4D printing intelligent tubular stent and preparation method thereof

Abstract

The invention provides a 4D printing intelligent tubular stent and a preparation method thereof, and relates to the technical field of covered stents. The 4D printing intelligent tubular stent comprises a supporting skeleton and a covering film, the covering film is attached to the surface, facing an inner cavity, of the supporting skeleton, the material of the covering film comprises a shape memory polymer material, and the surface, facing the inner cavity, of the covering film is provided with one or more of carboxyl, amino and sulfonic acid groups. The surface, facing the inner cavity, of the covering film is provided with one or more of carboxyl, amino and sulfonic acid groups, the carboxyl, amino and sulfonic acid groups are introduced to the surface of the film and can enhance the adsorption capacity for cations in blood, the cations are effectively captured and released through an ion exchange mechanism so as to generate a friction electric signal, and when disturbed by blood flow and the like, the friction electric signal can be generated. The triboelectricity can generate a corresponding electric signal, the blood flow can be monitored by collecting the electric signal, and the microcurrent generated by the triboelectricity can construct a bioelectric microenvironment beneficial to cell growth.

Description

Technical Field

[0001] The present invention relates to the technical field of coated stents, and in particular to a 4D printed intelligent tubular stent and a preparation method thereof. Background Art

[0002] In order to solve various vascular blockage problems, people have spent a lot of time and energy on research and analysis. So far, the main methods for treating these diseases are: taking medicine, bypass surgery and surgical instruments (such as luminal stents). The effect of drug treatment is generally very slow, which makes the treatment cycle long and is accompanied by great side effects. Bypass surgery often requires the establishment of a new vascular channel to bypass the occluded vascular site. This surgical procedure is relatively cumbersome and highly dependent on the professional skills of medical staff. It is also relatively traumatic to the patient, resulting in slow recovery. Therefore, luminal stent placement is the main treatment for luminal stenosis, but minimally invasive implantation of traditional luminal stents has the risk of displacement due to changes in blood flow in the blood vessels, resulting in changes in the force of the luminal stent. Summary of the invention

[0003] The problem solved by the present invention is how to solve the risk of displacement caused by changes in the force applied to the luminal stent due to changes in blood flow in the blood vessel.

[0004] In order to solve the above problems, the present invention provides a 4D printed intelligent tubular stent and a preparation method thereof.

[0005] In a first aspect, the present invention provides a 4D printed intelligent tubular stent, comprising:

[0006] A supporting frame, the supporting frame being a tubular structure with an inner cavity formed by a mesh body; and

[0007] The coating is attached to the surface of the supporting frame facing the inner cavity. The material of the coating includes a shape memory polymer material. The surface of the coating facing the inner cavity is provided with one or more of carboxyl groups, amino groups, and sulfonic acid groups.

[0008] Optionally, the surface of the coating facing the inner cavity is provided with micro-columns, which have a collapsed state and an upright state. The micro-columns can be transformed from a collapsed state to an upright state under the stimulation of a magnetic field, a light field or an electric field, thereby exerting a stretching force on the cells to promote cell endothelialization.

[0009] Optionally, the coating has a thickness of 100-800 microns, has pores with a pore size of 400-600 μm, and has a plurality of microcolumns on the surface of the coating, with a microcolumn height of 20-50 microns and a microcolumn spacing of 10-30 microns.

[0010] Optionally, the coating material also includes drugs, and the mass ratio of the drugs to the shape memory polymer material is (1:20)-(3:20).

[0011] Optionally, the mesh body includes basic structural units of concave hexagons, concave decagons and axisymmetric hexagons, and the basic structural units of different shapes are arranged alternately and repeatedly.

[0012] Optionally, the thickness of the mesh body is 0.1-3 mm, and the inner diameter of the tubular structure is 1-30 mm.

[0013] Optionally, the supporting skeleton is composed of shape memory polymer material, nano-ferroferric oxide and nano-barium titanate.

[0014] Optionally, the support frame has a deformation state and a working state.

[0015] The temperature is raised to above 45°C, and an external force is applied to the support frame in the working state to deform it. After maintaining for 5-10 seconds, the support frame is cooled to room temperature, and the support frame remains in the deformed state;

[0016] The supporting frame can be transformed from a deformation state to a working state under the drive of a magnetic field, a light field or an electric field.

[0017] Optionally, the shape memory polymer material is one or a combination of two of shape memory polylactic acid, shape memory polyglycolide, shape memory poly(lactide-glycolide), shape memory poly(p-dioxanone), shape memory polycaprolactone, shape memory chitosan and shape memory polyurethane.

