Mold of membrane-aerogel composite tubular tissue engineering scaffold and preparation method of membrane-aerogel composite tubular tissue engineering scaffold

Abstract

The invention discloses a membrane-aerogel composite tubular tissue engineering scaffold mold and a preparation method thereof, the membrane-aerogel composite tubular tissue engineering scaffold mold comprises a plurality of shelves, a plurality of struts, a plurality of gaskets, a middle core column and a hollow transparent tube, the struts are used for supporting the shelves; at least one annular gasket groove is coaxially formed in each layer of shelf and is used for fixing the gasket; the middle core column is fixed through the middle core column positioning holes of the upper gasket and the lower gasket; and the hollow transparent tube is fixed through the transparent tube positioning hole of the middle gasket and the transparent tube positioning groove of the lower gasket. The invention further discloses a preparation method of the membrane-aerogel composite tubular tissue engineering scaffold, the mold is adopted, accurate axis matching of the inner-layer tubular fiber membrane and the outer-layer tubular aerogel is achieved, and therefore the stability and integrity of the overall structure are guaranteed, and long-term storage is facilitated.

Description

Technical Field

[0001] The invention relates to the field of tissue engineering scaffolds, and in particular to a mold of a membrane-aerogel composite tubular tissue engineering scaffold and a preparation method thereof. Background Art

[0002] Tubular tissues, such as ureters, blood vessels, intestines, and trachea, are widely present in mammals. When these tubular tissues are damaged or diseased, they usually require replacement therapy using autologous tissue, donor tissue, or artificial prosthesis. However, there may be collateral damage when obtaining autologous tissue, and the source of donor tissue is limited. There may also be immune rejection problems, all of which limit the development of tissue transplantation technology. The advantages of artificial catheter prostheses for replacement or repair therapy include ready-to-use, short operation time, low risk of infection, strong controllability, and low cost. Even if tubular artificial prostheses made of fiber membranes can meet the requirements in terms of mechanical properties, they are often difficult to simulate the complex multilayer structure of natural tissues due to the simple structure constructed by fiber membranes, which may lead to postoperative dysfunction and poor regeneration. The special morphology of tubular tissues and the different types of cells and their distribution are its important characteristics, which are crucial for the function and regeneration of tissues.

[0003] The ideal tubular structure replacement material needs to have sufficient mechanical properties to withstand the stress that may be applied during surgery and adjacent tissues. In addition, the material should have the ability to promote cell proliferation and differentiation and regulate the release of growth factors to meet the functional requirements of natural tissues.

[0004] In recent years, many studies have been devoted to the reconstruction and repair of damaged tissues using biomaterials and artificial implants. Synthetic materials such as polycaprolactone (PCL), polyurethane (PU), polyacetic acid (PLA), and natural materials such as sodium alginate, gelatin, chitosan hyaluronic acid, have been used in the reconstruction of tubular tissues such as ureters and blood vessels. Electrospinning technology has also been widely used in the preparation of tubular fiber membranes. Hydrogels also show great potential in tissue engineering due to their good biocompatibility and water retention. However, it is still a technical challenge to combine membranes and hydrogels to prepare long tubular tissue engineering scaffolds with uniform hydrogel thickness. The key lies in ensuring the consistency of the axes of the tubular fiber membranes and tubular hydrogels in three-dimensional space.

[0005] CN112999425B discloses a double-layer hydrogel tubular tissue engineering scaffold and a preparation method thereof, but the idea of ​​this preparation process is to pre-fill the hydrogel matrix, then assemble the two end molds to align the axis of the double-layer hydrogel, and then cross-link the hydrogel by photocrosslinking. The above device and method have the following shortcomings:

[0006] (1) For two hydrogel matrices that are rapidly chemically cross-linked after mixing, gelation can be achieved within seconds. In this case, the hydrogel has already been cross-linked before the mold is assembled, which can easily cause the axis of the double-layer hydrogel to be inconsistent, thereby weakening the bonding force between the hydrogels and affecting the stability and integrity of the overall structure.

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

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

[0009] (4) When manufacturing tubular structures with a smaller diameter, the center of gravity of the device may be unstable and the axis alignment may be inaccurate.

