Medical instrument for drug release
By introducing a restriction structure into the drug-coated balloon, providing pressure to prevent drug from falling off and releasing the drug when the balloon expands, the problem of large amounts of shedding during drug delivery is solved, and the drug payload and release efficiency of the drug are improved.
Patent Information
- Application Number
- CN202421296261.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-06-07
AI Technical Summary
The existing drug-coated balloons have large amounts of drug fall off during delivery, resulting in a low amount of effective drug reaching the lesion and insufficient drug release.
A medical device including a balloon body and a restriction structure is designed, with the outer side of the balloon body coated with drugs, which provides pressure when the balloon is folded, prevents the drug from falling off, and releases the drug when the balloon is expanded.
By reducing the shedding of the drug during delivery, the drug is delivered to the lesion to the maximum extent, the drug's payload is increased, and the drug is quickly released at the lesion.
Smart Images
Figure CN222871149U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of medical devices, and in particular relates to a medical device for drug release. Background Art
[0002] Vascular stenosis is the narrowing of the lumen of a blood vessel (usually an artery) due to the deposition of plaque material, such as fat and calcium, within the lumen. Percutaneous transluminal angioplasty (PTA) is a procedure in which a flexible catheter is inserted into an artery and guided to the location of the vascular stenosis. A balloon is set at the distal end of the catheter. When the catheter reaches the vascular stenosis, the balloon at the end of the tube expands, and the pressure of the balloon expansion is used to force the plaque material against the arterial wall to open the blood vessel and improve blood flow.
[0003] When a balloon catheter is used to treat vascular stenosis, the opened blood vessel segment will have the effect or tendency to return to its original caliber after expansion, which can easily cause restenosis of the blood vessel lumen and lead to reduced blood flow. In addition, balloon inflation can damage the blood vessel wall, thereby causing smooth muscle hyperplasia and restenosis of the blood vessel lumen.
[0004] The procedure of drug-coated balloon (DCB) angioplasty is similar to that of ordinary balloon angioplasty, but the outside of the balloon is coated with drugs that can act on plaque materials or blood vessel walls, such as antiproliferative drugs. After being delivered to the lesion site, the drug is released within a short expansion time (30 to 60 seconds) to inhibit the proliferation of vascular smooth muscle cells, thereby preventing restenosis. Since the drug balloon has a short expansion time, it is hoped that the drug on the surface of the balloon can be quickly released in a short time after the drug-coated balloon expands to the lesion site. At the same time, the drug may be washed away by the blood during the delivery process, so that very little drug acts on the lesion site. The amount of drug absorption is usually increased by increasing the drug loading, but a large amount of excess drug flows to the distal end of the blood vessel, affecting the health of the patient. Therefore, how to ensure the rapid release of the drug at the lesion site while reducing the drug shedding during the delivery process of the drug-coated balloon, so as to maximize the delivery of the loaded drug to the lesion site is a technical problem that needs to be solved in this field.
[0005] Therefore, there is a need in the art to develop a medical device for drug release, which can carry drugs, and the amount of drugs carried by the device that are lost during the delivery process is low, and the amount of effective drugs that reach the lesion is high. Utility Model Content
[0006] In view of the shortcomings of the prior art, one of the purposes of the present invention is to provide a medical device for drug release, the medical device comprising:
[0007] A balloon body capable of switching between an expanded state and a folded state, wherein the outer side of the balloon body is at least partially coated with a drug coating;
[0008] A catheter is inserted into the interior of the balloon body, and the balloon body is arranged at the distal end of the catheter;
[0009] A restriction structure is arranged outside the balloon body, at least one of the proximal end and the distal end of the restriction structure is fixed on the catheter, the other of the proximal end and the distal end of the restriction structure is slidably arranged on the catheter, the proximal end of the restriction structure is close to the proximal end of the balloon body, and the distal end of the restriction structure is close to the distal end of the balloon body; the restriction structure is in a first state when the balloon body is in a folded state, and is in a second state when the balloon body is in an expanded state;
[0010] In the first state, the restriction structure applies a pressure greater than zero to the balloon body.
