CN108025108B

CN108025108B - Personalized polymer stent and preparation method and application thereof

Info

Publication number: CN108025108B
Application number: CN201580083108.4A
Authority: CN
Inventors: 赵庆洪; 石桂欣; 刘青; 赵清华; 崔淑君; 郑博
Original assignee: Beijing Advanced Medical Technologies Inc
Current assignee: Beijing Advanced Medical Technologies Inc
Priority date: 2015-12-14
Filing date: 2015-12-14
Publication date: 2021-08-31
Anticipated expiration: 2035-12-14
Also published as: WO2017100977A1; CN108025108A

Abstract

A personalized polymer stent and a preparation method and application thereof. The stent has a shape and size matching the shape and size of the lumen or the outer contour of the lumen at the site to be used and has a stent structure consisting of polymer filaments deposited in a pre-designed pattern, the stent having at least one varying diameter along the length of the stent. Preparing a hollow or solid personalized bracket mould matched with the shape and size of the inner cavity or the cavity outer contour of the part to be used according to the data of the inner cavity or the cavity outer contour of the medical image scanning of the part to be used; and sleeving the mold on a fourth shaft of the four-shaft rapid forming system or directly serving as the fourth shaft for receiving the polymer to prepare an individualized bracket product. The shape and the size of the bracket are matched with the part to be used, the length, the angle and the curvature of the bracket are more suitable for the structural form of the part to be used, the special requirements of the part to be used can be met, and the wall-adhering performance and the treatment effect of the bracket are improved.

Description

Personalized polymer stent and preparation method and application thereof

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to a personalized polymer stent, and a preparation method and application thereof.

Background

The stent is a net tubular device, which is placed in an organ having a lumen structure of a human body, and is used for treating intraluminal stenosis due to a lesion. The bracket can support the lumen and keep the lumen unobstructed. Some stents also have the effect of preventing restenosis of the lumen.

Stents are usually placed at the lesion under the guidance of imaging equipment (e.g. angiographic, fluoroscopy, CT, MR, B-ultrasound) by means of percutaneous puncture, or through the original tract of the body, a procedure known as stenting. Because of its minimal invasiveness and high efficiency, Dotter has rapidly developed and applied since 1964 in the United states of America using coaxial catheter technology to perform angioplasty on patients.

Currently, in interventional medicine, there are sites where a stent needs to be implanted: blood vessels, biliary tract, urinary tract, trachea, esophagus, pancreatic duct, stomach, intestine, etc., wherein the blood vessels are used in the largest amount. Since these different sites to be used have different shapes, lumen diameters, lesion lengths, and the like, it is necessary to provide diversified stents that can be better matched thereto with respect to the shape and size of the inner lumen or the outer lumen profile of the sites to be used.

However, the stent models sold at home and abroad are standardized or normalized at present, and the size difference requirements of the lesion parts of patients are not considered. For example, cardiovascular stents and peripheral vascular stents are almost straight mesh tubular in shape, the diameter of the cardiovascular stent is usually 2.5, 3.0 and 4.0mm, the common length is 13, 18, 23, 29, 33 and 38mm, the diameter of the cerebrovascular stent is usually 3.5, 4.0 and 4.5mm, the common length is 7, 10, 13 and 16mm, the diameter of the peripheral stent is usually 5-10 mm, 12-18 mm and 24-42 mm, the common length is 20-80 mm, 60-100 mm and 140-160 mm, and compared with the conditions that the thickness of human blood vessels is different, the length of diseased blood vessels and the stenosis length are different from person to person, the model of the stent is obviously single. The specification of the bracket is fixed, and the requirement of the change of the length and the diameter of the pathological change part of a clinical patient cannot be met.

Although interventional stent therapy is currently the most effective treatment for vascular disease, intravascular restenosis and intrastent thrombosis after stent implantation limit the application of this technique. The shape of the stent is one of main causes influencing restenosis and thrombosis, and clinical results show that different stresses can be caused to different joint parts of a blood vessel wall in the expansion process after implantation of the straight-tube-shaped blood vessel stent, so that the blood vessel wall is torn and damaged in different degrees, and subsequent immune reactions are caused, such as excessive migration and proliferation of smooth muscles and restenosis caused by intimal hyperplasia; meanwhile, poor adherence can also lead blood cells to be adhered and gathered on the surface of the stent, and thrombus in the stent is easily formed.