[0010] (5) The tubular structure prepared using hydrogel cannot be preserved for a long time due to its water content, as the water evaporates easily, which limits its engineering and large-scale production. Summary of the invention

[0011] In order to overcome at least one of the shortcomings of the above-mentioned prior art, the purpose of the present invention is to design a mold for a membrane-aerogel tubular tissue engineering scaffold so that the tubular tissue engineering scaffold can meet the requirements of mechanical properties and multifunctionality while also meeting the consistency of the axes of the multi-layer structure in three-dimensional space to ensure the stability of the bonding force between the multi-layer structures, thereby ensuring the stability and integrity of the overall structure of the tubular tissue engineering scaffold and facilitating long-term storage.

[0012] In order to achieve the above-mentioned object, the present invention provides a mold of a membrane-aerogel composite tubular tissue engineering scaffold, comprising a plurality of layers, a plurality of pillars, a plurality of gaskets, a central core column and a hollow transparent tube, wherein:

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

[0014] The shelf comprises an upper shelf, a middle shelf and a lower shelf; at least one annular gasket groove is coaxially arranged in each shelf for fixing the gasket;

[0015] The gasket comprises an upper gasket, a middle gasket and a lower gasket; a central core column positioning hole is provided at the center of the upper gasket, a transparent tube positioning hole is provided at the center of the middle gasket, a central core column positioning hole and a transparent tube positioning groove are provided cocentrically at the center of the lower gasket, and the diameter of the central core column positioning hole is smaller than the diameter of the transparent tube positioning groove; the central core column is fixed by the central core column positioning holes of the upper gasket and the lower gasket; the hollow transparent tube is fixed by the transparent tube positioning hole of the middle gasket and the transparent tube positioning groove of the lower gasket; a gel cavity is formed between the outer wall of the central core column and the inner wall of the hollow transparent tube; the upper gasket is also provided with an injection port, which is connected to the gel cavity and is used to inject a hydrogel solution;

[0016] The length of the central core column is greater than 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.

[0017] Furthermore, the pillars include at least three pillars for stably supporting the shelf.

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

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

[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, providing a tubular fiber membrane;

[0022] Step S2, assembling the mold, placing the lower gasket into the annular gasket groove of the lower frame, placing the middle gasket into the annular gasket groove of the middle frame, inserting the hollow transparent tube, the upper end of the hollow transparent tube is fixed through the transparent tube positioning hole of the middle gasket, and the lower end of the hollow transparent tube is engaged with the transparent tube positioning groove of the lower gasket;

[0023] Step S3, after the tubular fiber membrane is sleeved on the central column, the central column is inserted into the hollow transparent tube, and the lower end of the central column is fixed through the central column positioning hole of the lower gasket; the central column positioning hole of the upper gasket is penetrated downward from the upper end of the central column, and the upper gasket is placed in the annular gasket groove of the upper frame;

[0024] Step S4, injecting a hydrogel solution into the gel cavity through the injection port, and cross-linking the solution to obtain a membrane-hydrogel composite tubular tissue scaffold;

[0025] Step S5, drying the membrane-hydrogel composite tubular tissue scaffold to obtain a membrane-aerogel composite tubular tissue scaffold.

[0026] Furthermore, the material of the tubular fiber membrane is 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 preparation method of the tubular fiber membrane comprises any one of a traditional coating method, an electrospinning method, a melt-blowing method, a fiber weaving method, a 3D printing method, a thermally induced phase separation method or a self-assembly method.

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

[0029] Furthermore, in step S4, the cross-linking treatment is chemical cross-linking.

[0030] Furthermore, in step S5, the drying process includes any one of vacuum freeze drying, normal 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 a plurality of pillars support the frame to stabilize the scaffold; the central core column positioning holes in the upper gasket and the lower gasket fix the central core column, and the transparent tube positioning holes in the middle gasket and the transparent tube positioning grooves in the lower gasket fix the hollow transparent tube, so that the axes of the hollow transparent tube and the central core column are stable and consistent; a gel cavity is formed between the outer wall of the central core column and the inner wall of the hollow transparent tube, so that the axes of the tubular membrane and the tubular gel of the prepared membrane-aerogel tubular tissue engineering scaffold are precisely matched, thereby enhancing the adhesion and bonding 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 order effectively avoids the phenomenon that the axis cannot be aligned in the multilayer structure due to the rapid cross-linking of the hydrogel caused by injection first 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 precise matching of the axis even in the case of rapid cross-linking.

