E7 peptide grafted methacrylamide karaya harlequin tree hydrogel scaffold and preparation method thereof

Abstract

The invention relates to an E7 peptide grafted methacrylamide karaya harlequin tree hydrogel scaffold and a preparation method thereof, the hydrogel scaffold is a comprehensive bone tissue engineering scaffold, the diameter is 140-680 nm, and the hydrogel scaffold includes but is not limited to regeneration and repair of bone defects clinically; the methacrylamide and karaya karaya are mainly used as main base materials and grafted with E7 peptide, and the finally obtained methacrylamide karaya karaya hydrogel scaffold grafted with E7 peptide has a plurality of uniformly distributed pores and has a good intercommunication microstructure. The method is simple and clear in design, the shape and the microstructure of the scaffold can be accurately controlled, the mechanical property can be adjusted according to needs, the cost is relatively low, the method is suitable for tissue repair, and a preliminary research foundation is laid for exploring a novel tissue engineering scaffold.

Description

Technical Field

[0001] The invention relates to the technical field of biomedicine, and in particular to a methacrylamide karaya hydrogel scaffold grafted with E7 peptide and a preparation method thereof. Background Art

[0002] Tissue engineering has revolutionized the field of regenerative medicine by providing innovative approaches to tissue and organ repair and regeneration. Traditional methods such as electrospinning have played an important role in producing biocompatible scaffolds for tissue engineering applications, however, they may have shortcomings in replicating the complex three-dimensional microenvironment required for biomimetic tissues and organs. 3D printing technology has emerged as a promising solution to precisely position biomolecules and living cells to create complex three-dimensional structures that mimic natural tissues and organs.

[0003] 3D bioprinting technology, especially photopolymerization-based methods, can precisely control the accumulation of biomaterials, spatial cell distribution, and microenvironmental remodeling within tissues and organs. Despite its potential, the challenge is that biomaterials lack personalized biochemical and mechanical properties, which hinders the wider application of 3D printing in tissue engineering. Natural hydrogels commonly used as bioinks usually lack ideal mechanical properties for immediate use in 3D printing, so strengthening techniques are needed to enhance their biomechanical properties.

[0004] Hydrogels have become popular bio-inks in bioprinting due to their high water absorption, biocompatibility, and ability to mimic the extracellular matrix, which facilitates the creation of biomimetic 3D structures. Hydrogels include natural hydrogels and synthetic hydrogels. Unlike natural hydrogels, synthetic hydrogels such as PEGDA and PCL are limited in their application due to poor biocompatibility, poor biochemical properties, and inflammation caused by degradation products in large animals. Natural hydrogels such as hyaluronic acid (HA), sodium alginate, and gelatin are commonly used as bio-inks due to their good biocompatibility and low immunogenicity. However, the application of these bio-inks is limited by factors such as poor cell-material interactions, which may affect biological functions. At present, natural hydrogels for 3D bioprinting still face challenges, such as shear thinning, high printing pressure that affects cell viability, and low viscosity that affects shape fidelity. Therefore, it is necessary to create a comprehensive bio-ink with shear-thinning behavior, photocuring, good adhesion, and cell-friendliness.

[0005] Chinese invention patent CN119060329A (publication date: December 3, 2024) discloses an enzyme-responsive polyamino acid; after the enzyme-responsive polyamino acid is implanted into the body, the ALP secreted by the body itself or secreted by BM-MSCs after osteogenesis in the subsequent system diffuses to the surface of the cartilage to form an ALP gradient, and the induction system forms a self-generated gradient hydrogel scaffold through different degrees of dynamic conformational enhancement, thereby realizing the orderly repair of the multi-layer cartilage structure by BM-MSCs.

[0006] Chinese invention patent CN119139544A (publication date: December 17, 2024) discloses a 3D printed hydrogel scaffold and its preparation method; the 3D hydrogel scaffold has good biocompatibility with the human body, can restore the human body to its original state after being implanted for a period of time, can play the role of a bile duct stent, and has good bile duct biochemical properties.

