Nylon elastomer composite material for penetrating micro catheter as well as preparation method and application of nylon elastomer composite material

Abstract

The invention discloses a nylon elastomer composite material for a through miniature conduit and a preparation method and application thereof, the nylon elastomer composite material for the through miniature conduit comprises the following components in parts by weight: 40-80 parts of block polyether amide, 30-50 parts of tungsten powder and 0.5-2 parts of an interface regulating agent, and the mass ratio of the tungsten powder to the block polyether amide is (0.5-1.2): 1. The nylon elastomer composite material for the through micro catheter is moderate in hardness, can realize balance of catheter penetrating power and flexibility when being used as a top end material of the through micro catheter, improves accuracy and success rate of an operation, and also can take safety and comfort of a patient into account.

Description

Technical Field

[0001] The present invention relates to the technical field of interventional materials, and in particular to a nylon elastomer composite material for penetrating a micro-catheter, and a preparation method and application thereof. Background Art

[0002] Minimally invasive medical surgery has the advantages of less bleeding, less trauma, fewer complications, high safety, and rapid postoperative recovery, and has become an inevitable development trend in clinical medical applications. Interventional surgery is a type of minimally invasive surgery, which is a minimally invasive surgical treatment method based on high-tech means. That is, with the help of high-precision medical imaging equipment, special catheters, guide wires and other precision instruments are introduced into the human body from natural channels or incision positions to diagnose or locally treat diseased tissues in the human body. The performance level of minimally invasive interventional medical devices determines the safety of minimally invasive interventional medical surgery, the difficulty of doctor's operation, and the comfort level of patients. Therefore, minimally invasive interventional medical devices are the key link of minimally invasive interventional treatment surgery. Only high-performance minimally invasive interventional medical devices can ensure the smooth completion of minimally invasive interventional treatment surgery. Interventional catheters are the most basic consumables among interventional medical devices. Interventional catheters need to be inserted into the human body, so they need to maintain a certain hardness. Excessive hardness will cause certain damage to the surrounding tissues after the catheter is inserted into the body. Therefore, in order to reduce the damage to the patient during the intervention process, traditional interventional catheters generally use soft materials as the top material, which can protect the blood vessels when entering the body. However, because the material is too soft, the support effect of the top of the catheter is small, and it is easy to collapse or deform during use. Therefore, how to balance the penetration and softness of the front end of the catheter has become an urgent problem to be solved for interventional catheters. The surface of the interventional catheter will produce friction with the human tissue after entering the human body. Excessive friction will also cause damage to blood vessels or tissues, which will cause pain to the patient. Therefore, the interventional catheter also needs to have low friction.

[0003] Therefore, there is an urgent need to develop a material that can take into account both the penetration force and softness of the front end of the catheter and has low friction. Summary of the invention

[0004] In view of the defects in the prior art, the present invention proposes a nylon elastomer composite material for penetrating a micro-catheter and a preparation method and application thereof.

[0005] The present invention provides a nylon elastomer composite material for penetrating a micro-catheter, which comprises the following components in parts by weight: 40-80 parts of block polyether amide, such as 40, 45, 50, 55, 60, 65, 70, 75, and 80 parts; 30-50 parts of tungsten powder, such as 30, 35, 40, 45, and 50 parts; 0.5-2 parts of an interface regulator, such as 0.5, 1, 1.5, and 2 parts; the mass ratio of the tungsten powder to the block polyether amide is (0.5-1.2):1, such as 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, and 1.2:1, preferably (0.7-1):1.

[0006] Block polyetheramide (Pebax) is a thermoplastic elastomer material, which is copolymerized by hard segment polyamide (PA12) and soft segment polytetramethylene ether (PTMO) through ABAB blocks. The cross-linking effect of PA12 and the softness imparted by PTMO make block polyetheramide have a wide range of hardness selection. However, if the hardness of Pebax is too low or too high, the crystallinity of the copolymer will increase, thereby increasing the degree of microphase separation of Pebax. In minimally invasive interventional surgery, the catheter needs to pass through complex blood vessels and tissue structures. Therefore, it is also necessary to maintain good biocompatibility of the catheter material, and biocompatibility is closely related to the degree of microphase separation of Pebax. If Pebax is selected as the catheter material alone, it will be difficult to balance the hardness and biocompatibility of the material in a wide hardness range. By compounding segmented polyetheramide with tungsten powder, not only can the excellent softness and high torsional strength of Pebax be utilized to significantly improve the success rate of surgery and the comfort of patients, but the hardness of the material can also be adjusted by adding tungsten powder, so that the material has softness and a certain rigidity at the same time, thus obtaining a material with appropriate hardness and rigidity. In addition, since Pebax has a large friction coefficient, it can also be given low friction properties by compounding it with tungsten powder in a specific proportion.

