A method of making a balloon catheter protective sheath

Abstract

The application relates to a preparation method of a balloon catheter protective sleeve, which comprises the following steps: a, immersing the folded balloon in a degradable polymer solution; b, removing the excess degradable polymer solution on the surface of the balloon; and c, solidifying the degradable polymer solution on the surface of the balloon to form the protective sleeve in situ. The degradable protective sleeve formed on the outer side of the balloon of the balloon catheter can effectively prevent the balloon from being loosened and inflated after being folded and wound, and the balloon catheter is affected in use; the protective sleeve can be naturally dissolved in the blood vessel during the operation process, and does not need to be manually removed, so that the safety is better.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a method for preparing a protective sleeve for a balloon catheter. Background Technology

[0002] Existing balloon dilation catheters typically use a protective sheath to cover the balloon. The balloon is folded using a balloon folding machine before the protective sheath is put on to prevent it from unraveling and expanding, thus affecting its use. However, this protective sheath needs to be manually removed by medical staff during surgery, increasing the difficulty of the procedure. Furthermore, there is a risk that the sheath may be too tight for the doctor to remove, or that an intern may insert the catheter directly into the body without removing the protective sheath. This is inconvenient and poses certain safety risks. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a protective sleeve for a balloon catheter, which forms a biodegradable protective sleeve in situ on the outside of the balloon. This protective sleeve can dissolve naturally in the blood vessel without the need for manual removal.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] This invention provides a method for preparing a protective sleeve for a balloon catheter. The balloon catheter includes a catheter and a balloon disposed on the catheter and capable of expansion or contraction. The preparation method includes folding the balloon into segments, and then forming the protective sleeve on the balloon using a protective sleeve forming device. The protective sleeve forming device includes a container, a limiting member movably disposed within the container and having a relaxed state and a tightened state, a driving mechanism connected to the limiting member and used to drive the limiting member to switch between the relaxed and tightened states, a curing mechanism disposed within the container, and a feeding mechanism connected to the container and used to introduce or discharge a raw material liquid into the container.

[0006] Forming the protective sleeve on the balloon using the protective sleeve forming apparatus includes the following steps:

[0007] a. The raw material liquid is introduced into the container through the liquid feeding mechanism, and then the folded balloon is inserted into the relaxed restrictor and immersed in the raw material liquid. The balloon catheter is vacuumed to make the inside of the balloon catheter a vacuum environment or a low-pressure environment. The raw material liquid is a biodegradable polymer solution.

[0008] b. The driving mechanism drives the limiting member to switch from a relaxed state to a tightened state, removing excess biodegradable polymer solution from the surface of the balloon.

[0009] c. The biodegradable polymer solution in the container is discharged through the liquid feeding mechanism, and the curing mechanism is activated to cure the biodegradable polymer solution on the surface of the balloon, forming the protective sleeve in situ.

[0010] Preferably, the limiting member is a mesh-like annular structure. When the limiting member switches from a relaxed state to a tightened state, at least part of the inner diameter of the limiting member decreases and can compress the balloon.

[0011] Preferably, the limiting member has openings at both the top and bottom.

[0012] Preferably, when the limiting member is in a tightened state, the middle diameter of the limiting member is small and the diameters at the top and bottom ends are large.

[0013] In some embodiments, the limiting member is hourglass-shaped when it is in a tightened state.

[0014] Preferably, the drive mechanism is connected to at least one of the upper and lower ends of the limiting member, and is capable of driving that end to move away from the other end to switch the limiting member to a tightened state; or to move towards the other end to switch the limiting member to a relaxed state.

[0015] More preferably, the driving mechanism includes a slide rail extending along the height direction of the container, two connecting members disposed at the upper and lower ends of the slide rail, and a driving member. The upper and lower ends of the limiting member are respectively connected to the two connecting members. At least one of the two connecting members is connected to the driving member and can slide along the extension direction of the slide rail under the drive of the driving member. The driving mechanism has two sets symmetrically arranged on the outside of the limiting member.

[0016] In some embodiments, one of the two connectors is fixed, while the other is slidably mounted on the slide rail. Further, the upper connector slides.

[0017] In some embodiments, both connectors are slidably mounted on the slide rail, and the drive member has two sets corresponding to the two connectors.

[0018] Preferably, the preparation method further includes pressurizing the container after step a and before step b to control the pressure inside the container to 0.11-0.2 MPa and maintaining it for 1-3 minutes.

[0019] Preferably, step a includes immersing the limiting member in the biodegradable polymer solution for 20–60 seconds, and then evacuating the balloon catheter.

[0020] Preferably, the curing mechanism includes a plurality of ultraviolet lamps arranged along the inner periphery of the container within the container.

[0021] Preferably, the preparation method further includes, after step c, the step of causing the driving mechanism to drive the limiting member to switch from a tightened state to a relaxed state, and then removing the balloon catheter.

