CN106178130B

CN106178130B - Forming system and method of three-dimensional layered blood vessel stent of bifurcation structure

Info

Publication number: CN106178130B
Application number: CN201610538244.4A
Authority: CN
Inventors: 刘媛媛; 蒋维健; 谢明亮; 胡庆夕
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2016-07-10
Filing date: 2016-07-10
Publication date: 2019-12-13
Anticipated expiration: 2036-07-10
Also published as: CN106178130A

Abstract

the invention discloses a forming system and a forming method of a three-dimensional layered intravascular stent with a bifurcated structure. The system comprises: the mould system is manufactured by a 3D printing technology; the hydrogel perfusion system is combined with the mould system and driven by a micro pump to realize the perfusion process of the hydrogel solution; the sacrificial material printing system drives the micropump to move according to a specified path through the three-dimensional movement mechanism, so that the sacrificial material is printed; the computer control system drives the three-dimensional motion mechanism to move. The method is based on a hydrogel perfusion principle and a sacrificial material principle, a mold is manufactured through a 3D printing technology, and the intravascular stent is prepared layer by layer in a mode of perfusing hydrogel into the mold; the hollow structure of the intravascular stent is realized by adding sacrificial materials first and then by sacrificial methods, and finally the three-dimensional layered intravascular stent with a bifurcation structure is formed.

Description

Forming system and method of three-dimensional layered blood vessel stent of bifurcation structure

Technical Field

The invention relates to a forming system and a forming method of a three-dimensional layered intravascular stent with a layered structure, which can realize the formation of the three-dimensional layered intravascular stent with the layered structure and are applied to the technical field of mechanical manufacturing and biological manufacturing.

background

In recent years, cardiovascular diseases have become an important health-threatening factor, and a large number of patients need artificial blood vessel transplantation every year due to lack of suitable autologous blood vessels. The construction of the tissue vascular stent with functionality has wide application prospect.

The internal diameter of blood vessels in human bodies varies from 5 micrometers to 25 millimeters, and the blood vessel walls with larger sizes have obvious three-layer structures: inner membrane, middle membrane and outer membrane. The intima is a monolayer of endothelial cells attached to a basement membrane; the tunica media is composed of a large number of smooth muscle cells or elastic tissues; the adventitia consists mainly of fibroblasts and blood vessels.

The extracellular matrix collagen of the peripheral nerve.

at present, in the aspect of tissue engineering blood vessel stent forming process, the commonly used process methods can be mainly divided into two types: one is a pre-building method based on a vessel model; another class is methods based on the generation of vascular networks within tissue structures. The blood vessel model pre-establishing method can be divided into a method of utilizing mold casting and forming by combining an electrospinning technology; the method based on the generation of the vascular network in the tissue structure is mainly to form a fine channel in the biological stent spontaneously by using endothelial cells and the like through a 3D cell culture technology. Although these traditional methods obtain a successful vascular stent or a stent with a vascular network, the current process method for preparing a multilayer vascular stent is difficult to realize the three-dimensional space structure of the stent and the bifurcation shape of the blood vessel, and the process method capable of realizing a certain three-dimensional bifurcation flow passage structure is difficult to realize the three-layer structure of the blood vessel. For clinical application of tissue engineering, the preparation of the bifurcated vascular stent in the three-dimensional space with the vascular layered structure has very important significance. In addition, in the three-layered structure of the blood vessel, since the inner membrane is a single layer of endothelial cells, only two layers of solid scaffold structures corresponding to the middle membrane and the outer membrane need to be constructed when preparing the vascular stent, and the inner membrane can be formed by seeding the endothelial cells.

In the process of preparing tissue engineering blood vessel stents, a method of sacrificing materials is often used to achieve the purpose of forming the hollow structure of the final blood vessel stent. Commonly used sacrificial materials are divided into water-soluble materials and hot-melt materials. Polyvinyl alcohol is a commonly used water-soluble sacrificial material that is completely soluble in water at temperatures of 65 to 75 ℃; the pluronic F127 material, a commonly used hot-melt sacrificial material, is a thermally reversible material, is soluble in water and undergoes a transition from the gel state to the liquid state below the gel temperature, and can therefore be used as a sacrificial material in the test, i.e. it is removed by means of a temperature reduction, so as to obtain a hollow pipe structure.

