Drug stent

Abstract

The utility model discloses a medicine support which comprises a support body, the support body comprises a plurality of supporting frames, and every two adjacent supporting frames are connected with each other. A first open groove and a plurality of second open grooves are formed in the outer wall of the supporting frame, the supporting frame is divided into a plurality of independent areas by the first open groove and the second open grooves, and a plurality of micropores are formed in each area; the first open groove and the second open groove are filled with anti-inflammatory drugs; the micropores are filled with an anti-atherosclerosis medicine; an anti-proliferation drug is sprayed on the outer wall of the stent body, and the anti-proliferation drug covers the anti-atherosclerosis drug and the anti-inflammatory drug. Therefore, the pathological process can be accurately matched, different drugs are made to act on different time periods after the PCI operation respectively, different effects are achieved according to the pathological characteristics of the different time periods, short-term stent restenosis is prevented, and long-term stent restenosis can be effectively prevented.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a drug-eluting stent. Background Technology

[0002] In-stent restenosis is a common complication after stent implantation, significantly weakening the effectiveness of revascularization and potentially triggering the recurrence of major adverse cardiovascular events such as angina and acute myocardial infarction. While the incidence of in-stent restenosis has decreased compared to the bare-metal stent era (when its incidence was approximately 20%-35%) with the widespread clinical use of drug-eluting stents, it still occurs in 5%-10% of patients.

[0003] Currently, drug-eluting stent implantation can trigger two different pathological processes, ultimately leading to in-stent restenosis. One is excessive neointimal hyperplasia, which usually begins shortly after stent implantation and can last up to 12 months. The other is neoatherosclerosis, which typically occurs at least 12 months later. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, one objective of this invention is to propose a drug-eluting stent that can precisely match the pathological process, allowing different drugs to act at different time points after PCI and exert different effects according to the pathological characteristics at different time points. This not only prevents short-term in-stent restenosis but also effectively prevents long-term in-stent restenosis.

[0006] To achieve the above objectives, this utility model proposes a drug-eluting stent, comprising: a stent body, the stent body including multiple support frames, and adjacent support frames being connected to each other; a first slot and multiple second slots are formed on the outer wall of the support frame, the first slot and the second slots dividing the support frame into multiple independent regions, each region having multiple micropores; the first slot and the second slots are filled with anti-inflammatory drugs; the micropores are filled with anti-atherosclerotic drugs; and the outer wall of the stent body is sprayed with an anti-proliferative drug, the anti-proliferative drug covering the anti-atherosclerotic drug and the anti-inflammatory drug.

[0007] This novel drug-eluting stent, by setting multiple layers of drugs on the stent and controlling the release of these drugs at different times, can precisely match the pathological process, allowing different drugs to act on different time periods after PCI and exert different effects according to the pathological characteristics of different time periods. It not only prevents short-term in-stent restenosis, but also effectively prevents long-term in-stent restenosis.

[0008] In addition, the drug-eluting stent proposed in the application may also have the following additional technical features:

[0009] Specifically, the region has a third slot and multiple fourth slots, and the third slot and the fourth slots are filled with anti-inflammatory drugs.

[0010] Specifically, the openings of the third and fourth slots are smaller than those of the first and second slots.

[0011] Specifically, the plurality of fourth slots intersect with the third slots respectively, for dividing the region into multiple grids, and each grid has one of the micropores.

[0012] Specifically, multiple second slots intersect with the first slot, the third slot is connected to the second slot, and multiple fourth slots are connected to the first slot.

[0013] Specifically, the anti-inflammatory drug is coated with a biodegradable material.

[0014] Specifically, the antiproliferative drug is applied to the scaffold body using ultrasonic spraying technology in all directions.

[0015] Specifically, the anti-atherosclerotic drug is colchicine.

[0016] Specifically, the anti-inflammatory drug is dexamethasone.

[0017] Specifically, the antiproliferative drug is rapamycin. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a drug-eluting stent according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a support frame without drug filling according to an embodiment of the present invention;

[0022] Figure 3 According to one embodiment of the present utility modelFigure 2 A magnified structural diagram of area A in the middle.

[0023] As shown in the figure:

[0024] 1. Support body; 10. Support frame; 100. First slot; 101. Second slot; 102. Area; 103. Microhole; 104. Third slot; 105. Fourth slot. Detailed Implementation

[0025] To better understand the above-mentioned objectives, features, and advantages of this utility model, the solution of this utility model will be further described below. It should be noted that, unless otherwise specified, the embodiments of this utility model and the features thereof can be combined with each other.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the present invention, and not all embodiments.

[0027] The drug-eluting stent of this utility model embodiment will now be described with reference to the accompanying drawings.

