A mold for a membrane-aerogel composite tubular tissue engineering scaffold and its preparation method

Abstract

This invention discloses a mold and its preparation method for a membrane-aerogel composite tubular tissue engineering scaffold. The scaffold comprises several layers, several supports, several gaskets, a central core column, and a hollow transparent tube. The supports are used to support the layers. Each layer of the scaffold has at least one annular gasket groove coaxially arranged for fixing the gasket. The central core column is fixed through the central core column positioning holes of the upper and lower gaskets. The hollow transparent tube is fixed through the transparent tube positioning holes of the middle gasket and the transparent tube positioning groove of the lower gasket. This invention also discloses a method for preparing the membrane-aerogel composite tubular tissue engineering scaffold. Using the mold, the axes of the inner tubular fibrous membrane and the outer tubular aerogel are precisely matched, thereby ensuring the stability and integrity of the overall structure and facilitating long-term preservation.

Description

Technical Field

[0001] This invention relates to the field of tissue engineering scaffolds, specifically to a mold for a membrane-aerogel composite tubular tissue engineering scaffold and its preparation method. Background Technology

[0002] Tubular structures, such as ureters, blood vessels, intestines, and trachea, are widely present in mammals. When these tubular tissues are damaged or diseased, replacement therapy typically requires autologous tissue, donor tissue, or artificial prostheses. However, obtaining autologous tissue may involve collateral damage, the source of donor tissue is limited, and there may be issues with immune rejection; these factors restrict the development of tissue transplantation techniques. The advantages of artificial catheter prostheses for replacement or repair therapy include immediate use, short operation time, low risk of infection, high controllability, and low cost. Even if tubular artificial prostheses made of fibrous membranes meet the mechanical performance requirements, their simple structure often makes it difficult to simulate the complex multilayered structures of natural tissues, which may lead to postoperative functional impairment and poor regeneration. The unique morphology of tubular tissues and the different types and distribution of cells are important characteristics that are crucial for tissue function and regeneration.

[0003] An ideal tubular structure replacement material must possess sufficient mechanical properties to withstand the stresses that may be exerted during surgery and by adjacent tissues. Furthermore, the material should have the ability to promote cell proliferation and differentiation, and to regulate the release of growth factors to meet the functional needs of natural tissues.

[0004] In recent years, numerous studies have focused on the reconstruction and repair of damaged tissues using biomaterials and artificial implants. Synthetic materials such as polycaprolactone (PCL), polyurethane (PU), and polyacetic acid (PLA), as well as natural materials like sodium alginate, gelatin, chitosan, and hyaluronic acid, have been applied to the reconstruction of tubular tissues such as the ureter and blood vessels. Electrospinning technology has also achieved widespread application in the preparation of tubular fibrous membranes. Hydrogels, due to their excellent biocompatibility and water retention, also show great potential in tissue engineering. However, combining membranes and hydrogels to prepare long, uniformly thick tubular tissue engineering scaffolds remains a technical challenge, the key being ensuring the consistency of the axes of the tubular fibrous membrane and the tubular hydrogel in three-dimensional space.

[0005] CN112999425B discloses a bilayer hydrogel tubular tissue engineering scaffold and its preparation method. However, this preparation process involves first pre-filling the hydrogel matrix, then assembling molds at both ends to align the axes of the bilayer hydrogel, and finally cross-linking the hydrogel through photocrosslinking. The above-mentioned device and method have the following shortcomings:

[0006] (1) For two hydrogel matrices that are rapidly chemically cross-linked after mixing, they can form gel within seconds. If the hydrogel is already cross-linked before the mold is assembled, it is very easy to cause the axis of the two hydrogels to be inconsistent, which will weaken the bonding force between the hydrogels and affect the stability and integrity of the overall structure.

[0007] (2) Using multilayer hydrogel tubular tissue engineering scaffolds, for tubular structures in the human body such as ureters and trachea, the inside of the tube is the first medium (such as urine and gas), and the outside of the tube is the second medium. Due to the large pore structure of hydrogel, the first medium is very likely to permeate to the outside of the tube, causing physiological dysfunction.

[0008] (3) If the size of the tubular support needs to be adjusted, all mold parts need to be redrawn and remade, which is time-consuming and labor-intensive.

[0009] (4) When making tubular structures with a small diameter, there may be problems such as unstable center of gravity and inaccurate alignment of the axis.