[0034] (3) In the preparation method provided by the present invention, if the thickness of the membrane-aerogel tubular support needs to be fine-tuned, it is only necessary to select gaskets with different positioning holes or positioning grooves and corresponding types of hollow transparent tubes and core columns, without replacing the entire support system, thereby making it possible to realize engineering and large-scale production.

[0035] (4) The tubular tissue engineering scaffold of the present invention is a composite of an inner layer of tubular fiber membrane and an outer layer of aerogel. The inner layer of tubular fiber membrane provides the necessary mechanical strength for the tubular tissue engineering scaffold. At the same time, the smaller pore structure of the tubular fiber membrane can effectively isolate the medium inside and outside the biological tubular structure to maintain normal physiological functions; the larger pore structure of the outer layer of aerogel provides a regeneration environment for cells. The synergy of the two makes the tubular tissue engineering scaffold of the present invention have the ability to promote cell regeneration while having mechanical properties, thereby achieving specific functionality that can simulate natural tissues.

[0036] (5) In the preparation method provided by the present invention, the hydrogel is dried and converted into aerogel, and the risk of microbial growth and material hydrolysis is reduced after removing the moisture, and the aerogel can be stored for a long time after sterilization. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0040] Figure 4 This is a product photo of the membrane-aerogel composite tubular tissue engineering scaffold prepared by the present invention.

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

[0042] Description of the accompanying drawings:

[0043] Shelf 10, upper shelf 11, middle shelf 12, lower shelf 13, first stepped 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] Central column 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 fiber membrane 101, tubular aerogel 102. DETAILED DESCRIPTION

[0050] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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

[0054] To this end, the present invention designs a mold of a membrane-aerogel composite tubular tissue engineering scaffold, comprising a plurality of layers 10, a plurality of pillars 20, a plurality of gaskets 30, a core column 40 and a hollow transparent tube 50, wherein:

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

[0056] The shelf 10 includes an upper shelf 11, a middle shelf 12, and a lower shelf 13. At least one annular gasket groove 60 is coaxially provided in each shelf 10. In some embodiments, the gasket 30 and the gasket groove 60 are correspondingly provided with a fitting 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 is provided with a central core column positioning hole at the center, the middle gasket 32 ​​is provided with a transparent tube positioning hole at the center, the lower gasket 33 is provided with a central core column positioning hole and a transparent tube positioning groove 332 at the same center, and the diameter of the central core column positioning hole is smaller than the diameter of the transparent tube positioning groove 332. The central core column 40 is fixed by the central core column positioning holes of the upper gasket 31 and the lower gasket 33, and the hollow transparent tube 50 is fixed by the transparent tube positioning hole of the middle gasket 32 ​​and the transparent tube positioning groove 332 of the lower gasket 33. A gel cavity is formed between the outer wall of the central core column 40 and the inner wall of the hollow transparent tube 50. The upper gasket 31 is also provided with an injection port 312, which is connected to the gel cavity and is used to inject a hydrogel solution.

[0058] The length of the central core column 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. After the aerogel is made of hydrogel and the moisture is removed, it is easier to store for a long time in a sterilized environment.

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

[0061] Example 1

[0062] The method for preparing the membrane-aerogel composite tubular tissue engineering scaffold 100 comprises the following steps:

[0063] Step S1, providing a mold component.

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

[0065] Specifically, the upper frame 11, the middle frame 12, and the lower frame 13 are all annular. The outer diameter and the inner diameter of the upper frame 11, the middle frame 12, and the lower frame 13 are the same, and the inner ring holes in the upper frame 11, the middle frame 12, and the lower frame 13 form an annular gasket groove 60. The edges of the gasket groove 60 are all provided with a first stepped structure 14, and the first stepped structure 14 gradually decreases in step height from the edge of the gasket groove 60 toward the center of the circle. The outer edges of the upper gasket 31, the middle gasket 32, and the lower gasket 33 are provided with a second stepped structure 34 matching the first stepped structure 14, and the second stepped structure 34 gradually increases in step height from the edge of the gasket 30 toward the center of the circle. The first stepped structure 14 and the second stepped structure 34 can be locked with each other to fix the gasket 30 on the shelf 10.

[0066] The support 20 is vertically connected to the outer edge of the shelf 10 to support the shelf 10. Specifically, one end of the support 20 is vertically connected to the outer edge of the lower shelf 13, and the other end is vertically connected to the outer edge of the upper shelf 11. The middle of the support 20 is vertically connected to the outer edge of the middle shelf 12 to fix the position of the shelf 10. Preferably, the first support 21, the second support 22, and the third support 23 are arranged at equal intervals, which is conducive to ensuring the structural stability of the mold.