[0018] In a second aspect, the present invention provides a method for preparing a 4D printed intelligent tubular stent, which is used to prepare the 4D printed intelligent tubular stent as described in any one of the above items, comprising the following steps:

[0019] Design a structural model of the support skeleton, and use fused deposition or direct writing printing technology to print and shape it to obtain a tubular support skeleton with an inner cavity;

[0020] A film made of a shape memory polymer material is attached to the surface of the support frame facing the inner cavity;

[0021] Before the attachment operation, the surface of the covering film facing the inner cavity is subjected to one or more of the following pretreatments:

[0022] The surface of the film is treated by oxidation to add carboxyl groups;

[0023] The film surface is fumigated with ethylenediamine or hexamethylenediamine to add amino groups;

[0024] The film surface is fumigated with sulfur trioxide or sulfuric acid to add sulfonic acid groups.

[0025] The beneficial effects of a 4D printed intelligent tubular stent and a preparation method thereof of the present invention are as follows: the surface of the coating facing the inner cavity is provided with one or more of carboxyl groups, amino groups, and sulfonic acid groups, and carboxyl groups, amino groups, or sulfonic acid groups are introduced on the surface of the membrane, and these groups can enhance the adsorption capacity of cations in the blood, effectively capture and release cations through the ion exchange mechanism to generate triboelectric signals, and when disturbed by blood flow, etc., corresponding electrical signals will be generated, and by collecting the electrical signals, blood flow monitoring can be achieved, and then the monitoring of the stress state of the stent can be achieved, and the displacement of the 4D printed intelligent tubular stent due to the change of force can be avoided. At the same time, the microcurrent generated by triboelectricity can construct a bioelectric microenvironment that is conducive to cell growth. By using the surface microcolumns of the coating facing the inner cavity, stress stimulation is applied to endothelial cells during the switching process from the collapsed state to the upright state, and a mechanical microenvironment for cell differentiation is constructed, thereby promoting cell endothelialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the 4D printed intelligent tubular stent of this embodiment;

[0027] Figure 2 is a schematic structural diagram of the film covering the micro-column in the collapsed state of the present embodiment;

[0028] Figure 3 It is a schematic structural diagram of the film covering the micro-columns in the present embodiment in an upright state;

[0029] Figure 4 is a schematic structural diagram of a mesh body of a supporting skeleton of this embodiment;

[0030] Description of reference numerals:

[0031] 1. Support skeleton; 11. Reticular body; 2. Coating; 21. Microcolumn. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0034] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0035] In the related art, the negative Poisson's ratio structure of the stent made of 4D printed shape memory polymer material is a material structure with special mechanical properties. It can show a deformation mode different from traditional materials when subjected to force. The parametric design and shape memory performance of the negative Poisson's ratio structure give the stent spatial and temporal adaptability. In order to promote the endothelialization of the stent, the surface microcolumns facing the inner cavity of the coating are used to apply stress stimulation to the endothelial cells during the switching process from collapsed to upright state, constructing a mechanical microenvironment for cell differentiation, thereby promoting cell endothelialization. In addition, the microcurrent generated by triboelectricity / piezoelectricity stimulates the endothelialization of cells during the growth season, constructing a biological microelectric environment that is conducive to cell growth and differentiation.

[0036] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a 4D printed intelligent tubular stent and a preparation method thereof.

[0037] like Figure 1 As shown, a 4D printed intelligent tubular stent provided by an embodiment of the present invention includes:

[0038] A support frame 1, which is a tubular structure with an inner cavity formed by a mesh body 11; and

[0039] The coating 2 is attached to the surface of the support frame 1 facing the inner cavity. The material of the coating 2 includes a shape memory polymer material. The surface of the coating 2 facing the inner cavity is provided with one or more of carboxyl groups, amino groups, and sulfonic acid groups.

[0040] In this embodiment, the support skeleton 1 is a tubular structure that can support blood vessels and other pipelines, and the mesh body is conducive to increasing the tensile and compressive deformation of the support skeleton when it is shaped. The surface of the coating 2 facing the inner cavity is provided with one or more of carboxyl groups, amino groups, and sulfonic acid groups. Carboxyl groups, amino groups, or sulfonic acid groups are introduced on the surface of the membrane. These groups can enhance the adsorption capacity of cations in the blood, effectively capture and release cations through the ion exchange mechanism to generate triboelectric signals, and when disturbed by blood flow, etc., corresponding electrical signals will be generated. By collecting the electrical signals, the blood flow disturbance (such as blood flow velocity) can be judged to achieve blood flow monitoring. When the blood flows through the stent, the stent is stressed, and then the stress state of the stent is monitored, which can avoid the displacement of the 4D printed intelligent tubular stent due to the change of force. At the same time, the microcurrent generated by triboelectricity can construct a bioelectric microenvironment that is conducive to cell growth. The shape memory polymer material of the coating 2 has good biocompatibility, and can reduce a series of complications such as immune rejection after implantation into the human body.

