Medicine carrying device

Abstract

The invention provides a medicine carrying device which comprises a medicine carrying support and medicine, and the medicine carrying support can be compressed after being subjected to external force and can be unfolded after the external force is removed; the drug-loading stent is provided with a drug-loading area for loading the drug; the medicine carrying area can prevent at least part of the medicine from being exposed on the outer surface of the medicine carrying support when the medicine carrying support is in a compressed state, and then medicine loss in the conveying process is reduced. According to the drug-loading stent, drugs can be loaded in the drug-loading area, so that drug loss caused by the fact that the drugs are exposed on the outer surface of the drug-loading stent in the conveying process is avoided, the drug conveying rate is increased, and then the treatment effect on diseased blood vessels is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a drug carrying device. Background Art

[0002] Interventional therapy is an effective method for treating atherosclerotic stenosis, usually using devices such as drug-eluting stents or balloon catheters. In order to avoid permanent implantation of drug-eluting stents in the body and reduce the occurrence of complications related to drug-eluting stents, balloon catheter dilation of local lesions is a commonly used method.

[0003] In recent years, drug-eluting balloons are a new technology for preventing restenosis after interventional surgery. This treatment method involves coating the surface of the balloon with drugs that prevent intimal hyperplasia. When the balloon reaches the diseased vessel wall and is inflated and expanded, the drugs on the balloon surface can contact the intima of the vessel wall and be transferred to the vessel wall through rapid release under pressure. The drugs on the vessel wall can play a role in preventing intimal hyperplasia, thereby preventing restenosis after vascular intervention.

[0004] Since the drug balloon blocks blood flow when it is filled and expanded in the blood vessel, the drug balloon releases the drug for too long, which can cause myocardial ischemia. Therefore, the time that the drug balloon can act on the blood vessel wall after filling is very limited, and the limited action time of the drug on the blood vessel wall will affect the treatment effect of vascular stenosis. In addition, when the drug balloon in the prior art is delivered through a catheter, the drug coating on the outer surface of the drug balloon is more easily damaged by the friction of the microcatheter, thereby affecting the treatment effect of the drug balloon on the diseased blood vessel. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a drug carrying device, whose drug carrying stent can load drugs in the drug carrying area to avoid drug loss during delivery due to exposure of drugs on the outer surface of the drug carrying stent, thereby improving the drug delivery rate and thus enhancing the treatment effect.

[0006] To achieve the above-mentioned objectives, the present invention provides a drug-carrying device, comprising a drug-carrying stent and a drug, wherein the drug-carrying stent can be compressed after being subjected to an external force, and can be expanded after the external force is removed; the drug-carrying stent has a drug-carrying area for loading the drug, and the drug-carrying area can prevent at least a portion of the drug from being exposed on the outer surface of the drug-carrying stent when the drug-carrying stent is in a compressed state, thereby reducing drug loss during transportation.

[0007] Optionally, the drug-carrying area can also release the drug when the drug-carrying stent is in an expanded state; after releasing the drug, the drug-carrying stent can also be compressed and recovered.

[0008] Optionally, the drug-loaded stent includes a stent body and a coating, wherein the coating covers at least a portion of the outer surface of the stent body; the drug-loading area on the coating and / or the stent body is loaded with the drug.

[0009] Optionally, after the drug-loaded stent is compressed, the covering film includes a folded area and an unfolded area, the folded area wraps the unfolded area, and the drug-loaded area is located between the folded area and the unfolded area.

[0010] Optionally, after the drug-loaded stent is deployed, the area of ​​the drug-loaded region in the coating accounts for 10% to 90% of the surface area of ​​the coating.

[0011] Optionally, the drug loading area includes a plurality of receiving grooves arranged on the outer surface of the coating.

[0012] Optionally, the drug-carrying area is disposed on the outer surface of the stent body, and the coating is used for allowing the drug to penetrate, so that the drug on the stent body can be released through the coating.

[0013] Optionally, the coating is woven from fiber filaments, and gaps are formed between adjacent fiber filaments; the gaps constitute the drug-loading area, or the gaps are used for the drug to pass through.

[0014] Optionally, the size of the gap is 0.1um to 80um.

[0015] Optionally, the stent body includes a proximal segment, a middle segment and a distal segment which are sequentially connected along the axial direction from the proximal end to the distal end; and the coating covers at least a portion of the outer surface of the middle segment.

