Step S1, the mandrel is a stainless steel bar with a diameter between 0.1 - 0.5 mm; when winding the thin wire, the gap width between the coils is 0.0008 inches - 0.008 inches, and the winding angle is 65° - 80°; the range of the heat setting temperature is 120°C - 250°C, and the heat setting time is 5 - 45 minutes.

[0023] Furthermore, the adhesive used in Step S2 is any one or more of adhesives such as polyester, polyurethane, polyamide, and α-cyanoacrylate.

[0024] Furthermore, Step S3 includes: dissolving a certain mass of sodium alginate in physiological saline to obtain Solution A; dissolving a certain mass of acrylamide substances in deionized water, then sequentially adding a certain mass of calcium carbonate and a thrombus-promoting drug and mixing evenly to obtain Solution B; mixing Solution A and Solution B, performing uniform stirring and heating, and then adding an initiator for polymerization reaction to obtain Solution C; the hydrogel solution can be obtained after naturally cooling Solution C.

[0025] Furthermore, in the mixed solution C, the mass concentration of the sodium alginate is 0.1-3%; the mass concentration of the acrylamide substance is 5-40%; the mass concentration of the calcium carbonate is 2-6%; the mass concentration of the thrombogenic drug is 0.1-1.5%; the mass concentration of the initiator is 2-8%; the acrylamide substance is any one of N-isopropylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid; the thrombogenic drug is any one or more of vitamin K, aminomethylbenzoic acid, snake venom thrombin, prothrombin complex, aminocaproic acid, thrombin and freeze-dried human fibrinogen, anloxin, phenolsulfonamide, banifen, alpha 9SD coagulation factor; the initiator is any one of ammonium persulfate, hydrogen peroxide, potassium persulfate, benzoyl peroxide, methyl ethyl ketone peroxide, and tert-butyl benzoyl peroxide; the temperature range of the heating reaction is 30-80°C, and the polymerization reaction time is 1-5h.

[0026] Furthermore, in step S3, the coating method is spraying, brushing, electrostatic coating, dipping, spin coating or cast coating; after coating, the drying temperature range is 20-230° C., the pressure range is 0.001-3 bar, and the drying time is 2-256 h.

[0027] Compared with the prior art, the present invention has the following beneficial effects: the degradable hydrogel-coated spring coil based on zinc-iron-copper alloy provided by the present invention has high embolic density, good biocompatibility, excellent development performance and is completely degradable, thereby solving the current problems of low embolic filling rate of spring coils, space-occupying effect caused by non-degradable metal implants, and the like, while satisfying the development function of the spring coil during the pushing process. The specific advantages are as follows:

[0028] 1. The spring coil of the present invention overcomes technical prejudice and uses zinc alloy as the main material of the spring coil, which can be degraded in the body, and the degraded elements can be used by the human body.

[0029] 2. The zinc alloy coil of the present invention is uniformly mixed with platinum tungsten powder to provide good X-ray development; at the same time, the high hardness tungsten can increase the physical properties of the coil and better form a basket in the aneurysm cavity.

[0030] 3. The main material of the spring coil of the present invention is a degradable zinc alloy, and the spring coil will gradually degrade after the lesion is completely filled. For aneurysms, the space-occupying effect caused by non-degradable materials can be reduced or completely eliminated, alleviating the pain of patients.

[0031] 4. The hydrogel drug-loaded coating on the surface of the spring coil of the present invention can expand rapidly when it comes into contact with water or blood, and the final volume can reach 3-5 times that before expansion, which greatly increases the embolization density and reduces the number of coils implanted, thereby reducing the economic burden on patients and the perioperative time of doctors.

[0032] 5. The hydrogel drug-loading coating on the surface of the coil of the present invention contains a thrombus-promoting drug, which can react with blood after being implanted into the lesion area, quickly cause thrombosis, and increase the embolization density and occlusion success rate.

[0033] 6. The coil with a hydrogel drug-loading coating of the present invention will not be restricted within the coil body during expansion compared with the coil with a gel inner core, so it has a larger expansion volume, and the thrombus-promoting drug in the coating can also respond more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of the coil according to an embodiment of the present invention;

[0035] Figure 2 is Figure 1 a schematic cross-sectional structural diagram of;

[0036] Figure 3 is a schematic diagram of the coil of the present invention for treating an aneurysm;

[0037] Figure 4 is a schematic cross-sectional structural diagram of the coil of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The present invention will be further described below with reference to the drawings and embodiments.

