A drug delivery system and method of delivery
Patent Information
- Application Number
- CN202611117010.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-27
- Publication Date
- 2026-08-21
AI Technical Summary
[0002]血管狭窄或者闭塞，这些病变限制了血液流动；药物球囊通过表面涂层药物抑制血管再狭窄，但其临床疗效常受限于药物转移不足；球囊扩张时与血管壁的接触时间极短，而药物从球囊表面释放并黏附至内膜的过程高度依赖瞬时贴合；若血管表面钙化严重或存在偏心斑块，药物难以均匀分布；血流冲刷会进一步带走未牢固结合的微粒；研究显示，实际转移至组织的药物不足涂层总量的20%，且深层中膜药物浓度更低，增加了远期再狭窄及靶病变血运重建风险
本发明中，将冲击波发生器与药物涂层支架分设于可相对滑动的两个组件上；在治疗过程中，先将第一组件的球囊输送至靶病变位置，充盈球囊并启动冲击波发生器，对钙化病变进行冲击波预处理，使病变处血管变得软化并打开管腔；之后收缩球囊，将第二组件的支架沿第一组件推送至球囊的上方；接着再次充盈球囊并启动冲击波发生器，支架被均匀向外撑开并紧密贴合血管壁；在冲击波作用下，支架上的药物涂层被击碎，释放出药物微粒并被推向血管壁，在冲击波作用下被定向地注入到内皮组织内；这种分体式可滑动双组件系统设计实现了先冲击波预处理、后支架植入的分步治疗，冲击波辅助药物主动定向注入可大幅提高药物在局部血管壁的浓度和渗透深度。
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Figure CN122605076A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, and in particular to a drug delivery system and delivery method. Background Technology
[0002] Vascular stenosis or occlusion restricts blood flow; drug-eluting balloons inhibit restenosis by coating the surface with medication, but their clinical efficacy is often limited by insufficient drug delivery; the contact time between the balloon and the vessel wall during balloon dilation is extremely short, and the process of drug release from the balloon surface and adhesion to the intima is highly dependent on instantaneous adhesion; if there is severe calcification on the vessel surface or eccentric plaques, the drug is difficult to distribute evenly; blood flow can further carry away unbound particles; studies show that less than 20% of the total drug is actually delivered to the tissue, and the drug concentration in the deep media is even lower, increasing the risk of long-term restenosis and target lesion revascularization. Summary of the Invention
[0003] The purpose of this invention is to provide a drug delivery system and delivery method to solve the problems existing in the prior art. By placing the shock wave generator and the drug-coated stent on two relatively slidable components, the calcified lesion is first pretreated with shock waves, and then the stent is pushed to the same position. The balloon is then inflated again and the shock wave is activated to break up the drug coating and push it towards the blood vessel wall tissue, thereby realizing shock wave-assisted active targeted drug delivery.
[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a drug delivery system, comprising: A first component includes an inner tube, a balloon, and at least one shock wave generator, the balloon being fixed to the distal end of the inner tube, and the shock wave generator being disposed inside the balloon; and, The second component includes a central tube and a stent, the stent being connected to the distal end of the central tube, and the surface of the stent being coated with a drug coating. The first component is slidably inserted into the central tube of the second component for allowing the balloon and the stent to move relative to each other along the axial direction. When the balloon is inflated, it is used to expand the stent and make the stent conform to the blood vessel wall. The shock wave generator is used to generate a shock wave when the balloon is inflated to break the drug coating on the surface of the stent and push it toward the blood vessel wall tissue.
[0005] Optionally, it also includes an outer tube, in which the second component is slidably inserted, and the support is compressed and housed within the outer tube during transport.
[0006] Optionally, the inner diameter of the stent is smaller than the outer diameter of the balloon under working pressure, so that when the balloon is inflated, the stent is evenly expanded outward and closely fits the blood vessel wall.
[0007] Optionally, the surface of the stent is provided with at least one protruding mechanism that extends outward from the outer surface of the stent and is used to penetrate the blood vessel wall tissue when the stent is expanded.
[0008] Optionally, the surface of the protruding mechanism is coated with the drug coating.