[0007] Most of the existing hydrogel materials are insufficient in photosensitivity and mechanical properties (such as elasticity and strength), and the degree of functionalization is not high, making it difficult to achieve multifunctional applications. Therefore, the present invention proposes a methacrylamide karyophyllum hydrogel scaffold grafted with E7 peptide and a preparation method thereof, which is expected to overcome the problems of insufficient photosensitivity, poor mechanical properties and insufficient functionalization of existing hydrogel materials. Summary of the invention

[0008] The purpose of the present invention is to overcome the problems of insufficient photosensitivity, poor mechanical properties and insufficient functionalization of existing hydrogel materials.

[0009] A method for preparing a methacrylamide karaya hydrogel scaffold grafted with E7 peptide, characterized in that the method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide comprises the following steps:

[0010] Step S1, preparing modified karaya gum;

[0011] Step S2, preparing the modified karaya gum from step S1 into a hydrogel;

[0012] Step S3, compounding the modified Karaya gum hydrogel or the stem cell solution and then performing 3D extrusion printing to prepare Karaya gum hydrogel bioscaffold;

[0013] Step S4, cross-linking and strengthening the karaya gum hydrogel bioscaffold obtained in step S3;

[0014] Step S5, subjecting the cross-linked Karaya gum hydrogel scaffold obtained in step S4 to E7 peptide grafting modification, rinsing, and freeze-drying.

[0015] Furthermore, the specific preparation method of step S1 is: dissolving the karaya gum raw material in ultrapure water, preparing a karaya gum aqueous solution in an ice bath, adding a modifier for modification, stirring sufficiently, then adding sodium hydroxide dropwise to maintain the pH of the reaction system at 8-11, continuing the reaction overnight at 3-5°C in the dark, adjusting the pH to 7-8 with 1-3M hydrochloric acid, preparing a grafted derivative, dialyzing the resulting product, and freeze-drying it to obtain modified karaya gum.

[0016] Furthermore, the specific preparation method of step S2 is: using PBS with a photoinitiator concentration of 0.1-0.3% w / v to completely dissolve the modified karaya gum to prepare the modified karaya gum hydrogel.

[0017] Furthermore, the specific preparation method of step S3 is: compounding the karaya gum hydrogel or the stem cell solution, and then performing 3D extrusion printing, and forming the karaya gum hydrogel bioscaffold by stacking the ejected fiber filaments layer by layer;

[0018] The specific preparation method of step S4 is: subjecting the karaya gum hydrogel scaffold to ultraviolet light cross-linking to obtain a reinforced karaya gum hydrogel scaffold.

[0019] Furthermore, the specific preparation method of step S5 is as follows: placing the scaffold obtained in step S4 in 8-10% w / v 1,6-hexanediamine prepared in isopropanol at 36-38° C. for 1-2 hours; rinsing with deionized water, double distilled water, and PBS in sequence; adding a crosslinker 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid-3-sulfosuccinimide ester, and placing at room temperature for 1-2 hours; rinsing with PBS again, and then adding 0.1-0.3 mg / ml E7 peptide solution, and keeping at 3-5° C. overnight; rinsing and vacuum freeze-drying to obtain a methacrylamide karaya hydrogel scaffold grafted with E7 peptide.

[0020] Furthermore, the concentration of the Karaya gum aqueous solution is 1-2% w / v, and the modifier is methacrylic anhydride.

[0021] Furthermore, when the karaya gum hydrogel is combined with the stem cell solution for 3D extrusion printing, the concentration of the karaya gum hydrogel is 4-8%.

[0022] Furthermore, the duration of UV cross-linking of the karaya gum hydrogel scaffold was 55-65 seconds.

[0023] Furthermore, the concentration of the stem cell solution is 2×10 6 -4×10 6 cell / ml.

[0024] Furthermore, the diameter of the methacrylamide karaya hydrogel scaffold grafted with E7 peptide is between 140 and 680 nm, and has a number of evenly distributed pores.

