Bendable anti-extrusion threaded pipe and preparation method and application thereof

Abstract

The invention relates to a bendable anti-extrusion threaded pipe and a preparation method and application thereof, the bendable anti-extrusion threaded pipe is of a tubular structure, and the pipe wall of the tubular structure comprises a first fiber membrane, a middle layer and a second fiber membrane which are stacked in sequence; the middle layer comprises reinforcing fibers; and the reinforced fiber is of a monofilament or bunched filament structure. According to the bendable anti-extrusion threaded pipe, the free bending capacity is obtained through structural arrangement, the excellent anti-extrusion and bending performance is achieved, and the application requirement in nerve injury repair can be met.

Description

Technical Field

[0001] The invention relates to the technical field of medical materials, and in particular to a bendable and extrusion-resistant threaded tube and a preparation method and application thereof. Background Art

[0002] Repair of nerve injury is a series of complex pathological processes. The nerve regeneration process is slow, and factors such as scar tissue formation, inhibition of microenvironment, motor terminal tissue, and functional degradation all restrict the repair of damaged nerves. Small segment nerve defects can be restored by the nerve's own repair ability, but the repair and functional reconstruction of long segment defect nerves are still clinical problems in neurosurgery, which seriously affects the health status and quality of life of patients.

[0003] During the extension process, the regenerated nerve fibers can identify and extend to the distal gaps, and the newly generated motor and sensory nerve fibers can grow into the corresponding functional bundles at the distal end and finally reach the target organ, thus achieving nerve repair and even functional recovery. Currently, most of the relevant nerve bridging materials are nerve conduits, which play the role of forming nerve regeneration chambers at the proximal and distal ends of the nerves, providing gaps for nerve fiber growth. For example, CN101543645A discloses a polycaprolactone (PCL) electrospun nerve conduit, which comprises an inner layer and an outer layer, wherein the inner layer is a mesh conduit made of polymer degradable fibers, and the outer layer is a high specific surface area, high porosity, three-dimensional network structure made of PCL submicron fibers sprayed by electrospinning. The preparation method comprises: (1) weaving the polymer degradable fibers and inserting them into an electrospinning device; (2) dissolving PCL in a chloroform / methanol solution and stirring; (3) electrospinning the PCL / chloroform / methanol solution; (4) after the electrospinning is completed, removing the nerve conduit, packaging and disinfecting it; the wall of the nerve conduit not only guides and transports nutrients, but also serves as a tissue engineering scaffold for regenerating nerves; the preparation method is simple to operate, low in cost, environmentally friendly, and highly economical, and can be used for the repair of the peripheral nervous system.

[0004] However, due to structural and material limitations, this type of nerve conduit is prone to compression of the conduit cavity during joint movement, causing deformation and hindering nerve growth, resulting in poor repair of the area. Bending of the joint can also cause suture pullout, inducing secondary nerve damage. The commonly used treatment method in clinical practice is to fix the joint to avoid secondary damage caused by movement. During the stage of nerve self-repair, long-term fixation can easily cause a series of problems such as postoperative stiffness of the joint, tissue adhesion, and muscle atrophy.

[0005] Therefore, there is an urgent need to develop nerve catheter products that are resistant to extrusion and bending to solve the problems of nerve defects in the muscle environment and hip joints. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a bendable, anti-extrusion threaded tube and a preparation method and application thereof. The bendable, anti-extrusion threaded tube can be bent freely through structural settings, and the inner cavity maintains a certain space when bending, so that it has excellent anti-extrusion and bending properties, can achieve good nerve repair effects, and effectively avoid the problems existing in the prior art in the repair of hip joint nerve injuries.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a bendable and anti-extrusion threaded pipe, wherein the bendable and anti-extrusion threaded pipe has a tubular structure, and a tube wall of the tubular structure comprises a first fiber membrane, an intermediate layer and a second fiber membrane stacked in sequence;

[0009] The middle layer includes reinforcing fibers;

[0010] The reinforcing fibers are in the form of monofilaments or bundled fibers.

