An interventional guide wire and a method for preparing the same

Abstract

The present invention discloses an interventional guidewire and a preparation method thereof. The interventional guidewire comprises: a core wire, which is composed of a nickel-titanium alloy; a winding layer, which is composed of a polymer material covering the outer surface of the core wire in a winding manner; a coating layer, which is a material coated on the outer surface of the winding layer, and the material is a composite material of polytetrafluoroethylene and carbon nanotubes; the polymer material is any one of polyarylsulfone or polyphenylene sulfide. The present invention selects a specific polymer material and covers the outer surface of the core wire in a winding manner to form a guidewire, which achieves an optimal balance between rigidity and flexibility, maintains superelasticity under high bending stress and has excellent toughness, and is suitable for use in medical operations requiring high precision and high stability.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an interventional guide wire and a preparation method thereof. Background Art

[0002] Interventional therapy technology has been widely used in the medical field in recent years, especially in the diagnosis and treatment of cardiovascular, neurological and peripheral vascular diseases. Among them, interventional guidewires are the core instruments in interventional therapy, and their performance is crucial to the success rate and safety of the operation. However, the existing guidewire technology still has some limitations that need to be solved in practical applications, including: (1) Material performance limitations: Traditional guidewires mainly use stainless steel or nickel-titanium alloy as core wire materials. Stainless steel guidewires have good rigidity, which makes it easy for doctors to manipulate the guidewires for precise positioning during surgery. However, the flexibility of stainless steel is relatively low, and it may be difficult to pass smoothly in complex vascular pathways, thereby increasing the difficulty of surgery. In contrast, nickel-titanium alloy guidewires have better flexibility due to their shape memory properties and superelasticity, but their rigidity is relatively low, and they may lack sufficient thrust during operation, affecting the positioning accuracy of the guidewire. (2) Fatigue strength and service life: In complex surgical environments, guidewires need to withstand multiple bending, twisting and pushing and pulling operations, which places high demands on the fatigue strength of the material. Traditional materials may suffer fatigue damage during long-term operation or repeated use, resulting in guidewire breakage or performance degradation, increasing surgical risks. In addition, during long-term use, the surface of the guidewire material may be worn or corroded, further shortening the service life of the guidewire. (3) Chemical resistance and biocompatibility issues: During interventional surgery, the guidewire will inevitably come into contact with various drugs, blood, and other body fluids. If the chemical resistance of the guidewire material is poor, corrosion or degradation may occur, resulting in a decrease in material performance and even adverse effects on the patient. In addition, materials with insufficient biocompatibility may trigger inflammatory or allergic reactions in patients, posing a potential threat to patient safety.

[0003] Therefore, how to further improve the comprehensive performance of the guidewire, especially the mechanical properties and durability of the guidewire itself, has become a key issue that needs to be solved urgently. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides an interventional guide wire and a preparation method thereof.

[0005] The present invention provides an interventional guidewire, comprising:

[0006] core wire, composed of nickel-titanium alloy;

[0007] The winding layer is composed of a polymer material covering the outer surface of the core wire in a winding manner, and the polymer material is any one of polyarylsulfone or polyphenylene sulfide;

[0008] The coating layer is a material coated on the outer surface of the winding layer, and the material on the outer surface of the winding layer is a composite material of polytetrafluoroethylene and carbon nanotubes.

[0009] The present invention proposes to use polymer materials to wrap around the surface of the nickel-titanium alloy core wire to form a fine texture structure, which can effectively improve the rigidity and ductility of the guide wire. Polyarylsulfone has a strong aromatic structure and high molecular chain rigidity. The molecular structure of polyphenylene sulfide contains a combination of benzene rings and sulfur elements, which has good mechanical properties and adds additional rigidity and toughness to the guide wire. Both have excellent chemical stability, the operational flexibility and safety of the guide wire, and ensure the long-term stability and biocompatibility of the material.

[0010] The winding layer is further coated with a composite material of polytetrafluoroethylene and carbon nanotubes. Through this combination, the guide wire has an extremely low friction coefficient and excellent wear resistance, while the rigidity and toughness of the guide wire are improved.

[0011] In some embodiments, the winding density of the polymer material is 5 to 50 turns per millimeter of core wire.

[0012] The winding density directly affects the control performance of the guidewire. A higher winding density can enhance the conductivity of the guidewire, so that when the doctor pushes the guidewire, the force can be transmitted more evenly to the end of the guidewire, thereby improving the accuracy and efficiency of control.