[0025] Compared with the prior art, the advantages and effects of this application are as follows:

[0026] 1. The present invention successfully introduces methacrylamide photosensitive groups into the hydrogel, so that the hydrogel can undergo physical changes under ultraviolet light, thereby enhancing the elasticity and strength of the hydrogel.

[0027] 2. The present invention enhances the biological functionality of the hydrogel and promotes cell attachment and growth by grafting the bioactive molecule E7 peptide onto the surface of the hydrogel.

[0028] 3. The present invention optimizes the mechanical properties and biological functionality of the hydrogel by adjusting the synthesis process and structural parameters of the material, so that it exhibits excellent comprehensive performance in various tissue repair engineering applications.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings as follows.

[0030] Based on the detailed description of the specific embodiments of the present application in combination with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0032] in:

[0033] Figure 1 It is a physical diagram of the present invention;

[0034] Figure 2 It is the electron microscope image of the present invention;

[0035] Figure 3 This is a graph showing the results of nuclear magnetic resonance testing of karaya gum, low-methacrylamide karaya gum, medium-methacrylamide karaya gum, and high-methacrylamide karaya gum;

[0036] Figure 4 This is the result of nuclear magnetic resonance detection of methacrylamide-modified Karaya gum grafted with E7;

[0037] Figure 5 This is a graph showing the tensile strength test results of the present invention;

[0038] Figure 6 This is a diagram showing the compression resistance test results of the present invention;

[0039] Figure 7 Electron microscopic images of cell activity results of karaya gum, medium methacrylamide karaya gum, and medium methacrylamide karaya gum grafted with E7 after 7 and 14 days of printing of chondrocytes in the present invention;

[0040] Figure 8 The cell activity diagram of karaya gum, medium methacrylamide karaya gum, and medium methacrylamide karaya gum grafted with E7 after 7 and 14 days of printing of chondrocytes in the present invention;

[0041] Fig. 9 The present invention provides the chemical formula of Karaya gum and the synthesis of methacrylamide Karaya gum. Specific embodiments

[0042] To make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all of the embodiments. In the following description, specific details such as specific configuration and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures is omitted in the embodiment.

[0043] It should be understood that the references to "one embodiment" or "this embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present application. Therefore, the references to "one embodiment" or "this embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0044] In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0045] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that there can be two relationships. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The term "at least one" in this article is merely a description of the association relationship of associated objects, indicating that there may be three relationships. For example, at least one of A and B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0047] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusions.

[0048] Example 1

[0049] This example introduces a method for preparing a methacrylamide karaya hydrogel scaffold grafted with E7 peptide. The methacrylamide karaya hydrogel scaffold grafted with E7 peptide has a diameter of 140 to 680 nm and has a number of evenly distributed pores. For a physical diagram, please refer to Figure 1 , please see the electron microscope image Figure 2 , we can see that the figure shows evenly distributed pores, which indicates that its pore distribution is even and it has a certain good interconnected microstructure, which is conducive to cell adhesion and proliferation.

[0050] The preparation method of the methacrylamide karaya hydrogel scaffold grafted with E7 peptide comprises the following steps:

[0051] Step S1, preparing modified karaya gum;

[0052] Step S2, preparing the modified karaya gum from step S1 into a hydrogel;

[0053] Step S3, compounding the modified Karaya gum hydrogel or the stem cell solution and then performing 3D extrusion printing to prepare Karaya gum hydrogel bioscaffold;

[0054] Step S4, cross-linking and strengthening the karaya gum hydrogel bioscaffold obtained in step S3;

[0055] Step S5, subjecting the cross-linked Karaya gum hydrogel scaffold obtained in step S4 to E7 peptide grafting modification, rinsing, and freeze-drying.

[0056] Preferably, the specific preparation method of step S1 is: dissolving the karaya gum raw material in ultrapure water, preparing a karaya gum aqueous solution in an ice bath, adding different modifiers for modification, stirring sufficiently, then dripping sodium hydroxide to maintain the pH of the reaction system at 8-11, continuing the reaction overnight at 4° C. in the dark, adjusting the pH to 7.4 with 1M hydrochloric acid, preparing a grafted derivative, dialyzing and freeze-drying the obtained product, and obtaining modified karaya gum;

[0057] Preferably, the concentration of the karaya gum aqueous solution is 1% w / v, and the modifier is methacrylic anhydride, which has the beneficial effect that methacrylic anhydride is successfully grafted onto the karaya gum structure.