[0022] Preferably, based on 100% of the total mass of the biodegradable polymer solution, the biodegradable polymer solution comprises:

[0023] 5-10% polyethylene glycol diacrylate

[0024] Photoinitiator 0.1–2.5%,

[0025] Dissolution promoter 0.5-1%,

[0026] Solvent balance.

[0027] In some embodiments, the number-average molecular weight of the polyethylene glycol diacrylate is 700 to 1000.

[0028] In some embodiments, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0029] In some embodiments, the solubility promoter is lactic acid and / or lactide.

[0030] In some embodiments, the solvent is water.

[0031] In some embodiments, the biodegradable polymer solution further includes phosphate-buffered saline (PBS) to adjust the pH of the biodegradable polymer solution to 7.35–7.45.

[0032] Due to the application of the above-mentioned technical solution, the present invention has the following advantages compared with the prior art:

[0033] This invention forms a biodegradable protective sleeve in situ on the outside of the balloon of the balloon catheter, which can effectively prevent the balloon from expanding after being folded and rolled up, thus affecting its use. The protective sleeve can dissolve naturally in the blood vessels during the operation, without the need for manual removal, thus improving safety. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1This is a perspective view of the protective sleeve forming apparatus provided in Embodiment 1, wherein the restraint is in a relaxed state;

[0036] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure;

[0037] Figure 3 This is a perspective view of the protective sleeve forming apparatus provided in Embodiment 1, wherein the limiting member is in a tightened state;

[0038] Figure 4 This is a schematic diagram of the structure of the limiting member in the tightened state provided in Embodiment 1;

[0039] Figure 5 A schematic cross-sectional view of the protective sleeve formed on the balloon provided in Example 1;

[0040] Figure 6 This is a photograph showing the protective sleeve formed on the balloon as provided in Example 1.

[0041] The components include: 1. balloon; 11. leaflet; 2. catheter; 3. container; 31. pressure gauge; 32. feed liquid pipeline; 4. restraint; 41. stainless steel wire; 5. slide rail; 6. connector; 7. ultraviolet lamp; 8. protective sheath. Detailed Implementation

[0042] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0043] In the description of the embodiments of the present invention, it should be understood that "distal end" refers to the end of the instrument or component away from the operator, and "proximal end" refers to the end of the instrument or component closer to the operator; "axial direction" refers to the direction parallel to the line connecting the centers of the distal and proximal ends of the instrument or component; "inner" and "outer" are positions defined by distance relative to the center of the instrument or component, where "inner" is the position closer to the center of the instrument or component, and "outer" is the position away from the center of the instrument or component; "upper" and "lower" refer to the orientation of the instrument in its actual use or working state. The above description of directional terms is only for the convenience of describing the embodiments of the present invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0047] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0048] Example 1

[0049] This invention provides a protective sleeve forming device, such as... Figures 1 to 3 As shown, it includes a container 3, a limiting member 4 movably disposed within the container 3 and having a relaxed state and a tightened state, a drive mechanism connected to the limiting member 4 and used to drive the limiting member 4 to switch between the relaxed state and the tightened state, a curing mechanism disposed on the container 3, and a feeding mechanism (not shown in the figure) connected to the container 3 and used to introduce or discharge raw material liquid into the container 3.

[0050] like Figures 1 to 4As shown, the limiting member 4 is a mesh-like annular structure, specifically woven from stainless steel wire 41. The limiting member 4 is located in the middle region of the container 3, and at least one of its upper and lower ends has an opening to facilitate the entry of the balloon 1. In this embodiment, both the upper and lower ends of the limiting member 4 have openings. When the limiting member 4 switches from a relaxed state to a tightened state, at least a portion of the inner diameter of the limiting member 4 decreases. Preferably, when the limiting member 4 is in the tightened state, the inner diameter of the middle limiting member 4 decreases, so that it presents an hourglass shape with a small diameter in the middle and large diameters at both ends.

[0051] The drive mechanism is connected to at least one of the upper and lower ends of the limiting member 4 and can drive that end to move away from the other end so that the limiting member 4 switches to a tightened state; or move towards the other end so that the limiting member 4 switches to a relaxed state.

[0052] In this embodiment, the drive mechanism has two sets symmetrically arranged outside the limiting member 4. Taking one set as an example, the drive mechanism includes a slide rail 5 extending along the height direction of the container 3, two connecting members 6 respectively disposed at the upper and lower ends of the slide rail 5, and a drive member (not shown in the figure). The upper and lower ends of the limiting member 4 are respectively connected to the two connecting members 6. The drive member may have only one set connected to one of the connecting members 6, or two sets respectively connected to the two connecting members 6. Preferably, the drive member has one set connected to the upper connecting member 6 for driving the upper connecting member 6 to slide along the extension direction of the slide rail 5. The drive member may be a telescopic motor, the telescopic rod of which is connected to the connecting member 6 and the telescopic direction is consistent with the extension direction of the slide rail 5. In some other embodiments, the drive member may also include a belt disposed in the slide rail 5, a gear meshing on the belt, and a motor that drives the gear to rotate to drive the belt to move. The connecting member 6 is connected to the belt and is carried by the belt to slide on the slide rail 5.

