Preparation method of bionic high-adhesion tissue repair hydrogel based on silk fibroin

Abstract

The invention provides a preparation method of bionic high-adhesion tissue repair hydrogel based on silk fibroin, and relates to the technical field of biomedical tissue engineering materials. The preparation method of the PDA-silk-PAM hydrogel provided by the invention comprises the following steps: firstly, carrying out a Schiff base reaction on silk fibroin and dopamine, and then further carrying out in-situ free radical polymerization on the obtained product and acrylamide hydrogel, thereby obtaining the PDA-silk-PAM hydrogel. The maximum tensile strain of the PDA-silk-PAM hydrogel prepared by the method disclosed by the invention can reach 1000%, the tensile strength can reach 220kPa, and the PDA-silk-PAM hydrogel has excellent mechanical properties; the composition has strong adhesion to natural surfaces such as glass, leaves, paper, plastics, aluminum and fresh organ tissues containing tissue fluid, and shows excellent tissue healing capability and capability of promoting wound healing faster and more efficiently.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical tissue engineering materials, and in particular to a method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin. Background Art

[0002] Tissue engineering is an excellent alternative for repairing and regenerating damaged tissues and organs, such as skin, cartilage, and spinal cord. Scaffolds or matrices play a key role in tissue engineering and regenerative medicine. Excellent scaffolds / matrices should possess biocompatibility, suitable structure and stiffness, and a high specific surface area. They should mimic the structure and biological functions of the natural extracellular matrix (ECM) to provide a microenvironment that promotes the exchange of biomolecules without affecting their biological activity.

[0003] Adhesive hydrogels are excellent biomaterials for mimicking the extracellular matrix due to their high water content in three-dimensional networks, excellent biocompatibility, broad adhesion range, and deformability. While reported adhesive hydrogels have partially realized their potential in terms of adhesion or deformability, achieving all of these functions simultaneously remains a major challenge. Importantly, previous adhesive hydrogels have focused on repairing the surface or top layer of tissue, with less attention paid to functional vascular regeneration in complex organs and tissues.

[0004] Polydopamine-silk fibroin-polyacrylamide (PDA-silk-PAM) hydrogel is a novel extracellular matrix (ECM)-mimicking biomaterial. Based on a mussel-inspired adhesion mechanism and the vascularization capacity of silk fibroin, it exhibits excellent adhesion, robust mechanical properties, easily controllable deformability, and the ability to promote vascularization of complex organs and tissues. These capabilities give PDA-silk-PAM hydrogels strong potential for clinical application. Based on this background, the present invention aims to provide a method for preparing a highly adhesive hydrogel based on silk fibroin with vascularization capacity. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies in the prior art, the present invention provides a method for preparing a biomimetic high-adhesion tissue repair hydrogel of silk fibroin.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] The present invention provides a method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin. The tissue repair hydrogel is prepared based on the Schiff base reaction of silk fibroin and dopamine and the in situ free radical polymerization of acrylamide hydrogel. The method comprises the following steps:

[0010] (1) Add the silk fibroin solution to the dopamine (DA) solution and stir continuously for 12-24 hours to obtain a silk fibroin / PDA suspension obtained by the reaction of silk fibroin and dopamine through Schiff base.

[0011] (2) At room temperature, acrylamide, ammonium persulfate, and N,N-methylenebenzene (acrylamide) were mixed to obtain a hydrogel system, which was then added to the above-mentioned silk fibroin / PDA suspension and stirred for 5-10 minutes. The suspension was then immersed in a 60-65°C water bath for 3-5 hours to obtain a biomimetic high-adhesion polydopamine-silk fibroin-polyacrylamide tissue repair hydrogel, referred to as PDA-silk-PAM hydrogel.

[0012] Furthermore, in step (1), the mass ratio of silk fibroin to dopamine is 35-60:3-7.

[0013] Furthermore, in step (2), the mass ratio of N,N-methylenebenzene(acrylamide) to acrylamide is 0.05:100-0.1:100 to obtain a gel-like hydrogel.

[0014] Furthermore, in step (2), the mass ratio of N,N-methylenebenzene(acrylamide) to acrylamide is 0.2:100-1:100, and a solid block hydrogel is obtained.