[0011] The present invention allows the bendable anti-extrusion threaded tube to bend freely by embedding a reinforcing fiber of a monofilament or bundled filament structure in the prosthesis, thereby improving its anti-extrusion and bending performance, so that it can still maintain space for nerve growth when it is bent and restored to its original position. The bendable anti-extrusion threaded tube provided by the present invention can be applied to the repair of nerve damage in the hip joint, solving the problems that the mechanical strength of the prosthesis made of a polymer by electrospinning alone is not enough for peripheral nerve repair, and the repair prosthesis at the hip joint is prone to catheter cavity extrusion during joint movement.

[0012] Preferably, the thickness of the tube wall is 0.3-0.6 mm, for example, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm or 0.55 mm.

[0013] As a preferred technical solution of the present invention, the wall thickness of the bendable anti-extrusion threaded tube is 0.3-0.6mm, which can not only provide the mechanical support required for the prosthesis after implantation, but also avoid the discomfort caused by local tissue expansion due to excessive thickness of the product after implantation into human tissue.

[0014] In the present invention, the wall thickness (ie, tube wall thickness) refers to the distance from the side of the first fiber membrane away from the middle layer to the side of the second fiber membrane away from the middle layer.

[0015] Preferably, the inner diameter of the bendable anti-extrusion threaded tube is 0.7-30 mm, for example, it can be 1 mm, 3 mm, 5 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm, 22 mm, 25 mm or 28 mm.

[0016] Preferably, the thickness of the first fiber membrane and the second fiber membrane is independently 0.1-0.5 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0017] Preferably, the pore sizes of the first fiber membrane and the second fiber membrane are independently 10-30 μm, for example, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm or 28 μm.

[0018] Preferably, the diameter of the fiber filaments in the first fiber membrane and the second fiber membrane is 1-6 μm, for example, 1.5 μm, 2 μm, 3 μm, 4 μm or 5 μm.

[0019] As a preferred technical solution of the present invention, the specific fiber diameter and pore size range adopted by the bendable anti-extrusion threaded tube can prevent the infiltration of fibroblasts into the damaged part during the repair stage, prevent the occurrence of neuroma during the repair process, and allow the entry of small molecule nutrients to promote nerve repair.

[0020] Preferably, the first fiber membrane and the second fiber membrane each independently comprise a degradable polymer.

[0021] Preferably, the degradable polymer comprises any one of polylactic acid, polylactic acid-polyethylene glycol copolymer (PELA), lactide-caprolactone copolymer (PLCL), poly(lactide-glycolide) copolymer, polydioxanone, polycaprolactone or polyurethane, or a combination of at least two thereof, preferably a lactide-caprolactone copolymer or a combination of polylactic acid-polyethylene glycol copolymer and lactide-caprolactone copolymer. Preferably, the content of the lactide-caprolactone copolymer is 50-100% of the mass of the degradable polymer, for example, it can be 50%, 60%, 70%, 80%, 83%, 85%, 87%, 90% or 100%, etc.

[0022] As the preferred technical method of the present invention, natural polymer materials polylactic acid-polyethylene glycol copolymer and lactide-caprolactone copolymer are used to prepare a blended fiber membrane, wherein the lactide-caprolactone copolymer has excellent resilience, and the bendable and anti-extrusion threaded tube made in a specific proportion has good bending and recovery properties, and the material constituting the bendable and anti-extrusion threaded tube can be completely degraded in the human body, and has little biological hazard to the human body.

[0023] Preferably, the method for preparing the first fiber membrane or the second fiber membrane comprises the following steps:

[0024] The degradable polymer is dissolved in a solvent to obtain an electrospinning stock solution; the electrospinning stock solution is subjected to electrostatic spinning, and the spinning is received to obtain the first fiber membrane or the second fiber membrane.

[0025] Preferably, the solvent includes any one or a combination of at least two of hexafluoroisopropanol, dichloromethane, N,N-dimethylformamide, acetone, chloroform, glacial acetic acid or water, preferably a combination of hexafluoroisopropanol and dichloromethane.

[0026] Preferably, the mass / volume ratio of hexafluoroisopropanol to dichloromethane is 1:(1-10), wherein the specific value of (1-10) can be, for example, 1, 3, 5, 7 or 9.

