A tissue engineered tubular scaffold and method of manufacturing the same

Abstract

The present application relates to the technical field of tissue engineering scaffold, and especially relates to a tissue engineering tubular scaffold and a manufacturing method thereof, which comprises: a tubular support framework, a plurality of holes are arranged on the tube wall of the tubular support framework, the tubular support framework is etched and surface modified by low-temperature plasma; a hydrogel coating layer, which comprises an axially extending hydrogel coating inner layer and a hydrogel coating outer layer, the tubular support framework is arranged between the hydrogel coating inner layer and the hydrogel coating outer layer, and the hydrogel coating layer completely covers the tubular support framework; and the tubular support framework is used for supporting the hydrogel coating inner layer and the hydrogel coating outer layer. By being arranged in this way, the tissue engineering tubular scaffold of the present application is beneficial to the culture of tubular tissues in vitro and meets the requirements of biological performance and mechanical performance after being implanted into the body, and solves the problems of poor form retention ability, insufficient mechanical performance and poor bonding strength of different materials of the hydrogel 3D printing tissue engineering tubular scaffold.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tubular stents, in particular to a tissue engineering tubular stent and a manufacturing method thereof. BACKGROUND

[0002] Tissue engineering blood vessels have great significance in the treatment of vascular diseases. Hydrogel biological 3D printed tissue engineering blood vessel stents have certain advantages in the construction of tissue engineering blood vessels and are considered as an effective measure to realize the in vitro reconstruction of blood vessels and other tubular human tissues and implantation into the human body to treat diseases. However, the forming of tissue engineering blood vessel stents is difficult, the configuration maintaining ability is poor, and the mechanical properties are insufficient, which restricts their application in tissue engineering technology.

[0003] The degradable blood vessel stent is a degradable implant for blood vessel reconstruction in cardiovascular diseases, and the mechanical properties meet the requirements of supporting the diseased blood vessel wall. It is delivered to the diseased blood vessel by a delivery system in a minimally invasive form for blood vessel reconstruction. At present, the degradable blood vessel stent mainly made of polylactic acid is used to treat diseases such as vascular stenosis due to its excellent mechanical properties, good biocompatibility and biodegradability.

[0004] At the same time, the particles in the low-temperature plasma can be used for surface etching and surface modification, which can form micro-pore structures on the surface of the object by etching and improve the surface hydrophilicity. At the same time, the low-temperature plasma has the functions of sterilization and regulation of biological protein expression.

[0005] Therefore, how to combine hydrogel with polylactic acid support skeleton to make tissue engineering blood vessel stents with easy forming, strong configuration maintaining ability and strong mechanical properties is a problem faced by current tissue engineering blood vessels. SUMMARY

[0006] The present application provides a tissue engineering tubular stent and a manufacturing method thereof.

[0007] To achieve the above-mentioned purpose, a tissue engineering tubular stent of the present application comprises:

[0008] A tubular support skeleton, a plurality of holes are arranged on the tube wall of the tubular support skeleton, and the tubular support skeleton is etched and surface modified by low-temperature plasma; a hydrogel coating layer, comprising an axially extending hydrogel coating inner layer and a hydrogel coating outer layer, the tubular support skeleton is arranged between the hydrogel coating inner layer and the hydrogel coating outer layer, and the hydrogel coating layer completely covers the tubular support skeleton;

[0009] The tubular support skeleton is used to support the hydrogel coating inner layer and the hydrogel coating outer layer.

[0010] Preferably, the tubular support framework comprises a first spiral framework, a second spiral framework, a third spiral framework and a fourth spiral framework;

[0011] The first spiral framework and the third spiral framework have the same axial rotation direction, the second spiral framework and the fourth spiral framework have the same axial rotation direction, the first spiral framework and the second spiral framework have opposite axial rotation directions, and the third spiral framework and the fourth spiral framework have opposite axial rotation directions.

[0012] The first spiral framework, the second spiral framework, the third spiral framework and the fourth spiral framework are interwoven to form a plurality of uniformly distributed and grid-shaped holes, and the minor axis of each hole extends along the axial direction of the tubular support framework.

[0013] Preferably, the hydrogel coating layer further comprises a hydrogel coating middle layer, which is arranged between the tubular support framework and the hydrogel coating outer layer.

[0014] Preferably, the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating inner layer is determined by the cells in the vascular intima layer, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating inner layer ranges from 12-17:1.5-2.5.