[0028] like Figures 1-3 As shown, the drug stent of this utility model embodiment may include a stent body 1, the stent body 1 includes a plurality of support frames 10, and two adjacent support frames 10 are connected to each other. It can be understood that two support frames 10 may be connected along the width direction of the support frame 10 or along the length direction of the support frame 10.

[0029] It should be noted that the stent body 1 can be made of materials such as cobalt-chromium alloy or platinum-chromium alloy. Cobalt-chromium alloy has high strength and good elasticity, which helps to reduce vascular damage and improve blood flow, while platinum-chromium alloy is more ductile than cobalt-chromium alloy and has good radiometric visibility.

[0030] The outer wall of the support frame 10 is provided with a first slot 100 and a plurality of second slots 101. The first slot 100 and the second slots 101 divide the support frame 10 into a plurality of independent regions 102. Each region 102 is provided with a plurality of microholes 103. By implementing the above scheme, it is possible to achieve precise loading of different drugs at specific positions and to clearly define the drug loading positions.

[0031] The first slot 100 and the second slot 101 divide the support frame 10 into multiple independent areas 102. This design not only enhances the flexibility of the support frame 10, but also effectively disperses stress, reduces the pressure on the local blood vessel wall, and reduces the damage to the blood vessel wall caused by pressure. This significantly improves the wall-adhering performance of the stent body 1. Furthermore, the dual arrangement of the first slot 100 and the second slot 101 ensures the amount of drug filling and the duration of drug action, thereby improving the therapeutic effect on vascular symptoms.

[0032] In addition, the microporous 103 design has a stronger adsorption capacity for drugs, thus ensuring strong adhesion after drug filling.

[0033] It should be noted that the first groove 100, the second groove 101, and the micropore 103 all face the inner wall of the blood vessel so that the drug filled inside can directly act on the inner wall of the blood vessel. The drug can be directly released and come into contact with the inner lining of the blood vessel, achieving precise and targeted drug release, thereby increasing the local concentration of the drug at the lesion site and ensuring the therapeutic effect of the drug on the disease.

[0034] The first slot 100 and the second slot 101 are filled with anti-inflammatory drugs to reduce the inflammatory response caused by metal stimulation of target blood vessels and inhibit local fibrosis. The anti-inflammatory drugs can be everolimus, prednisolone, dexamethasone, etc., with dexamethasone being preferred. It has strong anti-inflammatory efficacy and a long duration of action. At the same time, dexamethasone has low mineral corticosteroid activity, which means that while achieving anti-inflammatory effects, it has little impact on electrolyte balance and water and sodium metabolism. This is especially important for intravascular application, as it helps reduce side effects and has good biocompatibility.

[0035] The micropores 103 are filled with anti-atherosclerotic drugs, which are applied to the surface of atherosclerotic plaques to effectively prevent the aggravation of local atherosclerosis and recurrence of plaque stenosis. Among them, the anti-atherosclerotic drugs can be colchicine, rosuvastatin, atorvastatin, etc., with colchicine being the preferred anti-atherosclerotic drug. It not only has anti-atherosclerotic effects but also anti-inflammatory effects, which can inhibit neutrophil chemotaxis and reduce the release of inflammatory mediators, thereby alleviating the inflammatory response of the blood vessel wall.

[0036] The outer wall of the stent body 1 is coated with an anti-proliferative drug to inhibit the proliferation of vascular endothelial cells, smooth muscle cells, and fibroblasts. The anti-proliferative drug can be rapamycin, paclitaxel, everolimus, etc., with rapamycin being the preferred choice. Rapamycin has moderate lipophilicity and can maintain an effective concentration within the vascular wall for several weeks to months, inhibiting proliferation without excessive retention leading to long-term side effects. Furthermore, rapamycin also has a certain anti-inflammatory effect, reducing the inflammatory response of the vascular wall.

[0037] Furthermore, the antiproliferative drug is applied to the stent body 1 using ultrasonic spraying technology, ensuring that the antiproliferative drug is fully covered on the stent body 1. In other words, the antiproliferative drug forms a covering layer on the stent body 1, completely enveloping the outer wall of the stent body 1. This helps to avoid uneven or missed drug coverage, improves the uniformity of drug distribution on the surface of the stent body 1, and ensures the effect of inhibiting the proliferation of vascular endothelial cells, smooth muscle cells, and fibroblasts.

[0038] Furthermore, ultrasonic spraying technology enables comprehensive and uniform coverage of the stent body 1, ensuring that each surface is protected by anti-proliferative drugs. This prevents excessive local cell proliferation due to incomplete coverage. Simultaneously, ultrasonic spraying atomizes the drug solution into micron-sized particles (10-50 μm), achieving nanometer-level thickness control (error <5%) and avoiding the "paint droplet effect" (local accumulation) of traditional spraying. Moreover, by adjusting parameters (frequency, flow rate, distance), the drug loading (e.g., rapamycin 1.4 μg / mm² ± 0.2) can be precisely controlled. Compared to traditional spot application or unilateral spraying, this reduces the drug coverage gap at vascular bends. In bifurcation lesions, the full coverage design reduces the restenosis rate of lateral branch ostia.