[0010] (5) Tubular structures prepared using hydrogels cannot be preserved for a long time due to their water content and the fact that the water evaporates very easily. This limits their engineering and large-scale production. Summary of the Invention

[0011] To overcome at least one of the shortcomings of the prior art, the purpose of this invention is to design a mold for a membrane-aerogel tubular tissue engineering scaffold, so that the tubular tissue engineering scaffold not only meets the requirements of mechanical performance and multifunctionality, but also meets the requirement of consistency of the axis of the multi-layer structure in three-dimensional space, so as to ensure the stability of the bonding force between the multi-layer structure, thereby ensuring the stability and integrity of the overall structure of the tubular tissue engineering scaffold and facilitating long-term storage.

[0012] To achieve the above objectives, the present invention provides a mold for a membrane-aerogel composite tubular tissue engineering scaffold, comprising several layers, several supports, several pads, a central core column, and a hollow transparent tube, wherein...

[0013] The support column is vertically connected to the shelf and is used to support the shelf;

[0014] The shelf includes an upper shelf, a middle shelf, and a lower shelf; each shelf has at least one annular gasket groove coaxially provided for fixing the gasket.

[0015] The gasket includes an upper gasket, a middle gasket, and a lower gasket. The upper gasket has a central core positioning hole, the middle gasket has a central transparent tube positioning hole, and the lower gasket has a central core positioning hole and a central transparent tube positioning groove concentrically located at its center. The diameter of the central core positioning hole is smaller than the diameter of the central transparent tube positioning groove. The central core is fixed by the central core positioning holes of the upper and lower gaskets. The hollow transparent tube is fixed by the central transparent tube positioning holes of the middle and lower gaskets. A gel cavity is formed between the outer wall of the central core and the inner wall of the hollow transparent tube. The upper gasket also has an injection port communicating with the gel cavity for injecting a hydrogel solution.

[0016] The length of the central core is greater than the height of the mold, and the length of the hollow transparent tube is less than or equal to the height of the mold, but greater than or equal to the height between the middle gasket and the lower gasket.

[0017] Furthermore, the support column comprises at least three columns for stable support of the shelf.

[0018] Furthermore, the edge of the annular gasket groove is provided with a first stepped structure, the step height of the first stepped structure gradually decreases from the edge of the annular gasket groove toward the center; the edge of the gasket is provided with a second stepped structure, the step height of the second stepped structure gradually increases from the edge of the gasket toward the center; the first stepped structure and the second stepped structure are interlocked with each other.

[0019] Furthermore, the injection port has a fan-shaped notch, through which the long needle of the syringe can extend into the bottom of the gel cavity.

[0020] The present invention also provides a method for preparing a membrane-aerogel composite tubular tissue engineering scaffold using the above-mentioned mold, comprising:

[0021] Step S1: Provide a tubular fiber membrane;

[0022] Step S2: Assemble the mold, place the lower pad into the annular pad groove of the lower shelf, place the middle pad into the annular pad groove of the middle shelf, insert the hollow transparent tube, fix the upper end of the hollow transparent tube through the transparent tube positioning hole of the middle pad, and fit the lower end of the hollow transparent tube into the transparent tube positioning groove of the lower pad;

[0023] Step S3: After the tubular fiber membrane is fitted onto the core column, the core column is inserted into the hollow transparent tube, and the lower end of the core column is fixed through the core column positioning hole of the lower gasket; the core column positioning hole of the upper gasket is inserted downward from the upper end of the core column, and the upper gasket is placed into the annular gasket groove of the upper shelf;

[0024] Step S4: Inject hydrogel solution into the gel cavity through the injection port, perform cross-linking treatment, and obtain a membrane-hydrogel composite tubular tissue scaffold.

[0025] Step S5: The membrane-hydrogel composite tubular tissue scaffold is dried to obtain the membrane-aerogel composite tubular tissue scaffold.

[0026] Furthermore, the tubular fiber membrane is made of any one or more of polyvinyl alcohol, polytetrafluoroethylene, polylactic acid-glycolic acid copolymer, polycaprolactone, polylactide, polyacrylonitrile, polyetherimide, or polyvinylidene fluoride.

[0027] Furthermore, in step S1, the method for preparing the tubular fiber membrane includes any one of the following: traditional coating method, electrospinning method, meltblown spinning method, fiber weaving method, 3D printing method, thermally induced phase separation method, or self-assembly method.