[0015] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating middle layer is determined by the cells in the vascular basement membrane layer, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating middle layer ranges from 8-12:1.5-2.5.

[0016] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating outer layer is determined by the cells in the vascular adventitia layer, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating outer layer ranges from 12-17:1.5-2.5.

[0017] Preferably, the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating inner layer is 15:2.

[0018] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating middle layer is 10:2.

[0019] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating outer layer is 15:2.

[0020] To achieve the above-mentioned purposes, the application further provides a manufacturing method of a tissue engineering tubular support, comprising:

[0021] Preparation of a tubular support framework with a plurality of holes on the tube wall;

[0022] etching the tubular support framework by low-temperature plasma to form micro-holes on the surface of the micro-filaments of the tubular support framework;

[0023] surface modification of the tubular support framework by low-temperature plasma to graft hydrophilic functional groups on the surface of the tubular support framework;

[0024] 3D printing a hydrogel coated inner layer on the first rotating shaft, spraying the hydrogel coated inner layer with a 2% calcium chloride solution during the continuous rotation of the first rotating shaft, and cooling the hydrogel coated inner layer until the hydrogel coated inner layer is cross-linked;

[0025] sleeving the tubular support framework on the hydrogel coated inner layer, the length of the tubular support framework being shorter than that of the hydrogel coated inner layer, to form a chimera of the tubular support framework and the hydrogel coated inner layer;

[0026] 3D printing a hydrogel coated outer layer on the surface of the chimera to obtain a tissue engineering tubular scaffold.

[0027] Preferably, the step of preparing the tubular support framework with multiple holes on the tube wall comprises:

[0028] providing a 3D printing extrusion nozzle at a predetermined distance from the surface of the second rotating shaft, the predetermined distance being less than the diameter of the 3D printing extrusion nozzle;

[0029] moving the 3D printing extrusion nozzle along the axial direction of the second rotating shaft at a predetermined speed while extruding material and rotating the second rotating shaft in the first rotating direction to generate a first spiral framework;

[0030] resetting the 3D printing extrusion nozzle, moving the 3D printing extrusion nozzle along the axial direction of the second rotating shaft at the predetermined speed while extruding material and rotating the second rotating shaft in the second rotating direction to generate a second spiral framework interwoven with the first spiral framework;

[0031] resetting the 3D printing extrusion nozzle, moving the 3D printing extrusion nozzle along the axial direction of the second rotating shaft at the predetermined speed while extruding material and rotating the second rotating shaft in the first rotating direction to generate a third spiral framework interwoven with the first spiral framework and the second spiral framework;

[0032] resetting the 3D printing extrusion nozzle, moving the 3D printing extrusion nozzle along the axial direction of the second rotating shaft at the predetermined speed while extruding material and rotating the second rotating shaft in the second rotating direction to generate a fourth spiral framework interwoven with the first spiral framework, the second spiral framework, and the third spiral framework;

[0033] The first rotation direction and the second rotation direction are opposite.

[0034] Preferably, the method for manufacturing a tissue engineering tubular scaffold further comprises:

[0035] Before printing the hydrogel coating outer layer, a hydrogel coating middle layer is 3D printed on the chimera surface.

[0036] Preferably, the first spiral skeleton, the second spiral skeleton, the third spiral skeleton and the fourth spiral skeleton are interwoven to form a plurality of uniformly distributed, grid-shaped holes, and the minor axis of each hole extends along the axial direction of the tubular support skeleton.

[0037] Preferably, the material is medical-grade polylactic acid.

[0038] Based on this, the beneficial effects of the present application are:

[0039] 1. By the scheme of the present application, embedding the tubular support skeleton in the hydrogel coating layer can enhance the shape retention ability of the hydrogel coating layer and the pressure resistance of the inner and outer walls of the lumen, and can naturally degrade after the cells complete division and tissue differentiation and are implanted into the body, reducing the possibility of body rejection;

[0040] 2. By the scheme of the present application, embedding the tubular support skeleton in the hydrogel coating layer, this structural feature is beneficial for the tubular support skeleton to withstand pressure from the outside and inside of the tube wall in the radial direction, on the one hand, it ensures the shape retention ability of the tissue engineering tubular scaffold during in vitro culture, and on the other hand, it ensures that the tissue engineering tubular scaffold can withstand the impact brought by physiological activities during the initial stage of in vitro culture and implantation into the body;