[0015] Furthermore, in the hydrogel system in step (2), silk fibroin / acrylamide = 2-5 wt.%; PDA / acrylamide = 0.1-0.4 wt.%.

[0016] Furthermore, in step (2), ammonium persulfate / acrylamide = 8 wt %.

[0017] The present invention also provides the use of the hydrogel material prepared by the above method in preparing tissue repair products.

[0018] (3) Beneficial effects

[0019] The PDA-silk-PAM hydrogel preparation method provided by the present invention comprises firstly subjecting silk fibroin (silk) and dopamine (PDA) to a Schiff base reaction, wherein the silk fibroin can significantly promote the self-polymerization of dopamine hydrochloride under acidic conditions; and then further reacting the PDA-silk-PAM hydrogel with acrylamide hydrogel to prepare the hydrogel through in situ free radical polymerization.

[0020] The PDA-silk-PAM hydrogel prepared using the present method exhibits a uniform, three-dimensional structure with large pores, and PDA particles can be visually observed embedded within it using a scanning electron microscope. This method effectively protects the aromatic ring structure of polydopamine and the amide group structure of silk fibroin during the formation of the PDA-silk-PAM hydrogel, preserving the key chemical groups of polydopamine and silk fibroin during synthesis, thus providing a foundation for the chemical stability of the material. Furthermore, the PDA-silk-PAM hydrogel prepared using the present method exhibits a significant increase in C=O bonds, likely due to the silk fibroin triggering the oxidation of the phenolic hydroxyl groups in PDA. The PDA doping results in the addition of more quinone groups, which plays a key role in enhancing adhesion.

[0021] The PDA-silk-PAM hydrogel prepared by the method of the present invention can achieve a maximum tensile strain of 1000% and a tensile strength of 220 kPa, and has excellent mechanical properties; it has strong adhesion to natural surfaces such as glass, leaves, paper, plastic, aluminum, and fresh organ tissues containing tissue fluid, and shows excellent tissue healing ability.

[0022] The results of animal experiments show that the PDA-silk-PAM hydrogel prepared by the method of the present invention has better adhesion performance, good water absorption and water retention, which is conducive to the hydrogel material to play a long-term role in promoting tissue repair, can promote the regeneration of blood vessels, hair follicles and collagen fibers, and promote wound healing faster and more efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram and mechanism of the preparation of PDA / silk fibroin polymer.

[0024] Figure 2 Surface and cross-sectional SEM images of DA-silk-PAM, silk-PAM, and PAM hydrogels.

[0025] Figure 3 FT-IR spectra of PDA-silk-PAM tissue repair hydrogel; A: FT-IR spectra of DA·HCl, PDA, silk, and DA·HCl / silk; B: FT-IR spectra of PDA, silk, and DA·HCl / silk at 580-1660 cm -1 FT-IR spectra at ; C: FT-IR spectra of DA-silk-PAM, silk-PAM and PAM hydrogels. Figure 4 These are the XPS results of PDA, silk, and DA·HCl / silk.

[0026] Figure 5XPS results of PDA-silk-PAM, silk-PAM and PAM hydrogels.

[0027] Figure 6 Mechanical properties, hygroscopicity, and adhesion of PDA-silk-PAM hydrogels; (A) Digital photograph of the tensile test of PDA-silk-PAM hydrogel, showing its high ductility; (B) Typical tensile stress-strain curves of PAM, silk-PAM, and PDA-silk-PAM hydrogels; (C) Digital photographs of PAM, silk-PAM, and PDA-silk-PAM hydrogels before and after complete immersion in water; (D) Swelling ratios of PAM, silk-PAM, and PDA-silk-PAM hydrogels in complete immersion in water, PBS, and sodium chloride solutions; (E) Adhesion of PDA-silk-polyacrylamide hydrogels on glass and mouse tissue; (F) Self-healing process of the two-part composition of PDA-silk-polyacrylamide hydrogel.

[0028] Figure 7 : Digital photographs of PDA-silk-PAM hydrogels (a) with cross-linking degrees (bis(AM)) of 0.1%, 0.2%, 0.5% and 1.0%, respectively, from left to right; (b) Tensile lengths of PDA-silk-PAM hydrogels at different cross-linking degrees (bis(AM)), 0.2%, 0.5% and 1.0%, respectively; (c) Digital photographs and schematic diagrams of PDA-silk-PAM hydrogel films at different cross-linking degrees (bis(AM)), after being placed in a U-shaped groove pattern for 12 hours under ambient conditions; (d) Digital photographs of PDA-silk-PAM hydrogels at different cross-linking degrees (bis(AM)), 0.1% (left) and 1.0% (right); (e) Digital photographs of PDA-silk-PAM hydrogels covering finger joints.