In order to better solve the stenosis of the blood vessel, the tapered blood vessel stent appears in the markets at home and abroad,

and RX

(Abbott, 2mm taper, length 30, 40mm, suitable for carotid diameter of 4-9 mm),

(Medtronic，2&3mm taper and 30 mm length&40mm, and is suitable for carotid artery diameter of 4-9 mm),

(Medtronic, 4mm taper, length 150mm, for thoracic aorta diameter 22-46 mm), Hercules (TM) (minimally invasive medical treatment: 4 mm)&The taper of 6mm is suitable for thoracic aorta; 2mm taper, suitable for iliac arteries), a patent related to a variable-diameter vessel stent is gradually disclosed, WO 98/53759(YADAV et al) discloses a variable-diameter carotid artery stent, US 2001/0010013 a1(Daniel L et al) discloses a self-expanding tapered stent, WO 02/13727 a1(life sciences) discloses a trumpet-shaped carotid artery stent, CN 201135516Y (lep medical treatment) discloses a metal or alloy variable-diameter vessel stent, CN 203425071U (Jiangsu university) discloses a metal or alloy stent suitable for tapered vessels, CN 203388973U (perijeikey) discloses a tapered metal vessel stent, and CN 202875544U (liaoning center for biomedical materials research and development limited) discloses a variable-diameter stent suitable for physiological characteristics of pulmonary arteries. Cartoid stenting used and non-ported stents: associated neurological compositions and stress rates (Ann Vasc Surg.2009)Jul-Aug; 23(4): 439-45. doi: 10.1016/j.avsg.2008.11.007.Epub 2009 Jan 6.), Radial force measures in cartid stents: clinical studies at home and abroad, such as influece of stent design and length of the division (J Vasc Interv radio.2011 May; 22 (5): 661-6. doi: 10.1016/j.jvir.2011.01.450.), observation of blood pressure change after carotid sinus taper stent molding (Chongqing medicine 2009, volume 38, phase 11, 1299 and 1300), and the like, also prove that the variable-diameter stent has lower stent implantation complications than the straight stent.

The vascular stents are all made of medical metal or alloy materials, the processing method generally adopts weaving, laser engraving, etching, micro-charge processing, electric forming, die casting and the like, at present, laser engraving is mostly adopted, and the main defects of the stent system are as follows: 1. the traditional straight cylindrical support product is prepared by a laser engraving method, the process is long, engraving pipes need to be prepared first, and then 70-80% of materials are wasted after cutting; 2. the diameter-variable support is prepared by a laser engraving method, a straight tubular pipe is also required to be prepared, cut and expanded by a diameter-variable saccule or subjected to heat treatment on a conical die at the later stage, and the process is more complicated; 3. the laser engraving cannot prepare the bracket product with irregular shape or more complex shape, and still cannot meet the requirements of clinical pathology and physiology.

Meanwhile, the interventional stent technology is also an effective treatment method in the aspects of dredging stenosis, opening a drainage channel, closing abnormal channels and the like of non-vascular body cavities such as biliary tracts, urethra, trachea, esophagus, pancreatic ducts, stomach, intestines and the like, and the materials and the manufacturing methods of the current clinically used stent and vascular stent are basically the same. For example, CN 2424786Y discloses a high contrast biliary stent woven by metal wires, CN 203852712U discloses a single phoenix tail biliary stent made of polyurethane or polyethylene material, CN 2220875Y discloses a urethral stent woven by nickel-titanium wires, CN 101480506 a discloses a degradable tracheal stent woven by poly-p-dioxanone or polyglycolide monofilaments, CN 103607975A discloses an esophageal stent cut by nickel-titanium alloy laser, and CN 102202605A discloses a stent for preventing pancreatic diseases, which is prepared by high molecular polymer. None of these approaches address the need for patient-individualized stents.