[0009] Optionally, the height of the protruding mechanism is 0.2 to 0.5 mm.
[0010] Optionally, the protruding mechanism may be in the shape of a cone, a triangular pyramid, or a square pyramid.
[0011] Optionally, the inner tube is a multi-lumen catheter, including a guidewire lumen and an injection lumen; the guidewire lumen extends through the distal end face of the inner tube along the axial direction of the inner tube for the guidewire to pass through; the injection lumen communicates with the interior of the balloon for injecting or withdrawing fluid into the balloon.
[0012] Optionally, the drug coating contains an antiproliferative drug, such as paclitaxel or rapamycin.
[0013] A drug delivery method using the drug delivery system described above is also provided, comprising the following steps: S1. Deliver the balloon of the first component to the target lesion location, inflate the balloon and activate the shock wave generator to perform shock wave pretreatment on the calcified lesion; S2. Contract the balloon to push the second component's stent along the first component above the balloon; S3. Re-inflate the balloon to expand the stent and make it fit the blood vessel wall. At the same time, activate the shock wave generator to break the drug coating on the stent surface and push it toward the blood vessel wall tissue.
[0014] The present invention achieves the following technical effects compared to the prior art: In this invention, the shockwave generator and the drug-coated stent are mounted on two relatively slidable components. During treatment, the balloon of the first component is first delivered to the target lesion, the balloon is inflated, and the shockwave generator is activated to pre-treat the calcified lesion with shockwaves, softening the blood vessels at the lesion site and opening the lumen. Then, the balloon is deflated, pushing the stent of the second component above the balloon along the first component. Next, the balloon is inflated again, and the shockwave generator is activated, causing the stent to be evenly expanded outward and closely adhered to the blood vessel wall. Under the action of the shockwave, the drug coating on the stent is broken, releasing drug particles that are pushed towards the blood vessel wall and directionally injected into the endothelial tissue under the action of the shockwave. This split, slidable dual-component system design realizes stepwise treatment of shockwave pre-treatment followed by stent implantation. Shockwave-assisted active targeted drug injection can significantly increase the concentration and penetration depth of the drug in the local blood vessel wall.
[0015] This addresses the problem that existing drug-eluting balloons, when treating vascular stenosis or occlusion, rely heavily on instantaneous adhesion for drug release from the balloon surface and adhesion to the vascular intima. In such cases, less than 20% of the total drug is actually transferred to the tissue, and the concentration is even lower in the deep media, leading to a high risk of long-term restenosis and target lesion revascularization. By placing the shockwave generator and the drug-eluting stent on two relatively sliding components, the calcified lesion is first pretreated with shockwaves. Then, the stent is pushed to the same position, the balloon is re-inflated, and the shockwave is activated to break up the drug coating and push it towards the vascular wall tissue, achieving shockwave-assisted active targeted drug delivery. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are 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.
[0017] Figure 1 This is a schematic diagram of the distal longitudinal cross-sectional structure of a catheter system in an example disclosed in this invention; Figure 2 for Figure 1 Enlarged structural diagram of the surface of the support frame; Figure 3 for Figure 1 The example shown is a schematic diagram of the working state of a blood vessel cross section under balloon inflation and stent apposition. Figure 4 This is a schematic diagram of the distal longitudinal cross-sectional structure of the catheter system in another example disclosed in this invention; Figure 5 for Figure 4 Enlarged structural schematic diagram of the surface of the protruding mechanism; Figure 6 for Figure 4 The example shown is a schematic diagram of the cross-sectional structure of the protruding mechanism on the stent after balloon dilation, with the protrusion on the stent piercing the blood vessel wall. Among them, 1-guidewire lumen; 2-stent; 3-balloon; 4-shock wave generator; 5-injection chamber; 6-inner tube; 7-middle tube; 8-outer tube; 9-drug coating; 10-stenotic lesion tissue; 11-blood vessel; 12-protruding mechanism; 13-media and adventitia of blood vessel; 14-intima of blood vessel. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] The purpose of this invention is to provide a drug delivery system and delivery method to solve the problems existing in the prior art. By placing the shock wave generator and the drug-coated stent on two relatively slidable components, the calcified lesion is first pretreated with shock waves, and then the stent is pushed to the same position. The balloon is then inflated again and the shock wave is activated to break up the drug coating and push it towards the blood vessel wall tissue, thereby realizing shock wave-assisted active targeted drug delivery.