[0028] Furthermore, in step S4, the hydrogel solution contains oxidized sodium alginate and / or GelMA.

[0029] Furthermore, in step S4, the crosslinking treatment is chemical crosslinking.

[0030] Furthermore, in step S5, the drying process includes any one of vacuum freeze drying, atmospheric pressure drying, and supercritical drying.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] (1) The present invention designs a mold for a membrane-aerogel composite tubular tissue engineering scaffold, wherein several pillars support the scaffold to make the scaffold stable; the positioning holes of the core column in the upper and lower pads fix the core column, and the positioning holes of the transparent tube in the middle pad and the positioning groove of the transparent tube in the lower pad fix the hollow transparent tube, so that the axis of the hollow transparent tube and the core column is stable and consistent; a gel cavity is formed between the outer wall of the core column and the inner wall of the hollow transparent tube, thereby making the axis of the tubular membrane and the tubular gel of the prepared membrane-aerogel tubular tissue engineering scaffold precisely matched, enhancing the adhesion and binding force between the membrane and the aerogel.

[0033] (2) In the preparation method provided by the present invention, the mold is first stably built and then the hydrogel is injected. This sequence effectively avoids the phenomenon that the axis cannot be aligned due to the rapid cross-linking of the hydrogel in the multilayer structure caused by injection and then assembly. Therefore, the preparation method of the membrane-aerogel composite tubular tissue engineering scaffold of the present invention can adapt to hydrogel matrices with different cross-linking methods, and can ensure accurate axis matching even in the case of rapid cross-linking.

[0034] (3) In the preparation method provided by the present invention, if it is necessary to finely adjust the thickness of the membrane-aerogel tubular scaffold, it is only necessary to select the pads of different positioning holes or positioning grooves and the corresponding hollow transparent tubes and core columns, without replacing the entire scaffold system, which makes it possible to achieve engineering and large-scale production.

[0035] (4) The tubular tissue engineering scaffold of the present invention is composed of an inner tubular fibrous membrane and an outer aerogel composite. The inner tubular fibrous membrane provides the necessary mechanical strength for the tubular tissue engineering scaffold, and at the same time, the small pore structure of the tubular fibrous membrane can effectively isolate the medium inside and outside the biological tubular structure and maintain normal physiological function. The outer aerogel has a larger pore structure, which provides a regenerative environment for cells. The two work together to enable the tubular tissue engineering scaffold of the present invention to have both mechanical properties and the ability to promote cell regeneration, thereby achieving the specific functions that can simulate natural tissues.

[0036] (5) In the preparation method provided by the present invention, the hydrogel is dried and converted into aerogel. After removing the moisture, the risk of microbial growth and material hydrolysis is reduced, and it can be stored for a longer period of time after sterilization. Attached Figure Description

[0037] Figure 1 This is an exploded view of the mold of Embodiment 1 of the present invention.

[0038] Figure 2 This is a schematic diagram of the structure of the gasket involved in the present invention; wherein, a represents the upper gasket, and a1, a2, and a3 represent the top, side, and bottom views of the upper gasket, respectively; b represents the middle gasket, and b1, b2, and b3 represent the top, side, and bottom views of the upper gasket, respectively; c represents the lower gasket, and c1, c2, and c3 represent the top, side, and bottom views of the upper gasket, respectively.

[0039] Figure 3 This is a photograph of the mold of Embodiment 1 of the present invention.

[0040] Figure 4 Photograph of the membrane-aerogel composite tubular tissue engineering scaffold product prepared according to the present invention.

[0041] Figure 5 This is a schematic diagram of the outer frame of the mold in Embodiment 2 of the present invention.

[0042] Explanation of reference numerals in the attached diagram:

[0043] Shelf 10, upper shelf 11, middle shelf 12, lower shelf 13, first tiered structure 14.

[0044] Pillar 20, First Pillar 21, Second Pillar 22, Third Pillar 23

[0045] Gasket 30, upper gasket 31, middle gasket 32, lower gasket 33, second stepped structure 34, first positioning hole 311, injection port 312, second positioning hole 321, third positioning hole 331, transparent tube positioning groove 332.