[0041] Specifically, carboxyl groups are introduced on the surface of the film 2 by oxidation treatment. The oxidation treatment is to generate plasma by using oxygen or other active gases (such as air, argon mixed with oxygen) under vacuum conditions, and the surface chemical structure of the polymer is changed by bombardment of high-energy particles. The polymer surface of the film 2 can be oxidized without using chemical reagents. The surface of the film 2 is treated with amination to introduce amino groups. For example, ethylenediamine (EDA) or hexamethylenediamine is used to fumigate the surface of the film 2 to react with the film 2 material, and amino groups are introduced on the surface of the film 2. Sulfonation treatment is performed on the surface of the film 2 to introduce sulfonic acid groups. Sulfonating agents such as sulfur trioxide (SO3) or sulfuric acid (H2SO4) are used to directly fumigate the surface of the film 2 material to effectively introduce sulfonic acid groups. By introducing carboxyl groups, amino groups or sulfonic acid groups, these groups can enhance the adsorption capacity of cations (such as sodium and potassium) in the blood, and effectively capture and release cations through ion exchange mechanisms to generate triboelectric signals.

[0042] Optionally, the surface of the covering film 2 facing the inner cavity is provided with micro-pillars 21, and the micro-pillars 21 have a collapsed state and an upright state. The micro-pillars 21 can be transformed from the collapsed state to the upright state under the stimulation of a magnetic field, a light field or an electric field, thereby exerting a stretching force on the cells to promote cell endothelialization, such as Figure 2 and Figure 3 shown.

[0043] In this optional embodiment, the surface of the coating 2 has a controllable micro-column 21 structure, which can be restored from a collapsed state to an upright state under the stimulation of a magnetic field, a light field, an electric field, etc. The micro-column 21 deforms and stretches the cells, inducing and promoting the endothelialization function of the luminal stent. When blood flows through the micro-column 21 structure on the surface of the coating 2, the micro-column 21 structure produces a small deformation, which can trigger a piezoelectric signal, further inducing and promoting the endothelialization function of the luminal stent.

[0044] In addition, the triboelectric and piezoelectric functions of the coating 2 can both give the 4D printed intelligent tubular stent a sensing function. By utilizing its self-generating function, there is no need to maintain the monitoring system. By collecting energy from the arterial pulsation of the blood vessels to self-power the system, the stress state of the stent, blood flow velocity and lesion condition can be monitored.

[0045] Specifically, the driving frequency of the magnetic field can be 27.5KHz-40KHz; the light field stimulation can choose to use infrared light, and the power of the infrared light can be 100W-300W.

[0046] Optionally, the film 2 has a thickness of 100-800 microns, has pores with a pore size of 400-600 μm, and has a plurality of microcolumns 21 on its surface, with a microcolumn height of 20-50 microns and a microcolumn spacing of 10-30 microns.

[0047] In this optional embodiment, the toughness of the coating 2 is changed by adjusting the thickness of the coating 2 material and the content of the enhanced shape memory polymer material. The size of the micro-pillar 21 structure on the surface of the coating 2 can also be adjusted as needed to induce endothelialization on the stent surface as needed.

[0048] Optionally, the material of the coating 2 also includes drugs, and the mass ratio of the drugs to the shape memory polymer material is (1:20)-(3:20).

[0049] In this optional embodiment, the medicine on the coating 2 can better reach the affected area and alleviate the corresponding symptoms of the patient. The medicine is an anti-inflammatory medicine, a nutritional medicine, or a combination of two or more. When the medicine is a combination of two or more medicines, the medicines can be combined in any ratio. When the medicine carried on the coating 2 is an anti-inflammatory medicine, the inflammatory reaction caused by stent implantation can be alleviated.

[0050] Shape memory polymer materials have good biocompatibility and can reduce a series of complications such as immune rejection reactions after being implanted into the human body.