[0011] The utility model can provide a certain restraint effect for the folded balloon body by setting a restriction structure that exerts pressure on the balloon body outside the balloon body, so that the folded flaps of the balloon will not spread out during the delivery process, reducing the shedding of the drug coating in the area covered by the folded flaps, thereby minimizing the risk of the drug shedding before reaching the lesion. At the same time, the restriction structure separates the balloon body from the blood vessel wall, provides space for the drug coated on the outside of the folded flap of the balloon body, reduces the friction between the balloon body and the blood vessel wall, and can also reduce the shedding of the drug near the restriction structure to a certain extent.
[0012] When the medical device for drug release reaches the lesion, the balloon expands, the restriction structure is inflated by the balloon, the restriction structure and the balloon body move relative to each other, and the drug on the outside of the balloon body falls off from the balloon body due to exposure or scratching, thereby achieving the release of the drug at the lesion.
[0013] That is, the utility model reduces drug shedding during the delivery process by providing a limiting structure with contraction pressure on the balloon body, thereby delivering the loaded drug to the lesion to the maximum extent and increasing the effective loading amount of the drug.
[0014] Preferably, the distal end of the limiting structure is fixed on the catheter, and the proximal end of the limiting structure is slidably disposed on the catheter.
[0015] The proximal end of the limiting structure is slidably arranged on the catheter, and the distal end is fixed on the catheter, so that the extension distance of the distal end can be controlled, which is more conducive to the special blood vessel environment and reduces the probability of damage to the blood vessel wall.
[0016] Preferably, in the first state, the balloon body is contracted into a folding flap, and after the folding flap is rolled up, the balloon body is in a folded state, and the folding flap has an exposed outer upper surface and an inner lower surface folded and rolled up inside; in the first state, the limiting structure is at least arranged at the edge position of the outer upper surface of the folding flap of the balloon body.
[0017] The limiting structure is arranged on the outer upper surface of the folded flap, which can be understood as being arranged at the folded opening of the folded flap, and the limiting structure can keep the folded opening in a closed state during the delivery process through the restraining pressure to reduce the amount of drug falling off. However, this does not prove that the limiting structure must be arranged at the edge position of the outer upper surface of the folded flap, and can also be arranged at other positions of the outer upper surface.
[0018] It should be noted that the limiting structure can be set in a continuous or discontinuous manner at the edge position of the outer upper surface of the folding flap of the balloon body; illustratively, when the limiting structure has an extended silk thread along the edge position of the outer upper surface of the folding flap of the balloon body, it is continuous; when the limiting structure is a linear structure spirally wrapped around the balloon body, it is spaced at the edge of the outer upper surface of the folding flap of the balloon body.
[0019] In a specific embodiment, the proximal end of the limiting structure is limited to the proximal side of the proximal end of the balloon body; the distal end of the limiting structure is limited to the distal side of the distal end of the balloon body.
[0020] Limiting the proximal end (and / or distal end) of the restriction structure can improve the position stability of the restriction structure and reduce damage to the end of the balloon body.
[0021] The present invention does not limit the manner in which the proximal (and / or distal) limiting structure can be achieved, and those skilled in the art may select a suitable limiting manner according to actual conditions, such as any one of a limiting protrusion and a traction line, or a combination of at least two of them.
[0022] In the first state, the utility model does not impose any specific restrictions on the way in which the limiting structure provides pressure to the balloon body, and it can be any one of a predetermined shape and a traction wire, or a combination of at least two of them.
[0023] Preferably, the limiting structure has a predetermined structure or a traction wire is arranged at the proximal end, so as to provide pressure of the limiting structure on the balloon body in the first state.
[0024] In a specific embodiment, the restriction structure is pre-shaped to be in a radially contracted state, and the inner diameter of the restriction structure is pre-shaped to be smaller than the outer diameter of the balloon body in a folded state.
[0025] In another specific embodiment, the traction wire extends to the proximal end of the catheter and is used to control the switching of the restriction structure between the first state and the second state.
[0026] In a specific embodiment, the limiting structure is formed by axially extending struts arranged side by side and converged at both ends; or, the limiting structure is formed by winding at least one unidirectional spiral strut; or, the limiting structure is formed by a diamond-shaped hollow grid; or, the limiting structure is formed by axially extending silk threads arranged side by side and converged at both ends.
[0027] Optionally, the restriction structure is formed by laser engraving or by weaving silk threads.
[0028] Preferably, the material of the limiting structure is shape memory alloy.