The 3D printing technology (incremental manufacturing technology) is a new type of mechanical manufacturing technology that has been developed in recent years, and belongs to one of rapid prototyping technologies. A model to be processed is designed by using Computer Aided Design (CAD) software, and materials such as metal powder, ceramic powder, plastic and the like are piled up and bonded layer by using modes such as laser beams, hot melting nozzles and the like through a software layering dispersion and numerical control forming system, and finally, the materials are superposed and formed. The 3D printing technology can be applied to quick printing of the die, can realize the manufacturing of the die with a complex space structure, and greatly shortens the manufacturing period of the die.

disclosure of Invention

The invention aims to provide a forming system and a forming method of a three-dimensional layered intravascular stent with a bifurcated structure aiming at the defects of the existing intravascular stent preparation process, wherein the system is used for manufacturing a mould by a 3D printing technology and preparing the intravascular stent layer by pouring hydrogel into the mould; the hollow structure of the intravascular stent is realized by using the Pluronic F127 sacrificial material through a method of adding firstly and then sacrificing, and finally the three-dimensional layered intravascular stent with a bifurcation structure is formed.

In order to achieve the purpose, the invention adopts the following technical scheme:

a three-dimensional layered intravascular stent forming system having a bifurcated structure, comprising a mold system, a hydrogel infusion system, a sacrificial material printing system, and a computer control system, wherein: the mould system uses a 3D printer to print each mould by designing a CAD file of the mould; the hydrogel perfusion system is used for perfusing hydrogel into a flow channel formed by combining two dies by pushing a syringe piston through a micro pump; according to the sacrificial material printing system, a sacrificial material is filled into a syringe cylinder, the syringe is fixed on a micro pump, the micro pump is installed on a three-dimensional movement mechanism, the micro pump is driven to move through the three-dimensional movement mechanism, and the micro pump pushes a syringe piston to extrude the sacrificial material, so that the sacrificial material is printed.

The mold system comprises 5 molds, wherein the mold 1 can be respectively matched with the mold 2, the mold 3, the mold 4 and the mold 5. The path of each mold projection or depression is identical.

The hydrogel perfusion system consists of a micro-pump controller A, a micro-pump actuating mechanism A, an injector piston cylinder A, an inlet conduit, an outlet conduit and the mould.

The sacrificial material printing system consists of a three-dimensional movement mechanism, a micro pump controller B, a micro pump executing mechanism B, an injector piston cylinder B and an injector needle head.

The computer control system comprises a computer system connected with a control system, and the control system is connected with a motor for controlling the three-dimensional motion mechanism.

a forming method for preparing a three-dimensional layered vascular stent with a bifurcation structure by using the system is based on a 3D printing mold, and is used for carrying out test operation by pouring hydrogel and printing a sacrificial material Pluronic F127, and is characterized in that:

1) forming the lower half layer of the outer layer of the blood vessel stent: the mould 1 and the mould 2 are brought together so that the respective pipe axes coincide. After die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the die 1, and taking down the die 2 after the hydrogel solution is gelatinized to obtain a lower half-layer structure of the outer layer of the intravascular stent;

2) Forming the lower half layer of the inner layer of the blood vessel stent: the dies 1 and 3 are brought together so that the respective pipe axes coincide. After die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the die 1, and taking down the die 3 after the hydrogel solution is gelatinized to obtain a lower half-layer structure of the inner layer of the intravascular stent;

3) printing of the sacrificial material: the injector filled with the Pluronic F127 material is fixed on a micro pump, the micro pump is fixed on a three-dimensional motion platform, a computer control system controls the three-dimensional motion platform to move according to a designed path, and the injector piston cylinder B is driven by the micro pump to realize the printing of the sacrificial material. It follows that the speed of movement of the needle and the rate of extrusion of the material must be matched to ensure the integrity of the extrusion path. The printing process is shown in fig. 5, and the piston movement speed of the syringe driven by the micro pump is set as v0, the material extrusion speed is set as v1, the syringe translation speed is set as v, the syringe inner diameter is set as d0, the extruded material diameter is set as d1, and the extrusion flow rate is set as Q. The extrusion flow rate can be expressed by equation (1) and equation (2):