[0051] Optionally, the mesh body 11 includes basic structural units of an indented hexagon, an indented decagon and an axisymmetric hexagon, and the basic structural units of different shapes are alternately and repeatedly arranged.

[0052] In this optional embodiment, if Figure 1 and Figure 4 As shown, Figure 4The middle mesh body 11 is composed of structural figure No. 1, structural figure No. 2 and structural figure No. 3. Structural figure No. 1 is a concave hexagon, and its two sides are connected to an axially symmetrical hexagon, namely structural figure No. 2, and the bottom of structural figure No. 2 is connected to a concave decagon, namely structural figure No. 3. The three graphic structures are arranged at equal intervals, and the magnetically driven shape memory polymer that constitutes the lumen structure is located at the intervals. This design is conducive to increasing the tensile and compressive deformation of the shape memory vascular stent during shaping, and then the vascular stent is printed and formed using fused deposition or direct writing printing technology.

[0053] Optionally, the thickness of the mesh body 11 is 0.1-3 mm, and the inner diameter of the tubular structure is 1-30 mm.

[0054] In this optional embodiment, the toughness of the supporting skeleton 1 can be changed by adjusting the thickness of the mesh body 11 and the size of the tubular structure.

[0055] Optionally, the supporting skeleton 1 is composed of shape memory polymer material, nano-ferroferric oxide and nano-barium titanate.

[0056] In this optional embodiment, the shape memory polymer material can sense the stimulation of changes in the external environment (temperature, force, electromagnetic, etc.), change its own state parameters (shape, position, etc.), complete the shape recovery process and return to the pre-set initial form, and use the shape memory effect of the shape memory polymer material to reduce the diameter of the vascular stent by shaping before surgery, reducing the damage to the patient during implantation. By compounding nano-iron tetroxide powder in the shape memory polymer material, the nano-iron tetroxide powder can be developed under nuclear magnetic resonance, and the in vitro remote driving effect of the vascular stent is realized. After the stent reaches the affected area, the shape is restored by in vitro remote excitation such as under the irradiation of magnetic field and infrared lamp, so as to achieve the medical treatment purpose of supporting blood vessels, and the driving is simple and the risk is reduced. The drug-loaded coating 2 on the surface of the support skeleton 1 is prepared by light-curing 4D printing technology, and the surface of the coating 2 has a micron-level micro-column 21 structure, and the anti-inflammatory drugs carried can reduce the inflammatory response caused by the implantation of the stent.

[0057] The shape memory material has a special Poisson's ratio and can adapt to any deformation of the trachea without bending, forming a stable supporting structure with a circular cross-section.

[0058] Shape memory polymer materials have good biocompatibility and can reduce a series of complications such as immune rejection after implantation in the human body. In addition, the 4D printed intelligent tubular stent made of shape memory polymer materials can be degraded in the body, further reducing the chance of complications caused by the long-term presence of the stent in the body and avoiding the risk of secondary surgery to remove the stent.

[0059] Specifically, the mass content of nano-ferroferric oxide in the composite material of the support skeleton 1 is 6%-25%, preferably 15%, and the mass fraction of nano-barium titanate material in the composite material of the support skeleton 1 is 2%-15%, preferably 5%.

[0060] Optionally, the support frame 1 has a deformation state and a working state.

[0061] The temperature is raised to above 45°C, and an external force is applied to the support frame 1 in the working state to deform it. After maintaining for 5-10 seconds, the support frame 1 is cooled to room temperature, and the support frame 1 remains in the deformed state;

[0062] The support frame 1 can be transformed from a deformed state to a working state under the drive of a magnetic field, a light field or an electric field.

[0063] In this optional embodiment, the shape memory polymer material is able to sense the stimulation of changes in the external environment (temperature, force, electromagnetism, etc.), change its own state parameters (shape, position, etc.), complete the shape recovery process and return to the pre-set initial form. By utilizing the shape memory effect of the shape memory polymer material, the diameter of the vascular stent can be reduced by shaping before surgery, thereby reducing the damage to the patient during implantation.

[0064] Optionally, the shape memory polymer material is one or a combination of two of shape memory polylactic acid, shape memory polyglycolide, shape memory poly(lactide-glycolide), shape memory poly(p-dioxanone), shape memory polycaprolactone, shape memory chitosan and shape memory polyurethane.

[0065] Specifically, the shape memory polymer material used by the coating 2 is the same as the shape memory polymer material of the supporting skeleton 1 , so that the coating 2 can be deformed better along with the supporting skeleton 1 .