[0016] Optionally, the proximal section is a trumpet-mouth structure or a sloped-mouth structure whose surface area gradually increases toward the distal end.

[0017] Optionally, the drug-loaded stent has at least one of the following structures:

[0018] The length of the proximal segment in the axial direction of the stent body accounts for 0.1% to 30% of the total length of the stent body;

[0019] The length of the middle section in the axial direction of the stent body accounts for 60% to 90% of the total length of the stent body;

[0020] The length of the distal segment in the axial direction of the stent body is less than 10% of the total length of the stent body.

[0021] Optionally, the coating forms a plurality of fixing points when connected to the stent body.

[0022] Optionally, the stent body comprises a proximal segment, a middle segment and a distal segment connected in sequence along the axial direction from the proximal end to the distal end; the fixing point is set at one or more positions in the proximal segment, the middle segment and the distal segment; the area of ​​the fixing point is 1mm 2 ~20mm 2 ; The number of the fixing points in the circumferential direction of the bracket body is 1 to 10.

[0023] Optionally, the outer diameters of different regions of the drug-loaded stent along its own axial direction are the same or different, and the outer diameter of the drug-loaded stent is 1 mm to 10 mm.

[0024] Optionally, the drug-carrying device further comprises at least one connecting rod, which is connected to the proximal end of the drug-carrying stent and can be pulled to compress the drug-carrying stent and then retract it.

[0025] The present invention provides a drug-carrying device, comprising a drug-carrying stent and a drug, wherein the drug-carrying stent can be compressed after being subjected to an external force, and can be expanded after the external force is removed; the drug-carrying stent has a drug-carrying area for loading the drug, and the drug-carrying area can prevent at least a portion of the drug from being exposed on the outer surface of the drug-carrying stent when the drug-carrying stent is in a compressed state, thereby preventing the loss of the drug during the delivery process.

[0026] With such a configuration, the drug can be loaded into the drug loading area of ​​the drug loading stent. On the one hand, it can better avoid the loss of drugs in the drug loading stent during the delivery process, increase the drug delivery rate, and enhance the therapeutic effect of the drug loading stent. On the other hand, since the internal part of the drug loading stent can supply blood circulation after it is deployed, it can avoid blocking the blood flow and causing ischemia of the distal brain tissue, so that the drug loading stent can be in contact with the blood vessel wall for a longer time, further enhancing the therapeutic effect of the drug and improving the success rate of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the axial structure of a drug-loaded stent in a preferred embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the axial structure of a drug-eluting stent in another preferred embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of the radial structure of a drug-loaded stent in a preferred embodiment of the present invention, wherein the drug-loaded stent is in a compressed state;

[0030] Figure 4 This is a schematic diagram of the radial structure of a drug-loaded stent in a preferred embodiment of the present invention, wherein the drug-loaded stent is in a semi-expanded state;

[0031] Figure 5It is a schematic diagram of the radial structure of a drug-loaded stent in a preferred embodiment of the present invention, wherein the drug-loaded stent is in a fully expanded state;

[0032] Figure 6 It is a schematic structural diagram of a drug-loaded stent and a connecting rod in a preferred embodiment of the present invention.

[0033] In the figure: a drug-eluting stent 1; a stent body 11; a coating 12; a folded area 13; a covered position 131; an exposed position 132; an unfolded area 14; and a connecting rod 2. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0035] The terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. The term "proximal end" generally refers to the end close to the operator; the "distal end" is the end opposite to the "proximal end", and generally refers to the end away from the operator.

[0036] A preferred embodiment of the present invention provides a drug-carrying device for delivering and releasing drugs to diseased blood vessel walls. The drugs may be anticoagulant drugs such as rapamycin, paclitaxel, rapamycin derivatives, heparin, etc. After being released onto the blood vessel wall, the drugs can play an anti-intimal hyperplasia role, thereby preventing restenosis after vascular intervention.

[0037] Reference Figure 1 and Figure 2As shown, the drug-carrying device includes a drug-carrying stent 1 and a drug, and the drug-carrying stent 1 is used to be compressed after being subjected to an external force, and to be deployed after the external force is removed. The drug-carrying stent 1 has a drug-carrying area (not shown) for loading the drug, and the drug-carrying area can prevent at least part of the drug from being exposed on the outer surface of the drug-carrying stent 1 when the drug-carrying stent 1 is in a compressed state, thereby reducing the loss of the drug during the delivery process. That is to say, in the present application, the drug is not coated on the outer surface of the drug-carrying stent 1 in a compressed state, but is placed in the drug-carrying area inside the drug-carrying stent 1. It should be understood that the outer surface of the drug-carrying stent 1 in the compressed state refers to the surface of the drug-carrying stent 1 exposed to the outside when the drug-carrying stent 1 is in a compressed state.