[0053] The curing mechanism includes multiple ultraviolet lamps 7 evenly arranged along the inner circumference of the container 3 inside the container 3.

[0054] The container 3 is preferably a pressure vessel 3, which can be pressurized. Its bottom end is connected to a raw material liquid pipeline 32 and its top end has a feed port for the balloon conduit to enter. The raw material liquid pipeline 32 is connected to the feeding mechanism, and the feed port is located in the middle position. A pressure gauge 31 is also connected to the container 3.

[0055] This invention also provides a method for preparing a protective sleeve for a balloon catheter. The balloon catheter includes a catheter and a balloon disposed on the catheter that can expand or contract. The specific structure can be referred to in the prior art, and this invention is not limited thereto. The preparation method includes the following steps:

[0056] S1, Surface treatment of balloon 1:

[0057] S1.1. Selectively use micro-grinding equipment or chemical treatment (such as low-concentration acidic solution) to slightly increase the roughness of the surface of balloon 1, thereby increasing the bonding force between the surface of balloon 1 and the biodegradable polymer solution and avoiding uneven adhesion of the biodegradable polymer coating.

[0058] S1.2 Use non-woven fabric and special cleaning solvent to clean the surface of balloon 1 to ensure that there is no dust, grease and impurities on the surface of balloon 1.

[0059] S2. Preparation of biodegradable polymer solution:

[0060] Based on a total mass of 100% biodegradable polymer solution, the biodegradable polymer solution includes:

[0061] 7.5% polyethylene glycol diacrylate (PEGDA) with a number average molecular weight of 700-1000;

[0062] 2-Hydroxy-2-methyl-1-phenyl-1-propanone (HMPP) 2%;

[0063] Lactic acid or lactide 0.75%;

[0064] Water balance.

[0065] Weigh out each component according to the above formula and set aside. Under the protection of an inert gas (such as nitrogen), dissolve PEGDA in deionized water to form a PEGDA solution. Add HMPP and lactic acid or lactide to prepare a biodegradable polymer solution. Finally, adjust the pH of the biodegradable polymer solution to 7.35–7.45 using phosphate-buffered saline (PBS). Lactic acid or lactide can reduce the crosslinking density of PEGDA, thereby increasing its degradation rate in vivo; the use of phosphate-buffered saline ensures the solubility and stability of the formed protective sheath in the in vivo environment.

[0066] S3. Preparation of the protective sleeve:

[0067] (1) Use a balloon folding machine to fold balloon 1 into segments, such as... Figure 5 As shown, the balloon 1 forms multiple leaflets 11, and the multiple leaflets 11 are rolled together;

[0068] (2) The biodegradable polymer solution is introduced into the container 3 through the liquid feeding mechanism. Then, the folded balloon 1 is inserted into the relaxed restrictor 4 and immersed in the biodegradable polymer solution for 20-60 seconds. The balloon catheter is then vacuumed to make the inside of the balloon catheter a vacuum or low-pressure environment to prevent air or bubbles from entering the balloon 1.

[0069] (3) Pressurize container 3 to maintain the pressure inside container 3 at 0.15MPa for 1 to 3 minutes to ensure that the solution is evenly distributed on the entire surface of balloon 1 without bubbles and can penetrate into every fold of balloon 1; then drive mechanism to drive the upper end of limiting member 4 to move upward, limiting member 4 switches from a relaxed state to a tightened state and squeezes balloon 1, so that excess biodegradable polymer solution on the surface of balloon 1 seeps out from the mesh and falls down;

[0070] (4) The biodegradable polymer solution in container 3 is discharged through the liquid feeding mechanism, and the curing mechanism is activated to cure the biodegradable polymer solution on the surface of the balloon 1, forming a protective sleeve in situ. The curing is carried out by irradiation with ultraviolet light with a wavelength of 365nm. The curing process is controlled within 1 to 2 minutes. The specific curing time can be finely adjusted according to the crosslinking rate of the PEGDA formulation and the intensity of the ultraviolet light source to ensure that the ultraviolet light source irradiates the surface of the balloon 1 evenly, so as to avoid incomplete curing or over-curing in some areas.

[0071] (5) After curing, the drive mechanism drives the upper end of the limiting part 4 to move downward, the limiting part 4 switches from the tightened state to the relaxed state, releases the negative pressure state of the balloon catheter, and removes the balloon catheter.