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] like Figures 1 to 6 As shown, the present invention provides a drug delivery system, including a first component and a second component; the first component includes an inner tube 6, a balloon 3, and at least one shock wave generator 4; the balloon 3 is fixed to the distal end of the inner tube 6, and the balloon 3 has a closed structure; the shock wave generator 4 is disposed inside the balloon 3 and fixed to the inner tube 6; the second component includes a middle tube 7 and a stent 2; the stent 2 is connected to the distal end of the middle tube 7, and the surface of the stent 2 is coated with a drug coating 9; the first component is slidably inserted into the middle tube 7 of the second component for allowing the balloon 3 and the stent 2 to move relative to each other along the axial direction; the balloon 3, when inflated, is used to expand the stent 2 and make the stent 2 conform to the blood vessel wall; the shock wave generator 4 is used to generate a shock wave when the balloon 3 is inflated, breaking the drug coating 9 on the surface of the stent 2 and pushing it towards the blood vessel wall tissue.
[0022] In this invention, the shockwave generator 4 and the stent 2 with drug coating 9 are separately mounted on two relatively slidable components. During treatment, the balloon 3 of the first component is first delivered to the target lesion location, the balloon 3 is inflated, and the shockwave generator 4 is activated to pre-treat the calcified lesion with shockwave, softening the blood vessel 11 at the lesion site and opening the lumen. Then, the balloon 3 is deflated, pushing the stent 2 of the second component above the balloon 3 along the first component. Next, the balloon 3 is inflated again, and the shockwave generator 4 is activated, causing the stent 2 to be evenly expanded outward and closely adhered to the blood vessel wall. Under the action of the shockwave, the drug coating 9 on the stent 2 is broken, releasing drug particles that are pushed towards the blood vessel wall and directionally injected into the endothelial tissue under the action of the shockwave. This split-type slidable dual-component system design realizes step-by-step treatment with shockwave pre-treatment followed by stent 2 implantation. Shockwave-assisted active targeted drug injection can significantly increase the concentration and penetration depth of the drug in the local blood vessel wall.
[0023] This addresses the problem that existing drug-eluting balloons 3, when treating stenotic or occluded lesions of blood vessels 11, rely heavily on instantaneous adhesion for drug release from the balloon 3 surface and adhesion to the vascular intima 14. The actual drug delivered to the tissue is less than 20% of the total coating amount, and the drug concentration in the deep media is even lower, leading to a high risk of long-term restenosis and target lesion revascularization. By placing the shockwave generator 4 and the stent 2 with the drug coating 9 on two relatively sliding components, the calcified lesion is first pretreated with shockwaves, then the stent 2 is pushed to the same position, the balloon 3 is re-inflated, and the shockwave is activated to break up the drug coating 9 and push it towards the vascular wall tissue, achieving shockwave-assisted active targeted drug delivery.
[0024] In one embodiment, an outer tube 8 is also included; the second component is slidably inserted into the outer tube 8, and the stent 2 is compressed and housed in the outer tube 8 during delivery; the inner tube 6 of the first component can be retracted into the outer tube 8; after retraction, the inner diameter of the stent 2 after compression is greater than the maximum outer diameter of the inner tube 6 of the first component; the multi-layer retractable delivery structure makes all components in a nested contracted state during the delivery stage, significantly reducing the outer diameter of the system, facilitating the passage through tortuous, narrow or calcified blood vessel segments 11, and improving the delivery success rate.
[0025] In one embodiment, the inner diameter of the stent 2 is smaller than the outer diameter of the balloon 3 under working pressure, so that when the balloon 3 is inflated, the stent 2 is evenly expanded outward and closely fits the blood vessel wall; the design that the inner diameter of the stent 2 is slightly smaller than the working outer diameter of the balloon 3 avoids gaps between the stent 2 and the blood vessel wall, ensuring that the stent 2 is fully fitted to the wall and reducing the risk of thrombosis and restenosis.