[0013] In some embodiments, the thickness of the winding layer is less than 5 μm. A thicker winding layer may increase the contact area between the guide wire and the tissue to a certain extent, affect the softness of the guide wire, and thus increase the potential risk of damage to the blood vessel wall.

[0014] In some embodiments, the coating layer has a thickness of 6 to 10 μm. A coating layer of a certain thickness can provide better biocompatibility, reduce the chance of direct contact between the guide wire and the inner wall of the blood vessel, thereby reducing stimulation and damage to the tissue, which is crucial to reducing postoperative complications and inflammatory reactions. In addition, it can more effectively isolate the metal core wire inside the guide wire to avoid adverse biological reactions caused by metal exposure.

[0015] In some embodiments, the diameter of the core wire is 0.1 to 0.5 mm. A core wire with a larger diameter generally has higher rigidity and can provide greater thrust and support. In the guidewire of the present invention, the diameter of the core wire can be adjusted within 0.1 to 0.5 mm to meet the requirements of high rigidity in different application scenarios.

[0016] In some embodiments, the overall outer diameter of the interventional guidewire does not exceed 0.9 mm.

[0017] In some embodiments, the weight percentage of carbon nanotubes in the composite material of polytetrafluoroethylene and carbon nanotubes is 0.1% to 2%. Both carbon nanotubes and PTFE are lightweight materials, and the combination of the two can greatly improve the strength and rigidity of the guide wire without significantly increasing its weight, making the guide wire easier to control during application.

[0018] The present invention also provides a guiding device, comprising the interventional guide wire.

[0019] The present invention also provides a zebra guidewire, which comprises the interventional guidewire and a zebra mark and a length mark arranged on the coating layer.

[0020] The present invention also provides a method for preparing the interventional guide wire, comprising the following steps:

[0021] A core wire is prepared by using nickel-titanium alloy, and a wire drawing machine is used for step-by-step wire drawing by a mechanical processing method to cover the outer surface of the core wire with polyarylsulfone;

[0022] The composite material of polytetrafluoroethylene and carbon nanotubes is covered on the outer surface of the winding layer by coating to obtain the interventional guide wire.

[0023] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0024] 1. The present invention selects specific polymer materials and covers the outer surface of the core wire in a winding manner to form a guide wire, achieving an optimal balance between rigidity and flexibility, maintaining superelasticity and excellent toughness under high bending stress, and is suitable for use in medical operations requiring high precision and high stability.

[0025] 2. The present invention reasonably designs the density of the winding layer and the thickness of the coating layer to make the guide wire have a lower friction coefficient, so that it can smoothly pass through narrow and tortuous vascular pathways, reduce surgical difficulty and improve operating efficiency, and ensure that it can provide sufficient thrust and stability during surgery and can flexibly adapt to complex vascular pathways. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a structural schematic diagram of the interventional guide wire of the present invention;

[0028] Figure 2This is the appearance diagram of the interventional guidewire prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0030] The present invention provides an interventional guide wire, the structure of which includes a core wire, a winding layer and a coating layer, such as Figure 1 The core wire is made of nickel-titanium alloy; the use of nickel-titanium alloy makes the core wire have excellent rigidity and toughness, and is not easy to break. The diameter of the core wire can be adjusted within 0.1~0.5 mm to meet the high rigidity requirements of different application scenarios.

[0031] The polymer material used in the winding layer of the guidewire can be polyarylsulfone or polyphenylene sulfide. Polyarylsulfone has a strong aromatic structure and high molecular chain rigidity, which makes the material have high bending strength and tensile strength. The molecular structure of polyphenylene sulfide contains a combination of benzene rings and sulfur elements, which can not only improve the rigidity and toughness, but also ensure the long-term stability and biocompatibility of the material. The above materials can ensure that the winding layer can maintain the operational flexibility and safety of the guidewire while adding additional rigidity and toughness to the guidewire, and is suitable for use in medical operations that require high precision and high stability.

[0032] The coating layer of the guide wire is coated on the outer surface of the winding layer, and the material used is a composite material of polytetrafluoroethylene (PTFE) and carbon nanotubes. Carbon nanotubes are a nanomaterial composed of carbon atoms arranged in a hexagonal structure, which has extremely high tensile strength and elastic modulus. When carbon nanotubes are evenly dispersed in PTFE to form a composite material, the high strength and high modulus of the carbon nanotubes will significantly improve the overall rigidity and strength of the guide wire, and it is not easy to deform when subjected to force. At the same time, a certain amount of carbon nanotubes can form a good interface bonding with PTFE, so that the guide wire can effectively disperse stress when stretched or bent, reduce local stress concentration, and enhance toughness.

[0033] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used are all commercially available unless otherwise specified.