From the principle of flow equality, it can be derived that:

And because the material extrusion speed is equal to the injector translation speed, i.e.:

v＝v₁ (4)

The relationship between the piston movement speed and the syringe translation speed can be obtained by the formulas (3) and (4):

4) forming the upper half layer of the inner layer of the blood vessel stent: the dies 1 and 4 are brought together so that the respective pipe axes coincide. After die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the die 1, and taking down the die 4 after the hydrogel solution is gelatinized to obtain an upper half layer structure of the inner layer of the intravascular stent;

5) Forming the upper half layer of the outer layer of the blood vessel stent: the mould 1 and the mould 5 are brought together so that the respective pipe axes coincide. After die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at one side of the die 1, and taking down the die 5 after the hydrogel solution is gelatinized to obtain an upper half layer structure of the outer layer of the intravascular stent;

6) Removing the sacrificial material: and reducing the ambient temperature of the system to liquefy and flow out the pluronic F127 material, thereby forming a hollow pipeline structure. And (3) taking down the stent from the mold 1 to obtain the three-dimensional layered intravascular stent with the bifurcation structure.

Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:

1) the invention utilizes 3D printing technology to manufacture the die, and can manufacture the designed die in a short period.

2) The CAD model of the corresponding mould can be generated according to the existing medical blood vessel data model, and the mould is manufactured in a 3D printing mode, so that the blood vessel support with the simulated real structure in the living body can be constructed.

3) the vascular stent with a double-layer structure can be realized, so that the physiological structure of a blood vessel in a living body can be better simulated.

4) The blood vessel stent with the bifurcation structure can be realized, so that the process has incomparable advantages compared with the process of forming a single blood vessel stent.

5) Can realize the vascular stent with a certain three-dimensional structure, thereby better meeting the requirement of clinical transplantation.

6) the difference of hydrogel materials among different layers of the vascular stent can be realized, and the different types of cells in different layers of the blood vessel have different requirements on the surrounding matrix, so that good inoculation conditions are provided for subsequent cell inoculation.

In conclusion, the system of the invention utilizes the mould system, the hydrogel perfusion system and the sacrificial material printing system to comprehensively realize the formation of the three-dimensional layered vascular stent with the bifurcation structure. The system has the advantages of simple and reliable structure, high automation degree, easy control, short period and the like, and is suitable for forming the three-dimensional layered intravascular stent with multiple materials and a bifurcation structure in tissue engineering.

Drawings

fig. 1 is a system for forming a three-dimensional layered vessel stent of a bifurcated structure of the present invention.

fig. 2 is a mold system.

Figure 3 is a schematic diagram of the structure of a hydrogel infusion system.

FIG. 4 is a schematic diagram of a sacrificial material printing process and various parameters.

Fig. 5 is a sectional view of the mold system during printing (in which the fitting of the respective molds during printing is shown by fig. (a) to (j)).

in fig. 1 to 3:

i-mould system, 11-mould 1, 12-mould 2, 13-mould 3,

14-moulds 4, 15-moulds 5,

II-hydrogel perfusion system, 21-micro pump controller A, 22-micro pump actuating mechanism A,

23-syringe piston cylinder, 24-inlet conduit, 25-outlet conduit,

III-sacrificial material printing system, 31-three-dimensional motion mechanism, 32-micro pump actuating mechanism B,

33-syringe piston cylinder B, 34-syringe needle, 35-micropump controller B,

4-the computer system,

And 5, a frame.