[0039] Meanwhile, ultrasonic spraying technology also offers the advantage of precisely controlling drug loading, and the resulting drug coating is more robust. This characteristic effectively prevents the drug from dissolving and detaching from the stent body 1, thereby significantly prolonging the drug's residence time on the stent body 1, ensuring continuous drug release and long-term efficacy.

[0040] Antiproliferative drugs are layered around antiatherosclerotic and anti-inflammatory drugs, with the antiproliferative drugs on the outermost layer. These are released first to rapidly inhibit the excessive proliferation of smooth muscle cells, endothelial cells, and fibroblasts, thereby preventing early intimal hyperplasia. Subsequently, the antiatherosclerotic and anti-inflammatory drugs are released with a delay due to their layering, allowing them to continue their effects in later stages of vascular repair. This layered release strategy ensures that each drug exerts its optimal effect within the most suitable time window.

[0041] Furthermore, the formation of a capping layer by antiproliferative drugs can effectively reduce the risk of underlying drugs (antiatherosclerotic and anti-inflammatory drugs) being washed away by blood flow, mechanical damage, or environmental degradation in the initial stages, thereby maintaining drug stability and activity. This delayed-release mechanism helps maintain drug action for a longer period of time and reduces the risk of local high concentrations caused by the initial "burst release" of drugs.

[0042] Specifically, within 12 months after PCI (Percutaneous Coronary Intervention, coronary stent surgery), the focus is on preventing intimal hyperplasia. Therefore, the anti-proliferative drug on the outer wall of the stent body 1, as the outermost layer, is in direct contact with the blood flow. As the blood flow washes over it, the drug gradually washes away and exerts its effect, inhibiting the proliferation of vascular endothelial cells, smooth muscle cells, and fibroblasts. The drug concentration gradually decreases, and the effect becomes less and less effective. As a result, the metal surface of the stent body 1 is gradually exposed. As a foreign body, the bare metal is prone to triggering an endothelial inflammatory response. Meanwhile, the anti-inflammatory drug (dexamethasone) filled in the first groove 100 and the second groove 101 on the surface of the stent body 1 is exposed at the same time as the metal surface. The anti-inflammatory drug exerts its anti-inflammatory effect, ensuring that the stent endothelialization can continue smoothly without fibrosis.

[0043] Beyond 12 months post-PCI, the focus shifts to anti-atherosclerosis. The inflammatory response induced by drug-eluting stent implantation leads to the recruitment of monocytes to the stent body 1 site. These monocytes, under conditions of endothelial dysfunction, are captured on the vessel surface and undergo a rolling and traversing process, eventually differentiating into macrophages. In the neointima, macrophages transform into foam cells by uptake of oxidized low-density lipoprotein. The aggregation of foam cells within the stent body 1 region leads to plaque formation, subsequently forming a necrotic core composed of apoptotic macrophages. This results in new atherosclerosis between the stent body 1 and the endothelium. The rapamycin on the stent body 1 surface has been washed away. After 12 months, the surface of the stent body 1 is exposed to micropores 103 and injected colchicine. Colchicine exerts its local anti-atherosclerotic effect through close contact.

[0044] Therefore, by placing multiple layers of drugs on the drug-eluting stent and controlling the release of the drugs in a tiered manner, it is possible to precisely match the pathological process, so that different drugs act on different time periods after PCI and play different roles according to the pathological characteristics of different time periods. This not only prevents short-term in-stent restenosis, but also effectively prevents long-term in-stent restenosis.

[0045] In one embodiment of this utility model, such as Figure 2 and Figure 3 As shown, a third slot 104 and multiple fourth slots 105 are provided in region 102, and the third slot 104 and the fourth slots 105 are filled with anti-inflammatory drugs.

[0046] In the above scheme, by setting the third slot 104 and the fourth slot 105, the loading capacity of anti-inflammatory drugs can be increased, ensuring that the effective concentration of anti-inflammatory drugs lasts longer. At the same time, the third slot 104 and the fourth slot 105 can increase the contact area with the inner wall of blood vessels, thereby improving the therapeutic effect on symptoms of the inner wall of blood vessels.

[0047] In one embodiment of this utility model, such asFigure 3 As shown, the openings of the third slot 104 and the fourth slot 105 are smaller than those of the first slot 100 and the second slot 101.