[0039] Figure 1 is a schematic structural diagram of the coil according to an embodiment of the present invention; Figure 2 is Figure 1 a schematic cross-sectional structural diagram of; Figure 4 is a schematic cross-sectional structural diagram of the coil of the present invention.

[0040] Please refer to Figure 1 、 Figure 2 and Figure 4 , the degradable hydrogel coil based on zinc-iron-copper alloy provided by the present invention mainly consists of a coil body 10, a hydrogel drug-loading coating 55 and an anti-unwinding wire 20, wherein the coil body 10 is a completely degradable coil body and has a radiopaque microparticle platinum-tungsten powder 30.

[0041] The coil body is made of a zinc-iron-copper alloy material with zinc as the main element. Zinc is an essential trace element in the human body, which participates in cell division and differentiation, can promote human growth and development, regulate the body's immune system, etc., and plays an important role in maintaining health; iron can help the human body maintain the normal function of the immune system and participate in the metabolism of vitamin A and other trace elements; copper can promote the development of human bones and internal organs and maintain the normal blood concentration in the human body. The zinc-iron-copper alloy can be completely degraded in the human body and the degradation products are non-toxic.

[0042] After the zinc, iron and copper raw materials are melted, platinum and tungsten powder are added and mixed evenly, and then stretched into a wire material by a precision machine, and its diameter ranges from 0.02 to 0.2 mm. Then the metal wire is wound into the initial shape of the spring coil by a wire winding machine or a core rod mold, and finally high-temperature shaping is performed by a heat treatment device, and the spring coil can be obtained after annealing. The core rod can be a stainless steel rod with a diameter between 0.05 and 1 mm, and the diameter range is preferably 0.1-0.5 mm; when the metal wire is wound, the gap width between the coils can be 0.0005 inches to 0.01 inches, the winding angle can be 60°-90°, and the preferred gap width range is 0.0008 inches to 0.008 inches, and the preferred winding angle range is 65°-80°; the heat setting temperature range can be 60°-800°C, and the preferred temperature range is 250°-400°C; the heat setting time range can be 3-60 minutes, and the preferred time range is 5-45 minutes. At this time, the platinum tungsten powder is evenly distributed on the surface of the spring coil or in the coil wire, and the diameter of the primary coil is between 0.05-1mm, and the diameter of the secondary spiral coil is between 0.2-5mm. By adjusting the proportion of zinc, iron and copper elements, the softness, degradation, mechanical properties and other characteristics of the spring coil can be adjusted. According to research, the zinc element should account for 58.5%-90.25% of the mass percentage of the entire spring coil, the iron element should account for 1.9%-7.6% of the mass percentage of the entire spring coil, the copper element should account for 0.65%-1.9% of the mass percentage of the entire spring coil, and the platinum tungsten powder should account for 5%-35% of the mass percentage of the entire spring coil. Preferably, the mass percentage of the zinc element is in the range of 68.5%-85%, the mass percentage of the iron element is in the range of 3%-5.8%, the mass percentage of the copper element is in the range of 0.8%-1.55%, and the mass percentage of the platinum tungsten powder is in the range of 10%-25%. The degradation rate of the spring coil increases with the increase of the mass percentage of zinc. In this preferred range, the spring coil is completely degraded within about 3-9 months. In platinum tungsten powder, platinum accounts for 92% of the total mass percentage and tungsten accounts for 8%. In this formula, the mass percentage of zinc element cannot exceed 90.25%. If the zinc content is too high, it will affect the overall degradation performance of the spring coil. The spring coil will degrade too quickly in the body and will not be completely degraded before achieving the therapeutic effect; if the platinum tungsten powder content is too high, there will be more non-degradable metal elements in the spring coil as a whole, and the space-occupying effect may not be eliminated or reduced; if the platinum tungsten powder content is too low, the overall development of the spring coil will be poor under X-rays. The addition of an appropriate amount of platinum tungsten metal can improve the mechanical strength of the spring coil and enhance its development.