In conclusion, the current clinical intravascular stent product is still a standardized product. The structure of the stent is mostly in a straight net tubular shape, and partial stents, such as a carotid stent, an iliac stent and a thoracic aorta stent, have a tapered external form, but are still relatively single compared with the diversification of lesion blood vessels. Thus, the individual needs of clinical patients are still not met.

The application of non-vascular stent products is also more and more extensive, but due to the permanent existence and the current situation of high restenosis rate caused by the shape unicity of the traditional stent, a novel personalized stent aiming at the pathological change part of a patient is urgently needed to appear clinically.

The development of clinical imaging medicine, such as angiography and Optical Coherence Tomography (OCT), makes it possible to obtain 3D dimensional information of a lesion region of a patient before surgery.

The Chinese patent application (application number: 201080002569.1) discloses a four-axis rapid prototyping system and a method for preparing a three-dimensional porous tubular scaffold, and the Chinese patent application (CN 104274867A) discloses a degradable polymer scaffold and a method for preparing a polymer scaffold by using the four-axis rapid prototyping system. However, the above patent application still does not solve the defect of single external shape of the stent, and cannot well meet the special requirements of the part to be used. Aiming at the defects in the prior art, the invention carries out further research and development to obtain a novel personalized polymer stent.

Disclosure of Invention

It is therefore an object of the present invention to provide a personalized polymer stent. The shape and the size of the inner cavity or the outer contour of the cavity of the bracket and the part to be used are matched better, and the special requirements of the part to be used can be met. Meanwhile, the problem of follow-up complications of the bracket can be solved, and the safety and effectiveness of the bracket are improved.

It is another object of the present invention to provide a method for preparing the personalized polymer scaffold.

It is yet another object of the present invention to provide the use of the personalized polymer scaffold.

To facilitate an understanding of the present invention, certain terms are defined below. Terms defined herein have meanings as commonly understood by one of ordinary skill in the art to which the invention pertains.

Unless otherwise indicated, the term "solid or hollow personalized stent mold" used herein refers to a part whose outer contour matches the inner cavity or outer cavity contour of a lesion site of a patient, and when the stent is manufactured by adopting a four-axis rapid prototyping system, the solid or hollow personalized stent mold is sleeved on a fourth axis or directly used as the fourth axis for receiving a polymer to realize the processing of the stent shape. When the fourth shaft is sleeved with the fourth shaft, the workpiece has a specific hollow inner cavity shape. The personalized stent mold is prepared according to the 3D size information of the lesion part of the patient. The personalized die can be prepared by adopting a numerical control machine tool machining mode, and can also be prepared by adopting a 3D printing method and the like.

As used herein, unless otherwise indicated, the term "zig-zag and/or braided structure" refers to the form of a stent structure formed using a "zig-zag" path and/or a "warp and weft" braided path.

The term "rounded structure" as used herein, unless otherwise indicated, refers to the internal structure of a stent formed using a "rounded" curved path of travel.

Unless otherwise indicated, the term "circular arc double-chamfer structure" used herein refers to a curved wire-running path with "peak-valley" like "sine and cosine", and a peak or valley separated by one peak or valley is equally divided into two parts, like a double chamfer, to form a circular arc double-chamfer stent inner structure.

As used herein, unless otherwise indicated, the term "braided bridge structure" means that two "parallel" filaments are used from filament to filament, similar to two adjacent "bridges" in a river, with the individual filaments being designed to weave to form the internal structure of the braided bridge stent.

The purpose of the invention is realized by the following technical scheme:

in one aspect, the present invention provides a personalized polymer stent having a shape and dimensions matching the shape and dimensions of the lumen or the outer contour of the lumen at the site of use and having a stent structure consisting of polymer filaments deposited in a pre-designed pattern, wherein the stent has at least one varying diameter along the length of the stent.

Preferably, the site to be used is a blood vessel or a body cavity, such as a cardiovascular and cerebrovascular vessel, a peripheral blood vessel, a biliary tract, a urinary tract, a trachea, an esophagus, a pancreatic duct, a stomach, an intestine, or the like.

Preferably, the stent has a regular or irregular shape, including but not limited to a tapered cone, a dumbbell shape, an irregular curved shape, and the like.

Preferably, the stent structure is a zigzag and/or woven structure, a circular arc double-chamfer structure, and/or a woven bridge structure.