[0027] Preferably, the mass fraction of the degradable polymer in the electrospinning stock solution is 10-25%, for example, 12%, 14%, 16%, 18%, 20%, 22% or 24%.

[0028] Preferably, the electrospinning method includes injecting the electrospinning stock solution into a syringe and performing electrospinning under the action of a propulsion pump.

[0029] Preferably, the electrospinning injection speed is 20-30 μL / min, for example, 21 μL / min, 23 μL / min, 25 μL / min, 27 μL / min or 29 μL / min.

[0030] Preferably, the loading voltage of the electrospinning is 15-25 kV, for example, 16 kV, 18 kV, 20 kV, 22 kV or 24 kV.

[0031] Preferably, the electrospinning time is 50-90 min, for example, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min or 85 min.

[0032] Preferably, the rotation receiving speed of the receiving spinning is 150-300 r / h, for example, it can be 160 r / h, 180 r / h, 200 r / h, 220 r / h, 250 r / h or 280 r / h.

[0033] In the present invention, the first fiber membrane or the second fiber membrane can be obtained by repeating the electrostatic spinning step to obtain a multilayer fiber membrane with a desired diameter and pore size.

[0034] Preferably, the diameter of the reinforcing fiber is 0.05-0.3 mm, for example, it may be 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm or 0.25 mm.

[0035] Preferably, the distance between two adjacent reinforcing fibers in the middle layer is 1-4 mm, for example, 1.5 mm, 2 mm, 2.5 mm, 3 mm or 3.5 mm.

[0036] As a preferred technical solution of the present invention, the specific reinforcing fiber spacing adopted in the bendable anti-extrusion threaded tube can ensure that the prosthesis can restore its original appearance after bending without irreversible bending deformation, thereby ensuring the growth path of the nerves during the repair process.

[0037] Preferably, the reinforcement fibers are arranged in a threaded direction perpendicular to the axial direction.

[0038] As a preferred technical solution of the present invention, the arrangement direction of the reinforcing fibers in the bendable anti-extrusion threaded tube is perpendicular to the axial thread arrangement, which helps to provide uniform mechanical support in the circumferential direction when the prosthesis rotates at any angle, so that its anti-extrusion performance is not affected by the bending angle, which is in line with the clinical application scenarios of joint motion positions.

[0039] Preferably, the material of the reinforcing fiber includes any one of polylactic acid, polyglycolic acid-polycaprolactone copolymer, polyglycolic acid, polydioxanone or poly(lactide-glycolide) copolymer, or a combination of at least two thereof.

[0040] In a second aspect, the present invention provides a method for preparing the bendable and extrusion-resistant threaded pipe as described in the first aspect, the preparation method comprising the following steps:

[0041] Arranging the reinforcing fibers on the first fiber membrane and covering the second fiber membrane thereon to obtain a composite fiber membrane;

[0042] The composite fiber membrane is wound and shaped to form a tubular structure to obtain the bendable and extrusion-resistant threaded tube.

[0043] Preferably, the wiring arrangement method includes passing one end of the reinforcing fiber through a wiring arrangement device, fixing it on one end of a rotating receiving disk to which a first fiber membrane has been attached, starting the rotating receiving, so that the reinforcing fiber is wound on the rotating receiving disk, and after the wiring arrangement is completed, fixing the tail reinforcing fiber.

[0044] In the present invention, covering the second fiber membrane includes directly covering the prepared second fiber membrane or preparing the second fiber membrane by electrostatic spinning.

[0045] Preferably, the winding method includes winding the composite fiber membrane along the direction of the reinforcing fibers.

[0046] Preferably, the winding is performed using cut composite fiber membranes.

[0047] Preferably, the setting is performed in the presence of a setting liquid.

[0048] Preferably, the fixing liquid comprises any one or a combination of at least two of hexafluoroisopropanol, dichloromethane, ethanol, N,N-dimethylformamide, acetone, chloroform, glacial acetic acid or water, and more preferably a combination of hexafluoroisopropanol and ethanol or a combination of dichloromethane and ethanol.

[0049] Preferably, the volume fraction of ethanol in the fixing solution is 70-99%, for example, it can be 72%, 75%, 80%, 85%, 90% or 95%.