[0041] 3. By the scheme of the present application, the tubular support skeleton is made of a first spiral skeleton, a second spiral skeleton, a third spiral skeleton and a fourth spiral skeleton, the rotation direction of the first spiral skeleton and the second spiral skeleton is opposite, the rotation direction of the third spiral skeleton and the second spiral skeleton and the fourth spiral skeleton is opposite, and the tubular support skeleton is made by interweaving the four groups of spiral skeletons, and the interwoven structure of the spiral tube is more beneficial for 3D printing; at the same time, the cross section of the microfilament of the 3D printed spiral interwoven structure support skeleton is close to a circle, which is isotropic in mechanics, is beneficial for in vitro culture of tissue engineering blood vessels, and has uniform bearing capacity for pressure from the inside and outside of the tube after implantation into the body, and has high mechanical consistency with autologous tubular tissue;

[0042] 4. By the scheme of the present application, after the tubular support skeleton is etched by low-temperature plasma, micro-holes can be formed on the surface of the microfilament of the tubular support skeleton, which is beneficial for the infiltration of hydrogel and enhances the bonding strength between the hydrogel coating layer and the tubular support skeleton;

[0043] 5. Through the scheme of the present application, the tubular support framework is improved in hydrophilicity after being surface modified by low-temperature plasma, which is conducive to improving the bonding strength between the hydrogel coating layer and the tubular support framework;

[0044] 6. Through the scheme of the present application, the tubular support framework is improved in sterility level after being treated by low-temperature plasma, which is conducive to the survival of tubular tissue cells in the tissue engineering tubular scaffold;

[0045] 7. Through the scheme of the present application, the support framework with pores is prepared by means of fused deposition modeling 3D printing, the inner hydrogel coating layer, the middle hydrogel coating layer and the outer hydrogel coating layer are printed by means of micro-extrusion 3D printing, the support framework is embedded in the hydrogel coating layer, and the tissue engineering tubular scaffold is manufactured, the overall process is simple and efficient, and is suitable for personalized needs in medical applications. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A structural schematic diagram of a tissue engineering tubular scaffold according to an embodiment of the present application is shown schematically;

[0047] Figure 2 A preparation process schematic diagram of a support framework according to an embodiment of the present application is shown schematically;

[0048] Figure 3 A cross-sectional view of a tissue engineering tubular scaffold according to an embodiment of the present application is shown schematically;

[0049] Figure 4 A flowchart of a manufacturing method of a tissue engineering tubular scaffold according to an embodiment of the present application is shown schematically;

[0050] Figure 5 A manufacturing process schematic diagram of a tissue engineering tubular scaffold according to an embodiment of the present application is shown schematically;

[0051] The reference signs are as follows: tubular support framework 10, first spiral framework 101, second spiral framework 102, third spiral framework 103, fourth spiral framework 104, hydrogel coating layer 20, inner hydrogel coating layer 201, outer hydrogel coating layer 202, middle hydrogel coating layer 203. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0053] The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0054] It should be noted that the terms "upper", "lower", "left", "right", and the like as used herein are described in the angle shown in the drawings, and should not be understood as limiting the embodiments of the application. In addition, in the context, it should also be understood that when referring to an element formed "on" or "under" another element, it can be directly formed "on" or "under" another element, or indirectly formed "on" or "under" another element through an intermediate element.

[0055] Figure 1 The structural schematic diagram of a tissue engineering tubular scaffold according to an embodiment of the application is shown in FIG. 1. Figure 1 As shown in FIG. 1, a tissue engineering tubular scaffold according to an embodiment of the application comprises:

[0056] A tubular support framework 10, which is provided with a plurality of holes on the tube wall, and the tubular support framework 10 is etched and surface modified by low-temperature plasma;

[0057] A hydrogel coating layer 20, which comprises an axially extending hydrogel coating inner layer 201 and a hydrogel coating outer layer 202, and the tubular support framework 10 is arranged between the hydrogel coating inner layer 201 and the hydrogel coating outer layer 202, and the hydrogel coating layer 20 completely coats the tubular support framework 10;

[0058] The tubular support framework 10 is used to support the hydrogel coating inner layer 201 and the hydrogel coating outer layer 202.