[0066] Specifically, when the materials used for the coating 2 are a combination of two materials, the two combined materials are mixed in an arbitrary ratio.

[0067] An embodiment of the present invention provides a method for preparing a 4D printed intelligent tubular stent, which is used to prepare the 4D printed intelligent tubular stent as described in any one of the above items, comprising the following steps:

[0068] Design a structural model of the support skeleton 1, and use fused deposition or direct writing printing technology to print and shape it, so as to obtain a support skeleton 1 with a tubular structure having an inner cavity;

[0069] A coating 2 made of a shape memory polymer material is attached to the surface of the support frame 1 facing the inner cavity;

[0070] Before the attachment operation, the surface of the film 2 facing the inner cavity is subjected to one or more of the following pretreatments:

[0071] The surface of the film 2 is treated by oxidation to add carboxyl groups;

[0072] The surface of the film 2 is fumigated with ethylenediamine or hexamethylenediamine to add amino groups;

[0073] The surface of the film 2 is fumigated with sulfur trioxide or sulfuric acid to add sulfonic acid groups.

[0074] In this embodiment, the surface of the coating 2 facing the inner cavity is provided with one or more of carboxyl groups, amino groups, and sulfonic acid groups. Carboxyl groups, amino groups, or sulfonic acid groups are introduced on the surface of the membrane. These groups can enhance the adsorption capacity of cations in the blood, effectively capture and release cations through the ion exchange mechanism to generate triboelectric signals. When disturbed by blood flow, etc., corresponding electrical signals will be generated. By collecting the electrical signals, blood flow can be monitored, and then the stress state of the stent can be monitored, which can avoid the displacement of the 4D printed intelligent tubular stent due to stress changes. At the same time, the microcurrent generated by triboelectricity can build a bioelectric microenvironment that is conducive to cell growth. The shape memory polymer material of the coating 2 has good biocompatibility, and can reduce a series of complications such as immune rejection after implantation into the human body.

[0075] The present invention is further described below in conjunction with specific embodiments.

[0076] Example 1

[0077] The method for preparing a 4D printed intelligent tubular stent comprises the following steps:

[0078] (1) Figure 1 As shown, the three-dimensional structure of the blood vessel support skeleton 1 is designed with the concave hexagon, the concave decagon, and the axisymmetric hexagon as the basic structural units, as shown in FIG. Figure 4 As shown, the three patterns have a spacing of 0.1 mm and are arranged in parallel and repeatedly. The spacing between AB is 2.2 mm, the spacing between EF is 1 mm, the spacing between CD is 1.2 mm, and the spacing between BG is 3.465 mm. Moreover, ∠D is 120°, ∠A is 30°, the spacing between JK is 1.2 mm, the spacing between HI is 0.2 mm, and ∠J is 60°. The basic structure of the support frame 1 is a mesh body 11, and the aperture of the support frame 1 is 5×10 mm, the wall thickness is 1.5 mm, and the diameter is 10 mm.

[0079] (2) The fused deposition modeling 4D printing technology is used to complete the molding and printing of the support skeleton 1 of the shape memory polylactic acid material. The printing line is nano-iron tetroxide powder. The mass content of the nano-iron tetroxide powder is 10%, and the mass fraction of nano-barium titanate is 5%. Nano-barium titanate is used as the standard printing line of the polylactic acid composite material.

[0080] (3) The coating 2 on the surface of the supporting skeleton 1 is prepared by using the photocuring 4D printing technology. The material of the coating 2 is shape memory polylactic acid, and the drug is a drug that stimulates ciliary activity (cholinergic drug). The drug loading amount is 1:20 (mass ratio of drug to shape memory polylactic acid). The thickness of the coating 2 is 100 μm, and the column height of the microcolumns 21 on its surface is 30 μm, and the column spacing is 15 μm.

[0081] The shape memory polymer material used in the coating 2 is the same as the shape memory polymer material of the supporting frame 1 , so that the coating 2 can be deformed better along with the supporting frame 1 .

[0082] (4) The printed 4D printed intelligent tubular stent is heated to a glass transition temperature, that is, heated to above 45°C to give shape to the 4D printed intelligent tubular stent, an external force is applied to the deformed state and maintained for 5-10 seconds, and then cooled to room temperature, the 4D printed intelligent tubular stent is given a temporary shape as a deformed state, and the deformed 4D printed intelligent tubular stent is implanted into the body,

[0083] (5) After the 4D printed intelligent tubular stent is implanted in the body, it is placed in a magnetic field with a magnetic field strength of 30KHz. Under the stimulation of the magnetic field, the shape recovery is completed and the 4D printed intelligent tubular stent is restored to the working state. Under the stimulation of infrared light, the topological micro-pillars 21 on the surface of the coating 2 change from a collapsed state to an upright state, inducing the endothelium of the cells.