[0050] Preferably, the shaping is followed by drying to obtain the bendable and extrusion-resistant threaded tube.

[0051] Preferably, the drying time is 5-30 min, for example, 8 min, 10 min, 12 min, 15 min, 20 min or 25 min.

[0052] In a third aspect, the present invention provides a use of the bendable, extrusion-resistant threaded tube as described in the first aspect in the preparation of a nerve repair material.

[0053] Compared with the prior art, the present invention has at least the following beneficial effects:

[0054] The bendable, anti-extrusion threaded tube provided by the present invention can be bent freely through structural settings and the inner cavity maintains a certain space when bending. It has excellent anti-extrusion and bending performance, and effectively avoids the problems existing in the prior art in the repair of hip joint nerve damage. In some preferred technical schemes, the bendable, anti-extrusion threaded tube has specific fiber pores that allow small molecule nutrients to pass through and block the infiltration of fibroblasts, thereby avoiding the occurrence of neuromas during the repair process. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of radial mechanical test;

[0056] Figure 2 This is a bending performance diagram of the bendable and extrusion-resistant threaded pipe in Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0058] The materials used in the following examples are as follows:

[0059] Polylactic acid-polyethylene glycol copolymer, purchased from Xi'an Qiyue Biotechnology Co., Ltd., with a molecular weight of 5000 Daltons and a lactide:ethylene glycol ratio of 75:25 mol%;

[0060] Lactide-caprolactone copolymer, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd., with a molecular weight of 174,000 Daltons and a ratio of lactide to caprolactone of 70:30 mol %;

[0061] The reinforcing fiber is polyglycolic acid, purchased from Shandong Boda Medical Supplies Co., Ltd., with a specification of 2-0.

[0062] Example 1

[0063] This embodiment provides a bendable and anti-extrusion threaded tube, which is prepared by the following method:

[0064] (1) Dissolving polylactic acid-polyethylene glycol copolymer (PELA) and lactide-caprolactone copolymer (PLCL) in a mixture of hexafluoroisopropanol and dichloromethane in a volume ratio of 1:6 to prepare an electrospinning stock solution, wherein the mass fraction of PELA in the electrospinning stock solution is 2% and the mass fraction of PLCL is 10%; injecting the electrospinning stock solution into a syringe, and performing electrospinning under the action of a propulsion pump, adjusting the injection speed to 20 μL / min, and the loading voltage to 15 kV, using a metal rotating receiving disk to receive the blended filaments obtained by electrospinning, adjusting the rotating receiving speed to 200 r / h, and the spinning time to 60 min, to obtain a first fiber membrane with a fiber diameter of 4-6 μm and a fiber membrane pore size of 25-30 μm (the fiber diameter and fiber membrane pore size obtained in actual production cannot be kept completely consistent, so the actual measured value is a range value);

[0065] (2) Fix one end of the monofilament to one end of the rotating receiving disk to which the first fiber membrane has been attached through a wire arrangement device, start the rotating receiving device, and wind the monofilament around the rotating receiving disk, arranging the monofilament in a thread perpendicular to the axial direction with a spacing of 2 mm; after the wire arrangement is completed, fix the tail of the monofilament to prevent the wire arrangement from loosening;

[0066] (3) repeating step (1) to cover the second fiber membrane on the side of the reinforcing fiber away from the first fiber membrane, thereby obtaining a composite fiber membrane;

[0067] (4) Hexafluoroisopropanol and ethanol are mixed in a volume ratio of 2:8 to form a setting liquid for standby use; the composite fiber membrane obtained in step (3) is cut, and then wound along the direction of the reinforcing fibers, and a setting liquid is added to fix it into a tube shape, and dried in a drying oven at 45° C. for 10 minutes to obtain the bendable and anti-extrusion threaded tube.