[0029] Figure 8 Figure 3: Effect of PDA-silk-PAM on treating dorsal skin wounds in rats; A: Schematic diagram of experimental grouping and digital photographs of wound healing on days 0, 6, 9, and 13; BC: Shows the adhesion of PDA-silk-PAM and PAM hydrogel in rat skin wounds after 8 hours; D: Overlay heat map analysis of wound area on days 0, 6, and 9; E: Quantitative analysis of wound healing.

[0030] Figure 9 The diagram shows the histomorphological changes of wound regeneration after treatment with PBS, PAM, silk-PAM and PDA-silk-PAM hydrogel on the 16th day.

[0031] Figure 10Masson staining assessment of wound regeneration after PBS, PAM, silk-PAM, and PDA-silk-PAM hydrogel treatment on day 16. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1

[0034] Preparation of biomimetic high-adhesion polydopamine-silk fibroin-polyacrylamide (PDA-silk-PAM) tissue repair hydrogel:

[0035] (1) Adding the silk fibroin solution to the dopamine (DA) solution and stirring continuously for 12-24 hours to obtain a silk fibroin / PDA suspension obtained by the Schiff base reaction of silk fibroin and dopamine; wherein the mass ratio of silk fibroin to dopamine is 10:1;

[0036] (2) At room temperature, N,N-methylenebenzene (acrylamide) and acrylamide were mixed in a mass ratio of 0.2:100, and ammonium persulfate accounting for 8% of the mass of acrylamide was added and mixed evenly to obtain a hydrogel system. Subsequently, the above-mentioned silk fibroin / DA suspension was added to the hydrogel system and stirred for 5-10 minutes, and then immersed in a 60-65°C water bath for 3-5 hours to obtain a biomimetic high-adhesion polydopamine-silk fibroin-polyacrylamide (PDA-silk-PAM) tissue repair hydrogel.

[0037] Furthermore, in the hydrogel system in step (2), silk fibroin / acrylamide = 2 wt.%; PDA / acrylamide = 0.4 wt.%.

[0038] like Figure 1 As shown in the figure, when dopamine hydrochloride (DA·HCl) is mixed with a silk fibroin solution that has been treated for 18 hours, the solution turns inky black, indicating the presence of PDA in the system. However, this phenomenon is not observed when DA·HCl is mixed with water without silk fibroin. This result indicates that silk fibroin promotes the self-polymerization of dopamine hydrochloride under acidic conditions.

[0039] Comparative Example 1

[0040] Preparation of silk-PAM hydrogel

[0041] N,N-methylenebenzene (acrylamide) and acrylamide were mixed in a mass ratio of 0.2:100, and ammonium persulfate accounting for 8% of the mass of acrylamide was added and mixed evenly to obtain a hydrogel system. Subsequently, silk fibroin was added to the hydrogel system and stirred for 5-10 minutes, and then immersed in a 60-65°C water bath for 3-5 hours to obtain a silk-PAM hydrogel; wherein the silk fibroin / acrylamide = 2 wt.%.

[0042] Comparative Example 2

[0043] PAM hydrogel

[0044] N,N-methylenebenzene (acrylamide) and acrylamide were mixed at a mass ratio of 0.2:100, and ammonium persulfate accounting for 8% of the mass of acrylamide was added, and the mixture was mixed evenly to obtain a PAM hydrogel.

[0045] Example 2

[0046] Structural Characterization of PDA-silk-PAM Tissue Repair Hydrogel

[0047] 1 Scanning electron microscopy observation of the microstructure of PDA-silk-PAM hydrogel

[0048] The microstructures of PDA-silk-PAM, silk-PAM, and PAM hydrogels were observed using a scanning electron microscope (JSM 6390, JEOL, Japan). The hydrogels were freeze-dried, cut to expose their internal structures, and cross-sections were observed using a scanning electron microscope.