Preferably, the polymer is a degradable polymer, wherein the degradable polymer is selected from one or more of the following: polylactic acid (PLA), levorotatory polylactic acid (PLLA), dextrorotatory polylactic acid (PDLA), polyethylene glycol-polyglycolic acid (PGA), Polycaprolactone (PCL), polyethylene glycol (PEG), polyanhydride, Polyhydroxyalkanoate (PHA), polydioxanone, polyiminocarbonate, polyfumaric acid, degradable polyurethane, copolymers or mixtures of the above materials, and mixtures of one or more of the above materials with other degradable polymeric materials.

Preferably, the polymer is a non-biodegradable polymer, wherein the non-biodegradable polymer is selected from one or more of the following: polyesters, including, but not limited to, polyethylene terephthalate, polybutylene terephthalate; nylons, including, but not limited to, nylon 6, nylon 66; polyethylene, polytetrafluoroethylene, polypropylene, polyurethane, silicone rubber, and copolymers or mixtures of the foregoing.

Preferably, the stent is a vascular stent or a body lumen stent, such as a cardiovascular stent, a peripheral vascular stent, a biliary stent, a urinary tract stent, a tracheal stent, an esophageal stent, a pancreatic duct stent, a gastric stent, or an intestinal stent; preferably, the surface of the stent is sprayed with a drug for inhibiting cell growth.

In another aspect, the present invention provides a method of preparing the stent of the present invention, wherein the method is performed using a four-axis rapid prototyping system as a manufacturing apparatus, the four-axis rapid prototyping system comprising:

(i) a base;

(ii) a three-axis X-Y-Z positioning system coupled to the base, wherein the X-Y-Z positioning system defines X, Y, Z directions, respectively;

(iii) a dispensing system mounted on and movable by said X-Y-Z positioning system, said dispensing system including a nozzle;

(iv) a fourth shaft system connected to the base, comprising a rotating rod connected to the base below the nozzle, wherein the rotating rod can rotate around its central axis in a forward or reverse direction; the middle axis of the rotating rod is parallel to the Y axis; and

(v) a computer control system which can precisely control the X-Y-Z positioning system according to a set program so as to precisely control the movement of the nozzle of the distribution system in the direction X, Y, Z, and precisely control the rotation of the rotating rod of the fourth shaft system around the central axis thereof;

the method comprises the following steps:

1) preparing a solid or hollow personalized bracket mould matched with the shape and size of the inner cavity or the outer contour of the cavity of the part to be used according to the structural data of the inner cavity or the outer contour of the cavity of the part to be used;

2) editing and setting the shape and size of the bracket and the program of the bracket structure by adopting a computer according to the personalized bracket mould;

3) generating a bracket processing program by adopting an automatic or manual method according to the set bracket appearance, size and bracket structure;

4) setting operation parameters of a distribution system;

5) fixing the personalized bracket die at the position of a rotating rod of a fourth shaft system of the four-shaft rapid prototyping system, so that the personalized bracket die can rotate forwards or backwards along with the rotating rod of the fourth shaft system under the control of a computer control system; adding the polymer into a distribution system of a four-axis rapid prototyping system;

6) the X-Y-Z positioning system and the fourth shaft system are controlled by the computer control system, so that the distribution system extrudes polymer filaments accurately according to the set bracket structure pattern, and the polymer filaments are deposited at a specific position of a personalized bracket die which can rotate on the fourth shaft, and the designed personalized bracket with a specific shape, size and structure is prepared.

Preferably, the personalized stent mold in step 1) is prepared by obtaining a 3D model of the lesion site of the patient through in vitro 3D reconstruction according to a medical imaging technology (such as CT, MRI, angiography data or OCT data) of the lesion site of the patient, and then adopting a 3D printing technology or a numerical control machining method.

Preferably, the method further comprises the step of removing the prepared scaffold from the fourth shaft.

Preferably, the fixing in step 5) is performed by using a clamp, or by sleeving the hollow personalized stent die on a rotating rod of the fourth shaft system.