[0059] Specifically, the tubular support framework 10 is arranged in a tubular shape, and when the hydrogel coating inner layer 201 is arranged on the inner wall thereof and the hydrogel coating outer layer 202 is arranged on the outer wall thereof, the whole can be more matched to the structure of the blood vessel, and can be more matched to the blood vessel environment during in-vitro cell culture.

[0060] The tubular support framework 10 is provided with a plurality of holes on the tube wall, and this kind of pore structure can withstand the pressure from the outside and the inside of the tube wall, on the one hand, to ensure the configuration maintaining ability of the tissue engineering tubular scaffold during in-vitro culture, and on the other hand, to ensure that the tissue engineering tubular scaffold can withstand the impact brought by physiological activities in the initial stage after completing in-vitro culture and being implanted into the human body.

[0061] Meanwhile, the tubular support framework 10 is also subjected to surface etching treatment and surface modification treatment by low-temperature plasma, so as to form micro-holes and graft hydrophilic functional groups on the surface thereof, thereby enhancing the bonding strength between the hydrogel coating layer 20 and the tubular support framework 10.

[0062] The hydrogel coating layer 20 completely covers the tubular support framework 10, which on one hand avoids adverse reactions such as rejection reaction, late inflammation, thrombosis and blockage in blood vessels after the tissue engineering tubular support is implanted into the human body, and on the other hand avoids the secondary risk caused by the fragments of the exposed tubular support framework 10 falling into the lumen of the human body after the in-vitro culture is completed and the tubular support is implanted into the human body.

[0063] Further, Figure 2 A schematic diagram of the preparation process of the support framework in an embodiment of the present application is shown in Fig. 1. Figure 2 As shown in Fig. 1.

[0064] The tubular support framework 10 comprises a first spiral framework 101, a second spiral framework 102, a third spiral framework 103 and a fourth spiral framework 104; the first spiral framework 101 and the third spiral framework 103 have the same axial rotation direction, the second spiral framework 102 and the fourth spiral framework 104 have the same axial rotation direction, the first spiral framework 101 and the second spiral framework 102 have opposite axial rotation directions, and the third spiral framework 103 and the fourth spiral framework 104 have opposite axial rotation directions.

[0065] The first spiral framework 101, the second spiral framework 102, the third spiral framework 103 and the fourth spiral framework 104 are interwoven to form a plurality of uniformly distributed and grid-shaped holes, and the minor axis of each hole extends along the axial direction of the tubular support framework 10.

[0066] Specifically, the tubular support framework 10 is composed of the first spiral framework 101, the second spiral framework 102, the third spiral framework 103 and the fourth spiral framework 104, which have good structural strength and are beneficial to 3D printing.

[0067] Meanwhile, the tubular support framework 10 is made of biodegradable material, preferably medical-grade polylactic acid, which can provide sufficient structural retention for the hydrogel coating layer 20 in the initial stage, and can be naturally degraded after the cells complete division and tissue differentiation and are implanted into the human body, thereby reducing the possibility of rejection reaction.

[0068] The minor axis of the hole formed by the interweaving of the first spiral framework 101, the second spiral framework 102, the third spiral framework 103 and the fourth spiral framework 104 extends along the axial direction of the tubular support framework 10, and the major axis of the hole extends along the radial direction, which can further enhance the overall compression resistance of the tubular support framework 10.

[0069] The holes of the tubular support framework 10 are formed by interlacing a plurality of line segments, and the inner walls around the holes are arc-shaped, which is more isotropic and more conducive to improving the compression resistance of the overall structure.

[0070] It should be noted that the tubular support framework 10 with a plurality of holes in the tube wall can also be made by other methods, such as laser engraving, mechanical engraving, injection molding, etc.

[0071] Further, Figure 3 A cross-sectional view of a tissue engineering tubular scaffold according to an embodiment of the present application is shown in FIG. 2. Figure 3 As shown in FIG. 2:

[0072] The hydrogel coating layer 20 further comprises a hydrogel coating middle layer 203, which is arranged between the tubular support framework 10 and the hydrogel coating outer layer 202.

[0073] In this way, the hydrogel coating layer 20 comprises the hydrogel coating inner layer 201, the hydrogel coating middle layer 203, and the hydrogel coating outer layer 202. Through this three-layer structure, the growth environment of cells in the blood vessel can be more matched and simulated.