[0049] The results are as follows Figure 2 As shown in Figure 3, the cross-section of the PDA-silk-PAM hydrogel showed that the pores (~50 μm) in the three-dimensional structure were more uniform and larger than those of silk-PAM and PAM hydrogels. Many PDA particles were observed to be inserted on the surface of the PDA-silk-PAM hydrogel.

[0050] Chemical structure of PDA-silk-PAM tissue repair hydrogel determined by 2FT-IR

[0051] Firstly, the chemical structures of dopamine hydrochloride (DA·HCl), DA·HCl / silk and polydopamine (PDA) were determined by Fourier transform infrared spectroscopy (FTIR, Nicolet iS20, Termo). Figure 3 The FT-IR measurement results in A show that DA·HCl / silk has a wavelength of about 1600 cm -1Indole-related structures appeared at the 37°C, which is the characteristic peak of PDA, but not in DA·HCl. This indicates that dopamine underwent polymerization during its interaction with silk to form polydopamine (PDA). Silk may act as a catalyst or template to promote the polymerization of dopamine. Figure 3 In B, the vibration of the aromatic ring in PDA is located at 1610 cm -1 , while the amide group in silk fibroin is located at 1512 cm -1 DA·HCl / silk also has the above two characteristic peaks that are the same as PDA and silk fibroin. This result further confirms the formation of polydopamine in DA·HCl / silk and proves that the structure of silk fibroin itself still exists in the DA·HCl / silk composite system and is not destroyed.

[0052] Subsequently, PDA-silk-PAM, silk-PAM, and PAM hydrogels were characterized by FT-IR measurements. Compared with silk-PAM and PAM hydrogels, PDA-silk-PAM hydrogel has an indole-related structure located at approximately 1600 cm -1 There is an obvious PDA characteristic peak at 1510 cm -1 The above results show that the aromatic ring structure of dopamine and the amide group structure of silk fibroin are not destroyed in the process of forming PDA-silk-PAM hydrogel. During the synthesis process, polydopamine and silk fibroin still retain their respective key chemical groups, which provides a basis for the chemical stability of the material. Figure 3 C).

[0053] 3X-ray photoelectron spectroscopy

[0054] The chemical structures of PDA, silk, DA·HCl / silk, PAM, silk-PAM, and PDA-silk-PAM were measured using an X-ray photoelectron spectrometer (Kratos, Axis Ultra DLD, UK). Figure 2-3 shown.

[0055] Figure 4 The XPS results in Figure 3 show the C1s peaks of PDA, silk, and DA·HCl / silk. These peaks are divided into three peaks at 284.6, 286.0, and 287.63 eV, which are attributed to CN / CC, CO, and C=O, respectively. Compared with the XPS spectra of PDA and silk, the CC / CN bonds in DA·HCl / silk are significantly increased.

[0056] The C1s peak in the XPS spectra of PAM, silk-PAM and PDA-silk-PAM hydrogels is divided into three peaks, located at 284.6, 286.0 and 287.63 eV, corresponding to CN / CC, CO and C=O( Figure 5 Compared with PAM and silk-PAM, the C=O bonds in PDA-silk-PAM hydrogel increased significantly. This may be because silk fibroin triggered the oxidation of phenolic hydroxyl groups in PDA. After PDA doping, more quinone groups were added, which played a key role in improving the adhesion function.

[0057] Example 3

[0058] Physical properties test of PDA-silk-PAM hydrogel

[0059] 1 Mechanical properties test

[0060] The tensile test was carried out on a universal testing machine (Instron 5567, USA). The PDA-silk-PAM hydrogel sample had a length of 40 mm and a thickness of 10 mm. Figure 6 As shown in A, the PDA-silk fibroin-polyacrylamide hydrogel can be stretched to at least 5 times its initial length and can recover to its initial length within 1 minute.

[0061] We then performed uniaxial tensile tests on PAM, silk-PAM, and PDA-silk-PAM hydrogels at a crosshead speed of 120 mm / min and plotted the typical stress-strain curves of the hydrogels. Figure 6 As shown in Figure 2, the maximum tensile strain of the PDA-silk-PAM hydrogel is 1000%, which is in sharp contrast to the maximum strain of 114% for PAM and 164% for silk-PAM hydrogel. At the same time, the tensile strength of the PDA-silk-PAM hydrogel is approximately 220 kPa, which is much higher than that of the PAM hydrogel (92 kPa) and silk-PAM hydrogel (110 kPa).