Detailed Description

the following detailed description of the present invention will be made with reference to the accompanying drawings and preferred embodiments for illustrating the specific structure, operation principle and operation process of the present invention:

the first embodiment is as follows:

Referring to fig. 1 to 3, the forming system of the three-dimensional layered intravascular stent with the bifurcation structure comprises a frame (5), a mold system (i), a hydrogel perfusion system (ii), a sacrificial material printing system (iii) and a computer control system (iv), and is characterized in that: the mould system (I) is arranged on a base of the frame (5); the hydrogel perfusion system (II) is movably arranged on the frame (5), and one injector needle (34) is communicated with a mould inlet conduit (24) of the mould system (I); the sacrificial material printing system (III) is arranged on the rack (5) and is connected with and drives the hydrogel filling system (II) to move; and the computer control system (IV) is electrically connected and used for controlling the three-dimensional movement of a three-dimensional movement mechanism (31) in the sacrificial material printing system (III) and the extrusion of the sacrificial material by an injector piston cylinder body B (33).

Example two:

This embodiment is substantially the same as the first embodiment, and is characterized in that:

The mould system (I) comprises a mould 1(11), a mould 2(12), a mould 3(13), a mould 4(14) and a mould 5 (15); the inlet and the outlet at the two ends of the mould 1(11) are respectively connected with an inlet conduit (24) and an outlet conduit (25); in the process of pouring the hydrogel, the convex or concave paths of the mold 2(12), the mold 3(13), the mold 4(14) and the mold 5(15) are respectively matched with the concave path of the mold 1 (11).

The hydrogel perfusion system (II) consists of a micro-pump controller A (21), a micro-pump actuating mechanism A (22), an injector piston cylinder A (23), an inlet conduit (24) and an outlet conduit (25); the syringe piston cylinder A (23) is installed on the micro pump executing mechanism A (22) and fixed through a fastening bolt, the micro pump executing mechanism A (22) pushes the syringe piston cylinder A (23) to extrude hydrogel under the driving of a micro pump controller A (21), the outlet of the syringe piston cylinder A (23) is connected with an inlet conduit (24), the inlet conduit (24) is inserted into the inlet of the die 1(11), and the hydrogel solution flows out of an outlet conduit (25).

The sacrificial material printing system (III) is composed of a three-dimensional movement mechanism (31), a micro-pump execution mechanism B (32), a syringe piston cylinder B (33), a syringe needle (34) and a micro-pump controller B (35), the syringe needle (34) is installed on the syringe piston cylinder B (33), the syringe piston cylinder B (33) is installed on the micro-pump execution mechanism B (32) and fixed through a fastening bolt, the micro-pump execution mechanism B (32) is installed on the three-dimensional movement mechanism (31) and moves along with the three-dimensional movement mechanism (31), the micro-pump execution mechanism B (32) pushes the syringe piston cylinder B (33) to extrude sacrificial materials under the driving of the micro-pump controller B (35), and the three-dimensional movement mechanism (31) moves under the driving of a computer system (4).

The computer control system (IV) comprises a computer system (4) connected with a control system, and the control system is connected with a motor of the three-dimensional movement mechanism (31).

example three:

The forming method of the three-dimensional layered intravascular stent with the bifurcation structure adopts the system to operate, and comprises the following operation steps:

3) Printing of the sacrificial material: the injector filled with the Pluronic F127 material is fixed on a micro pump, the micro pump is fixed on a three-dimensional motion platform, a computer control system controls the three-dimensional motion platform to move according to a designed path, and the injector piston cylinder B is driven by the micro pump to realize the printing of the sacrificial material.

5) forming the upper half layer of the outer layer of the blood vessel stent: the mould 1 and the mould 5 are brought together so that the respective pipe axes coincide. After die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the die 1, and taking down the die 5 after the hydrogel solution is gelatinized to obtain an upper half layer structure of the outer layer of the intravascular stent;

example four:

referring to fig. 5, the method for preparing the three-dimensional layered vessel stent with the bifurcation structure by using the system comprises the following operation steps:

1) manufacturing of the mold system: firstly, designing a mold model through three-dimensional modeling software to generate corresponding 5 mold design models, converting the models into STL format files, and inputting the STL format files into a 3D printer to print the molds. The mold material used was ABS plastic and the resulting 5 molds were as shown in fig. 1.