Preferably, the personalized stent mould is used in step 5) to receive the polymer instead of the rotating rod of the fourth shaft system, fix the polymer on the fourth shaft system and enable the polymer to rotate forwards or backwards under the control of the computer control system.

A four-axis rapid prototyping system, such as that disclosed in chinese invention patent application No. 201080002569.1, can be used to make the personalized polymer scaffold of the present invention. Four-axis rapid prototyping system includes: (i) a base; (ii) a three-axis X-Y-Z positioning system coupled to the base, wherein the X-Y-Z positioning system defines X, Y, Z directions, respectively; (iii) a dispensing system mounted on and movable by said X-Y-Z positioning system, said dispensing system including a nozzle; (iv) a fourth shaft system connected to the base, comprising a rotating rod connected to the base below the nozzle, wherein the rotating rod can rotate around its central axis in a forward or reverse direction; the middle axis of the rotating rod is parallel to the Y axis; and (v) a computer control system that can precisely control the X-Y-Z positioning system according to a set program to precisely control the movement of the nozzle of the dispensing system in the direction X, Y, Z, and to precisely control the rotation of the rotary lever of the fourth shaft system about its central axis.

The invention provides a method for producing an in vivo stent in a personalized way by adopting a novel personalized stent processing technology. Preparing a support model needing individuation of the support to realize the individuation of the external form of the support, wherein the support model can be obtained by scanning the structure of a part to be used through a 3D medical imaging technology, obtaining a 3D model of the part to be used after in vitro 3D reconstruction, then preparing a corresponding solid or hollow individuation support mold matched with the shape and the size of the inner cavity or the outer contour of the cavity of the part to be used by adopting the traditional technologies such as a 3D printing method or a numerical control machine tool processing method, and the like, fixing the solid or hollow individuation support mold at the position of a rotating rod of a fourth shaft system of the four-shaft rapid prototyping system, for example, directly fixing the individuation support mold on the rotating rod of the fourth shaft system through a clamp or fixing the hollow individuation support mold on the rotating rod of the fourth shaft system, or replacing the rotating rod of the fourth shaft system with the individuation support mold to receive the polymer, it is fixed on the fourth shaft system and can rotate in the forward or reverse direction under the control of the computer control system. Editing programs according to a mould model and an expected support structure, inputting the programs into a computer, synchronously controlling X, Y, Z shafts and rotating rods through a computer control system, designing reasonable X, Y and Z-shaft routing paths according to the ideal structure of the support, feeding materials into a distribution system of an extrusion device, enabling the material distribution system to accurately extrude filaments according to a set pattern, and depositing the filaments at a specific position on a personalized mould, thereby manufacturing the support with a required shape, size and structure.

The four-shaft rapid forming system adopted by the invention can comprise a material extruding or conveying device and a set of operation system for controlling the material conveying condition. More specifically, the molding system can comprise a feeding system, an extrusion system, a four-axis positioning system and a temperature control system. In a preferred embodiment, the material delivery system is a polymer melt extrusion system that can directly extrude a thermal fuse of polymer material. A four axis positioning system refers to a computer controlled space X, Y, Z axis and a fourth axis of rotation lever that rotates, driven by a stepper motor or servo motor, at a speed that precisely rotates, stops, rotates forward or backward as needed. The rotating rod may be equipped with a heater or operate in a temperature controlled environment in order to control the softness and viscosity of the received material in order to develop optimal properties of the material. For example, a polymer melt can adhere well to other materials and maintain a shape while being transported in a molten state, and a thermal fuse can adhere to a previously extruded filament which meets the thermal fuse, so that the use of glue can be omitted. For each given polymeric material, an ideal set of combination parameters needs to be established to ensure adequate adhesion between the polymer extrudates that meet. Such set of combined parameters include extrusion rate, material extrusion system movement rate, and melt chamber temperature, among others.

When the support is prepared by adopting the extrusion molding equipment, the XYZ axes and the rotating rods are simultaneously controlled by a set of program edited by a computer control system, so that the support with the set internal structure and external form is synchronously prepared.

The system is also suitable for preparing the polymer scaffold made of mixed materials, and different polymer materials are sequentially extruded on the rotary rod or the die on the rotary rod according to the structural design of the scaffold.