[0048] In the above scheme, the size of the slot opening can flexibly change the drug release characteristics. A larger opening allows for faster drug release and timely treatment, while a smaller opening can limit the drug release rate, allowing anti-inflammatory drugs to be released into the blood vessel wall tissue more slowly and for a longer period of time. This helps to prolong the duration of drug action and improve drug utilization efficiency and efficacy.

[0049] In one embodiment of this utility model, such as Figure 3 As shown, multiple fourth slots 105 intersect with the third slots 104 respectively, which are used to divide the region 102 into multiple grids, and each grid has a microhole 103.

[0050] In the above scheme, the intersecting design of the fourth slot 105 and the third slot 104 forms a stable grid structure, which divides the micropores 103 into independent parts, which helps to enhance the overall mechanical strength and stability of the stent body 1. The independent micropore design can reduce the loss of drugs in non-target areas, ensure that the drugs mainly act on the lesion site, and improve drug utilization.

[0051] In one embodiment of this utility model, such as Figure 3 As shown, multiple second slots 101 intersect with the first slot 100, the third slot 104 is connected to the second slot 101, and multiple fourth slots 105 are connected to the first slot 100.

[0052] In the above design, the interconnected slotted channels allow the drug to be flushed by blood flow from multiple angles, creating multiple release points on the stent surface and significantly reducing drug residue on the stent body 1 surface. This helps ensure complete drug release, preventing drug accumulation and waste on the stent body 1 surface. Furthermore, the multi-slotted channel design improves the hydrodynamic properties of the stent body 1 surface, reducing the impact and shear force of blood flow on the stent body 1 surface and extending the lifespan of the stent body 1.

[0053] In addition, the interconnected slotted structure allows the drug to be activated and released from multiple directions under the action of blood flow, avoiding the problem of drug accumulation or uneven release at specific locations, thereby ensuring full coverage of the treatment site and improving the treatment effect.

[0054] In one embodiment of this invention, the anti-inflammatory drug is coated with a biodegradable material.

[0055] In the above scheme, after the biodegradable material is coated with anti-inflammatory drugs, it can effectively fix the drugs in the slots on the stent body 1, prevent the drugs from falling off or being lost during implantation and blood flow, and ensure the stable presence of the drugs at the target site.

[0056] Furthermore, the degradation rate of biodegradable materials is controllable. By selecting appropriate materials and thicknesses, the drug release rate can be precisely controlled, prolonging the duration of drug action and reducing adverse reactions such as restenosis. At the same time, using biocompatible biodegradable materials as drug carriers can reduce inflammatory reactions caused by polymers, reduce the risk of late thrombosis, and promote the healing of vascular endothelium. Biodegradable materials can be polylactic acid, polylactic acid-glycolic acid copolymers, etc., which can be selected according to the actual situation.

[0057] In summary, the drug-eluting stent of this invention can precisely match the pathological process, allowing different drugs to act at different time points after PCI and exert different effects according to the pathological characteristics at different time points. It can not only prevent short-term in-stent restenosis, but also effectively prevent long-term in-stent restenosis.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A drug-eluting stent, characterized in that, include: The support body includes multiple support frames, and adjacent support frames are connected to each other. The outer wall of the support frame is provided with a first slot and a plurality of second slots, the first slot and the second slots dividing the support frame into a plurality of independent regions, each region being provided with a plurality of micropores; The first and second slots are filled with anti-inflammatory drugs; The micropores are filled with anti-atherosclerotic drugs; The outer wall of the stent body is coated with an antiproliferative drug, and the antiproliferative drug covers the anti-atherosclerotic drug and the anti-inflammatory drug.

2. The drug-eluting stent according to claim 1, characterized in that, The region has a third slot and multiple fourth slots, and the third and fourth slots are filled with anti-inflammatory drugs.

3. The drug-eluting stent according to claim 2, characterized in that, The openings of the third and fourth slots are smaller than those of the first and second slots.

4. The drug-eluting stent according to claim 3, characterized in that, The multiple fourth slots intersect with the third slots respectively, and are used to divide the region into multiple grids, with one micropore in each grid.

5. The drug-eluting stent according to claim 4, characterized in that, The plurality of second slots intersect with the first slot, the third slot is connected to the second slot, and the plurality of fourth slots are connected to the first slot.

6. The drug-eluting stent according to any one of claims 1-5, characterized in that, The anti-inflammatory drug is coated with a biodegradable material.

7. The drug-eluting stent according to claim 1, characterized in that, The antiproliferative drug is applied to the scaffold body using ultrasonic spraying technology in all directions.

8. The drug-eluting stent according to claim 1, characterized in that, The anti-atherosclerotic drug is colchicine.

9. The drug-eluting stent according to claim 1, characterized in that, The anti-inflammatory drug is dexamethasone.

10. The drug-eluting stent according to claim 1, characterized in that, The antiproliferative drug is rapamycin.

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