[0046] Core pillar 40,

[0047] Hollow transparent tube 50,

[0048] Gasket groove 60, upper gasket groove 61, middle gasket groove 62, lower gasket groove 63

[0049] Membrane-aerogel composite tubular tissue engineering scaffold 100, tubular fibrous membrane 101, tubular aerogel 102. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] As described in the background art, in order to solve the problems of unstable structure, inability to be preserved for a long time and inability to be mass-produced in existing tubular tissue engineering scaffolds, the present invention provides a mold for a membrane-aerogel composite tubular tissue engineering scaffold. The mold components are precisely matched and designed to ensure that the assembled mold structure is stable. Then, hydrogel solution is injected to ensure that the axis of the fiber membrane and the gel are aligned, thus ensuring that the membrane and the gel are tightly bonded.

[0054] Therefore, this invention designs a mold for a membrane-aerogel composite tubular tissue engineering scaffold, comprising several layers 10, several supports 20, several pads 30, a central core column 40, and a hollow transparent tube 50, wherein:

[0055] The support column 20 is vertically connected to the shelf 10 and is used to support the shelf 10.

[0056] The shelf 10 includes an upper shelf 11, a middle shelf 12, and a lower shelf 13. Each shelf 10 has at least one annular gasket groove 60 coaxially arranged. In some embodiments, the gasket 30 and the gasket groove 60 are respectively provided with an interlocking structure to achieve mutual fixation between the gasket 30 and the gasket groove 60.

[0057] The gasket 30 includes an upper gasket 31, a middle gasket 32, and a lower gasket 33. The upper gasket 31 has a central core positioning hole at its center, the middle gasket 32 ​​has a central transparent tube positioning hole at its center, and the lower gasket 33 has a central core positioning hole and a central transparent tube positioning groove 332 concentrically located at its center. The diameter of the central core positioning hole is smaller than the diameter of the central transparent tube positioning groove 332. The central core 40 is fixed by the central core positioning holes of the upper gasket 31 and the lower gasket 33, and the hollow transparent tube 50 is fixed by the central transparent tube positioning hole of the middle gasket 32 ​​and the central transparent tube positioning groove 332 of the lower gasket 33. A gel cavity is formed between the outer wall of the central core 40 and the inner wall of the hollow transparent tube 50. The upper gasket 31 also has an injection port 312, which communicates with the gel cavity for injecting a hydrogel solution.

[0058] The length of the central core 40 is greater than or equal to the height of the mold, the length of the hollow transparent tube 50 is less than or equal to the height of the mold, and greater than or equal to the height between the middle gasket 32 ​​and the lower gasket 33.

[0059] The present invention also provides a method for preparing a membrane-aerogel composite tubular tissue engineering scaffold using the above-mentioned mold. The membrane-aerogel composite tubular tissue engineering scaffold 100 includes an inner tubular fiber membrane 101 and an outer tubular aerogel 102. The aerogel is made by removing water from hydrogel, which makes it easier to preserve for a long time under sterile conditions.

[0060] The present invention will be specifically described below with reference to the embodiments.

[0061] Example 1

[0062] The preparation method of the membrane-aerogel composite tubular tissue engineering scaffold 100 includes the following steps:

[0063] Step S1: Provide mold components.

[0064] like Figure 1 As shown, the mold components include a shelf 10, support columns 20, gaskets 30, a central core column 40, and a hollow transparent tube 50. The shelf includes an upper shelf 11, a middle shelf 12, and a lower shelf 13; the support columns include a first support column 21, a second support column 22, and a third support column 23; and the gaskets 30 include an upper gasket 31, a middle gasket 32, and a lower gasket 33.

[0065] Specifically, the upper shelf 11, middle shelf 12, and lower shelf 13 are all annular. The outer and inner diameters of the upper shelf 11, middle shelf 12, and lower shelf 13 are the same, and the inner annular cavity in the upper shelf 11, middle shelf 12, and lower shelf 13 forms an annular gasket groove 60. Each gasket groove 60 has a first stepped structure 14 at its edge, with the step height gradually decreasing from the edge of the gasket groove 60 towards the center. The outer edges of the upper gasket 31, middle gasket 32, and lower gasket 33 have a second stepped structure 34 that matches the first stepped structure 14, with the step height gradually increasing from the edge of the gasket 30 towards the center. The first stepped structure 14 and the second stepped structure 34 can be locked together to fix the gasket 30 on the shelf 10.

[0066] The support column 20 is perpendicularly connected to the outer edge of the shelf 10 to support the shelf 10. Specifically, one end of the support column 20 is perpendicularly connected to the outer edge of the lower shelf 13, and the other end is perpendicularly connected to the outer edge of the upper shelf 11. The middle part of the support column 20 is perpendicularly connected to the outer edge of the middle shelf 12 to fix the position of the shelf 10. Preferably, the first support column 21, the second support column 22, and the third support column 23 are evenly spaced, which helps to ensure the structural stability of the mold.