[0067] like Figure 2 As shown, the outer diameters of the upper gasket 31, the middle gasket 32 ​​and the lower gasket 33 are the same. Figure 2 As shown in a, the center of the upper gasket 31 is provided with a first positioning hole 311; Figure 2 As shown in b, a second positioning hole 321 is provided in the center of the middle gasket 32; Figure 2As shown in c, the center of the lower gasket is cocentrically provided with a third positioning hole 331 and a transparent tube positioning groove 332. 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. The first positioning hole 311 and the third positioning hole 331 are both central column positioning holes, and the inner diameters of the first positioning hole 311 and the third positioning hole 331 are both equivalent to the outer diameter of the central column 40 (the inner diameter of the central column positioning hole is slightly larger than or equal to the outer diameter of the central column 40). The second positioning hole 321 is a transparent tube positioning hole, and the inner diameter of the second positioning hole 321 is equivalent 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 in the longitudinal direction of the mold coincides with the transparent tube positioning groove 332 ; the projection of the first positioning hole 311 in 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 column 40 can be fixed through 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 through the second positioning hole 321 of the central gasket 32 ​​and the transparent tube positioning groove 332 of the lower gasket.

[0069] Therefore, the shelf 10 limits the displacement of the gasket 30, the pillar 20 limits the displacement of the shelf 10, the upper gasket 31 and the lower gasket 33 together limit the displacement of the core column 40, and the middle gasket 32 ​​and the lower gasket 33 together limit the displacement of the hollow transparent tube 50. Under the action of mutual restriction, according to the axis theory, the axes of the core column 40 and the hollow transparent tube 50 can be precisely matched.

[0070] Continue to see Figure 1 Since the core column 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 column 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 column 40 is smaller than the inner diameter of the hollow transparent tube 50, so a gel cavity can be formed between the outer wall of the hollow transparent tube 50 and the inner wall of the core column 40 for accommodating the hydrogel solution.

[0071] Continue to see Figure 2The side of the upper gasket 31 is also provided with an injection port 312, which is connected to 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, which is used to expose the gel cavity, so that the long needle of the syringe can be inserted into the bottom of the gel cavity, so that the hydrogel solution can be injected upward from the bottom to empty the air in the gel cavity, so as to prevent bubbles from affecting the uniform gelation of the hydrogel.

[0072] Step S2, preliminary assembly of the mold.

[0073] The middle gasket 32 ​​and the lower gasket 33 are respectively placed into the gasket grooves 60 of the middle frame 12 and the lower frame 13 between any two of the pillars 20 to ensure 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 engaged with the transparent tube positioning groove 332 of the lower gasket 33 .

[0075] Check whether the mold parts are properly matched. The mold is preliminarily assembled and ready for use.

[0076] Step S3, providing a tubular fiber membrane 101 and completing mold assembly.

[0077] The tubular fiber membrane 101 can be prepared by conventional coating method, electrostatic spinning method, melt-blown spinning method, fiber weaving method, 3D printing method, thermal phase separation method or self-assembly method, among which the electrostatic spinning method has the advantage of being able to produce a fiber membrane with high porosity and specific structure. Preferably, the present embodiment adopts electrostatic spinning method. The electrostatic spinning method is: under a high-voltage electrostatic field, a polymer solution is sprayed to form nano or micro fibers, which are then deposited on a tubular support material to form a tubular fiber membrane 101. The polymer solution includes but is not limited to any one or more of polyvinyl alcohol, polytetrafluoroethylene, polylactic acid-co-glycolic acid copolymer, polycaprolactone, polylactide, polyurethane, polyacrylonitrile, polyetherimide or polyvinylidene fluoride. In this embodiment, the tubular fiber membrane 101 is prepared by reference (Bioact Mater. 2022Mar10; 16: 433-450). The inner diameter of the tubular fiber membrane 101 is equal to the outer diameter of the core column 40. Cut a tubular fiber membrane 101 of appropriate length and put the tubular fiber membrane 101 on the central core column 40 from top to bottom. The outer wall of the central core column 40 contacts 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, thereby causing its deformation, during the subsequent drying step.