[0038] Preferably, the drug loading area can be disposed on the folded or covered surface of the drug loading stent 1 when in a compressed state, or can be disposed in micropores or microgrooves inside the drug loading stent 1 .

[0039] Since the outer surface of the drug-loaded stent 1 in a compressed state may rub against the delivery device, friction loss between the drug and the delivery device may be caused during delivery. In the drug-loaded device provided by the present invention, the drug can be loaded in the drug-loaded area of ​​the drug-loaded stent 1. On the one hand, it can better avoid the loss of the drug during the delivery of the drug-loaded stent 1, improve the drug delivery rate, and enhance the therapeutic effect of the drug-loaded stent 1; on the other hand, since the drug-loaded stent 1 can supply blood circulation inside after being unfolded, it can avoid blocking the blood flow and causing ischemia of the distal brain tissue, so that the drug-loaded stent 1 can contact the blood vessel wall for a longer time, further enhance the therapeutic effect of the drug, and improve the success rate of the operation. In addition, the drug-loaded stent 1 is more flexible than the drug balloon, and is easier to conform to the curvature of the blood vessel, so that the wall adhesion is better, so that the drug can fully contact the blood vessel wall, and it is not easy to straighten the blood vessel and damage the blood vessel branch.

[0040] In addition, the drug loading area can also release drugs when the drug loading stent 1 is in the expanded state. The drug loading stent 1 after releasing the drug can also be compressed and recovered. In more detail, the drug loading stent 1 in the expanded state is used to abut against a target position to release the drug to the target position. Generally, the target position refers to a stenotic blood vessel wall, and the drug is used to be released to the stenotic blood vessel wall to prevent restenosis of the blood vessel wall.

[0041] The present application does not limit the shape of the drug-loaded stent 1. The outer diameters of different regions of the drug-loaded stent 1 along its own axis are the same or different. In other words, the drug-loaded stent 1 along its own axis can be a constant diameter structure or a variable diameter structure. The outer diameter of the drug-loaded stent 1 is 1 mm to 10 mm. The operator can choose to use a drug-loaded stent 1 with an appropriate shape according to actual conditions.

[0042] In order to match with delivery devices of different specifications and facilitate deployment, in the compressed state, the diameter of the drug-loaded stent 1 is 0.13 inch to 0.04 inch.

[0043] In a specific embodiment, the drug loading area includes a receiving groove (not shown) disposed on the outer surface of the drug loading stent 1 , and the drug is placed in the receiving groove. The receiving groove can be a groove or a through groove on the outer surface of the drug loading stent 1 .

[0044] In more detail, when the drug-loaded stent 1 is in a compressed state, since the drug is placed in the receiving groove, the drug will not fall off due to friction when the delivery device (such as a delivery catheter) moves relative to the drug-loaded stent 1, thereby avoiding drug loss, so that the drug-loaded stent 1 can carry a sufficient dose of the drug to the blood vessel wall. After the delivery device is withdrawn and the drug-loaded stent 1 is automatically deployed, the drug can be released from the receiving groove and released onto the blood vessel wall, thereby allowing the drug to be released onto the blood vessel wall to prevent blockage and restenosis of the blood vessel.

[0045] Reference Figure 1 and Figure 2 As shown, in a preferred embodiment, the drug-eluting stent 1 includes a stent body 11 and a coating 12. The stent body 11 has a shape memory property, and the coating 12 covers at least a portion of the outer surface of the stent body 11. Specifically, the coating 12 can cover the entire outer surface of the stent body 11, or the coating 12 can only cover a portion of the outer surface of the stent body 11.

[0046] The present application does not limit the materials of the drug-loaded stent body 11 and the coating 12. The material of the stent body 11 can be a combination of one or more of polylactic acid, polycaprolactone, polyurethane, and derivatives or copolymers of the above polymers. The material of the stent body 11 can also be a combination of one or more of nickel-titanium alloy or nickel-titanium alloy containing a precious metal core. The material of the coating 12 can be a combination of one or more of polyurethane, silicone, polytetrafluoroethylene, polylactic acid, polyester, and polyurethane.