[0067] like Figure 2 As shown, the upper gasket 31, the middle gasket 32, and the lower gasket 33 have the same outer diameter. Figure 2 As shown in Figure a, the upper gasket 31 has a first positioning hole 311 in its center; as Figure 2 As shown in b, the middle gasket 32 ​​has a second positioning hole 321 in the center; as Figure 2As shown in Figure c, the lower gasket has a third positioning hole 331 and a transparent tube positioning groove 332 at its center. The third positioning hole 331 is located at the center of the transparent tube positioning groove 332, and the inner diameter of the third positioning hole 331 is smaller than the diameter d1 of the transparent tube positioning groove 332. Both the first positioning hole 311 and the third positioning hole 331 are core post positioning holes, and their inner diameters are approximately equal to the outer diameter of the core post 40 (the inner diameter of the core post positioning hole is slightly larger than or equal to the outer diameter of the core post 40). The second positioning hole 321 is a transparent tube positioning hole, and its inner diameter is approximately equal to the outer diameter of the hollow transparent tube 50 (the inner diameter of the second positioning hole 321 is slightly larger than or equal to the outer diameter of the hollow transparent tube 50); the diameter d1 of the transparent tube positioning groove 332 is slightly larger than or equal to the outer diameter of the hollow transparent tube 50. The projection of the second positioning hole 321 on the longitudinal direction of the mold coincides with the transparent tube positioning groove 332; the projection of the first positioning hole 311 on the longitudinal direction of the mold is located at the center of the second positioning hole 321 and coincides with the third positioning hole 331.

[0068] The central core 40 can be fixed by the first positioning hole 311 of the upper gasket 31 and the third positioning hole 331 of the lower gasket 33, and the hollow transparent tube 50 can be fixed by the second positioning hole 321 of the middle gasket 32 ​​and the transparent tube positioning groove 332 of the lower gasket.

[0069] Therefore, the shelf 10 restricts the displacement of the pad 30, the support column 20 restricts the displacement of the shelf 10, the upper pad 31 and the lower pad 33 together restrict the displacement of the central core column 40, and the middle pad 32 and the lower pad 33 together restrict the displacement of the hollow transparent tube 50. Under the mutual restriction, according to the axis theory, the axes of the central core column 40 and the hollow transparent tube 50 can achieve precise matching.

[0070] See also Figure 1 Since the core pillar 40 is fixed by the upper gasket 31 and the lower gasket 33, and the hollow transparent tube 50 is fixed by the middle gasket 32 ​​and the lower gasket 33, the length of the core pillar 40 is greater than or equal to the height of the mold, and the length of the hollow transparent tube 50 is less than or equal to the height of the mold, but greater than or equal to the distance between the middle gasket 32 ​​and the lower gasket 33. The outer diameter of the core pillar 40 is smaller than the inner diameter of the hollow transparent tube 50; therefore, a gel cavity can be formed between the outer wall of the hollow transparent tube 50 and the inner wall of the core pillar 40 to accommodate the hydrogel solution.

[0071] See also Figure 2The upper pad 31 is further provided with an injection port 312 on its side. The injection port 312 communicates with the gel cavity, and the hydrogel solution is injected through the injection port 312. In this embodiment, the injection port 312 is a fan-shaped notch to expose the gel cavity, making it easy to insert the long needle of the syringe into the bottom of the gel cavity, so that the hydrogel solution is injected from the bottom to the top to expel the air in the gel cavity and avoid air bubbles affecting the uniform gelation of the hydrogel.

[0072] Step S2: Initial assembly of the mold.

[0073] The middle pad 32 and the lower pad 33 are respectively placed into the pad grooves 60 of the middle shelf 12 and the lower shelf 13 between any two of the pillars 20, ensuring that the first stepped structure 14 and the second stepped structure 34 are interlocked.

[0074] The hollow transparent tube 50 is inserted into the second positioning hole 321 of the middle gasket 32, and the lower end of the hollow transparent tube 50 is fitted into the transparent tube positioning groove 332 of the lower gasket 33.

[0075] Check whether the various mold components are properly matched. The mold is initially assembled and ready for use.