[0074] Further, the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating inner layer 201 is determined by the cells in the intima layer of the blood vessel, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating inner layer 201 ranges from 12-17:1.5-2.5, preferably 15:2;

[0075] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating middle layer 203 is determined by the cells in the basement membrane layer of the blood vessel, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating middle layer 203 ranges from 8-12:1.5-2.5, preferably 10:2;

[0076] The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating outer layer 202 is determined by the cells in the adventitia layer of the blood vessel, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coating outer layer 202 ranges from 12-17:1.5-2.5, preferably 15:2.

[0077] Specifically, the tissue engineering tubular scaffold of the present application is used in blood vessels, and the human blood vessel comprises an intima layer, a basement membrane layer, and an adventitia layer. Therefore, in order to more simulate the environment of the blood vessel, the hydrogel coating layer 20 is arranged in three layers, and the ratio of gelatin to sodium alginate in each layer is adaptively adjusted to match the growth environment of each layer in the blood vessel.

[0078] The mass percentage of gelatin and sodium alginate is related to the long side size of the cells, and the mass percentage of gelatin and sodium alginate is different for different parts of the blood vessels.

[0079] The long side size of the endothelial cells in the intima layer of the blood vessel is generally between 20-50 microns, and the mass percentage of gelatin and sodium alginate in the hydrogel coating the inner layer is 12-17:1.5-2.5, preferably 15:2;

[0080] The long side size of the smooth muscle cells in the basement membrane layer of the blood vessel is generally between 50-200 microns, and the mass percentage of gelatin and sodium alginate in the hydrogel coating the middle layer is 8-12:1.5-2.5, preferably 10:2;

[0081] The long side size of the smooth muscle cells in the basement membrane layer of the blood vessel is generally between 50-200 microns, and the mass percentage of gelatin and sodium alginate in the hydrogel coating the middle layer is 8-12:1.5-2.5, preferably 10:2;

[0082] In the above preferred proportions, the prepared hydrogel has high strength and high porosity, which is more conducive to cell growth.

[0083] Further, Figure 4 A flow chart of a method for manufacturing a tissue-engineered tubular stent according to an embodiment of the present application is shown in Figure 5 A schematic diagram of the manufacturing process of a tissue-engineered tubular stent according to an embodiment of the present application is shown in Figure 4 、 5 The present application also provides a method for manufacturing a tissue-engineered tubular stent, which comprises:

[0084] S01: preparing a tubular support skeleton 10 provided with a plurality of holes on the wall thereof;

[0085] S02: performing surface etching treatment on the tubular support skeleton 10 by using low-temperature plasma to form micro-holes on the surface thereof;

[0086] S03: performing surface modification treatment on the tubular support skeleton 10 by using low-temperature plasma to graft hydrophilic functional groups on the surface molecules thereof;

[0087] S04: 3D printing a hydrogel coating inner layer 201 on the first rotation axis, spraying the hydrogel coating inner layer 201 with a 2% calcium chloride solution during the continuous rotation of the first rotation axis, and performing cooling treatment on the hydrogel coating inner layer 201 until the hydrogel coating inner layer 201 is crosslinked;

[0088] S05: fitting the tubular support framework 10 on the hydrogel coated inner layer 201, the length of the tubular support framework 10 being shorter than the hydrogel coated inner layer 201, to form a hybrid of the tubular support framework 10 and the hydrogel coated inner layer 201;

[0089] S06: 3D printing the hydrogel coated outer layer 202 on the surface of the hybrid, to obtain a tissue engineering tubular scaffold.

[0090] Specifically, in step S04, after the hydrogel coated inner layer 201 is cross-linked, the hydrogel coated inner layer 201 is treated by low-temperature plasma to form a plasma-activated liquid in the hydrogel coated inner layer 201, and in step S06, after the hydrogel coated outer layer 202 is printed, the hydrogel coated outer layer 202 is treated by low-temperature plasma to form a plasma-activated liquid in the hydrogel coated outer layer 202, so that after the low-temperature plasma treatment, the sterility level of the tubular scaffold is improved, which is conducive to the survival of the tubular tissue cells in the tissue engineering tubular scaffold.

[0091] Meanwhile, in step S04, the cooling treatment is to pass cooling liquid into the first rotating shaft to cool and lower the temperature of the first rotating shaft, thereby realizing the temperature-lowering cross-linking of the hydrogel coated inner layer 201.