2) Test materials: the hydrogel material used for perfusing the outer layer of the vascular stent is gelatin (chemical pure CP, molecular weight [9000-70-8], Chinese medicine): dissolving gelatin in water to prepare a solution with the mass fraction of 10%; the hydrogel material used for perfusing the inner layer of the intravascular stent is sodium alginate (chemical pure CP, molecular weight [9005-38-3], Chinese medicine): dissolving sodium alginate in deionized water to prepare a solution with the mass fraction of 5%; the sacrificial material used was pluronic F127 (chemically pure, molecular weight [9003-11-6], chinese medicine): dissolving Pluronic F127 in deionized water to prepare a solution with the mass fraction of 30%.

3) forming the lower half layer of the outer layer of the blood vessel stent: the prepared gelatin solution is filled into a syringe piston cylinder (23) and is fixed on a micro pump actuator A (22), the outlet of the syringe piston cylinder (23) is connected with an inlet conduit (24), and the die 1(11) and the die 2(12) are combined together, so that the axes of the respective pipelines are superposed. After the mold is closed, the feeding flow rate of a micro pump controller (21) is set to be 6mL/min, the micro pump controller (21) drives a micro pump actuating mechanism A (22), a syringe piston cylinder (23) is pushed to inject gelatin solution from an inlet conduit (24) at one side of the mold 1(11) until the gelatin solution flows out from an outlet conduit (25) at the other side of the mold 1(11), and after the gelatin solution is gelatinized, the mold 2(12) is taken down, so that the lower half layer structure of the outer layer of the intravascular stent can be obtained;

4) Forming the lower half layer of the inner layer of the blood vessel stent: and (2) filling the prepared sodium alginate solution into a syringe piston cylinder A (23), fixing the syringe piston cylinder A (23) on a micro pump actuating mechanism A (22), connecting an outlet of the syringe piston cylinder A (23) with an inlet conduit (24), and combining the die 1(11) and the die 3(13) together to ensure that the axes of the respective pipelines coincide. After the mold is closed, the feeding flow rate of a micro-pump controller A (21) is set to be 5mL/min, the micro-pump controller A (21) drives a micro-pump actuating mechanism A (22), a syringe piston cylinder A (23) is pushed to inject sodium alginate solution from an inlet conduit (24) at one side of the mold 1(11) until the solution flows out from an outlet conduit (25) at the other side of the mold 1(11), and after the sodium alginate solution is gelatinized, the mold 3(13) is taken down, so that the lower half-layer structure of the inner layer of the intravascular stent can be obtained;

5) Printing of the sacrificial material: the prepared pluronic F127 material is loaded into a syringe piston cylinder B (33) and fixed on a micro-pump executing mechanism B (32), the micro-pump executing mechanism B (32) is fixed on a three-dimensional moving platform (31), a computer control system (IV) transmits a G code of a printing path to the three-dimensional moving platform (31), a motor of the three-dimensional moving platform (31) is controlled to move according to the designed printing path, the translation speed of the three-dimensional moving platform (31) is set to be 8mm/s, the feeding flow rate of a micro-pump controller B (35) is set to be 534 mu L/min, the micro-pump controller B (35) drives the micro-pump executing mechanism B (32), and the syringe piston cylinder B (33) is pushed to extrude the pluronic F127 material.

6) Forming the upper half layer of the inner layer of the blood vessel stent: and (2) filling the prepared sodium alginate solution into a syringe piston cylinder A (23), fixing the syringe piston cylinder A (23) on a micro pump actuating mechanism A (22), connecting an outlet of the syringe piston cylinder A (23) with an inlet conduit (24), and combining the die 1(11) and the die 4(14) together to ensure that the axes of the respective pipelines coincide. After the mold is closed, the feeding flow rate of a micro-pump controller A (21) is set to be 5mL/min, the micro-pump controller A (21) drives a micro-pump actuating mechanism A (22), a syringe piston cylinder A (23) is pushed to inject sodium alginate solution from an inlet conduit (24) on one side of the mold 1(11) until the solution flows out from an outlet conduit (25) on the other side of the mold 1(11), and after the sodium alginate solution is gelatinized, the mold 4(14) is taken down, so that the upper half layer structure of the inner layer of the intravascular stent can be obtained;