[0068] Example 2

[0069] This embodiment provides a bendable and anti-extrusion threaded tube, which is prepared by the following method:

[0070] (1) dissolving polylactic acid-polyethylene glycol copolymer (PELA) and lactide-caprolactone copolymer (PLCL) in a mixture of hexafluoroisopropanol and dichloromethane in a volume ratio of 1:4 to prepare an electrospinning stock solution, wherein the mass fraction of PELA in the electrospinning stock solution is 2.5% and the mass fraction of PLCL is 15%; injecting the electrospinning stock solution into a syringe, and performing electrospinning under the action of a propulsion pump, adjusting the injection speed to 25 μL / min, and the loading voltage to 20 kV, using a metal rotating receiving disk to receive the blended filaments obtained by electrospinning, adjusting the rotating receiving speed to 250 r / h, and the spinning time to 70 min, to obtain a first fiber membrane with a fiber diameter of 2-4 μm and a fiber membrane pore size of 10-18 μm;

[0071] (2) Fix one end of the monofilament to one end of the rotating receiving disk to which the first fiber membrane has been attached through a wire arrangement device, start the rotating receiving device, and wind the monofilament around the rotating receiving disk, arranged in a thread perpendicular to the axial direction with a spacing of 3 mm; after the wire arrangement is completed, fix the tail of the monofilament to prevent the wire arrangement from loosening;

[0072] (3) repeating step (1) to cover the second fiber membrane on the side of the reinforcing fiber away from the first fiber membrane, thereby obtaining a composite fiber membrane;

[0073] (4) mixing dichloromethane and ethanol in a volume ratio of 2:8 to form a setting liquid for standby use; cutting the composite fiber membrane obtained in step (3), winding it along the direction of the reinforcing fibers, and adding the setting liquid to set it into a tube shape, and drying it in a drying oven at 45° C. for 15 minutes to obtain the bendable and anti-extrusion threaded tube.

[0074] Example 3

[0075] This embodiment provides a bendable and anti-extrusion threaded tube, which is prepared by the following method:

[0076] (1) dissolving polylactic acid-polyethylene glycol copolymer (PELA) and lactide-caprolactone copolymer (PLCL) in a mixture of hexafluoroisopropanol and dichloromethane in a volume ratio of 1:8 to prepare an electrospinning stock solution, wherein the mass fraction of PELA in the electrospinning stock solution is 3% and the mass fraction of PLCL is 20%; injecting the electrospinning stock solution into a syringe, and performing electrospinning under the action of a propulsion pump, adjusting the injection speed to 30 μL / min, and the loading voltage to 25 kV, using a metal rotating receiving disk to receive the blended spun fibers obtained by electrospinning, adjusting the rotating receiving speed to 300 r / h, and the spinning time to 80 min, to obtain a first fiber membrane with a fiber diameter of 1-3 μm and a fiber membrane pore size of 10-14 μm;

[0077] (2) Fix one end of the bundle of wires to one end of the rotating receiving disk to which the first fiber membrane has been attached through the wire arrangement device, start the rotating receiving device, and wind the bundle of wires around the rotating receiving disk, arranged in a thread perpendicular to the axial direction with a spacing of 4 mm; after the wire arrangement is completed, fix the tail of the bundle of wires to prevent the wire arrangement from loosening;

[0078] (3) repeating step (1) to cover the second fiber membrane on the side of the reinforcing fiber away from the first fiber membrane, thereby obtaining a composite fiber membrane;

[0079] (4) Mixing dichloromethane and ethanol in a volume ratio of 2:8 to form a setting liquid for standby use; cutting the composite fiber membrane obtained in step (3), winding it along the direction of the reinforcing fibers, and adding the setting liquid to set it into a tube shape, and drying it in a drying oven at 45° C. for 20 minutes to obtain the bendable and anti-extrusion threaded tube.

[0080] Example 4

[0081] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is 1.7%, the mass fraction of PLCL is 8.3%, the fiber diameter is 2-4 μm, and the fiber membrane pore size is 18-24 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0082] Example 5

[0083] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is 4.2%, the mass fraction of PLCL is 20.8%, the obtained fiber diameter is 5-6 μm, and the fiber membrane pore size is 27-30 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0084] Example 6

[0085] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is 5%, the mass fraction of PLCL is 25%, the fiber diameter is 8-12 μm, and the fiber membrane pore size is 30-60 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0086] Example 7