[0092] After printing the hydrogel coated inner layer 201 on the first rotating shaft, when fitting the tubular support framework 10, the midpoint of the tubular support framework 10 is ensured to be roughly aligned with the midpoint of the hydrogel coated inner layer 201, and when printing the hydrogel coated inner layer 201 and the hydrogel coated outer layer 202, the axial length of the hydrogel coated inner layer 201 and the hydrogel coated outer layer 202 is ensured to be greater than that of the tubular support framework 10, so that the two can completely cover the tubular support framework 10, avoiding the risk of fragments falling into the blood circulation system due to the exposure of the tubular support framework 10.

[0093] Further, as shown in FIG. 1, in step S01 of preparing the tubular support framework with multiple holes on the tube wall, the step includes: Figure 2

[0094] S101: arranging a 3D printing extrusion nozzle at a predetermined distance on the surface of the second rotating shaft, the predetermined distance being not greater than the diameter of the 3D printing extrusion nozzle;

[0095] S102: making the 3D printing extrusion nozzle extrude material while moving along the axial direction of the second rotating shaft at a predetermined speed, and rotating the second rotating shaft in the first rotating direction, to generate a first spiral framework 101;

[0096] ​S103: reset the 3D printing extrusion nozzle, let the 3D printing extrusion nozzle extrude material while moving along the axial direction of the second rotating shaft at a predetermined speed, and rotate the second rotating shaft in the second rotating direction, to generate a second spiral skeleton 102 interwoven with the first spiral skeleton 101;

[0097] S104: reset the 3D printing extrusion nozzle, let the 3D printing extrusion nozzle extrude material while moving along the axial direction of the second rotating shaft at a predetermined speed, and rotate the second rotating shaft in the first rotating direction, to generate a third spiral skeleton 103 interwoven with the first spiral skeleton 101 and the second spiral skeleton 102;

[0098] S105: reset the 3D printing extrusion nozzle, let the 3D printing extrusion nozzle extrude material while moving along the axial direction of the second rotating shaft at a predetermined speed, and rotate the second rotating shaft in the second rotating direction, to generate a fourth spiral skeleton 104 interwoven with the first spiral skeleton 101, the second spiral skeleton 102, and the third spiral skeleton 103;

[0099] Wherein, the first rotating direction and the second rotating direction are opposite, ensuring that the adjacent two spiral skeletons can interweave to form a hole, and the material used for printing is medical grade polylactic acid, which can be biodegraded.

[0100] Specifically, the diameter of the 3D printing extrusion nozzle is 0.4mm, the diameter of the core shaft of the second rotating shaft is 5mm, the rotating speed of the second rotating shaft is 60rpm, the 3D printing extrusion nozzle is arranged at a distance of 0.38mm from the surface of the second rotating shaft, the running speed of the 3D printing extrusion nozzle along the axial direction of the second rotating shaft is 120mm / min, the rotating starting phase angle of the second rotating shaft is set to 0°, the rotating direction is set to clockwise rotation, and the first spiral skeleton 101 is printed;

[0101] Reset the 3D printing extrusion nozzle, the parameters of the 3D printing extrusion nozzle remain unchanged, the rotating starting phase angle of the second rotating shaft remains unchanged, the rotating direction is set to counterclockwise rotation, and the second spiral skeleton 102 is printed;

[0102] Reset the 3D printing extrusion nozzle, the parameters of the 3D printing extrusion nozzle remain unchanged, the rotating starting phase angle of the second rotating shaft is set to 180°, and the rotating direction is set to counterclockwise rotation, and the third spiral skeleton 103 is printed;

[0103] Reset the 3D printing extrusion nozzle, the parameters of the 3D printing extrusion nozzle remain unchanged, the rotating starting phase angle of the second rotating shaft is set to 180°, and the rotating direction is set to clockwise rotation, and the fourth spiral skeleton 104 is printed, and the tubular support skeleton 10 is printed;

[0104] Therefore, the tubular support framework 10 is manufactured by 3D printing, which is more convenient for forming and has high material utilization rate. Meanwhile, the tubular support framework 10 can be printed by micro-extrusion on the second rotating shaft to customize the hole shape and density of the tubular support framework 10 according to actual use requirements, which is convenient for the construction of the tissue engineering tubular channel.

[0105] Meanwhile, when the tubular support framework 10 is printed, the first spiral framework 101, the second spiral framework 102, the third spiral framework 103 and the fourth spiral framework 104 are interwoven to form a plurality of uniformly distributed and grid-shaped holes, and the minor axis of each hole extends along the axial direction of the tubular support framework 10.