7) Forming the upper half layer of the outer layer of the blood vessel stent: filling the prepared gelatin solution into a syringe piston cylinder A (23), fixing the syringe piston cylinder A (23) on a micro pump actuating mechanism A (22), connecting an outlet of the syringe piston cylinder A (23) with an inlet conduit (24), and combining the die 1(11) and the die 5(15) together to ensure that the axes of the respective pipelines coincide. After the mold is closed, the feeding flow rate of a first micro-pump controller (21) is set to be 6mL/min, the first micro-pump controller (21) drives a first micro-pump actuating mechanism (22), a first syringe piston cylinder body (23) is pushed to inject gelatin solution from an inlet conduit (24) on one side of the mold 1(11) until the solution flows out from an outlet conduit (25) on the other side of the mold 1(11), and after the gelatin solution is gelatinized, the mold 5(12) is taken down, so that the upper half layer structure of the outer layer of the intravascular stent can be obtained;

8) removing the sacrificial material: and (3) placing the system in an environment with the temperature of 10 ℃ for 10min, so that the Pluronic F127 material is liquefied and flows out, and a hollow pipeline structure is formed. And (3) taking the stent off the mold 1(11) to obtain the three-dimensional layered intravascular stent with the bifurcation structure.

Claims

1. the utility model provides a three-dimensional layering intravascular stent's of bifurcation structure forming system, includes frame (5), mould system (I), aquogel perfusion system (II), sacrificial material print system (III) and computer control system (IV), its characterized in that: the mould system (I) is arranged on a base of the frame (5); the convex or concave paths of the mould for forming the upper half-layer structure of the blood vessel support and the mould for forming the lower half-layer structure of the blood vessel support are completely the same; the hydrogel perfusion system (II) is movably arranged on the frame (5), and one injector needle (34) is communicated with a mould inlet conduit (24) of the mould system (I); pouring hydrogel into the inlet catheter (24) through the injector needle (34) to sequentially form an outer-layer lower half-layer structure and an inner-layer lower half-layer structure of the intravascular stent, printing a sacrificial material on the inner-layer lower half-layer structure of the intravascular stent, sequentially pouring the hydrogel into the inlet catheter (24) to form an inner-layer upper half-layer structure and an outer-layer upper half-layer structure of the intravascular stent, forming a complete intravascular stent, and liquefying and flowing out the sacrificial material by reducing the temperature of a system to form a hollow pipeline structure of the intravascular stent; the sacrificial material is pluronic F127; the sacrificial material printing system (III) is arranged on the rack (5) and is connected with and drives the hydrogel filling system (II) to move; and the computer control system (IV) is electrically connected and used for controlling the three-dimensional movement of a three-dimensional movement mechanism (31) in the sacrificial material printing system (III) and the extrusion of the sacrificial material by an injector piston cylinder body B (33).

2. the system for forming a three-dimensional layered vessel stent of a bifurcated structure as recited in claim 1, wherein: the mould system (I) comprises a mould 1(11), a mould 2(12), a mould 3(13), a mould 4(14) and a mould 5(15), wherein the convex or concave paths on each mould are completely the same; the inlet and the outlet at the two ends of the mould 1(11) are respectively connected with an inlet conduit (24) and an outlet conduit (25); in the process of pouring the hydrogel, the convex or concave paths of the mold 2(12), the mold 3(13), the mold 4(14) and the mold 5(15) are respectively matched with the concave path of the mold 1 (11).