[0034] Source of raw materials:

[0035] Titanium-nickel alloy: Jiangyin Perl Technology Co., Ltd.;

[0036] Polyarylsulfone: Solvay P-3500 LCD from the United States;

[0037] Polyphenylene sulfide: Polyplastics, W-214A;

[0038] Polyurethane: Lubrizol Pellethane;

[0039] Polytetrafluoroethylene: Chemours, USA;

[0040] Carbon nanotubes: Yushuo, YSKC-30;

[0041] Coating composite material #1: 0.1% carbon nanotubes and 99.9% polytetrafluoroethylene;

[0042] Coating composite material #2: 1% carbon nanotubes and 99% polytetrafluoroethylene;

[0043] Coating composite material #3: contains 2% carbon nanotubes and 95% polytetrafluoroethylene.

[0044] The preparation method of the coating layer composite material is as follows:

[0045] The carbon nanotubes and polytetrafluoroethylene are weighed according to their mass, and the carbon nanotubes are uniformly dispersed in the polytetrafluoroethylene by mechanical stirring.

[0046] The preparation methods of the guide wires in the different embodiments and comparative examples are as follows:

[0047] Example 1

[0048] The preparation method of the interventional guide wire of this embodiment is as follows:

[0049] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0050] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyarylsulfone. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0051] (3) Coating layer: Use coating layer composite material #1 to cover the outer surface of the winding layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0052] Example 2

[0053] The preparation method of the interventional guide wire of this embodiment is as follows:

[0054] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0055] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyphenylene sulfide. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0056] (3) Coating layer: Use coating layer composite material #1 to cover the outer surface of the winding layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0057] The invasive guide wire prepared in this embodiment is as follows Figure 2 shown.

[0058] Example 3

[0059] The preparation method of the interventional guide wire of this embodiment is as follows:

[0060] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0061] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyarylsulfone. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0062] (3) Coating layer: Use coating layer composite material #2 to cover the outer surface of the winding layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0063] Example 4

[0064] The preparation method of the interventional guide wire of this embodiment is as follows:

[0065] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0066] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyarylsulfone. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0067] (3) Coating layer: Use coating layer composite material #3 to cover the outer surface of the winding layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0068] Example 5

[0069] The difference between the preparation method of the interventional guide wire of this embodiment and that of Embodiment 1 is that during the processing of the core wire, the final diameter of the core wire is precisely controlled to be 0.3 mm.

[0070] Example 6

[0071] The difference between the preparation method of the interventional guide wire of this embodiment and that of Embodiment 1 is that during the processing of the core wire, the final diameter of the core wire is precisely controlled to be 0.5 mm.

[0072] Example 7

[0073] The difference between the preparation method of the interventional guide wire of this embodiment and that of Embodiment 1 is that when the automatic winding machine is used for precision winding, 10 turns are wound per millimeter of the core wire.

[0074] Example 8

[0075] The difference between the preparation method of the interventional guide wire of this embodiment and that of Embodiment 1 is that when the automatic winding machine is used for precision winding, 50 turns are wound per millimeter of the core wire.

[0076] Example 9

[0077] The difference between the preparation method of the interventional guide wire in this embodiment and that in Embodiment 1 is that the thickness of the coating layer is 10 μm.

[0078] Comparative Example 1

[0079] The preparation method of the interventional guidewire of this comparative example is as follows:

[0080] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0081] (2) Intermediate layer: The surface of the core wire is covered with a polysulfone coating with a thickness of 5 μm.

[0082] (3) Coating layer: Use coating layer composite material #1 to cover the outer surface of the middle layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0083] Comparative Example 2

[0084] The preparation method of the interventional guide wire of this embodiment is as follows:

[0085] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0086] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyurethane. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0087] (3) Coating layer: Use coating layer composite material #1 to cover the outer surface of the winding layer by coating. Use a laser thickness gauge to monitor the thickness of the winding layer to ensure that the coating thickness is 6 μm.

[0088] Comparative Example 3

[0089] The preparation method of the interventional guide wire of this embodiment is as follows:

[0090] (1) Processing of core wire: The core wire is made of nickel-titanium alloy and mechanically processed using a wire drawing machine for step-by-step wire drawing. The diameter is gradually reduced at each stage, and the final diameter of the core wire is precisely controlled to be 0.1 mm.

[0091] (2) Winding layer: Use an automatic winding machine for precision winding to cover the outer surface of the core wire with polyurethane. The winding machine is set to 30 degrees to ensure uniformity and control of winding density. Five turns are wound per millimeter of core wire. A laser thickness gauge is used to monitor the thickness of the winding layer to ensure that each layer meets the thickness requirement of 5 μm.