[0087] The present embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is 0.8%, the mass fraction of PLCL is 4.2%, the first fiber membrane obtained is scattered and cannot be formed, the fiber diameter cannot be measured, the fiber pore size is visible to the naked eye, and is about 1-6 cm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0088] Example 8

[0089] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that PELA is not added in step (1), and the mass fraction of PLCL is adjusted to 12%, resulting in a fiber diameter of 3-6 μm and a fiber membrane pore size of 10-25 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0090] Example 9

[0091] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is 6%, the mass fraction of PLCL is 6%, the fiber diameter is 5-6 μm, and the fiber membrane pore size is 15-30 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0092] Example 10

[0093] This embodiment provides a bendable, extrusion-resistant threaded tube, which differs from Embodiment 1 in that the mass fraction of PELA in step (1) is adjusted to 6.6%, and the mass fraction of PLCL is adjusted to 5.4%, so that the fiber diameter is 4-10 μm and the fiber membrane pore size is 20-50 μm. Other raw materials, contents and preparation methods are the same as those in Embodiment 1.

[0094] Comparative Example 1

[0095] A bendable and anti-extrusion threaded pipe, wherein the bendable and anti-extrusion threaded pipe is prepared by the following method:

[0096] (1) dissolving polylactic acid-polyethylene glycol copolymer (PELA) and lactide-caprolactone copolymer (PLCL) in a mixture of hexafluoroisopropanol and dichloromethane in a volume ratio of 1:6 to prepare an electrospinning stock solution, wherein the mass fraction of PELA in the electrospinning stock solution is 2% and the mass fraction of PLCL is 10%; injecting the electrospinning stock solution into a syringe, and performing electrospinning under the action of a propulsion pump, adjusting the injection speed to 20 μL / min, and the loading voltage to 15 kV, using a metal rotating receiving disk to receive the blended filaments obtained by electrospinning, adjusting the rotating receiving speed to 200 r / h, and the spinning time to 60 min, to obtain a first fiber membrane with a fiber diameter of 4-6 μm and a fiber membrane pore size of 25-30 μm;

[0097] (2) repeating step (1) to cover the second fiber membrane on the surface of the first fiber membrane to obtain a composite fiber membrane;

[0098] (3) Hexafluoroisopropanol and ethanol are mixed in a volume ratio of 2:8 to form a setting liquid for standby use; the composite fiber membrane obtained in step (2) is cut, and then wound along the fiber direction, and a setting liquid is added to fix it into a tube shape, and dried in a drying oven at 45° C. for 10 minutes to obtain the bendable and anti-extrusion threaded tube.

[0099] The following tests are performed on the above-mentioned bendable and anti-extrusion threaded pipe:

[0100] 1) Radial Mechanics

[0101] Place the prepared bendable and anti-extrusion threaded pipe horizontally on the parallel plate fixture without damage, so that the universal testing machine can measure its radial force. The direction of the radial force is as follows: Figure 1 As shown, at (37±2)℃, the bendable and extrusion-resistant threaded tube is compressed at a uniform speed of 2mm / min until its outer diameter is reduced by 50%. The load required to produce 50% outer diameter deformation is measured, which is its radial force.

[0102] The test results are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] According to the test results of Examples 1-10 in Table 1, it can be found that the bendable, extrusion-resistant threaded tube provided by the present invention has good radial force bearing capacity. By optimizing the preparation of the bendable, extrusion-resistant threaded tube, the maximum radial force it can withstand can be ≥1.4N, and the maximum radial force it can withstand can reach up to 2.3N.

[0107] By comparing Examples 1-3, it can be seen that the wall thickness of the bendable anti-extrusion threaded tube provided by the present invention is 0.3-0.6mm. Within this range, by further enhancing the wall thickness of the bendable anti-extrusion threaded tube, the obtained bendable anti-extrusion threaded tube has an enhanced ability to resist outer diameter deformation under the combined action of the upper and lower bidirectional radial forces perpendicular to each other, thereby increasing the load it can withstand under the same deformation, and thus achieving a better technical effect of anti-extrusion performance. This proves that the bendable anti-extrusion threaded tube of the present invention can have a technical effect of good anti-extrusion performance while ensuring that its thickness does not cause local tissue expansion and discomfort.