3. the system for forming a three-dimensional layered vessel stent of a bifurcated structure as recited in claim 2, wherein: the hydrogel perfusion system (II) consists of a micro-pump controller A (21), a micro-pump actuating mechanism A (22), an injector piston cylinder A (23), an inlet conduit (24) and an outlet conduit (25); the syringe piston cylinder A (23) is installed on the micro pump executing mechanism A (22) and fixed through a fastening bolt, the micro pump executing mechanism A (22) pushes the syringe piston cylinder A (23) to extrude hydrogel under the connection driving of a micro pump controller A (21), the outlet of the syringe piston cylinder A (23) is connected with an inlet conduit (24), the inlet conduit (24) is inserted into the inlet of the die 1(11), and hydrogel solution flows out of an outlet conduit (25).

4. the system for forming a three-dimensional layered vessel stent of a bifurcated structure as recited in claim 3, wherein: the sacrificial material printing system (III) is composed of a three-dimensional movement mechanism (31), a micro-pump execution mechanism B (32), a syringe piston cylinder B (33), a syringe needle (34) and a micro-pump controller B (35), the syringe needle (34) is installed on the syringe piston cylinder B (33), the syringe piston cylinder B (33) is installed on the micro-pump execution mechanism B (32) and fixed through a fastening bolt, the micro-pump execution mechanism B (32) is installed on the three-dimensional movement mechanism (31) and moves along with the three-dimensional movement mechanism (31), the micro-pump execution mechanism B (32) pushes the syringe piston cylinder B (33) to extrude sacrificial materials under the driving of the micro-pump controller B (35), and the three-dimensional movement mechanism (31) moves under the driving of a computer system (4).

5. the system for forming a three-dimensional layered vessel stent of a bifurcated structure as recited in claim 4, wherein: the computer control system (IV) comprises a computer system (4) connected with a control system, and the control system is connected with a motor of the three-dimensional movement mechanism (31).

6. A method for forming a three-dimensional layered vascular stent with a bifurcation structure, which is operated by using the forming system of the three-dimensional layered vascular stent with the bifurcation structure according to claim 1, and is characterized by comprising the following steps:

1) forming the lower half layer of the outer layer of the blood vessel stent: combining the mould 1 and the mould 2 together to enable the axes of the respective pipelines to coincide; after die assembly, injecting a hydrogel solution from an inlet conduit at one side of the die 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the die 1, and taking down the die 2 after the hydrogel solution is gelatinized to obtain a lower half-layer structure of the outer layer of the intravascular stent;

2) Forming the lower half layer of the inner layer of the blood vessel stent: combining the mold 1 and the mold 3 together to enable the axes of the respective pipelines to coincide, after the mold is closed, injecting a hydrogel solution from an inlet conduit at one side of the mold 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the mold 1, and after the hydrogel solution is gelatinized, taking down the mold 3 to obtain a lower half-layer structure of the inner layer of the intravascular stent;

3) Printing of the sacrificial material: fixing the syringe filled with the Pluronic F127 material on a micro pump, fixing the micro pump on a three-dimensional motion platform, controlling the three-dimensional motion platform to move according to a designed path by a computer control system, and realizing the printing of the sacrificial material by a syringe piston cylinder B under the driving of the micro pump;

4) Forming the upper half layer of the inner layer of the blood vessel stent: combining the mold 1 and the mold 4 together to enable the axes of the respective pipelines to coincide, after the mold is closed, injecting a hydrogel solution from an inlet conduit at one side of the mold 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the mold 1, and after the hydrogel solution is gelatinized, taking down the mold 4 to obtain an upper half layer structure of the inner layer of the intravascular stent;

5) Forming the upper half layer of the outer layer of the blood vessel stent: combining the mould 1 and the mould 5 together to enable the axes of the respective pipelines to coincide, after mould closing, injecting a hydrogel solution from an inlet conduit at one side of the mould 1 through a syringe needle until the solution flows out from an outlet conduit at the other side of the mould 1, and after the hydrogel solution is gelatinized, taking down the mould 5 to obtain an upper half layer structure of the outer layer of the intravascular stent;

6) Removing the sacrificial material: the environmental temperature of the system is reduced to enable the Pluronic F127 material to be liquefied and flow out, so that a hollow pipeline structure is formed, and the stent is taken down from the mold 1, so that the three-dimensional layered intravascular stent with a bifurcation structure can be obtained.