[0043] The material of the anti-unwinding wire can be any one of polypropylene (PP), polyethylene (PE), polyisoprene (PI), nitinol alloy, magnesium alloy, etc. The anti-unwinding wire is preferably made of polydioxanone (PDO). The ether bond in the PDO material endows it with good flexibility and tensile strength, and it has good anti-bending fatigue performance. It can be bent multiple times at room temperature without deformation or damage. Using high molecular weight PDO as the anti-unwinding wire, the tensile force it can withstand is greater than 1N, and it is less likely to unwind during the operation. The PDO material also has good biocompatibility and biodegradability, can be naturally degraded in the body, and the PDO material is stable and will not react incompatibly with other component materials of the coil. The overall length of the anti-unwinding wire does not exceed the length of the coil, and the diameter is between 0.01 - 0.3 mm. The head and tail ends of the anti-unwinding wire are connected to the head and tail ends of the coil in a welded form or using an adhesive to form an integral body. The adhesive can be any one or more of adhesives such as polyester, polyurethane, polyamide, α-cyanoacrylate, etc.

[0044] The material of the hydrogel drug-loading coating can be any one of polyacrylic acid gel coatings, polyacrylamide gel coatings, polycarbonate gel coatings, polyurethane gel coatings, amphiphilic block copolymer gel coatings, transparent acetate gel coatings, chitosan gel coatings, alginate gel coatings, polyethylene glycol gel coatings, polyvinyl alcohol gel coatings, carrageenan gel coatings, etc. Any raw material that can make the hydrogel have water-swelling and drug-loading properties can be applicable here. The raw material of the hydrogel coating is preferably an acrylamide-based raw material because its structural unit contains an amide group, which is easy to form hydrogen bonds, thus having better water solubility and chemical activity. Dissolve a certain mass of sodium alginate in physiological saline to obtain solution A; dissolve a certain mass of acrylamide-based substance in deionized water, and then sequentially add a certain mass of calcium carbonate and thrombus-promoting drugs for uniform mixing to obtain solution B. Mix solution A and solution B, stir and heat uniformly, and then add an initiator for polymerization reaction to obtain solution C. The hydrogel solution can be obtained after the solution C is naturally cooled. In the overall mixed solution, the mass concentration of sodium alginate is 0.1-3%, preferably 0.1-1.5%; the mass concentration of acrylamide-based substance is 5-40%, preferably 10-30%; the mass concentration of calcium carbonate is 2-6%, preferably 3.5-5%; the mass concentration of thrombus-promoting drug is 0.1-1.5%, preferably 0.5-1%; the mass concentration of initiator is 2-8%, preferably 3-5%. The acrylamide-based substance can be any one of N-isopropylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid. The thrombus-promoting drug can be any one or more of vitamin K, aminomethylbenzoic acid, hemocoagulase, prothrombin complex, aminocaproic acid, thrombin and freeze-dried human fibrinogen, adrenosem, etamsylate, benyfen, alpha 9SD coagulation factor, etc. The initiator can be any one of ammonium persulfate, hydrogen peroxide, potassium persulfate, benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl benzoyl peroxide, etc. The temperature range of the heating reaction is 30-80°C, preferably 40-55°C; the polymerization reaction time is 1-5h, preferably 1.5-3h.

[0045] Place the head and tail ends of the anti-unwinding wire into the spring coil body, and connect them with the head and tail ends of the spring coil through welding or gluing technology to form an integral body. Specifically, the anti-unwinding wire is at the central position of the spring coil, so that the force is more uniform during the delivery stage. Then, coat the surface of the spring coil body with the hydrogel drug-loading solution. The coating method can be spraying, brushing, electrostatic coating, dip coating, spin coating or flow coating, etc., and spraying is preferably used, because this method has a more uniform coating and a controllable thickness. The thickness range of the coating is between 0.01 - 1 mm, preferably 0.01 - 0.5 mm, and more preferably 0.01 - 0.1 mm. After coating, dry the coating to form a film, the temperature range is 20 - 230 °C, preferably 30 - 120 °C; the pressure range is 0.001 - 3 bar, preferably 0.002 - 1 bar; the drying time is 2 - 256 h, preferably 6 - 96 h. After the film formation is completed, let it cool naturally to obtain the final spring coil product. As Figure 3 shown, 15 is the aneurysm body, 25 is the spring coil, and 35 is the blood vessel. The expanded spring coil 25 almost fills the aneurysm body 15; Figure 4 in which 45 is the spring coil body and 55 is the hydrogel drug-loading coating.