[0108] By comparing Example 1 with Examples 4-7, it can be seen that the mass fraction of the degradable polymer in the electrospinning solution of Example 6 exceeds 25%, the fiber pore size obtained by spinning is too large, and its density is insufficient. The ability of the obtained bendable and anti-extrusion threaded tube to resist outer diameter deformation under the combined action of the upper and lower bidirectional radial forces perpendicular to each other is weakened, thereby reducing the load it can withstand under the same deformation; the mass fraction of the degradable polymer in the electrospinning solution of Example 7 is lower than 10%, and it cannot be spun into shape. The fiber pore size obtained by spinning is visible to the naked eye, and its density is seriously insufficient. The ability of the obtained bendable and anti-extrusion threaded tube to resist outer diameter deformation under the combined action of the upper and lower bidirectional radial forces perpendicular to each other is poor, thereby The load it can withstand under the same deformation is also insufficient, which shows that the present invention can limit the content of the degradable polymer in the electrospinning solution, so that the obtained bendable and anti-extrusion threaded tube has good anti-extrusion performance.

[0109] By comparing Example 1 with Examples 8-10, it can be seen that when the mass of the lactide-caprolactone copolymer in the degradable polymer of Example 10 is less than 50%, the pore size of the fiber obtained by spinning is too large and its density is insufficient, so that the ability of the bendable anti-extrusion threaded tube to resist outer diameter deformation under the combined action of the upper and lower bidirectional radial forces perpendicular to each other is weakened, thereby reducing the load it can withstand under the same deformation, indicating that the present invention can optimize the content of the lactide-caprolactone copolymer in the degradable polymer, so that the obtained bendable anti-extrusion threaded tube has good anti-extrusion performance.

[0110] By comparing Example 1 with Comparative Example 1, it can be seen that the present invention can obtain the technical effect of radial mechanical enhancement by winding reinforcing fibers on the surface of the fiber membrane, while when the reinforcing fibers are not used / lack, the radial supporting force is weakened and it is impossible to achieve better anti-extrusion ability to achieve a better effect of protecting the nerves.

[0111] 2) Bending performance verification method

[0112] Insert the prepared bendable and anti-extrusion threaded tube into the middle of the hollow simulated tissue sleeve, keep it in a constant temperature environment of 37±2℃ for 1 minute, then bend the simulated tissue sleeve containing the product to 60° under the action of external force and keep it for 1 minute. Then remove all stresses applied to the simulated tissue sleeve to restore it to its natural state, and wait for the bendable and anti-extrusion threaded tube to cool to room temperature and observe it.

[0113] The results are as follows Figure 2 As shown, it can be seen that the catheter obtained from the control electrospinning catheter comparative example 1 is bent 60° and then formed into a dead fold, showing obvious creases, and the bending surface is a sharp acute angle. The freely bendable, bendable, and extrusion-resistant threaded tubes prepared in Examples 1-3 of the present invention have no dead folds after being bent 60°, and the bending surface is an arc shape.

[0114] In summary, the present invention obtains a bendable, extrusion-resistant threaded tube with excellent compression and bending performance by setting a specific structure. The bendable, extrusion-resistant threaded tube can be bent freely and the inner cavity maintains a certain space when bending, which meets the application requirements in the repair of hip joint nerve injuries.

[0115] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A bendable and anti-extrusion threaded pipe, characterized in that: The bendable anti-extrusion threaded tube has a tubular structure, and the tube wall of the tubular structure includes a first fiber membrane, an intermediate layer and a second fiber membrane stacked in sequence; The middle layer includes reinforcing fibers; The reinforcing fibers are in the form of monofilaments or bundled fibers.

2. The bendable anti-extrusion threaded pipe according to claim 1, characterized in that: The thickness of the tube wall is 0.3-0.6 mm; Preferably, the thickness of the first fiber membrane and the second fiber membrane is independently 0.1-0.5 mm; Preferably, the pore sizes of the first fiber membrane and the second fiber membrane are independently 10-30 μm; Preferably, the diameter of the fiber filaments in the first fiber membrane and the second fiber membrane is 1-6 μm.