[0062] 2 Hygroscopicity

[0063] After PAM, silk-PAM, and PDA-silk-PAM hydrogels were completely immersed in different solutions, the mass of the hydrogels before and after swelling was weighed to calculate the swelling rate.

[0064] like Figure 6 As shown in C, the degree of swelling of PDA-silk-PAM hydrogel after immersion in edema was significantly higher than that of PAM and silk-PAM hydrogel.

[0065] like Figure 6As shown in Figure 3D, the PDA-silk-PAM hydrogel exhibited higher swelling ratios than both PAM and silk-PAM hydrogels in water, PBS, and sodium chloride solution. In particular, in sodium chloride solution, the swelling ratio of PDA-silk-PAM was 17.11, significantly higher than that of PAM hydrogel (7.98) and silk-PAM hydrogel (8.53). Furthermore, the swelling ratio of PDA-silk-PAM was also higher than that in water (9.31) and PBS solution (11.54). The PDA-silk-PAM hydrogel exhibited the highest swelling ratio and swelling rate in sodium chloride solution, primarily attributable to the synergistic effects between PDA, silk fibroin, and PAM, as well as ionic effects. This synergistic effect optimized the hydrogel's network structure and enhanced its water absorption capacity. In particular, the phenolic hydroxyl groups in PDA and the amide groups in PAM interacted with the ions in the sodium chloride solution, further promoting the penetration and diffusion of water molecules.

[0066] 3 Adhesion performance test

[0067] The PDA-silk-PAM hydrogel was coated on the sample surface with a contact area of 15 mm × 15 mm. The research substrates we selected included glass, plastic, aluminum, leaves and paper, representing hydrophilic, hydrophobic and metal materials respectively. Mouse tissue was selected to simulate the adhesion on human tissue. Once the hydrogel was attached to the substrate surface, the adhesion test was performed immediately without curing time. The results are shown in Figure 2. Figure 6 As shown in E, the PDA-silk-PAM hydrogel prepared by the method of the present invention has strong adhesion to natural surfaces such as glass, leaves, paper, plastic, aluminum and fresh organ tissue containing tissue fluid.

[0068] 4. Self-healing ability

[0069] The cylindrical PDA-silk-PAM hydrogel was cut open and the two halves were spliced together. The two halves of the hydrogel in physical contact were able to recombine into a new whole, and no color unevenness was observed under an optical microscope. At the same time, the hydrogel did not crack when stretched by tweezers, showing excellent self-healing properties ( Figure 6 F).

[0070] 5 Rheological experiments

[0071] The viscoelastic behavior of PDA-silk-PAM hydrogels was characterized at room temperature using a Rheometric Scientific HAAKE (MARS, Germany) strain-controlled rheometer. The storage modulus (G′), loss modulus (G″), and loss tangent (the ratio of G″ to G′) of the PDA-silk-PAM hydrogels were measured at a strain amplitude of 1.0% over a frequency range of 0.01 to 10 Hz.

[0072] By adjusting the proportion of N,N-methylenebis(acrylamide) (BIS), the cross-linking agent, in the entire hydrogel system, adhesive PDA-silk-PAM hydrogels with different fluidities and different cross-linking degrees (Bis / AM) of 0.1%, 0.2%, 0.5% and 1.0% were obtained, and four hydrogels with a height of 1.4 cm were prepared.

[0073] After thermal polymerization at 60 °C for 3 h, the PDA-silk-PAM hydrogel with a cross-linking degree of 0.1% exhibited a flowing liquid state, while the PDA-silk-PAM hydrogels with a cross-linking degree of 0.2%, 0.5%, and 1.0% exhibited a stable solid state ( Figure 7 a).

[0074] The sliding compression test showed that the length of the PDA-silk-PAM hydrogel with a cross-linking degree of 0.2% adhered to the slide was significantly higher than that of the PDA-silk-PAM hydrogel with a cross-linking degree of 0.5% (2.7 cm) and 1.0% (1.4 cm). Figure 7 b).