In another aspect, the invention also provides an external shape design of the prepared personalized in-vivo polymer scaffold. The stent body has at least one variable diameter along its length, including but not limited to tapered cones, dumbbells, irregular curves, and the like.

In still another aspect, the invention provides the use of the personalized polymer stent as a vascular stent or a body lumen stent, such as a cardiovascular stent, a peripheral vascular stent, a biliary stent, a urinary tract stent, a tracheal stent, an esophageal stent, a pancreatic duct stent, a gastric stent, or an intestinal stent.

In yet another aspect, the present invention provides a method of treating a lesion-induced luminal narrowing in a subject, comprising:

(1) scanning the structure of a narrow tube cavity caused by a lesion of a subject to obtain structural data of an inner cavity or an outer cavity outline of the narrow tube cavity;

(2) preparing a personalized stent by using the method for preparing the personalized polymer stent;

(3) placing the stent in a conforming manner within or outside of the stenotic lumen to support the stenotic lumen.

Preferably, in the method of the present invention for treating luminal stenosis in a subject due to a disease, the subject is a human or animal body.

The invention provides more diversified bracket types, and the personalized bracket products aiming at different physiological and pathological parts of a patient are prepared by specially designing the part to be used and utilizing a rapid prototyping system and a polymer material, so that the part to be used obtains the best matched bracket, the length, the angle and the curvature of the bracket are more suitable for the structural form of the part to be used, the special requirement of the part to be used can be met, and the adherence performance and the treatment effect are improved. The scaffold is prepared from biodegradable materials, and the scaffold gradually disappears after the used part is healed, so that subsequent complications can not be generated; the biodegradable stent is prepared by the rapid stent forming system, the material, the external shape of the stent and the internal structure of the stent can be formed in one step, the preparation process is convenient and rapid, and the fitting performance of the stent and a lesion part is improved. The personalized polymer stent provided by the invention can meet the requirements of transportability, support and compliance.

The invention realizes the personalized stent design and the preparation method, improves the adaptability of the stent to the part to be used and solves the problem of poor passing capability of the traditional stent to the part to be used, which is circuitous; the method is simple to operate, easy to control, convenient and quick to change programs, easy to manufacture ideal supports and wide in application range; and a new technical research direction is provided for the personalized design of the bracket.

Brief description of the drawings

FIG. 1 is a schematic diagram showing a planar structure of an iliac artery stent which is prepared in example 1 of the present invention and is deployed in a longitudinal direction (i.e., a length direction of the stent);

FIG. 2 is a schematic diagram showing a longitudinally-deployed planar structure of another iliac artery stent prepared in example 1 of the present invention;

FIG. 3 is a schematic diagram showing a longitudinally-deployed planar structure of yet another iliac artery stent prepared in example 1 of the present invention;

FIG. 4 is a schematic view showing a longitudinally developed plan structure of an extra-tracheal stent prepared in example 2 of the present invention;

FIG. 5 is a schematic view showing a longitudinally developed plan structure of another extra-tracheal stent prepared in example 2 of the present invention;

fig. 6 shows a perspective view of the extra-tracheal stent shown in fig. 4;

fig. 7 shows a perspective view of the extra-tracheal stent shown in fig. 5;

FIG. 8 is a diagram illustrating the internal structure of an esophageal stent prepared in example 3 of the present invention;

figure 9 shows a perspective side view of the esophageal stent shown in figure 8.

Best Mode for Carrying Out The Invention

The present invention is described in further detail below with reference to the following examples, which are not intended to limit the invention.

Example 1

The degradable polymer stent suitable for the iliac artery uses polylactic acid as a raw material, adopts a equidirectional Z-shaped processing route, and comprises the following specific processing steps:

1) collecting local lumen data of the iliac artery, obtaining a 3D model of the artery lumen after in-vitro 3D reconstruction, and then preparing a hollow personalized stent mold matched with the iliac artery lumen surface by using a 3D printing technology or a traditional numerical control machine tool processing technology;

2) designing a structure of a support by adopting a computer program, and synchronously designing an XYZ wiring program and a fourth shaft rotation program by combining the appearance and the size of a die;

3) automatically or manually generating a bracket processing program according to the designed bracket structure, the shape and the size;