[0078] The central core column 40 is inserted into the hollow transparent tube 50 from top to bottom, and the lower end of the central core column 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 column 40 and insert the upper gasket 31 from top to bottom, and place 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 fix the position of the central core column 40 together, so that the axis of the central core column 40 is accurately consistent with the axis of the hollow transparent tube 50, and the assembly of all mold components is completed. Figure 3 It is a physical diagram after the mold is fully assembled (excluding the tubular fiber membrane 101).

[0080] Step S4, preparing a membrane-hydrogel composite tubular tissue engineering scaffold.

[0081] After two or more mutually cross-linkable hydrogel matrices are mixed evenly, a hydrogel solution is obtained. In this embodiment, 60 mg / mL of oxidized sodium alginate and 100 mg / mL of methacryloyl gelatin (Gelatin Methacryloyl, GelMA) are used and mixed in a volume ratio of 1:1 to obtain a hydrogel solution. Use a long needle syringe to absorb a sufficient amount of the hydrogel solution, extend the long needle of the syringe from the injection port 312 of the upper gasket 31 into the bottom of the gel cavity between the tubular fiber membrane 101 and the hollow transparent tube 50, and quickly inject the hydrogel solution. The oxidized sodium alginate and GelMA both have good biocompatibility and biological activity, which are beneficial to tissue regeneration and repair, and the oxidized sodium alginate contains aldehyde groups and the GelMA contains amino groups. The two can be chemically cross-linked through the Schiff base reaction to form a stable hydrogel network.

[0082] In this embodiment, the solidification of the hydrogel solution of oxidized sodium alginate and GelMA is achieved by standing still (chemical crosslinking). The standing still (chemical crosslinking) method is: standing still for 10 minutes, so that the oxidized sodium alginate and GelMA are chemically crosslinked through the Schiff base reaction to form a hydrogel, and a membrane-hydrogel composite tubular tissue engineering scaffold is obtained.

[0083] Step S5, preparing a membrane-aerogel composite tubular tissue engineering scaffold 100.

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

[0085] In this embodiment, the membrane-hydrogel composite tubular tissue engineering scaffold and the mold are placed in a refrigerator below -20°C and frozen overnight 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.), and fully freeze-dried for more than 48 hours to obtain a membrane-aerogel composite tubular tissue engineering scaffold 100.

[0086] The functions of the freezing and drying steps include: 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 the growth of cells entering the aerogel, thereby promoting wound healing and tissue repair; second, low-temperature freezing is performed first to prevent the liquid in the hydrogel from boiling violently under the negative pressure environment of direct freeze drying, thereby preventing the structure from being destroyed; third, during the freeze-drying process, the water in the hydrogel directly sublimates after forming ice crystals, which is conducive to retaining the morphological characteristics of the composite tubular tissue engineering scaffold.

[0087] The membrane-aerogel composite tubular tissue engineering scaffold 100 is freeze-dried to remove moisture, and the structure collapse caused by water evaporation that occurs in traditional hydrogel structures will not occur. In addition, a dry environment is not conducive to the growth of microorganisms and is not conducive to material degradation, so the membrane-aerogel composite tubular tissue engineering scaffold 100 can be stored for a long time in a sterilized environment.

[0088] Figure 4 The product diagram of the double-layer membrane-aerogel composite tubular tissue engineering scaffold 100 prepared by the preparation method of the present invention is shown in FIG. 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 the present invention, if the thickness of the membrane-aerogel composite tubular scaffold 100 needs to be fine-tuned, it is only necessary to select a gasket 30 with different positioning holes and a corresponding type of hollow transparent tube 50 and core column 40, without replacing the entire mold system. The present invention can also be used for the preparation of a single-layer, double-layer or multi-layer hydrogel, aerogel, membrane-hydrogel or membrane-aerogel tubular tissue engineering scaffold by making a plurality of 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 Figure 5 As shown, the three layers 10 of the mold designed in this embodiment are all rectangular, and each of the layers 10 is provided with three annular gasket grooves 60, which are evenly distributed in the transverse direction. The outer diameter of the gasket groove 60 is equal to the outer diameter of the gasket 30, which is used to accurately place the gasket 30. The upper layer frame 11 is provided with three upper gasket grooves 61, the middle layer frame 12 is correspondingly provided with three middle gasket grooves 62, and the lower layer frame 13 is correspondingly provided with three lower gasket grooves 63. The upper gasket grooves 61, the middle gasket grooves 62 and the lower gasket grooves 63 are longitudinally aligned with each other, and three rows of gasket grooves 60 are formed in the entire mold.