[0058] Preferably, the amount of methacrylic anhydride is 0.5 ml, 1 ml, and 2 ml methacrylic anhydride (94%), respectively; the beneficial effect is that the microstructure, mechanical properties, and cell activity of the scaffold are controlled by adjusting the degree of methacrylamide addition, thereby exploring a microenvironment conducive to cell growth.

[0059] Preferably, the specific preparation method of step S2 is: using PBS with a photoinitiator concentration of 0.1% w / v to completely dissolve the modified karaya gum to prepare the modified karaya gum hydrogel.

[0060] Preferably, the specific preparation method of step S3 is: compounding the karaya gum hydrogel or the stem cell solution, and then performing extrusion printing through a 3D-Bioplotter system, and forming a karaya gum hydrogel bioscaffold by stacking the ejected fiber filaments layer by layer; wherein the concentration of the stem cell solution is 2×10 6 cell / ml.

[0061] Preferably, the specific preparation method of step S4 is: subjecting the karaya gum hydrogel scaffold to ultraviolet light cross-linking to obtain a reinforced karaya gum hydrogel scaffold;

[0062] Preferably, the duration of UV cross-linking of the karaya gum hydrogel scaffold is 60 seconds, which has the beneficial effect of completing the cross-linking in a short time and better achieving the fidelity of the scaffold; see Figure 1 , it can be seen that after 60s, the karaya gum scaffold without photo-crosslinking collapsed and its shape could not be well preserved, while the modified karaya gum scaffold maintained its shape well after UV-crosslinking, indicating that UV-crosslinking can maintain the shape of the printed scaffold;

[0063] Preferably, the concentration of the karaya gum hydrogel during 3D extrusion printing is 6%, which has the beneficial effect that the printing voltage required for 6% (w / v) is relatively low, and it has less damage to the cell activity of the composite cell printing. During printing, pressure will be generated on the loaded cells, which may affect the activity of the cells, providing a preliminary research basis for cartilage repair.

[0064] Preferably, the specific preparation method of step S5 is: placing the scaffold obtained in step S4 in 10% w / v 1,6-hexanediamine prepared in isopropanol at 37°C for 1 hour; rinsing with deionized water, double distilled water and PBS for 3 times respectively; adding the cross-linking agent 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid-3-sulfosuccinimide ester, and placing at room temperature for 1 hour; rinsing with PBS again, and then adding 0.1 mg / ml E7 peptide solution, and keeping at 4°C overnight; rinsing and vacuum freeze-drying to obtain the methacrylamide karaya hydrogel scaffold grafted with E7 peptide.

[0065] Preferably, the methacrylamide karaya hydrogel scaffold grafted with E7 peptide has a diameter between 140 and 680 nm and has a number of evenly distributed pores.

[0066] The technical effects obtained in this embodiment are: the reaction conditions in the preparation method of the present application are mild and the required conditions are not harsh; the UV cross-linking of the scaffold is completed in a short time, the fidelity of the printed scaffold can be better achieved, and it can be used for cartilage repair.

[0067] Example 2

[0068] Based on the above examples, this example introduces an experiment on methacrylic anhydride-modified karaya gum, and the specific process is: add 5M sodium hydroxide dropwise to maintain a certain pH for reaction, and the pH is selected to be 7-8 or 8-11. Prepare methacrylated karaya gum according to the following steps: prepare a 1% (w / v) karaya gum solution under ice bath conditions, add methacrylic anhydride, stir magnetically to mix, and then add 5M sodium hydroxide dropwise to maintain the pH at 8-11. Continue the reaction overnight at 4°C in the dark, adjust the pH to 7.4 with 1M hydrochloric acid, dialyze with ultrapure water for one week, and lyophilize to obtain the product. Please refer to the chemical formula of karaya gum and the synthesis diagram of methacrylamidated karaya gum for details. Fig. 9 .