4) sleeving the hollow personalized bracket mould on a rotating rod of a fourth shaft system of the four-shaft rapid forming system, and fixing the hollow personalized bracket mould so that the hollow personalized bracket mould can rotate forwards or backwards along with the rotating rod of the fourth shaft under the control of a computer control system; adding polylactic acid granules into a distribution system of the equipment, and sequentially extruding filaments by the distribution system on a personalized stent die rotating on a fourth shaft according to a routing path set in the control system so as to prepare the iliac artery degradable polymer stent;

5) the extruded stent is removed from the personalized mold and used for subsequent procedures, such as crimping onto a balloon.

The three prepared iliac artery stent expansion structure schematics are shown in figures 1, 2 and 3, the body of the iliac artery stent expansion structure schematics is composed of conjoined net ring units and connecting units, the shape is integrally conical along the length direction, the diameters of net wires along the axial direction can be the same or different, the density of the net rings along the axial direction is the same, and the density of the supporting units along the radial direction is the same, so that the prepared stent has uniform radial supporting force under the condition of reducing.

Example 2

A degradable polymer stent for forming a tracheal lumen uses polylactic acid as a raw material, adopts a processing route in a shape like a Chinese character 'hui', and comprises the following specific processing steps:

1) acquiring outer contour data of a local cavity of the trachea, obtaining a 3D model of the trachea after in-vitro 3D reconstruction, and then preparing a solid personalized bracket mold matched with the outer contour of the trachea by using a 3D printing technology or a traditional numerical control machine tool machining technology;

4) replacing a rotating rod of a fourth shaft system of the four-shaft rapid prototyping system with the solid personalized bracket die to receive the polymer, and enabling the polymer to rotate forwards or backwards under the control of a computer control system according to a designed rotating program; adding polylactic acid granules into a distribution system of the equipment, and sequentially extruding filaments by the distribution system on a personalized support die rotating on a fourth shaft according to a routing path set in the control system so as to prepare the degradable polymer tracheal support;

5) and taking the extruded bracket down from the personalized bracket mould for subsequent working procedures.

The prepared two kinds of tracheal stents are longitudinally unfolded structures as shown in fig. 4 and 5, the body of the tracheal stent is formed by connected 'loop' -shaped units, the diameters of filaments in the 'loop' -shaped units can be the same or different, the densities of the filaments can be the same or different, the size of a hollow white part in the 'loop' -shaped units can be adjusted, and the tracheal stent with different radial supporting forces can be realized; the corresponding three-dimensional structures are respectively in a C-shaped structure as shown in fig. 6 and 7, when in use, the bracket is buckled on the trachea from the outside of the trachea, and is sutured on the trachea through an operation suture line, and the raw materials for preparation have certain elasticity, so that the inner diameter of the C shape is variable, and the flexibility of the bracket in use is improved.

Example 3

The degradable polymer stent for esophageal stenosis uses polylactic acid as a raw material, adopts a braided processing route, and comprises the following specific processing steps:

1) collecting local inner cavity data of the esophagus, obtaining a 3D model of the esophagus after in-vitro 3D reconstruction, and then preparing a hollow personalized bracket mould matched with the internal contour of the esophagus by using a 3D printing technology or a traditional numerical control machine tool processing technology;

4) sleeving the hollow personalized bracket mould on a rotating rod of a fourth shaft system of the four-shaft rapid forming system, and fixing the hollow personalized bracket mould so that the hollow personalized bracket mould can rotate forwards or backwards along with the rotating rod of the fourth shaft under the control of a computer control system; adding polylactic acid granules into a distribution system of the equipment, and sequentially extruding filaments by the distribution system on a personalized support die rotating on a fourth shaft according to a routing path set in the control system so as to prepare the degradable polymer esophageal support;

5) and taking the extruded bracket off the personalized die for subsequent working procedures.