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

[0093] Therefore, this embodiment can simultaneously prepare three membrane-aerogel composite tubular tissue engineering scaffolds 100. In addition, by expanding the area of ​​the layer frame 10 and providing multiple gasket grooves 60, it is possible to simultaneously prepare multiple membrane-aerogel composite tubular tissue engineering scaffolds 100.

[0094] In summary, the tubular tissue engineering scaffold mold of the present invention is precisely designed, and adopts the strategy of assembling the mold first and then injecting the hydrogel, which ensures the precise matching of the membrane and gel axis, enhances the bonding force, and is suitable for a variety of hydrogel curing methods. Through the composite design of the inner layer of tubular fiber membrane and the outer layer of tubular aerogel, the dual advantages of mechanical strength and cell regeneration environment are achieved, promoting tissue repair and simulating natural tissue functions. By forming a large-pore structure aerogel, cell growth is further promoted and microbial risks are reduced, achieving long-term preservation. In addition, the present invention can realize the preparation of membrane-aerogel composite tubular tissue engineering scaffolds of different thicknesses and different numbers of layers, and can also realize the simultaneous preparation of multiple membrane-aerogel composite tubular tissue engineering scaffolds, simplifying the engineering and large-scale production process, and significantly improving its application potential in the biomedical field.

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

Claims

1. A mold for a membrane-aerogel composite tubular tissue engineering scaffold, characterized in that: It includes several layers, several pillars, several gaskets, a central column and a hollow transparent tube, wherein: The pillar is vertically connected to the shelf and is used to support the shelf; The shelf comprises an upper shelf, a middle shelf and a lower shelf; at least one annular gasket groove is coaxially arranged in each shelf for fixing the gasket; The gasket comprises an upper gasket, a middle gasket and a lower gasket; a central core column positioning hole is provided at the center of the upper gasket, a transparent tube positioning hole is provided at the center of the middle gasket, a central core column positioning hole and a transparent tube positioning groove are provided cocentrically at the center of the lower gasket, and the diameter of the central core column positioning hole is smaller than the diameter of the transparent tube positioning groove; the central core column is fixed by the central core column positioning holes of the upper gasket and the lower gasket; the hollow transparent tube is fixed by the transparent tube positioning hole of the middle gasket and the transparent tube positioning groove of the lower gasket; a gel cavity is formed between the outer wall of the central core column and the inner wall of the hollow transparent tube; the upper gasket is also provided with an injection port, which is connected to the gel cavity and is used to inject 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 according to claim 1, characterized in that The support pillars include at least three pillars for stably supporting the shelf.

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

4. The mold according to claim 1, characterized in that The injection port is a fan-shaped notch, and the long needle of the syringe can extend into the bottom of the gel cavity through the injection port.

5. A method for preparing a membrane-aerogel composite tubular tissue engineering scaffold using the mold as described in any one of claims 1 to 4, characterized in that: include: Step S1, providing a tubular fiber membrane; Step S2, assembling the mold, placing the lower gasket into the annular gasket groove of the lower frame, placing the middle gasket into the annular gasket groove of the middle frame, inserting the hollow transparent tube, the upper end of the hollow transparent tube is fixed through the transparent tube positioning hole of the middle gasket, and the lower end of the hollow transparent tube is engaged with the transparent tube positioning groove of the lower gasket; Step S3, after the tubular fiber membrane is sleeved on the central column, the central column is inserted into the hollow transparent tube, and the lower end of the central column is fixed through the central column positioning hole of the lower gasket; the central column positioning hole of the upper gasket is penetrated downward from the upper end of the central column, and the upper gasket is placed in the annular gasket groove of the upper frame; Step S4, injecting a hydrogel solution into the gel cavity through the injection port, and cross-linking the solution to obtain a membrane-hydrogel composite tubular tissue scaffold; Step S5, drying the membrane-hydrogel composite tubular tissue scaffold to obtain a membrane-aerogel composite tubular tissue scaffold.

6. The preparation method according to claim 5, characterized in that: The material of the tubular fiber membrane is any one or more of 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 the step S1, the preparation method of the tubular fiber membrane includes any one of a traditional coating method, an electrospinning method, a melt-blowing method, a fiber weaving method, a 3D printing method, a thermally induced phase separation method or a self-assembly method.

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

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

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

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