[0076] Step S3: Provide the tubular fiber membrane 101 to complete the mold assembly.

[0077] The tubular fiber membrane 101 can be prepared using traditional coating methods, electrospinning, meltblown spinning, fiber weaving, 3D printing, thermally induced phase separation, or self-assembly. Among these methods, electrospinning has the advantage of producing fiber membranes with high porosity and specific structures. Preferably, this embodiment uses electrospinning. The electrospinning method involves spraying a polymer solution under a high-voltage electrostatic field to form nanofibers or microfibers, which are then deposited onto a tubular support material to form the tubular fiber membrane 101. The polymer solution includes, but is not limited to, any one or more of polyvinyl alcohol, polytetrafluoroethylene, polylactic acid-glycolic acid copolymer, polycaprolactone, polylactide, polyurethane, polyacrylonitrile, polyetherimide, or polyvinylidene fluoride. In this embodiment, the tubular fiber membrane 101 is prepared according to reference (Bioact Mater. 2022 Mar 10; 16:433-450). The inner diameter of the tubular fiber membrane 101 is equal to the outer diameter of the central core 40. Cut a tubular fiber membrane 101 of appropriate length and fit it onto the core column 40 from top to bottom. The outer wall of the core column 40 abuts against and supports the inner wall of the tubular fiber membrane 101. This design can prevent the tubular aerogel 102 from expanding and squeezing the tubular fiber membrane 101 during the subsequent drying step, thereby preventing it from deforming.

[0078] The central core post 40 is inserted into the hollow transparent tube 50 from top to bottom, and the lower end of the central core post 40 is inserted into the third positioning hole 331 of the lower gasket 33.

[0079] Align the first positioning hole 311 of the upper gasket 31 with the upper end of the central core 40 and insert it from top to bottom, placing the upper gasket 31 into the gasket groove 60 of the upper frame 11. At this time, the upper gasket 31 and the lower gasket 33 together fix the position of the central core 40, ensuring that the axis of the central core 40 is accurately aligned with the axis of the hollow transparent tube 50. This completes the assembly of all mold components. Figure 3 This is a solid image of the mold after all parts are assembled (excluding the tubular fiber membrane 101).

[0080] Step S4: Prepare a membrane-hydrogel composite tubular tissue engineering scaffold.

[0081] A hydrogel solution is obtained by uniformly mixing two or more cross-linkable hydrogel matrices. In this embodiment, 60 mg / mL of oxidized sodium alginate and 100 mg / mL of gelatin methacryloyl (GelMA) are mixed at a volume ratio of 1:1 to obtain the hydrogel solution. A sufficient amount of the hydrogel solution is drawn up using a long-needle syringe, and the long needle of the syringe is inserted through the injection port 312 of the upper pad 31 into the bottom of the gel cavity between the tubular fiber membrane 101 and the hollow transparent tube 50, and the hydrogel solution is rapidly injected. Both oxidized sodium alginate and GelMA possess good biocompatibility and bioactivity, which are beneficial for tissue regeneration and repair. Furthermore, oxidized sodium alginate contains aldehyde groups, and GelMA contains amino groups; the two can be chemically cross-linked through a Schiff base reaction to form a stable hydrogel network.

[0082] In this embodiment, the hydrogel solution of oxidized sodium alginate and GelMA is solidified by a static (chemical cross-linking) method. The static (chemical cross-linking) method is as follows: stand for 10 minutes to allow the oxidized sodium alginate and GelMA to undergo chemical cross-linking through a Schiff base reaction to form a hydrogel, thereby obtaining a membrane-hydrogel composite tubular tissue engineering scaffold.

[0083] Step S5: Prepare membrane-aerogel composite tubular tissue engineering scaffold 100.

[0084] The membrane-hydrogel composite tubular tissue scaffold is dried to obtain a membrane-aerogel composite tubular tissue scaffold. The drying process includes any one of vacuum freeze-drying, atmospheric pressure drying, and supercritical drying.

[0085] In this embodiment, the membrane-hydrogel composite tubular tissue engineering scaffold and mold are frozen overnight in a refrigerator at -20°C or below to perform preliminary freezing of the membrane-hydrogel composite tubular tissue engineering scaffold. The next day, the hollow transparent tube 50, the core column 40, and the membrane-hydrogel composite tubular tissue engineering scaffold are taken out together and placed in a freeze dryer (LC-10N-50A, Shanghai Lichen Bangxi Instrument Technology Co., Ltd.) for freeze-drying for more than 48 hours to obtain the membrane-aerogel composite tubular tissue engineering scaffold 100.