[0069] The technical effect obtained in this embodiment is: by comparing the degree of methacrylamide of the product, it is found that when the pH is 8-11, the efficiency of grafting methacrylic anhydride of the product is higher.

[0070] Example 3

[0071] Based on the above embodiment, this embodiment introduces a method for preparing a karaya gum hydrogel scaffold, wherein the printing concentration of karaya gum can be 4%, 5%, 6%, 7%, and 8%. The karaya gum hydrogel scaffold is prepared by the following steps: freeze-dried methacrylated karaya gum is completely dissolved in PBS containing a photoinitiator (0.1% w / v) to prepare a hydrogel; then the obtained hydrogel is mixed with stem cells (2×10 6 The composite of 100 cell / ml was extrusion-printed by 3D-Bioplotter system, and the ejected fiber filaments were stacked layer by layer to form a scaffold. The printed scaffold was cross-linked by UV light for 60 seconds to obtain the product.

[0072] The technical effect obtained in this embodiment is: by comparing the three types of brackets and printing parameters, it is found that the number of printed layers is all 10 layers, among which 6% (w / v) requires a lower printing voltage, which has less damage to the cell activity of composite cell printing.

[0073] Example 4

[0074] Based on the above embodiments, this embodiment introduces a preparation method of modified karaya gum, which is as follows: a 1%-2% (w / v) karaya gum aqueous solution is prepared from karaya gum raw material at 50°C, different concentrations of methacrylic anhydride are added to prepare derivatives with different grafting degrees, the obtained products are dialyzed, and freeze-dried to obtain modified karaya gum.

[0075] The technical effect obtained in this embodiment is: through comparison of the above preparation results, it is found that the degree of methacrylamide of the solution with a concentration of 1% is higher than that of the solution with other concentrations.

[0076] Example 5

[0077] Based on the above examples, this example introduces a method for preparing a methacrylamide karaya hydrogel scaffold grafted with E7 peptide, and the specific process is as follows: a 1% (w / v) karaya gum aqueous solution is prepared from karaya gum raw material under an ice bath, and different concentrations of methacrylic anhydride are added to modify and prepare derivatives with different grafting degrees, and the obtained products are dialyzed and freeze-dried to obtain modified karaya gum; then, the modified karaya gum is completely dissolved in PBS containing a photoinitiator (0.1% w / v) to prepare a hydrogel; and then the obtained hydrogel or the stem cells (2×10 6 The composite was extrusion-printed by a 3D-Bioplotter system, and the ejected fibers were stacked layer by layer to form a scaffold. The printed scaffold was cross-linked by UV light for 60 seconds to obtain the product.

[0078] Preferably, the amount of methacrylic anhydride is 0.5 ml, 1 ml, and 2 ml of methacrylic anhydride (94%), respectively, and the obtained products are KG-MA1, KG-MA2, and KG-MA3, respectively; see Figure 3 and Figure 4 , it can be seen that KG-MA1, KG-MA2, and KG-MA3 show new peaks at 5.7ppm and 6.1ppm wavenumbers compared with KG, indicating that methacrylic anhydride is successfully grafted onto the structure of Karaya gum.

[0079] The results of the mechanical properties test of the present invention can be found in Figure 5 and Figure 6 , it can be seen that the mechanical strengths of the three KG-MA hydrogel scaffolds (the compression moduli of KG-MA1, KG-MA2, and KG-MA3 are 0.537±0.148MPa, 0.831±0.263MPa, and 0.975±0.279MPa, respectively) are within the compression modulus range of natural cartilage tissue (240–1000kPa), making them suitable materials for cartilage repair engineering.

[0080] Figure 7 and Figure 8 The cell activity results of karaya gum, medium methacrylamide karaya gum, and medium methacrylamide karaya gum grafted with E7 after 7 and 14 days of printing are shown in the figure. Figure 7 Most cells are stained green (live cells). Figure 8 The results showed that the viability of cells increased gradually after printing, indicating that the material was suitable for bioprinting, and the methacrylamide-modified Karaya gum grafted with E7 had the highest survival rate, successfully optimizing its biofunctionality.