[0046] Example 1

[0047] The degradable hydrogel-coated coil based on zinc-iron-copper alloy in this embodiment, where zinc accounts for 90.25% of the total mass of the coil, iron is 3.75%, copper is 1%, and platinum-tungsten powder is 5%. After melting the raw materials of the zinc alloy elements and uniformly blending them with the platinum-tungsten powder, they are drawn into wires with a diameter ranging from 0.02 to 0.2 mm by a machine. Subsequently, the metal wires are wound into the initial shape of the coil by a wire winding machine, and finally, they are heat-set at a high temperature by a heat treatment device and annealed to obtain the coil. Among them, the diameter of the first-level coil is between 0.05 and 1 mm, and the diameter of the second-level spiral coil is between 0.2 and 5 mm. The anti-unwinding wire is placed into the coil body, and its head and tail ends are connected to the head and tail ends of the coil in the form of welding or gluing. Finally, the hydrogel drug-loaded solution is coated on the surface of the coil body. The diameter range of the anti-unwinding wire is between 0.01 and 0.3 mm. The adhesive can be any one or more of adhesives such as polyester, polyurethane, polyamide, α-cyanoacrylate, etc. The material of the anti-unwinding wire can be any one of polypropylene (PP), polyethylene (PE), polyisoprene (PI), nitinol alloy, magnesium alloy, etc.; the hydrogel drug-loaded coating is a material based on acrylamide. A certain amount of sodium alginate is dissolved in physiological saline to prepare solution A; a certain amount of acrylamide-based substance is dissolved in deionized water, and then a certain amount of calcium carbonate and a thrombus-promoting drug are added in sequence and uniformly mixed to prepare solution B. Solution A and solution B are mixed, stirred and heated uniformly, and then an initiator is added for a polymerization reaction to prepare solution C. The hydrogel solution can be obtained after solution C is naturally cooled. The mass concentration of sodium alginate is 0.5%; the mass concentration of the acrylamide-based substance is 20%; the mass concentration of calcium carbonate is 4%; the mass concentration of the thrombus-promoting drug is 0.5%; the mass concentration of the initiator is 4%. The acrylamide-based substance can be any one of N-isopropylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid. The thrombus-promoting drug can be any one or more of vitamin K, aminomethylbenzoic acid, hemocoagulase, prothrombin complex, aminocaproic acid, thrombin, freeze-dried human fibrinogen, adoniside, etamsylate, benyfin, alpha 9SD coagulation factor, etc. The initiator can be any one of ammonium persulfate, hydrogen peroxide, potassium persulfate, benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl benzoyl peroxide, etc. The temperature range of the heating reaction is 50 °C; the polymerization reaction time is 2 h. After the hydrogel solution is prepared, it is coated on the surface of the coil body by spraying, with a thickness of 0.05 mm, a drying temperature of 70 °C, a pressure of 0.5 bar, and a drying time of 24 h.

[0048] Example 2

[0049] The overall implementation process of this embodiment is generally the same as that of Embodiment 1. The difference from Embodiment 1 is the mass percentages of different elements in the spring coil. In this spring coil, zinc accounts for 86% of the total mass of the spring coil, iron is 2.5%, copper is 1.5%, and platinum-tungsten powder is 10%.

[0050] Embodiment 3

[0051] The overall implementation process of this embodiment is generally the same as that of Embodiment 1. The difference from Embodiment 1 is the mass percentages of different elements in the spring coil. In this spring coil, zinc accounts for 80% of the total mass of the spring coil, iron is 3.6%, copper is 1.4%, and platinum-tungsten powder is 15%.

[0052] Embodiment 4

[0053] The overall implementation process of this embodiment is generally the same as that of Embodiment 1. The difference from Embodiment 1 is the mass percentages of different elements in the spring coil. In this spring coil, zinc accounts for 72% of the total mass of the spring coil, iron is 6.8%, copper is 1.2%, and platinum-tungsten powder is 20%.

[0054] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the claims.

Claims

1. A degradable hydrogel-coated coil based on zinc-iron-copper alloy, comprising a coil body, characterized in that, The surface of the spring coil body is coated with a hydrogel drug-loading coating. An anti-unwinding wire is arranged inside the spring coil body. The material of the spring coil body contains the following components by mass percentage: Zinc element: 58.5% - 90.25%; Iron element: 1.9% - 7.6%; Copper element: 0.65% - 1.9%; Platinum-tungsten powder: 5% - 35%; The wire diameter range of the spring coil body is between 0.02 - 0.2 mm. The diameter of the first-level coil is between 0.05 - 1 mm, and the diameter of the second-level spiral coil is between 0.2 - 5 mm; The material of the anti-unwinding wire is any one of polypropylene, polyethylene, polyisoprene, nitinol alloy, magnesium alloy, and poly(p-dioxanone); The thickness of the hydrogel drug-loading coating is 0.01 - 1 mm; the hydrogel drug-loading coating is any one of polyacrylic acid gel coating, polyacrylamide gel coating, polycarbonate gel coating, polyurethane gel coating, amphiphilic block copolymer gel coating, hyaluronic acid gel coating, chitosan gel coating, alginate gel coating, polyethylene glycol gel coating, polyvinyl alcohol gel coating, and carrageenan gel coating.