[0047] Specifically, the stent body 11 can be prepared by cutting or weaving, or by a combination of cutting and weaving. The stent body 11 and the coating 12 can be fixedly connected by hot melting, gluing, suturing or electrostatic spinning.

[0048] In one embodiment, the coating 12 has a drug loading area, and the drug loading area on the coating 12 is loaded with drugs; in another embodiment, the stent body 11 has a drug loading area, and the drug loading area on the stent body 11 is loaded with drugs; in yet another embodiment, both the stent body 11 and the coating 12 have drug loading areas, and the drug loading areas on the stent body 11 and the coating 12 are used to load drugs.

[0049] Reference Figure 3As shown, in a preferred example, the drug-loaded stent 1 is in a compressed state, the coating 12 includes a folded area 13 and an unfolded area 14 , the folded area 13 wraps the unfolded area 14 , and the drug-loaded area is located between the folded area 13 and the unfolded area 14 .

[0050] In this embodiment, the folding area 13 includes a covering position 131 and an exposed position 132 that are arranged opposite to each other. In the folded state, the covering position 131 is in contact with the unfolded area 14. The cavity between the covering position 131 and the unfolded area 14 forms a drug loading area, and the drug can be coated on the covering position 131 and / or the unfolded area 14 to prevent the drug from being exposed on the outer surface of the drug loading stent 1.

[0051] Reference Figure 4 As shown, when the drug-loaded stent 1 reaches the target position, the restraint on the drug-loaded stent 1 is released, and the folded area 13 of the coating 12 can automatically unfold after the external force is removed, so that the covering position 131 gradually unfolds and forms the outer surface of the stent body 11 after unfolding.

[0052] Reference Figure 5 As shown, after the drug-loaded stent 1 is fully unfolded, both the folded area 13 and the unfolded area 14 can be fully unfolded. At this time, the folded area 13 and the unfolded area 14 together form the outer surface of the drug-loaded stent 1 and can be in contact with the blood vessel wall, thereby making the drug on the covering position 131 and / or the unfolded area 14 directly contact the blood vessel wall to release the drug to the blood vessel wall.

[0053] Generally speaking, the number of folding regions 13 in the covering film 12 is at least two, so that the covering position 131 of the folding region 13 can contact the blood vessel wall after being unfolded, thereby improving the treatment effect. In this embodiment, the number of folding regions 13 in the covering film 12 is three. In other embodiments, the number of folding regions 13 can also be 2, 4 or more.

[0054] Preferably, after the drug-loaded stent 1 is deployed, the area of ​​the drug-loaded region in the coating 12 accounts for 10% to 90% of the surface area of ​​the coating 12 , and as the proportion of the area of ​​the drug-loaded region increases, the therapeutic effect of the drug-loaded stent 1 increases.

[0055] In a preferred embodiment, the drug loading area includes a plurality of receiving grooves disposed on the outer surface of the coating 12. When the drug loading stent 1 is in the deployed state, the drug can escape from the receiving grooves and be released to the blood vessel wall. It should be understood that the outer surface of the coating 12 in the deployed state refers to the surface of the coating 12 exposed to the outside when the coating 12 is in the deployed state.

[0056] In more detail, the receiving groove may be located on the surface of the folded area 13 or the unfolded area 14. More preferably, the receiving groove may also be located on the surface of both the folded area 13 and the unfolded area 14, so that the drug-carrying stent 1 can carry more doses of drugs.

[0057] In one example, the coating 12 is preferably made of polytetrafluoroethylene (PTFE) or fiber textile material and woven from fiber filaments, with gaps formed between adjacent fiber filaments, the gaps constituting drug loading areas. The size of the gaps is 0.1 um to 80 um, so as to be able to load a corresponding dose of drug.

[0058] In another example, the coating 12 itself may be recessed inward to form a receiving groove. For example, the coating 12 may be configured as a pleated film, that is, the coating 12 may form grooves and microgrooves for storing drugs in a natural state or through processing.