[0026] In one embodiment, the surface of the stent 2 is provided with at least one protruding mechanism 12; the protruding mechanism 12 extends outward from the outer surface of the stent 2 and is used to pierce the blood vessel wall tissue when the stent 2 is expanded; when the balloon 3 is inflated, the stent 2 with the protruding mechanism 12 is opened, and the sharp end of the protruding mechanism 12 is forced to pierce the stenotic lesion tissue 10 and pass through the intima 14, reaching or piercing the media and adventitia 13 layers of the blood vessel; in this process, the protruding mechanism 12 physically breaks up the remaining calcified lesions and fibrotic lesions, making the blood vessel 11 more flexible and the compliance of the blood vessel 11 better.
[0027] In one embodiment, the surface of the protruding mechanism 12 is coated with a drug coating 9; the drug coating 9 on the protruding mechanism 12 is physically inserted into the intima 14 and media of the blood vessel along with the protruding mechanism 12, so that the drug can achieve a more sustained local release in the blood vessel wall, unaffected by blood flow, and can maintain a long-term effective concentration, thus achieving a better anti-proliferative effect.
[0028] In one embodiment, the height of the protrusion 12 is 0.2 to 0.5 mm. By controlling the height of the protrusion 12 within the range of 0.2 to 0.5 mm, it can effectively puncture the intima 14 of the blood vessel to reach the media, while avoiding puncturing the adventitia of the blood vessel 11 and causing perforation of the blood vessel 11. This ensures effective drug delivery while maintaining the structural integrity of the blood vessel wall.
[0029] In one embodiment, the protruding mechanism 12 is shaped as a cone, a triangular pyramid, or a square pyramid. The shape of the protruding mechanism 12 can be selected according to the type of lesion and the condition of the blood vessel 11. A cone shape is suitable for uniformly calcified lesions, while triangular and square pyramid shapes, with their angular features, are more conducive to breaking up locally hard calcified lesions.
[0030] In one embodiment, the inner tube 6 is a multi-lumen catheter, including a guidewire lumen 1 and an injection lumen 5. The guidewire lumen 1 extends through the distal end face of the inner tube 6 along the axial direction of the inner tube 6, allowing the guidewire to pass through. The injection lumen 5 communicates with the interior of the balloon 3, allowing for the injection or withdrawal of fluid into the balloon 3. The guidewire lumen 1 extends through the distal end face of the inner tube 6, enabling the entire system to be pushed along the pre-placed guidewire to the target lesion location, ensuring the accuracy and convenience of delivery. The injection lumen 5 communicates with the interior of the balloon 3, allowing for rapid inflation and deflation of the balloon 3, meeting the needs of repeated manipulation of the balloon 3 in stepwise treatment.
[0031] In one embodiment, the drug coating 9 comprises an antiproliferative drug, namely paclitaxel or rapamycin. The carrier for the antiproliferative drug can be a hydrophilic excipient, a biodegradable polymer, or a novel nanomaterial. Paclitaxel and rapamycin are widely used antiproliferative drugs in clinical practice, effectively inhibiting smooth muscle cell proliferation and reducing the incidence of restenosis in blood vessels 11. Hydrophilic excipients facilitate drug release and dispersion under shock wave action, biodegradable polymers enable sustained drug release, and novel nanomaterials improve drug bioavailability and tissue permeability.
[0032] Furthermore, the present invention also provides a delivery method using a drug delivery system according to any of the above embodiments, comprising the following steps: S1. Deliver the balloon 3 of the first component to the target lesion location, inflate the balloon 3 and start the shock wave generator 4 to perform shock wave pretreatment on the calcified lesion. S2. Contract the balloon 3 to push the second component's support 2 along the first component above the balloon 3; S3. Re-inflate balloon 3 to expand stent 2 and fit against the blood vessel wall. At the same time, activate shock wave generator 4 to break the drug coating 9 on the surface of stent 2 and push it towards the blood vessel wall tissue. In the case of using the stent 2 with the protruding mechanism 12, in step S3, the protruding mechanism 12 will penetrate into the intima 14 of the blood vessel and reach the media, further breaking down calcified lesions and fibrotic lesions, making the blood vessel 11 more flexible and improving its compliance; the drug on the protruding mechanism 12 is inserted into the intima 14 and media of the blood vessel along with the protruding mechanism 12, achieving a more sustained release within the blood vessel wall, thereby achieving a better anti-proliferative effect.