[0007] Furthermore, the Shore hardness of the segmented polyetheramide is 25D-55D. Selecting the hardness of the segmented polyetheramide within this range can ensure that the segmented polyetheramide has good biocompatibility, and can also have appropriate hardness when compounded with tungsten powder, thereby avoiding damage to body tissues caused by excessive hardness.

[0008] Furthermore, the interface regulator is any one or more of sodium hexametaphosphate, sodium pyrophosphate, and sodium tripolyphosphate. By adding the interface regulator to the material, the tungsten powder can be evenly distributed in the block polyetheramide, thereby improving the comprehensive performance of the material and maintaining the appropriate hardness of the material.

[0009] Furthermore, the particle size D50 of the tungsten powder is 1-8 μm, such as 1, 2, 3, 4, 5, 6, 7, 8 μm.

[0010] Furthermore, the nylon elastomer composite material also includes 0.5-2 parts by weight of an antioxidant, such as 0.5, 1, 1.5, or 2 parts. The antioxidant can be any one or more of antioxidant 1010 or antioxidant 168.

[0011] Furthermore, the Shore hardness of the composite material is 37D-67D, preferably 42D-60D. The composite material in this hardness range has moderate hardness and can more smoothly pass through some harder or resistant tissues when used as the tip material of a micro-catheter, and can play an extremely important role in certain interventional surgeries that require precise positioning and strong penetration. The tip of the catheter in this hardness range can also better resist external pressure and deformation, ensuring that the catheter maintains a stable shape in a complex anatomical structure and is not prone to bending or twisting, which helps the catheter maintain a stable position and direction during the operation, thereby improving the accuracy and success rate of the operation; further, the tip of the catheter in this hardness range also has a certain degree of softness, which can increase The flexibility of the microcatheter during penetration makes it easier to adapt to various complex anatomical structures. In medical applications such as angiography, drug delivery or interventional surgery, it can also reduce the resistance encountered by the microcatheter when passing through curved blood vessels or narrow channels, reduce damage to surrounding tissues, and improve the success rate of the operation. It also helps the microcatheter to remain stable after penetration. After the catheter successfully passes through the target area, the softer tip can better fit the surrounding tissues, reduce the movement and slippage of the catheter in the body, and ensure the stability and safety of the operation. The catheter with a soft tip can also reduce the pain of the microcatheter during penetration, better adapt to the softness of the tissue, reduce stimulation and damage to the tissue, and improve the comfort of the patient. Therefore, selecting the hardness according to different surgical needs can not only avoid the risk of damage to the surrounding tissues caused by the tip being too hard, but also avoid problems such as collapse or deformation during use caused by too soft materials.

[0012] The present invention also provides a method for preparing the nylon elastomer composite material, comprising the following steps: S1: Mix the interface regulator and tungsten powder according to weight, pre-stir and mix them evenly under heating conditions; S2: After the mixture obtained in S1 is cooled, it is crushed by a ball mill; S3: melt-blending the block polyether amide and the mixture obtained in S2 according to parts by weight, and obtaining the nylon elastomer composite material after discharging; The heating condition in step S1 is heat treatment at 340-380° C. for 15-20 min, and the temperature of melt blending in step S3 is 250-280° C. for 30-40 min.

[0013] The present invention also provides a penetrating microcatheter, comprising a tube body, a head end and a top end, wherein the head end comprises a polytetrafluoroethylene inner layer, a double-layer braided middle layer and an outer layer; the top end is joined to the head end, and the radius of the top end gradually decreases from the joint, presenting a pointed structure with a smooth taper; the material used for the top end is the nylon elastomer composite material.

[0014] The top of the catheter is designed to have a pointed structure with a smooth taper, so that the microcatheter will produce less propulsion resistance when entering the blood vessel, and will not damage the blood vessel during the process of entering the blood vessel. In addition, due to the use of a nylon elastomer composite material with moderate hardness, it can improve the patient's comfort during the operation.