[0106] Therefore, the minor axis of the hole extends along the axial direction of the tubular support framework 10, and the major axis extends along the radial direction of the tubular support framework 10, which is more conducive to the bending of the tubular support framework 10 and the radial compression resistance of the overall structure.

[0107] Further, after the tubular support framework 10 and the hydrogel coated inner layer 201 are formed into a composite, the hydrogel coated middle layer 203 is continuously printed on the composite in step S03.

[0108] The printing extrusion amount and the printing feed amount are controlled, the hydrogel coated middle layer 203 can permeate and fill into the holes of the tubular wall of the tubular support framework 10, the rotation speed of the rotating shaft and the cross-linking process are controlled, and the hydrogel coated middle layer 203 can form a complete coating of the tubular support framework 10.

[0109] Therefore, when the tissue engineering tubular support is manufactured, the hydrogel coated layer 20 has a three-layer structure, which is more matched with the human vascular structure and provides structural support for the construction of the tissue engineering blood vessel.

[0110] Further, the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coated inner layer 201 is in the range of 12-17:1.5-2.5, preferably 15:2, the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coated middle layer 203 is in the range of 8-12:1.5-2.5, preferably 10:2, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel coated outer layer 202 is in the range of 12-17:1.5-2.5, preferably 15:2.

[0111] In summary, by the scheme of the present application, the tubular support framework 10 is provided, the hydrogel coated inner layer 201, the hydrogel coated middle layer 203 and the hydrogel coated outer layer 202 are arranged around the tubular support framework 10, the tubular support framework 10 can enhance the shape retention ability of the hydrogel coated layer 20 and the compression resistance of the inner and outer walls of the lumen, and the three-layer structure of the hydrogel coated layer 20 is more matched with the human vascular structure, which is helpful for the construction of the external environment for cell growth and tissue differentiation.

[0112] The plurality of holes are arranged on the pipe wall of the tubular support framework 10, and the holes are arranged to form the first spiral framework 101, the second spiral framework 102, the third spiral framework 103 and the fourth spiral framework 104 interlaced with each other. Firstly, the plurality of holes arranged on the pipe wall of the tubular support framework 10 are beneficial to the tubular support framework 10 to bear the pressure from the outside and the inside of the pipe wall in the radial direction; secondly, the structure of the tubular support framework 10 is beneficial to 3D printing; thirdly, the holes arranged on the tubular support framework 10 are channels for the transmission of regulatory substances such as cell nutrient substances, metabolic products and cytokines in tissue culture; and meanwhile, the tubular support framework 10 and the hydrogel coating layer 20 are both made by 3D printing, and the overall process is simple, efficient and suitable for personalized needs in medical applications.

[0113] The above description is merely the preferred embodiments of the present application and the explanation of the technical principles applied. It should be understood by those skilled in the art that the inventive scope involved in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and meanwhile, it should also cover other technical solutions formed by the arbitrary combinations of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by the mutual replacement of the above features and the technical features disclosed in the present application (but not limited to) having similar functions.

Claims

1. A tissue engineering tubular scaffold, characterized in that, include: A tubular support frame with multiple holes in its tube wall is etched and surface modified using low-temperature plasma. The hydrogel coating layer includes an axially extending inner hydrogel coating layer and an outer hydrogel coating layer, wherein the tubular support skeleton is disposed between the inner hydrogel coating layer and the outer hydrogel coating layer, and the hydrogel coating layer completely covers the tubular support skeleton. The tubular support framework is used to support the hydrogel-coated inner layer and the hydrogel-coated outer layer; The tubular support framework is made of biodegradable material; The tubular support frame includes a first helical frame, a second helical frame, a third helical frame, and a fourth helical frame; The first and third helical skeletons rotate in the same axial direction, the second and fourth helical skeletons rotate in the same axial direction, the first and second helical skeletons rotate in opposite axial directions, and the third and fourth helical skeletons rotate in opposite axial directions. The first, second, third, and fourth helical skeletons interweave to form a plurality of uniformly distributed, grid-like holes, with the short axis of each hole extending along the axial direction of the tubular support skeleton. The hydrogel coating layer further includes a hydrogel coating middle layer, which is disposed between the tubular support skeleton and the hydrogel coating outer layer.