[0033] This delivery method enables stepwise treatment, with shockwave pretreatment followed by stent implantation. First, a shockwave balloon is used to thoroughly fragment the calcified lesion and restore vascular compliance. Then, stent 2 is precisely delivered to the same location, avoiding incomplete expansion due to calcification when directly implanting stent 2. The split sliding structure allows both devices to reach the target lesion sequentially via the same path, eliminating the need to change the guide sheath or re-establish the pathway, simplifying the procedure. The two shockwave actions target the calcified lesion and drug delivery respectively, with clear division of labor improving treatment effectiveness. Stent 2 is only delivered to the target site and expanded after the balloon 3 has completed calcification pretreatment, avoiding premature drug loss due to friction and blood flow during passage through the lesion, as is common with traditional drug-eluting balloons 3 or integrated stent 2, ensuring accurate drug delivery to the target tissue.
[0034] Any adaptive changes made according to actual needs are within the scope of protection of this invention.
[0035] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0036] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.
Claims
1. A drug delivery system, characterized in that, include: The first component includes an inner tube, a balloon, and at least one shock wave generator, wherein the balloon is fixed to the distal end of the inner tube, and the shock wave generator is disposed inside the balloon. as well as, The second component includes a central tube and a stent, the stent being connected to the distal end of the central tube, and the surface of the stent being coated with a drug coating. The first component is slidably inserted into the central tube of the second component for allowing the balloon and the stent to move relative to each other along the axial direction. When the balloon is inflated, it is used to expand the stent and make the stent conform to the blood vessel wall. The shock wave generator is used to generate a shock wave when the balloon is inflated to break the drug coating on the surface of the stent and push it toward the blood vessel wall tissue.
2. The drug delivery system according to claim 1, characterized in that, It also includes an outer tube, the second component being slidably inserted inside the outer tube, and the support being compressed and housed inside the outer tube during transport.
3. The drug delivery system according to claim 1, characterized in that, The inner diameter of the stent is smaller than the outer diameter of the balloon under working pressure, so that when the balloon is inflated, the stent is evenly expanded outward and closely fits the blood vessel wall.
4. The drug delivery system according to claim 1, characterized in that, The surface of the stent is provided with at least one protruding mechanism that extends outward from the outer surface of the stent and is used to penetrate the blood vessel wall tissue when the stent is expanded.
5. The drug delivery system according to claim 4, characterized in that, The surface of the protruding mechanism is coated with the drug coating.
6. The drug delivery system according to claim 4, characterized in that, The height of the protruding mechanism is 0.2 to 0.5 mm.
7. The drug delivery system according to claim 4, characterized in that, The protruding mechanism is shaped like a cone, a triangular pyramid, or a square pyramid.
8. The drug delivery system according to claim 1, characterized in that, The inner tube is a multi-lumen catheter, including a guidewire lumen and an injection lumen; the guidewire lumen extends through the distal end face of the inner tube along the axial direction of the inner tube for the guidewire to pass through; the injection lumen communicates with the interior of the balloon for injecting or withdrawing fluid into the balloon.
9. The drug delivery system according to claim 1, characterized in that, The drug coating contains an antiproliferative drug, which is either paclitaxel or rapamycin.
10. A delivery method using a drug delivery system as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Deliver the balloon of the first component to the target lesion location, inflate the balloon and activate the shock wave generator to perform shock wave pretreatment on the calcified lesion; S2. Contract the balloon to push the second component's stent along the first component above the balloon; S3. Re-inflate the balloon to expand the stent and make it fit the blood vessel wall. At the same time, activate the shock wave generator to break the drug coating on the stent surface and push it toward the blood vessel wall tissue.