[0015] Polytetrafluoroethylene has a low coefficient of friction and is suitable as an inner layer material. The delivery of therapeutic drugs or instruments through the inner cavity of polytetrafluoroethylene can reduce resistance during the process, which not only speeds up the process but also makes it easier for the instruments to be returned.

[0016] Furthermore, the material used for the outer layer of the head end is the nylon elastomer composite material. The material of the outer layer of the head end is the same as the material of the top end, has appropriate hardness, and can reduce damage to blood vessels during the intervention process.

[0017] Furthermore, the tube body can be made of polytetrafluoroethylene, the tube body is directly connected to the head end, the outer diameter is 2.5-3 mm, the inner diameter is 1-1.5 mm, the length of the head end part is 9-12 mm, and the length of the top part is 6-8 mm.

[0018] Furthermore, the inner layer of the double-layer braided intermediate layer is a polypropylene fiber braided layer, and the outer layer is a stainless steel braided layer. The double-layer braided layer of the polypropylene fiber braided layer and the stainless steel braided layer is used as the intermediate layer. The double-layer braided layer not only has high toughness and excellent anti-aging performance, but also can provide strong support for the catheter, further improve the elasticity and bending resistance of the top structure, make the catheter smoother during the access process, and at the same time ensure the safety of the intervention process.

[0019] The present invention also provides the use of the penetrating micro-catheter as a minimally invasive interventional catheter in medical treatment.

[0020] In summary, compared with the prior art, the present invention achieves the following technical effects: (1) The nylon elastomer composite material provided by the present invention has suitable hardness and softness and is suitable as a material for penetrating micro-catheters; (2) The nylon elastomer composite material provided by the present invention has low friction, which can prevent the catheter tip from damaging blood vessels and tissues during the intervention process; (3) The penetrating microcatheter provided by the present invention does not damage tissues and blood vessels during the intervention process, and the friction between the inner cavity and the outer layer of the catheter is small, the safety index is high, and therapeutic drugs or devices can be smoothly delivered, which is suitable as a medical minimally invasive interventional catheter. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work should fall within the scope of protection of the present invention.

[0022] Example The present invention is further described below in conjunction with specific examples and comparative examples. The following specific examples are all preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and are particularly not limited to the types of the various component raw materials used in the following specific examples.

[0023] 1. The sources of raw materials for the embodiments and comparative examples are as follows: Block polyetheramide #1: Pebax 3533, Shore hardness 35D, Arkema; Block polyetheramide #2: Pebax 2533, Shore hardness 25D, Arkema; Block polyetheramide #3: Pebax 4033, Shore hardness 40D, Arkema; Block polyetheramide #4: Pebax 5533, Shore hardness 55D, Arkema; Block polyetheramide #5: Pebax 6333, Shore hardness 63D, Arkema; Tungsten powder #1: brand name YT-W-08-3, D50 1μm, Shanghai Yaotian New Material Technology Co., Ltd. Tungsten powder #2: brand T32164, D50 5 μm, Shanghai Jizhi Biochemical Technology Co., Ltd.; Interface regulator: sodium hexametaphosphate. The same substance was used in parallel experiments.

[0024] The preparation method of the nylon elastomer composite material of the embodiment of the present invention and the comparative example comprises the following steps: S1: Mix the interface regulator and tungsten powder according to weight, pre-stir and mix them evenly under heating conditions; S2: After the mixture obtained in S1 is cooled, it is crushed by a ball mill; S3: melt-blending the block polyether amide and the mixture obtained in S2 according to parts by weight, and obtaining the nylon elastomer composite material after discharging; The heating condition in step S1 is heat treatment at 340-380° C. for 15-20 min, and the temperature of melt blending in step S3 is 250-280° C. for 30-40 min.

[0025] 2. Various performance test methods (1) Shore D hardness test: Tested according to GB / T 531.1-2008.

[0026] (2) Friction test: The test was conducted according to the standard YY / T 1536-2017 "Standard Experimental Model for Evaluation of Sliding Properties of Non-Intravascular Catheters". A friction tester was used in a 37°C water bath with a clamping force of 300 g, a test distance of 300 mm, and a speed of 4 mm / s. The test was performed three times and the friction force (average value) was recorded.