[0059] It needs to be explained that when the drug-loaded stent 1 is in a compressed state, the receiving groove on the outer surface of the coating 12 is in a closed or semi-closed state, and the receiving groove can contain drugs to avoid the drugs being exposed to the outer surface of the drug-loaded stent 1; when the drug-loaded stent 1 is in an expanded state, the gap between adjacent fiber filaments in the coating 12 increases, or the recessed area on the surface of the coating 12 becomes a plane after expansion, so that the drugs can be separated from the receiving groove and released to the blood vessel wall.

[0060] As a specific embodiment, the outer surface of the stent body 11 may not be covered with the coating 12. In this case, a receiving groove for loading drugs may be provided on the outer surface of the stent body 11. When the drug-loaded stent 1 is in the deployed state, the drugs can escape from the receiving groove and be released to the blood vessel wall.

[0061] In another preferred example, the drug-carrying area is disposed on the outer surface of the stent body 11 , and the coating 12 is used for drug permeation, so that the drug on the stent body 11 can pass through the coating 12 and be released to the blood vessel wall.

[0062] As a preferred example, the drug can be directly coated on the outer surface of the stent body 11, or the drug can be placed in a receiving groove on the outer surface of the stent body 11. The coating 12 can be configured as a porous structure, a microporous structure or a microgroove structure for convenient drug penetration.

[0063] In another example, the coating 12 is woven from fiber filaments, and gaps are formed between adjacent fiber filaments for the drug to penetrate. The size of the gaps is 0.1 um to 80 um to facilitate the penetration of the drug.

[0064] Reference Figure 1 and Figure 2As shown, the stent body 11 includes a proximal segment, an intermediate segment and a distal segment (not shown) connected in sequence along the axial direction from the proximal end to the distal end. After the stent body 11 is expanded, the proximal segment, the intermediate segment and the distal segment can all allow blood to flow through. The distal segment is preferably anchored on the inner wall of the blood vessel to achieve the fixation of the stent body 11 in the blood vessel.

[0065] In one embodiment, the coating 12 covers at least a portion of the outer surface of the middle segment. In another embodiment, the coating 12 covers at least a portion of the outer surface of the middle segment and at least a portion of the outer surface of the proximal segment and / or the distal segment.

[0066] Reference Figure 6 As shown, the drug-carrying device further comprises at least one connecting rod 2, which is connected to the proximal end of the drug-carrying stent 1 and can be pulled to compress the drug-carrying stent 1 and then recover it.

[0067] Preferably, the proximal end section is a bell mouth structure or a slope mouth structure whose surface area gradually increases toward the distal end (refer to Figure 2 ). With such a configuration, the operator can compress and recycle the drug-loaded stent 1 by simply pulling the connecting rod 2, thereby improving the recycling efficiency and reducing the difficulty of recycling, so that the drug-loaded stent 1 can be easily recycled into the delivery device. In other embodiments, the proximal section can also be a cylindrical structure.

[0068] To ensure a better therapeutic effect, the drug-loaded stent 1 has at least one of the following structures: the length of the proximal segment in the axial direction of the stent body 11 accounts for 0.1% to 30% of the total length of the stent body 11; the length of the middle segment in the axial direction of the stent body 11 accounts for 60% to 90% of the total length of the stent body 11; the length of the distal segment in the axial direction of the stent body 11 accounts for less than 10% of the total length of the stent body 11.

[0069] The present application does not limit the connection method between the stent body 11 and the coating 12. Preferably, the coating 12 forms multiple fixing points when connected to the stent body 11, that is, the coating 12 can be fixed to the stent body 11 at selected connection points in the unfolded state.

[0070] Furthermore, the fixing point can be set at one or more positions in the proximal section, the middle section or the distal section. To ensure firm fixation, the area of ​​the fixing point is preferably 1 mm 2 ~20mm 2 The number of the fixing points in the circumferential direction of the bracket body 11 is 1 to 10.

[0071] In other examples, the coating 12 is connected to the stent body 11 to form a line fixation or a surface fixation, that is, the coating 12 can be fixed to the stent body 11 by selecting a connection line or a connection surface in the unfolded state.