[0092] (3) Coating layer: Polytetrafluoroethylene is used to cover the outer surface of the winding layer by coating. The thickness of the winding layer is monitored by a laser thickness gauge to ensure that the coating thickness is 6 μm.

[0093] <Test Method>

[0094] (1) Rigidity test:

[0095] The three-point bending measurement was performed using an electronic universal testing machine. The guidewire was placed between the two fulcrums of the test device to ensure that both ends of the guidewire were fixed. A gradually increasing force was applied to the middle of the guidewire, and the force and degree of bending required for the guidewire to bend were recorded. According to the degree of deformation of the guidewire during the force application process and the force-displacement curve, the rigidity of the guidewire (bending stiffness, N / mm) was calculated.

[0096] The stiffness can be obtained from the slope of the curve, usually calculated in the small deformation range:

[0097] ;

[0098] Where R is the rigidity, It is the change of force. is the change in displacement.

[0099] (2) Toughness test: Fix a guide wire of fixed length on the fixture of the tensile testing machine and gradually apply tensile force until the guide wire breaks. Record the tensile strength and elongation at break of the guide wire. Calculate its toughness (elongation %) based on the breaking point and elongation of the guide wire. The formula is as follows:

[0100] Elongation rate (%) = (length of the guide wire after breakage - initial length of the guide wire) / initial length of the guide wire.

[0101] The test results are shown in Table 1:

[0102] Table 1 Test results of guidewire rigidity and toughness prepared in Examples and Comparative Examples

[0103]

[0104] From the performance test results in Table 1, it can be seen that the guidewire prepared in the embodiment has excellent mechanical properties, which can ensure that the guidewire has high bending strength and relatively high elongation. The increase in the thickness of the core wire has a relatively low effect on the elongation of the guidewire, showing the adjustability of the guidewire rigidity. In Comparative Example 1, the guidewire is not prepared in a winding manner, which has a greater impact on the bending rigidity and elongation of the guidewire, showing a decrease in bending rigidity and excessive elongation, and the material is soft; in Comparative Example 2, polyurethane is selected as the winding material, and the guidewire formed by winding the polyurethane material has a lower elongation and too high rigidity than the guidewire in the embodiment; in Comparative Example 3, the coating layer uses pure polytetrafluoroethylene material, and the guidewire has a lower rigidity and too high elongation.

[0105] The guidewire preparation method in Examples 1 to 9 of the present application is simple to operate and easy to implement, and can ensure that the bending stiffness of the guidewire is between 0.24 and 37 N / mm, while maintaining the elongation of the guidewire within 18.72 to 21.14%. The guidewire has excellent mechanical properties, good tactile feedback, controllability and passability, and excellent comprehensive performance.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An interventional guide wire, characterized in that: include: core wire, composed of nickel-titanium alloy; The winding layer is composed of a polymer material covering the outer surface of the core wire in a winding manner, and the polymer material is any one of polyarylsulfone or polyphenylene sulfide; The winding density of the polymer material is 5 to 50 turns per millimeter of core wire; A coating layer, a material coated on the outer surface of the winding layer, wherein the material on the outer surface of the winding layer is a composite material of polytetrafluoroethylene and carbon nanotubes; In the composite material of polytetrafluoroethylene and carbon nanotubes, the weight percentage of carbon nanotubes is 0.1%-2%.

2. The interventional guidewire according to claim 1, characterized in that: The thickness of the winding layer is less than 5 μm.

3. The interventional guidewire according to claim 1, characterized in that: The coating layer has a thickness of 6-10 μm.

4. The interventional guidewire according to claim 1, characterized in that: The diameter of the core wire is 0.1~0.5 mm.

5. The interventional guidewire according to claim 1, characterized in that: The overall outer diameter of the interventional guide wire does not exceed 0.9 mm.

6. A guiding device, characterized in that: Comprising the interventional guidewire as described in any one of claims 1 to 5.

7. A zebra guidewire, characterized in that: The zebra guidewire comprises the interventional guidewire according to any one of claims 1 to 5 and a zebra mark and a length mark arranged on the coating layer.

8. The method for preparing the interventional guidewire according to claim 1, characterized in that: The steps include: A core wire is prepared by using nickel-titanium alloy, and a wire drawing machine is used for step-by-step wire drawing by a mechanical processing method to cover the outer surface of the core wire with polyarylsulfone; The composite material of polytetrafluoroethylene and carbon nanotubes is covered on the outer surface of the winding layer by coating to obtain the interventional guide wire.

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