The internal structure of the prepared esophageal stent is shown in figure 8, the body of the esophageal stent is formed by connected rhombic units, the overall view is shown in figure 9, the design of the rhombic units and the curved surface outline can enable the stent to generate continuous and soft radial expansion, and the stent can follow the peristalsis of the esophagus, so that the smoothness of the esophagus is kept, the foreign body sensation of a patient is reduced, one end of the stent is in a conical design, the other end of the stent is in a cup-mouth-shaped design, the damage and even bleeding of the inner wall of the esophagus caused by the cutting effect of the stent on the mucosa of the esophagus are avoided, and the adherence of the stent prepared by the design to the wall of the esophagus is good, and the implantation effect of the stent is improved.

Claims

1. A personalized polymer stent having a shape and dimensions matching the shape and dimensions of the lumen or the outer contour of the lumen of a site to be used and having a stent structure consisting of polymer filaments deposited in a pre-designed pattern, wherein the stent has at least one varying diameter along the length of the stent;

wherein the scaffold is prepared by using a four-axis rapid prototyping system as a manufacturing apparatus, the four-axis rapid prototyping system comprising:

(i) a base;

the scaffold is prepared by a method comprising the steps of:

3) generating a bracket processing program according to the set bracket appearance, size and bracket structure;

4) setting operation parameters of a distribution system;

2. The stent of claim 1, wherein the stent has a regular or irregular shape.

3. The stent of claim 1, wherein the stent has an outer shape selected from the group consisting of a tapered cone, a dumbbell shape, and an irregularly curved shape.

4. The stent of claim 1, wherein the polymer is a degradable polymer selected from one or more of the following: polylactic acid (PLA), levorotatory polylactic acid (PLLA), dextrorotatory polylactic acid (PDLA), polyethylene glycol-polyglycolic acid (PGA), Polycaprolactone (PCL), polyethylene glycol (PEG), polyanhydride, Polyhydroxyalkanoate (PHA), polydioxanone, polyiminocarbonate, polyfumaric acid, degradable polyurethane, copolymers or mixtures of the above materials, and mixtures of one or more of the above materials with other degradable polymeric materials.

5. The stent of claim 1, wherein the polymer is a non-biodegradable polymer selected from one or more of the following: polyester, nylon, polyethylene, polytetrafluoroethylene, polypropylene, polyurethane, silicone rubber, and copolymers or mixtures of the foregoing.

6. The stent of claim 5, wherein the polyester is polyethylene terephthalate or polybutylene terephthalate.

7. The stent of claim 5, wherein the nylon is nylon 6 or nylon 66.

8. The stent of any one of claims 1 to 7, wherein the stent is a vascular stent or a body lumen stent.

9. The stent of claim 8, wherein the stent is a cardiovascular stent, a peripheral vascular stent, a biliary stent, a urinary tract stent, a tracheal stent, an esophageal stent, a pancreatic duct stent, a gastric stent, or an intestinal stent.

10. The stent of any one of claims 1 to 7, wherein the stent surface is sprayed with a drug that inhibits cell growth.

11. A method of making the stent of any one of claims 1 to 10, wherein the method is performed using a four-axis rapid prototyping system as the manufacturing apparatus, the four-axis rapid prototyping system comprising:

(i) a base;

the method comprises the following steps:

4) setting operation parameters of a distribution system;

12. The method of claim 11, wherein the preparing in step 1) is performed using a 3D printing technique or a numerical control machining method.

13. The method according to claim 11, wherein the fixing in step 5) is performed using a jig or by sleeving the hollow personalized stent mould on a rotating rod of a fourth shaft system.

14. The method of claim 11, wherein the personalized stent mold in step 5) replaces the rotating rod of the fourth shaft system to receive the polymer, to fix it on the fourth shaft system, and to allow it to rotate forward or backward under the control of the computer control system.

15. Use of the personalized polymer stent of any one of claims 1 to 10 in the manufacture of a vascular stent or a body lumen stent.

16. Use of the personalized polymer scaffold of any one of claims 1 to 10 in the preparation of a cardiovascular stent, a peripheral vascular stent, a biliary stent, a urinary tract stent, a tracheal stent, an esophageal stent, a pancreatic duct stent, a gastric stent, or an intestinal stent.

17. Use of a personalized stent prepared by the method of any one of claims 11 to 14 in the preparation of a stent to be placed in a conformable manner within or outside of a stenotic lumen to support the stenotic lumen.