[0086] The freezing and drying steps serve several purposes: First, low-temperature freezing causes the water in the membrane-hydrogel composite tubular tissue engineering scaffold to form ice crystals. Since the volume of ice crystals is larger than that of liquid water of the same mass, the pores of the aerogel formed by the hydrogel are larger, which is more conducive to cell growth and promotes wound healing and tissue repair. Second, low-temperature freezing first prevents the liquid in the hydrogel from boiling violently under the negative pressure environment of direct freeze-drying, which would damage the structure. Third, during the freeze-drying process, the water in the hydrogel sublimates directly after forming ice crystals, which helps to preserve the morphological characteristics of the composite tubular tissue engineering scaffold.

[0087] The membrane-aerogel composite tubular tissue engineering scaffold 100 undergoes freeze-drying to remove moisture, thus avoiding structural collapse caused by water evaporation, a common issue with traditional hydrogel structures. Furthermore, a dry environment inhibits microbial growth and material degradation, allowing the membrane-aerogel composite tubular tissue engineering scaffold 100 to be stored long-term under sterile conditions.

[0088] Figure 4 This image shows a product of a bilayer membrane-aerogel composite tubular tissue engineering scaffold 100 prepared by the method of the present invention. The inner layer of the membrane-aerogel composite tubular tissue engineering scaffold 100 is a tubular fiber membrane 101, and the outer layer is a tubular aerogel 102. The inner diameter of the membrane-aerogel composite tubular tissue engineering scaffold 100 is equal to the outer diameter of the core column 40, and the thickness of the membrane-aerogel composite tubular tissue engineering scaffold 100 is equal to the difference between the inner radius of the hollow transparent tube 50 and the outer radius of the core column 40.

[0089] In this invention, if the thickness of the membrane-aerogel composite tubular scaffold 100 needs to be finely adjusted, only gaskets 30 with different positioning holes and corresponding hollow transparent tubes 50 and core columns 40 need to be selected, without replacing the entire mold system. This invention can be used to prepare tubular tissue engineering scaffolds of single-layer, double-layer, or multi-layer hydrogels, aerogels, membrane-hydrogels, or membrane-aerogels by fabricating several hollow transparent tubes 50, core columns 40, and corresponding gaskets 30 with different outer diameters.

[0090] Example 2

[0091] The difference between this embodiment and Embodiment 1 is that, as Figure 5 As shown, in this embodiment, the three shelves 10 of the mold are all rectangular. Each shelf 10 has three annular gasket grooves 60, which are evenly distributed laterally. The outer diameter of the gasket groove 60 is equal to the outer diameter of the gasket 30, for accurate placement of the gasket 30. The upper shelf 11 has three upper gasket grooves 61, the middle shelf 12 has three corresponding middle gasket grooves 62, and the lower shelf 13 has three corresponding lower gasket grooves 63. The upper gasket grooves 61, middle gasket grooves 62, and lower gasket grooves 63 are longitudinally aligned with each other, forming three rows of gasket grooves 60 in the entire mold.

[0092] In this embodiment, four support pillars 20 are included. The four support pillars 20 are located at the four right angles of the rectangular structure of the shelf 10. Each support pillar 20 is perpendicularly connected to the upper shelf 11, the middle shelf 12 and the lower shelf 13 to provide support for the mold and make the mold structure stable.

[0093] Therefore, this embodiment can simultaneously fabricate three of the membrane-aerogel composite tubular tissue engineering scaffolds 100. Furthermore, by increasing the area of ​​the scaffold 10 and providing multiple gasket grooves 60, the simultaneous fabrication of multiple membrane-aerogel composite tubular tissue engineering scaffolds 100 can be achieved.

[0094] In summary, the tubular tissue engineering scaffold mold of this invention, through precise design and a strategy of assembling the mold before injecting the hydrogel, ensures accurate matching of the membrane and gel axes, enhances bonding strength, and is suitable for various hydrogel curing methods. The composite design of the inner tubular fibrous membrane and the outer tubular aerogel achieves the dual advantages of mechanical strength and a cell regeneration environment, promoting tissue repair and mimicking natural tissue functions. The aerogel, forming a large-pore structure, further promotes cell growth and reduces microbial risk, enabling long-term preservation. Furthermore, this invention can prepare membrane-aerogel composite tubular tissue engineering scaffolds of different thicknesses and numbers of layers, and can also simultaneously prepare multiple membrane-aerogel composite tubular tissue engineering scaffolds, simplifying the engineering and large-scale production process and significantly enhancing its application potential in the biomedical field.