[0029] Preferably, the balloon body is provided with a drug coating at least on the inner lower surface area of the folded valve.
[0030] The outer side of the balloon body described in the utility model is provided with a drug coating, and the drug coating is preferably provided in the inner lower surface area of the folding flap, and can also be provided simultaneously in other areas; when provided in the inner lower surface area of the folding flap, drug shedding is more easily suppressed, and the effective load of the drug can be further increased.
[0031] Compared with the prior art, the utility model has the following beneficial effects:
[0032] The utility model reduces the drug shedding during the delivery process by arranging a limiting structure with contraction pressure on the balloon body, thereby delivering the loaded drug to the lesion to the maximum extent and increasing the effective loading amount of the drug. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 A schematic diagram of the structure of the medical device for drug release provided in Example 1 during the delivery process;
[0034] Figure 2 A schematic diagram of the cross-sectional structure of the medical device for drug release provided in Example 1 during the delivery process;
[0035] Figure 3 It is a structural schematic diagram of a specific implementation of the restriction structure 300 in the second state B. DETAILED DESCRIPTION
[0036] The technical solution of the utility model is further explained below in conjunction with the specific implementation method. However, it should be noted that the specific implementation method is only a specific implementation and explanation of the essence of the technical solution of the utility model, and should not be understood as a limitation on the protection scope of the utility model.
[0037] The utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for the convenience of description, only the parts related to the relevant utility model are shown in the accompanying drawings.
[0038] In the description of the present invention, it should be understood that the terms "distal end" and "proximal end" should be understood as viewed from the direction of the surgical operator, the "distal end" is the end away from the surgical operator, and the "proximal end" is the end close to the surgical operator. The term "axial" should be understood as the direction of stent pushing, the length direction of the guide wire or the length direction of the stent, and the "radial" should be understood as the perpendicular direction of the "axial".
[0039] In the description of the present invention, it should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.
[0040] Example 1
[0041] like Figure 1-2 ( Figure 1 This is a schematic diagram of the structure of the medical device for drug release provided in Example 1 during the delivery process. Figure 2 As shown in the schematic diagram of the cross-sectional structure of the medical device for drug release provided in Example 1 during the delivery process, Example 1 provides a medical device for drug release, including:
[0042] The balloon body 100 and the catheter 200 passing through the balloon body 100 , wherein the catheter 200 includes a lumen for accommodating a guide wire and a lumen for introducing an inflation fluid, and the inflation fluid can switch the balloon body 100 between an expanded state A and a folded state B.
[0043] The medical device for drug release further includes a limiting structure 300 disposed outside the balloon body 100, the limiting structure 300 having an axially extending length, and the distal end of the limiting structure 300 is fixed to the catheter 200, and the proximal end of the limiting structure 300 is configured to be able to slide along the catheter 200. When the balloon body 100 is in the expanded state A, the limiting structure 300 is in the second state B; when the balloon body 100 is in the folded state B, the limiting structure 300 is in the first state A.
[0044] In the first state A, the limiting structure 300 applies a pressure of >0 to the balloon body 100. The pressure can be understood as the force applied to the balloon body 100 caused by the tendency of the limiting structure 300 to shrink inward. At this time, the balloon body 100 shrinks into a folding flap 110, and after the folding flap 110 is rolled up, the balloon body 100 is in a folded state, and the folding flap 110 has an exposed outer upper surface 111 and an inner lower surface 112 folded and rolled inside. The drug layer 400 of Example 1 is arranged on the inner lower surface 112 of the folding flap 110 and its coverage area. In other embodiments, the drug layer 400 can also be arranged on the outer surface of the balloon body 100 as a whole.
[0045] In the second state B, the proximal end of the limiting structure 300 slides to the proximal end of the balloon body 100 and is limited at the proximal end of the balloon body 100 by the balloon body 100 in the expanded state.
[0046] The limiting structure 300 includes parallel axially extending threads 310 with two ends gathered. In the first state A, the axially extending threads 310 of the limiting structure are arranged at the edge position 113 of the outer upper surface 111 of the folded flap 110 of the balloon body 100 .
[0047] The axially extending wire 310 is a shape memory alloy, and the proximal end is pulled by the traction wire 320, so that the axially extending wire 310 can be pressed more stably on the folded flap 110 of the balloon body 100 in the delivery state. In the first state A, the restriction structure is axially stretched and radially contracted to hold the balloon body 100.