[0081] The technical effect obtained in this embodiment is: by adjusting the degree of methacrylamide addition, the microstructure, mechanical properties and cell activity of the scaffold are controlled.

[0082] The above description is only the preferred embodiment of the present invention, which does not limit the protection scope of the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Within the spirit and principle of the present invention, any change, modification, replacement, integration and parameter change of these embodiments by conventional substitution or capable of achieving the same function without departing from the principle and spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a methacrylamide karaya hydrogel scaffold grafted with E7 peptide, characterized in that: The preparation method of the methacrylamide karaya hydrogel scaffold grafted with E7 peptide comprises the following steps: Step S1, preparing modified karaya gum; Step S2, preparing the modified karaya gum in step S1 into a hydrogel; Step S3, compounding the modified karaya gum hydrogel or the stem cell solution and then performing 3D extrusion printing to prepare a karaya gum hydrogel bioscaffold; Step S4, cross-linking and strengthening the karaya gum hydrogel bioscaffold obtained in step S3; Step S5, subjecting the cross-linked Karaya gum hydrogel scaffold obtained in step S4 to E7 peptide grafting modification, rinsing, and freeze-drying.

2. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 1, characterized in that: The specific preparation method of step S1 is as follows: dissolving the karaya gum raw material in ultrapure water, preparing a karaya gum aqueous solution in an ice bath, adding a modifier for modification, stirring sufficiently, then dripping sodium hydroxide to maintain the pH of the reaction system at 8-11, continuing the reaction overnight at 3-5° C. in the dark, adjusting the pH to 7-8 with 1-3M hydrochloric acid, preparing a grafted derivative, dialyzing the obtained product, and freeze-drying it to obtain modified karaya gum.

3. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 2, characterized in that: The specific preparation method of step S2 is: using PBS with a photoinitiator concentration of 0.1-0.3% w / v to completely dissolve the modified karaya gum to prepare the modified karaya gum hydrogel.

4. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 3, characterized in that: The specific preparation method of step S3 is: compounding the karaya gum hydrogel or the stem cell solution, and then performing 3D extrusion printing to form a karaya gum hydrogel biological scaffold by stacking the ejected fiber filaments layer by layer; the specific preparation method of step S4 is: cross-linking the karaya gum hydrogel scaffold by ultraviolet light to obtain a reinforced karaya gum hydrogel scaffold.

5. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 4, characterized in that: The specific preparation method of step S5 is as follows: placing the scaffold obtained in step S4 in 8-10% w / v 1,6-hexanediamine prepared in isopropanol at 36-38° C. for 1-2 hours; rinsing with deionized water, double distilled water, and PBS in sequence; adding a crosslinking agent 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid-3-sulfosuccinimide ester, and placing at room temperature for 1-2 hours; rinsing with PBS again, and then adding 0.1-0.3 mg / ml E7 peptide solution, and keeping at 3-5° C. overnight; rinsing and vacuum freeze-drying to obtain a methacrylamide karyophyllum hydrogel scaffold.

6. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 2, characterized in that: The concentration of the karaya gum aqueous solution is 1-2% w / v, and the modifier is methacrylic anhydride.

7. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 4, characterized in that: When the karaya gum hydrogel is combined with the stem cell solution for 3D extrusion printing, the concentration of the karaya gum hydrogel is 4-8%.

8. The method for preparing the methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claim 4, characterized in that: The duration of UV cross-linking of the karaya gum hydrogel scaffold was 55-65s.

9. The method for preparing the methacrylamide Kariya hydrogel scaffold grafted with E7 peptide according to claim 4, characterized in that: The concentration of the stem cell solution is 2×10 6 -4×10 6 cell / ml.

10. The methacrylamide karaya hydrogel scaffold grafted with E7 peptide according to claims 1-9, characterized in that: The methacrylamide karaya hydrogel scaffold grafted with E7 peptide has a diameter of 140 to 680 nm and has a plurality of evenly distributed pores.

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