[0072] In summary, the drug-carrying device provided by the present invention includes a drug-carrying stent 1, and the drug can be loaded in the drug-carrying area of ​​the drug-carrying stent 1. On the one hand, it can better avoid the loss of the drug in the drug-carrying stent 1 during the transportation process, improve the drug delivery rate, and enhance the therapeutic effect of the drug-carrying stent 1; on the other hand, since the drug-carrying stent 1 can supply blood circulation inside after being unfolded, it can avoid blocking the blood flow and causing ischemia of the distal brain tissue, so that the drug-carrying stent 1 can be in contact with the blood vessel wall for a longer time, so as to further enhance the therapeutic effect of the drug and improve the success rate of the operation. In addition, the drug-carrying stent 1 is more flexible than the drug balloon, and is easier to conform to the curvature of the blood vessel, so that the wall adhesion is better, so that the drug can fully contact the blood vessel wall, and it is not easy to straighten the blood vessel and damage the blood vessel branch.

[0073] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A drug carrying device, characterized in that: It includes a drug-loaded stent and a drug, wherein the drug-loaded stent can be compressed after being subjected to an external force, and can be expanded after the external force is removed; the drug-loaded stent has a drug-loading area for loading the drug; the drug-loading area can prevent at least a portion of the drug from being exposed on the outer surface of the drug-loaded stent when the drug-loaded stent is in a compressed state, thereby reducing drug loss during transportation.

2. The drug-carrying device as described in claim 1, wherein the drug-carrying area can also release the drug when the drug-carrying stent is in an expanded state; and the drug-carrying stent after releasing the drug can also be compressed and recovered.

3. The drug carrying device according to claim 1, characterized in that: The drug-loaded stent comprises a stent body and a coating, wherein the coating covers at least a portion of the outer surface of the stent body, and the drug-loaded area on the coating and / or the stent body is loaded with the drug.

4. The drug carrying device according to claim 3, characterized in that: After the drug-loaded stent is compressed, the covering film includes a folded area and an unfolded area, the folded area wraps the unfolded area, and the drug-loaded area is located between the folded area and the unfolded area.

5. The drug carrying device according to claim 4, characterized in that: After the drug-loaded stent is deployed, the area of ​​the drug-loaded region in the coating accounts for 10% to 90% of the surface area of ​​the coating.

6. The drug carrying device according to claim 3, characterized in that: The drug loading area includes a plurality of receiving grooves arranged on the outer surface of the coating.

7. The drug carrying device according to claim 3, characterized in that: The drug-carrying area is arranged on the outer surface of the stent body, and the coating is used for the drug to penetrate, so that the drug on the stent body can penetrate the coating and be released.

8. The drug carrying device according to claim 6 or 7, characterized in that: The coating is woven from fiber filaments, and gaps are formed between adjacent fiber filaments; the gaps constitute the drug-carrying area, or the gaps are used for the drug to pass through.

9. The drug carrying device according to claim 8, characterized in that: The size of the gap is 0.1um to 80um.

10. The drug carrying device according to any one of claims 3 to 7, characterized in that: The stent body comprises a proximal section, a middle section and a distal section which are sequentially connected along the axial direction from the proximal end to the distal end; the coating covers at least a portion of the outer surface of the middle section.

11. The drug carrying device according to claim 10, characterized in that: The proximal end section is a trumpet-mouth structure or a slope-mouth structure whose surface area gradually increases toward the distal end.

12. The drug carrying device according to claim 10, characterized in that: The drug-loaded stent has at least one of the following structures: The length of the proximal segment in the axial direction of the stent body accounts for 0.1% to 30% of the total length of the stent body; The length of the middle section in the axial direction of the stent body accounts for 60% to 90% of the total length of the stent body; The length of the distal segment in the axial direction of the stent body is less than 10% of the total length of the stent body.

13. The drug carrying device according to any one of claims 3 to 7, characterized in that: The coating forms a plurality of fixing points when connected to the stent body.

14. The drug carrying device according to claim 13, characterized in that: The stent body comprises a proximal segment, a middle segment and a distal segment which are connected in sequence along the axial direction from the proximal end to the distal end; the fixing point is arranged at one or more positions in the proximal segment, the middle segment and the distal segment; the area of ​​the fixing point is 1mm 2 ~20mm 2 ; The number of the fixing points in the circumferential direction of the bracket body is 1 to 10.

15. The drug carrying device according to any one of claims 1 to 7, characterized in that: The outer diameters of different regions of the drug-loaded stent along its own axial direction are the same or different, and the outer diameter of the drug-loaded stent is 1 mm to 10 mm.

16. The drug carrying device according to any one of claims 1 to 7, characterized in that: It also includes at least one connecting rod, which is connected to the proximal end of the drug-loaded stent and can be pulled to compress the drug-loaded stent and then retract it.

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