[0084] The blood flow status is monitored by using the triboelectric / piezoelectric function. The 4D printed intelligent tubular stent collects the energy of the electrical signal from the arterial pulsation of the blood vessel to monitor the stress status, blood flow velocity and lesion condition of the 4D printed intelligent tubular stent.

[0085] By utilizing triboelectric / piezoelectric functions, 4D printed intelligent tubular scaffolds can stimulate cells on their surface and create an internal environment that is conducive to cell growth.

[0086] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A 4D printed intelligent tubular stent, characterized in that: include: A support frame (1), wherein the support frame (1) is a tubular structure with an inner cavity formed by enclosing a mesh body (11); and A coating (2) is attached to the surface of the support frame (1) facing the inner cavity, the material of the coating (2) includes a shape memory polymer material, and the surface of the coating (2) facing the inner cavity is provided with one or more of a carboxyl group, an amino group, and a sulfonic acid group.

2. The 4D printed intelligent tubular stent according to claim 1, characterized in that: The surface of the covering film (2) facing the inner cavity is provided with micro-pillars (21), and the micro-pillars (21) have a collapsed state and an upright state. The micro-pillars (21) can be transformed from the collapsed state to the upright state under the stimulation of a magnetic field, a light field or an electric field, thereby exerting a stretching force on the cells to promote the endothelialization of the cells.

3. The 4D printed intelligent tubular stent according to claim 2, characterized in that: The thickness of the coating (2) is 100-800 microns, the coating (2) has holes, the pore diameter of the holes is 400-600 μm, a plurality of micro-pillars (21) are arranged on the surface of the coating (2), the column height of the micro-pillars (21) is 20-50 microns, and the column spacing of the micro-pillars (21) is 10-30 microns.

4. The 4D printed intelligent tubular stent according to claim 1, characterized in that: The material of the coating (2) also includes drugs, and the mass ratio of the drugs to the shape memory polymer material is (1:20)-(3:20).

5. The 4D printed intelligent tubular stent according to claim 1, characterized in that: The mesh body (11) comprises basic structural units of an inwardly concave hexagon, an inwardly concave decagon and an axisymmetric hexagon, and the basic structural units of different shapes are arranged alternately and repeatedly.

6. The 4D printed intelligent tubular stent according to claim 5, characterized in that: The thickness of the mesh body (11) is 0.1-3 mm, and the inner diameter of the tubular structure is 1-30 mm.

7. The 4D printed intelligent tubular stent according to claim 1, characterized in that: The support skeleton (1) is composed of the shape memory polymer material, nano-ferroferric oxide and nano-barium titanate.

8. The 4D printed intelligent tubular stent according to claim 7, characterized in that: The support frame (1) has a deformation state and a working state. Raising the temperature to above 45° C., applying external force to the support frame (1) in the working state to deform it, keeping the temperature for 5-10 seconds, and then cooling the support frame (1) to room temperature, wherein the support frame (1) remains in the deformed state; The support frame (1) can be transformed from a deformed state to a working state under the drive of a magnetic field, a light field or an electric field.

9. The 4D printed intelligent tubular stent according to claim 1, characterized in that: The shape memory polymer material is one or a combination of two of shape memory polylactic acid, shape memory polyglycolide, shape memory poly(lactide-glycolide), shape memory poly(p-dioxanone), shape memory polycaprolactone, shape memory chitosan and shape memory polyurethane.

10. A method for preparing a 4D printed intelligent tubular stent, used for preparing the 4D printed intelligent tubular stent according to any one of claims 1 to 9, characterized in that: The following steps are involved: Designing a structural model of the support skeleton (1), and using fused deposition or direct writing printing technology to print and shape the support skeleton (1) to obtain a tubular structure with an inner cavity; A coating (2) made of a shape memory polymer material is attached to the surface of the support frame (1) facing the inner cavity; Before the attachment operation, the surface of the covering film (2) facing the inner cavity is subjected to one or more of the following pretreatments: The surface of the coating (2) is treated by oxidation to add carboxyl groups; The surface of the coating (2) is fumigated with ethylenediamine or hexamethylenediamine to add amino groups; The surface of the coating (2) is fumigated with sulfur trioxide or sulfuric acid to add sulfonic acid groups.

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