2. The tissue engineering tubular scaffold according to claim 1, characterized in that, The mass percentage of gelatin to sodium alginate in the hydrogel of the inner hydrogel coating is determined by the cells in the vascular endothelial layer, and the mass percentage of gelatin to sodium alginate in the hydrogel of the inner hydrogel coating ranges from 12–17:1.5–2.

5. The mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel-coated middle layer is determined by the cells in the vascular basement membrane layer, and the mass percentage of gelatin to sodium alginate in the hydrogel of the hydrogel-coated middle layer ranges from 8–12:1.5–2.

5. The mass percentage of gelatin to sodium alginate in the hydrogel coating outer layer is determined by the cells in the adventitia of the blood vessels, and the mass percentage range of gelatin to sodium alginate in the hydrogel coating outer layer is 12–17:1.5–2.

5.

3. The tissue engineering tubular scaffold according to claim 2, characterized in that, The mass percentage of gelatin to sodium alginate in the hydrogel coating inner layer is 15:

2. The mass percentage of gelatin to sodium alginate in the hydrogel-coated middle layer is 10:

2. The mass percentage of gelatin to sodium alginate in the outer hydrogel coating is 15:

2.

4. A method for manufacturing the tissue-engineered tubular scaffold according to claim 1, characterized in that, include: Prepare a tubular support skeleton with multiple holes on the tube wall; The tubular support framework is etched using low-temperature plasma to form micropores on the surface of the tubular support framework microfilaments; The tubular support skeleton was surface modified using low-temperature plasma, and hydrophilic functional groups were grafted onto the surface of the tubular support skeleton. A hydrogel-coated inner layer is 3D printed on a first rotating shaft. During the continuous rotation of the first rotating shaft, the hydrogel-coated inner layer is sprayed with a calcium chloride solution of 2% by mass and the hydrogel-coated inner layer is cooled until the hydrogel-coated inner layer crosslinks. The tubular support skeleton is fitted onto the hydrogel-coated inner layer, and the length of the tubular support skeleton is shorter than that of the hydrogel-coated inner layer, so as to form a chimera of the tubular support skeleton and the hydrogel-coated inner layer. A hydrogel outer layer was 3D printed on the surface of the chimera to obtain a tissue-engineered tubular scaffold. The tubular support framework is made of biodegradable material; The tubular support frame includes a first helical frame, a second helical frame, a third helical frame, and a fourth helical frame. The first helical frame, the second helical frame, the third helical frame, and the fourth helical frame interweave to form a plurality of uniformly distributed, grid-like holes. The short axis of each hole extends along the axial direction of the tubular support frame. Also includes: Before printing the hydrogel-coated outer layer, a hydrogel-coated middle layer is 3D printed on the surface of the chimera.

5. The method for manufacturing a tissue engineering tubular scaffold according to claim 4, characterized in that, The steps for preparing a tubular support skeleton with multiple holes in its wall include: A 3D printing extrusion nozzle is positioned at a predetermined distance from the surface of the second rotating axis, the predetermined distance being less than the diameter of the 3D printing extrusion nozzle; The 3D printing nozzle extrudes material while moving along the axial direction of the second rotating axis at a predetermined speed, and at the same time rotates the second rotating axis in the first rotating direction to generate a first helical skeleton. Reset the 3D printing extrusion nozzle, so that the 3D printing extrusion nozzle extrudes material while moving along the axial direction of the second rotation axis at the predetermined speed, and at the same time rotates the second rotation axis in the second rotation direction to generate a second helical skeleton that interweaves with the first helical skeleton; Reset the 3D printing extrusion nozzle, so that the 3D printing extrusion nozzle extrudes material while moving along the axial direction of the second rotation axis at the predetermined speed, and at the same time rotates the second rotation axis in the first rotation direction to generate a third helical skeleton that interweaves with the first helical skeleton and the second helical skeleton. Reset the 3D printing extrusion nozzle, so that the 3D printing extrusion nozzle extrudes material while moving along the axial direction of the second rotation axis at the predetermined speed, and at the same time rotates the second rotation axis in the second rotation direction to generate a fourth helical skeleton that interweaves with the first helical skeleton, the second helical skeleton, and the third helical skeleton. The first rotation direction and the second rotation direction are opposite.

6. The method for manufacturing a tissue engineering tubular scaffold according to claim 5, characterized in that, The material is medical-grade polylactic acid.

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