[0027] Table 1 Technical solutions and effects of the embodiments (in parts by weight)

[0028] Table 2 Comparative Examples Technical Solutions and Effects (Units are parts by weight)

[0029] In Examples 1-11, segmented polyetheramide, tungsten powder and an interface regulator are introduced at the same time, and the mass ratio of tungsten powder to segmented polyetheramide is within a specific range. All composite materials of Examples 1-11 have an appropriate hardness, that is, when the composite materials are used in interventional catheters, they have good penetration and flexibility, so that the risk of damage to surrounding tissues and blood vessels by the interventional catheter after entering the human body is reduced. In particular, when the hardness is in the range of 42D-60D, it can not only enhance the penetration of the catheter tip, but also have a certain degree of flexibility, which can improve the safety of the operation while taking into account the comfort of the patient. The material also has low friction properties, which can avoid friction with surrounding tissues, further reducing the risk of damage to the patient.

[0030] Comparative Examples 1-5 are all compared with Example 1. In Comparative Example 1, no interface regulator is added, so that the tungsten powder cannot perfectly cooperate with the block polyether amide to improve the material performance, and the prepared material cannot be used as a qualified interventional catheter material. The mass ratio of tungsten powder to block polyether amide added in Comparative Example 2 is not within the specified range, and the amount of tungsten powder added is too much, which significantly increases the hardness of the material. Although it can improve the penetration of the material when used as an interventional catheter material, in human tissue, especially in areas rich in nerve endings, the harder catheter tip may cause pain or discomfort; the mass ratio of tungsten powder to block polyether amide added in Comparative Example 3 is not within the specified range, and the amount of tungsten powder added is too little, which increases the friction of the material, and it is easy to damage blood vessels during the advancement process as an interventional catheter tip material; in Comparative Example 4, the amount of interface regulator added is too much, so that agglomeration occurs inside the material, which in turn affects the friction of the material and is easy to damage blood vessels or tissues; the block polyether amide used in Comparative Example 5 has a low hardness itself. When used as an interventional catheter material, the overly soft material will cause the catheter to collapse or deform during use, making the surgical process more difficult. The materials in the above comparative examples cannot achieve both suitable hardness and softness at the same time, and cannot be used as the tip material of the interventional catheter to improve the catheter penetration and ensure safety at the same time.

[0031] Based on the test data of Shore D hardness and friction force in Tables 1 and 2, the nylon elastomer composite material for penetrating microcatheters prepared by Examples 1-11 has obvious advantages over the comparative examples and can effectively meet the high standards of customers and the market.

[0032] 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. A nylon elastomer composite material for penetrating a micro-catheter, characterized in that: By weight, it includes the following components: Block polyether amide 40-80 parts; 30-50 parts of tungsten powder; 0.5-2 parts of interface regulator; The mass ratio of the tungsten powder to the block polyether amide is (0.5-1.2):

1.

2. The nylon elastomer composite material according to claim 1, characterized in that: The Shore hardness of the block polyether amide is 25D-55D.

3. The nylon elastomer composite material according to claim 1, characterized in that: The interface regulator is any one or more of sodium hexametaphosphate, sodium pyrophosphate and sodium tripolyphosphate.

4. The nylon elastomer composite material according to claim 1, characterized in that: The particle size D50 of the tungsten powder is 1-8 μm.

5. The nylon elastomer composite material according to claim 1, characterized in that: The Shore hardness of the composite material is 37D-67D.

6. The method for preparing the nylon elastomer composite material according to any one of claims 1 to 5, comprising the following steps: S1: Mix the interface regulator and tungsten powder according to weight, pre-stir and mix them evenly under heating conditions; S2: After the mixture obtained in S1 is cooled, it is crushed by a ball mill; S3: melt-blending the block polyether amide and the mixture obtained in S2 according to parts by weight, and obtaining the nylon elastomer composite material after discharging.

7. A penetrating microcatheter, comprising a tube body, a head end and a top end, characterized in that: The head end comprises a polytetrafluoroethylene inner layer, a double-layer braided middle layer and an outer layer; The top end is connected to the head end, and the radius of the top end gradually decreases from the connection point to form a pointed structure with a smooth taper; The material used for the top end is the nylon elastomer composite material as described in any one of claims 1-5.

8. The penetrating microcatheter according to claim 7, characterized in that: The material used for the outer layer of the head end is the nylon elastomer composite material as described in any one of claims 1-5.

9. The penetrating microcatheter according to claim 7, characterized in that: The inner layer of the double-layer braided intermediate layer is a polypropylene fiber braided layer, and the outer layer is a stainless steel braided layer.

10. Use of the penetrating microcatheter according to any one of claims 7 to 9 as a minimally invasive interventional catheter in medical treatment.

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