[0048] The working principle of the medical device for drug release is roughly as follows:
[0049] During the delivery process, the balloon body 100 is in the folded state B, and the limiting structure 300 is in the first state A. At this time, the limiting structure 300 extends axially under the action of the traction wire 320, pressing the outer wall of the balloon body 100, so that the folded flap 110 of the balloon body 100 is under pressure and will not spread out, so that the balloon body 100 can carry enough drugs to the lesion, and the folded flap will not spread out during the delivery process, and the drug will not fall off before reaching the lesion. After reaching the lesion, the expansion medium enters the balloon body 100 from the catheter 200, expands it, and converts it from the folded state B to the expanded state A, the folded flap is opened, the drug coating is exposed, and is released from the balloon body 100 and transferred to the lesion. At this time, the traction wire 320 is appropriately relaxed to reduce the effect of the traction wire 320 on the balloon body. After the drug is released, the expansion medium is withdrawn from the catheter 200, and the balloon body 100 contracts according to a predetermined state. The traction wire 320 is pulled proximally to press the restriction structure on the balloon body 100, and then the balloon body 100 together with the restriction structure 300 are withdrawn from the body.
[0050] In a specific embodiment, the drug includes an antiproliferative drug and / or an immunosuppressive drug, and further preferably includes a hydrophilic antiproliferative drug and / or a hydrophilic immunosuppressive drug, such as any one of an albumin-bound paclitaxel drug and an albumin-bound docetaxel drug; or the albumin-bound immunosuppressive drug may also include any one of an albumin-bound sirolimus drug, an albumin-bound everolimus drug, an albumin-bound biolimus, an albumin-bound temsirolimus, an albumin-bound lidaformolimus, and an albumin-bound zotarolimus layer.
[0051] In other specific embodiments, the transition of the limiting structure 300 between the first state A and the second state B is achieved by pre-forming. Specifically, the axially extending wire 310 of the limiting structure 300 is pre-formed to be a straight line (without bends), that is, when no external force is applied, the limiting structure 300 is in a contracted state. At this time, the limiting structure is pressed against the balloon body 100 due to the pre-forming. When the balloon body 100 expands, the limiting structure 300 is subjected to an outward force and transitions to the second state B.
[0052] In a preferred embodiment, at least one end of the limiting structure 300 slides and the other end is fixed, wherein the sliding position of the sliding end is limited to the outside of the corresponding end of the balloon body 100. If the sliding end of the limiting structure 300 is the proximal end, the sliding end is limited to the proximal side of the proximal end of the balloon body 100; if the sliding end of the limiting structure 300 is the distal end, the sliding end is limited to the distal side of the distal end of the balloon body 100. In other embodiments, the proximal end of the limiting structure 300 is fixed to the catheter 200, the distal end of the limiting structure 300 is configured to be able to slide along the catheter 200, and the traction wire 320 is connected to the distal end of the limiting structure 300. The distal end of the limiting structure 300 is pushed to the farthest end by the traction wire 320 , and the limiting structure 300 is in the first state A. After the balloon body 100 expands, the limiting structure 300 is deformed to the second state B, and the distal end of the limiting structure 300 moves to the distal end of the balloon body 100 .
[0053] In a specific embodiment, Figure 3 As shown, a connecting strut is provided between adjacent axially extending wires 310 of the limiting structure 300, and the connecting strut has an S-shaped curved strut or a broken line strut 303 ( Figure 3 is a structural diagram of a specific embodiment of the restriction structure 300 in the second state B). In this specific embodiment, the transition of the restriction structure 300 between the first state A and the second state B can be achieved by pre-forming the restriction structure 300 to be able to compress the outer side of the balloon body 100 in the folded state B; or by pulling the wire to the proximal end (or distal end) of the restriction structure 300. If the pressure on the balloon body 100 in the folded state B is provided by pre-forming, the restriction structure 300 needs to be pre-formed into a radially contracted state, and the inner diameter of the pre-formed restriction structure 300 is preferably smaller than the outer diameter of the balloon body 100 in the folded state.