2. The degradable hydrogel-coated coil based on zinc-iron-copper alloy according to claim 1, characterized in that, The material of the spring coil body contains the following components by mass percentage: Zinc element: 68.5% - 85%; Iron element: 3% - 5.8%; Copper element: 0.8% - 1.55%; Platinum-tungsten powder: 10% - 25%.

3. The degradable hydrogel-coated coil based on zinc-iron-copper alloy according to claim 1, wherein In the platinum-tungsten powder, platinum accounts for 92% of the total mass percentage, and tungsten accounts for 8%.

4. A preparation method of a degradable hydrogel-coated coil based on a zinc-iron-copper alloy as described in any one of claims 1-3, characterized in that, It includes the following steps: Step S1: Melt the zinc, iron, and copper raw materials, add platinum-tungsten powder and mix evenly, draw them into filamentous materials by a machine, then wind the metal wire into the initial shape of the spring coil by a winding machine or a mandrel die, and finally perform high-temperature shaping through a heat treatment device. After annealing, a degradable spring coil can be obtained; Step S2: Place the head and tail ends of the anti-unwinding wire into the degradable spring coil, and connect them with the head and tail ends of the spring coil by welding process or gluing method to form an integral body; Step S3: Prepare a hydrogel drug-loading solution, coat the hydrogel drug-loading solution on the surface of the spring coil body, dry it to form a film, and form a hydrogel drug-loading coating on the surface of the spring coil body.

5. The preparation method of the degradable hydrogel-coated coil based on zinc-iron-copper alloy according to claim 4, wherein, In step S1, the mandrel is a stainless steel rod with a diameter between 0.1 - 0.5 mm; when winding the thin wire, the gap width between the coils is 0.0008 inches - 0.008 inches, and the winding angle is 65° - 80°; the range of the heat setting temperature is 120°C - 250°C, and the heat setting time is 5 - 45 minutes.

6. The preparation method of the degradable hydrogel-coated coil based on zinc-iron-copper alloy according to claim 4, characterized in that, The adhesive used in step S2 is any one or more of polyester, polyurethane, polyamide, and α-cyanoacrylate adhesives.

7. The preparation method of the degradable hydrogel-coated coil based on zinc-iron-copper alloy according to claim 4, wherein, Step S3 includes: Dissolve a certain mass of sodium alginate in physiological saline to obtain solution A; Dissolve a certain mass of acrylamide substances in deionized water, then sequentially add a certain mass of calcium carbonate and a thrombus-promoting drug and mix evenly to obtain solution B; Mix solution A and solution B, stir and heat evenly, and then add an initiator for polymerization reaction to obtain solution C; The hydrogel solution can be obtained after solution C is naturally cooled.

8. The preparation method of the degradable hydrogel-coated coil according to claim 7, wherein, In the mixed solution C, the mass concentration of sodium alginate is 0.1-3%; the mass concentration of acrylamide substances is 5-40%; the mass concentration of calcium carbonate is 2-6%; the mass concentration of thrombus-promoting drugs is 0.1-1.5%; the mass concentration of initiators is 2-8%; the acrylamide substances are any one of N-isopropylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid; the thrombus-promoting drugs are any one or more of vitamin K, aminomethylbenzoic acid, hemocoagulase, prothrombin complex, aminocaproic acid, thrombin, freeze-dried human fibrinogen, adrenosem, etamsylate, benyfen, and alpha 9SD coagulation factor; the initiators are any one of ammonium persulfate, hydrogen peroxide, potassium persulfate, benzoyl peroxide, methyl ethyl ketone peroxide, and tert-butyl benzoyl peroxide; the temperature range of the heating reaction is 30-80°C, and the polymerization reaction time is 1-5 h.

9. The preparation method of the degradable hydrogel-coated coil according to claim 4, characterized in that, In the step S3, the coating method is spraying, brushing, electrostatic coating, dip coating, spin coating or flowing; after the coating is completed, the drying temperature range is 20-230°C, the pressure range is 0.001-3 bar, and the drying time is 2-256 h.

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