3. The bendable anti-extrusion threaded pipe according to claim 1 or 2, characterized in that: The first fiber membrane and the second fiber membrane each independently include a degradable polymer; Preferably, the degradable polymer comprises any one of polylactic acid, polylactic acid-polyethylene glycol copolymer, lactide-caprolactone copolymer, poly(lactide-glycolide) copolymer, polydioxanone, polycaprolactone or polyurethane, or a combination of at least two thereof, preferably a lactide-caprolactone copolymer or a combination of a polylactic acid-polyethylene glycol copolymer and a lactide-caprolactone copolymer; Preferably, the mass of the lactide-caprolactone copolymer is 50-100% of the mass of the degradable polymer.

4. The bendable anti-extrusion threaded pipe according to any one of claims 1 to 3, characterized in that: The method for preparing the first fiber membrane or the second fiber membrane comprises the following steps: The degradable polymer is dissolved in a solvent to obtain an electrospinning stock solution; the electrospinning stock solution is subjected to electrostatic spinning, and the spinning is received to obtain the first fiber membrane or the second fiber membrane.

5. The bendable anti-extrusion threaded pipe according to claim 4, characterized in that: The solvent includes any one or a combination of at least two of hexafluoroisopropanol, dichloromethane, N,N-dimethylformamide, acetone, chloroform, glacial acetic acid or water, preferably a combination of hexafluoroisopropanol and dichloromethane; Preferably, the volume ratio of hexafluoroisopropanol to dichloromethane is 1:(1-10); Preferably, the mass fraction of the degradable polymer in the electrospinning stock solution is 10-25%; Preferably, the electrospinning method includes injecting the electrospinning stock solution into a syringe and performing electrospinning under the action of a propulsion pump; Preferably, the electrospinning injection speed is 20-30 μL / min; Preferably, the loading voltage of the electrospinning is 15-25 kV; Preferably, the electrospinning time is 50-90 min; Preferably, the rotation receiving speed of the receiving spinning is 150-300r / h.

6. The bendable anti-extrusion threaded pipe according to any one of claims 1 to 5, characterized in that: The diameter of the reinforcing fiber is 0.05-0.3 mm; Preferably, the distance between two adjacent reinforcing fibers in the middle layer is 1-4 mm; Preferably, the reinforcement fibers are arranged in a direction perpendicular to the axial direction. Preferably, the material of the reinforcing fiber includes any one of polylactic acid, polyglycolic acid-polycaprolactone copolymer, polyglycolic acid, polydioxanone or poly(lactide-glycolide) copolymer, or a combination of at least two thereof.

7. A method for preparing a bendable and extrusion-resistant threaded pipe according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: Arranging the reinforcing fibers on the first fiber membrane and covering the second fiber membrane thereon to obtain a composite fiber membrane; The composite fiber membrane is wound and shaped to form a tubular structure to obtain the bendable and extrusion-resistant threaded tube.

8. The preparation method according to claim 7, characterized in that: The wiring arrangement method includes passing one end of the reinforcing fiber through a wiring arrangement device, fixing it on one end of a rotating receiving disk to which a first fiber membrane has been attached, starting the rotating receiving, so that the reinforcing fiber is wound on the rotating receiving disk, and after the wiring arrangement is completed, fixing the tail reinforcing fiber.

9. The preparation method according to claim 7 or 8, characterized in that: The winding method includes winding the composite fiber membrane along the direction of the reinforcing fibers; Preferably, the setting is carried out in the presence of a setting liquid; Preferably, the fixing liquid comprises any one or a combination of at least two of hexafluoroisopropanol, dichloromethane, ethanol, N,N-dimethylformamide, acetone, chloroform, glacial acetic acid or water, and more preferably a combination of hexafluoroisopropanol and ethanol or a combination of dichloromethane and ethanol; Preferably, the volume fraction of ethanol in the setting liquid is 70-99%; Preferably, the shaping is followed by drying to obtain the bendable and anti-extrusion threaded tube; Preferably, the drying time is 5-30 minutes.

10. Use of the bendable, anti-extrusion threaded tube according to any one of claims 1 to 6 in preparing nerve repair materials.

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