[0054] In another specific embodiment, the limiting structure 300 may also be one or more spiral struts that rotate circumferentially and advance axially by laser engraving a shape memory alloy tube, or a diamond-shaped hollow grid formed by connecting struts end to end by laser engraving a shape memory alloy tube. In this specific embodiment, the transition of the limiting structure 300 between the first state A and the second state B may be achieved by pre-forming the outer side of the balloon body 100 that can be compressed in the folded state B; or by pulling the proximal end (or distal end) of the limiting structure 300 by a traction wire.
[0055] Comparative Example 1
[0056] The difference from the first embodiment is that the limiting structure 300 is not provided.
[0057] Performance Testing
[0058] The medical devices for drug release of Example 1, Example 2 and Comparative Example 1 were measured according to the following method:
[0059] (1) According to T / ZAMEI0003-2023 Paclitaxel Drug Coating for Medical Devices for Drug Release 5.12 Paclitaxel Drug Coating Performance The initial drug loading A (according to the method in Appendix A, in μg / mm2) of the medical devices for drug release of Example 1 and Comparative Example 1 was measured respectively. 2 );
[0060] (2) Pushing the medical devices for drug release to a distance of 1 m in the blood vessel model respectively, and quickly taking out the corresponding medical devices for drug release;
[0061] (3) The drug loading of the removed medical device for drug release is measured again according to Section 5.12 Performance of Paclitaxel Drug Coating of T / ZAMEI0003-2023 Paclitaxel Drug Coating for Medical Devices for Drug Release, and recorded as the drug loading remaining amount B;
[0062] Drug delivery loss % = (AB) / A x 100%.
[0063] It was determined that the drug delivery loss in Example 1 was 7%, and the drug delivery loss in Comparative Example 1 was 51.5%.
[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A medical device for drug release, characterized in that: The medical devices include: A balloon body capable of switching between an expanded state and a folded state, wherein the outer side of the balloon body is at least partially coated with a drug coating; A catheter is inserted into the interior of the balloon body, and the balloon body is arranged at the distal end of the catheter; A restriction structure is arranged outside the balloon body, at least one of the proximal end and the distal end of the restriction structure is fixed on the catheter, the other of the proximal end and the distal end of the restriction structure is slidably arranged on the catheter, the proximal end of the restriction structure is close to the proximal end of the balloon body, and the distal end of the restriction structure is close to the distal end of the balloon body; the restriction structure is in a first state when the balloon body is in a folded state, and is in a second state when the balloon body is in an expanded state; In the first state, the restriction structure applies a pressure greater than zero to the balloon body.
2. The medical device for drug release according to claim 1, characterized in that: The distal end of the limiting structure is fixed on the catheter, and the proximal end of the limiting structure is slidably disposed on the catheter.
3. The medical device for drug release according to claim 1, characterized in that: In the first state, the balloon body is contracted into a folded flap, and after the folded flap is rolled up, the balloon body is in a folded state, and the folded flap has an exposed outer upper surface and an inner lower surface folded and rolled up inside; in the first state, the limiting structure is at least arranged at the edge position of the outer upper surface of the folded flap of the balloon body.
4. The medical device for drug release according to claim 1, characterized in that: The proximal end of the restriction structure is limited to the proximal side of the proximal end of the balloon body; The distal end of the limiting structure is limited at the distal side of the distal end of the balloon body.
5. The medical device for drug release according to claim 1, characterized in that: The limiting structure has a predetermined structure or a traction wire is arranged at the proximal end, and is used to provide pressure of the limiting structure on the balloon body in the first state.
6. The medical device for drug release according to claim 5, characterized in that: The restriction structure is pre-shaped to be in a radially contracted state, and the inner diameter of the restriction structure is pre-shaped to be smaller than the outer diameter of the balloon body in a folded state.
7. The medical device for drug release according to claim 5, characterized in that: The limiting structure is formed by axially extending struts arranged side by side and bound at both ends; or, the limiting structure is formed by winding at least one unidirectional spiral strut; or, the limiting structure is formed by a diamond-shaped hollow grid; or, the limiting structure is formed by axially extending silk threads arranged side by side and bound at both ends.
8. The medical device for drug release according to claim 7, characterized in that: The limiting structure is formed by laser engraving or by weaving of silk threads.
9. The medical device for drug release according to claim 7, characterized in that: The material of the limiting structure is shape memory alloy.
10. The medical device for drug release according to claim 3, characterized in that: The balloon body is provided with a drug coating at least on the inner lower surface area of the folded valve.