[0095] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A mold for a membrane-aerogel composite tubular tissue engineering scaffold, characterized in that, It comprises several shelves, several pillars, several gaskets, a central core, and a hollow transparent tube, among which, The support column is vertically connected to the shelf and is used to support the shelf; The shelf includes an upper shelf, a middle shelf, and a lower shelf; each shelf has at least one annular gasket groove coaxially provided for fixing the gasket. The gasket includes an upper gasket, a middle gasket, and a lower gasket. The upper gasket has a central core positioning hole, the middle gasket has a central transparent tube positioning hole, and the lower gasket has a central core positioning hole and a central transparent tube positioning groove concentrically located at its center. The diameter of the central core positioning hole is smaller than the diameter of the central transparent tube positioning groove. The central core is fixed by the central core positioning holes of the upper and lower gaskets. The hollow transparent tube is fixed by the central transparent tube positioning holes of the middle and lower gaskets. A gel cavity is formed between the outer wall of the central core and the inner wall of the hollow transparent tube. The upper gasket also has an injection port communicating with the gel cavity for injecting a hydrogel solution. The length of the central core column is greater than or equal to the height of the mold, the length of the hollow transparent tube is less than or equal to the height of the mold, and greater than or equal to the height between the middle gasket and the lower gasket.

2. The mold as described in claim 1, characterized in that, The support column comprises at least three columns, which are used to stably support the shelf.

3. The mold as described in claim 1, characterized in that, The edge of the annular gasket groove is provided with a first stepped structure, the step height of which gradually decreases from the edge of the annular gasket groove toward the center; the edge of the gasket is provided with a second stepped structure, the step height of which gradually increases from the edge of the gasket toward the center; the first stepped structure and the second stepped structure are interlocked with each other.

4. The mold as described in claim 1, characterized in that, The injection port has a fan-shaped notch, through which the long needle of the syringe can be inserted into the bottom of the gel cavity.

5. A method for preparing a membrane-aerogel composite tubular tissue engineering scaffold using a mold as described in any one of claims 1-4, characterized in that, include: Step S1: Provide a tubular fiber membrane; Step S2: Assemble the mold, place the lower pad into the annular pad groove of the lower shelf, place the middle pad into the annular pad groove of the middle shelf, insert the hollow transparent tube, fix the upper end of the hollow transparent tube through the transparent tube positioning hole of the middle pad, and fit the lower end of the hollow transparent tube into the transparent tube positioning groove of the lower pad; Step S3: After the tubular fiber membrane is fitted onto the core column, the core column is inserted into the hollow transparent tube, and the lower end of the core column is fixed through the core column positioning hole of the lower gasket; the core column positioning hole of the upper gasket is inserted downward from the upper end of the core column, and the upper gasket is placed into the annular gasket groove of the upper shelf; Step S4: Inject hydrogel solution into the gel cavity through the injection port, perform cross-linking treatment, and obtain a membrane-hydrogel composite tubular tissue scaffold. Step S5: The membrane-hydrogel composite tubular tissue scaffold is dried to obtain the membrane-aerogel composite tubular tissue scaffold.

6. The preparation method according to claim 5, characterized in that, The tubular fiber membrane is made of any one or more of the following materials: polyvinyl alcohol, polytetrafluoroethylene, polylactic acid-glycolic acid copolymer, polycaprolactone, polylactide, polyacrylonitrile, polyetherimide, or polyvinylidene fluoride.

7. The preparation method according to claim 5, characterized in that, In step S1, the method for preparing the tubular fiber membrane includes any one of the following: traditional coating method, electrospinning method, meltblown spinning method, fiber weaving method, 3D printing method, thermally induced phase separation method, or self-assembly method.

8. The preparation method according to claim 5, characterized in that, In step S4, the hydrogel solution contains sodium oxidized alginate and / or GelMA.

9. The preparation method according to claim 8, characterized in that, In step S4, the crosslinking treatment is chemical crosslinking.

10. The preparation method according to claim 5, characterized in that, In step S5, the drying process includes any one of vacuum freeze drying, atmospheric pressure drying, and supercritical drying.

Images