[0072] (6) Check the thickness of the protective sleeve layer 8 (in this embodiment, the thickness of the protective sleeve layer 8 is 0.1mm ± 0.02mm) and perform a dissolution test on the protective sleeve, including placing the balloon 1 with the protective sleeve in phosphate buffer (pH = 7.4) at 37°C and observing the dissolution rate of the protective sleeve. The test showed that the protective sleeve completely dissolved within 30 minutes, and the dissolution product did not form any particle residue, and there was no risk of blocking blood vessels.

[0073] (7) Store the balloon catheter in an environment with a temperature of 4 to 25°C and a humidity of 3 to 50% to maintain the stability of the coating and avoid excessive temperature or humidity affecting the degradation characteristics of the protective layer.

[0074] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for producing a balloon catheter protective sheath, said balloon catheter comprising a catheter (2) and a balloon (1) arranged on said catheter (2) and capable of expanding or contracting, characterized in that: The balloon (1) is folded into segments, and then a protective sleeve is formed on the balloon (1) using a protective sleeve forming device. The protective sleeve forming device includes a container (3), a limiting member (4) movably disposed in the container (3) and having a relaxed state and a tightened state, a drive mechanism connected to the limiting member (4) and used to drive the limiting member (4) to switch between the relaxed state and the tightened state, a curing mechanism disposed in the container (3), and a feeding mechanism connected to the container (3) and used to introduce or discharge raw material liquid into the container (3). The process of forming the protective sleeve on the balloon (1) using the protective sleeve forming device includes the following steps: a. The raw material liquid is introduced into the container (3) through the liquid feeding mechanism, and then the folded balloon (1) is inserted into the loose restraint (4) and immersed in the raw material liquid. The balloon catheter is vacuumed so that the inside of the balloon catheter is in a vacuum environment. The raw material liquid is a biodegradable polymer solution. b. The driving mechanism drives the limiting member (4) to switch from a relaxed state to a tightened state, removing excess biodegradable polymer solution from the surface of the balloon (1); c. The biodegradable polymer solution in the container (3) is discharged through the liquid feeding mechanism, and the curing mechanism is activated to cure the biodegradable polymer solution on the surface of the balloon (1) to form the protective sleeve in situ.

2. The method of claim 1, wherein: The limiting member (4) is a mesh-like ring structure. When the limiting member (4) switches from a relaxed state to a tightened state, at least part of the inner diameter of the limiting member (4) is reduced and can compress the balloon (1).

3. The method of claim 2, wherein: When the limiting member (4) is in a tightened state, the middle diameter of the limiting member (4) is small and the diameters at the top and bottom ends are large.

4. The method of claim 3, wherein: When the limiting member (4) is in a tightened state, the limiting member (4) is hourglass-shaped.

5. The method of claim 1, wherein: The drive mechanism is connected to at least one of the upper and lower ends of the limiting member (4) and can drive that end to move away from the other end so that the limiting member (4) switches to a tightened state; or move towards the other end so that the limiting member (4) switches to a relaxed state.

6. The method of claim 5, wherein: The driving mechanism includes a slide rail (5) extending along the height direction of the container (3), two connecting pieces (6) respectively disposed at the upper and lower ends of the slide rail (5), and a driving member. The upper and lower ends of the limiting member (4) are respectively connected to the two connecting pieces (6). At least one of the two connecting pieces (6) is connected to the driving member and can slide along the extension direction of the slide rail (5) under the drive of the driving member. The drive mechanism has two sets symmetrically arranged on the outside of the limiting member (4).

7. The method of claim 1, wherein: The preparation method further includes pressurizing the container (3) after step a and before step b to control the pressure inside the container (3) to be 0.11~0.2 MPa and maintain it for 1~3 min.

8. The method of claim 1, wherein: Step a includes immersing the limiting element (4) in the biodegradable polymer solution for 20-60 seconds, and then evacuating the balloon catheter.

9. The method for preparing the balloon catheter protective sleeve according to claim 1, characterized in that: The curing mechanism includes a plurality of ultraviolet lamps (7) arranged along the inner periphery of the container (3) within the container (3).

10. The method of claim 1, wherein: The preparation method further includes, after step c, the step of driving the limiting member (4) from a tightened state to a relaxed state by the driving mechanism, and then removing the balloon catheter.

11. The method of claim 1, wherein: Based on a total mass of 100% for the biodegradable polymer solution, the biodegradable polymer solution comprises: 5-10% polyethylene glycol diacrylate Photoinitiator 0.1~2.5%, Dissolution accelerator 0.5~1%, Solvent balance.

12. The method of claim 11, wherein: The number-average molecular weight of the polyethylene glycol diacrylate is 700-1000; and / or, The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone; and / or, The solubility promoter is lactic acid and / or lactide; and / or, The solvent is water.

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