[0075] Cross-sectional images through a microscope. Hydrogel films were placed in a U-shaped groove pattern under ambient conditions for 12 hours. PDA-silk-PAM hydrogels with 0.5% and 1.0% cross-linking did not deform along the mold surface due to low fluidity. However, for films with 0.2% and 0.1% cross-linking, the PDA-silk-PAM hydrogel completely filled the grooves without gaps. These films showed sufficiently high fluidity ( Figure 7 c).

[0076] Therefore, PDA-silk-PAM hydrogel can be made into mobile glue or super-strong viscous elastomer ( Figure 7 d). The obtained PDA-silk-PAM hydrogel with a cross-linking degree of 0.2% has excellent stretchability and adhesion properties and can completely cover the finger joints ( Figure 7 e).

[0077] Example 3

[0078] Effect of PDA-silk-PAM hydrogel in promoting skin wound healing

[0079] 1 Experimental methods

[0080] Four healthy SD rats with a body weight of (200 ± 20) were selected. Four 1 cm2 holes were created on the back of the SD rats. 2 The full-thickness skin wounds were then covered with corresponding tissue repair materials, specifically: (upper left) PBS, (upper right) PAM, (lower left) silk-PAM, (lower right) PDA-silk-PAM (e.g. Figure 8 As shown in A), the corresponding tissue repair material remains attached to the wound until the wound heals.

[0081] 2. Detection indicators and methods

[0082] 2.1 Wound contraction rate

[0083] Wound healing was observed daily. Essential wound healing was monitored and recorded using optical imaging and a thermal image of wound healing. Wound area was measured daily and wound contraction rate was calculated as (original wound area - wound area on the day) / original wound area × 100%.

[0084] 2.2 Pathological changes of wound tissue

[0085] After the wounds of the rats in each group were basically healed, the rats were killed, and the skin tissues at the wounds were taken for H&E staining and Masson staining to observe the pathological changes of the skin tissues.

[0086] 3 Results

[0087] The shrinkage rate of PDA-silk-PAM hydrogel in rat skin wounds after 8 hours (32.2%) was lower than that of PAM hydrogel (65.4%) ( Figure 8 BC). The results show that the PDA-silk-PAM hydrogel provided by the present invention has better adhesion performance, good water absorption and water retention, which is conducive to the hydrogel material to play a long-term role in promoting tissue repair.

[0088] like Figure 8 As shown in A, the optical image of the wound showed that the healing process of the PDA-silk-PAM amine hydrogel-treated group was faster than that of the other three groups, and the wound healing overlay heat map also showed the same result ( Figure 8 D). From day 0 to day 9, the wound contraction rate of the PDA-silk-PAM hydrogel group increased from 0.0 to 96.86±1.8% ( Figure 8 E), and no scars were observed in all four groups on day 13 ( Figure 8 A). The above results show that the PDA-silk-PAM hydrogel provided by the present invention can promote wound healing faster and more efficiently.

[0089] H&E staining was used to assess epidermal regeneration and skin appendage formation on day 16. Figure 9 As shown, the PDA-silk-PAM hydrogel group showed more blood vessels and hair follicles compared with the other three groups. Masson staining image ( Figure 10 ) showed that there were a large number of collagen fibers in the PDA-silk-PAM hydrogel group, further confirming that the excellent adhesion properties, porous structure and high water content of PDA-silk-PAM hydrogel significantly improved its wound healing efficiency.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin, characterized in that: The tissue repair hydrogel is prepared based on the Schiff base reaction of silk fibroin and dopamine and the in-situ free radical polymerization of acrylamide hydrogel. The method comprises the following steps: (1) Add the silk fibroin solution to the dopamine (DA) solution and stir continuously for 12-24 hours to obtain a silk fibroin / PDA suspension obtained by the reaction of silk fibroin and dopamine through Schiff base. (2) At room temperature, acrylamide, ammonium persulfate, and N,N-methylenebenzene (acrylamide) are mixed to obtain a hydrogel system, which is then added to the above-mentioned silk fibroin / PDA suspension and stirred for 5-10 minutes. The system is then immersed in a 60-65°C water bath for 3-5 hours to obtain a biomimetic high-adhesion polydopamine-silk fibroin-polyacrylamide tissue repair hydrogel.

2. The method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin according to claim 1, characterized in that: In step (1), the mass ratio of silk fibroin to dopamine is 35-60:3-7.

3. The method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin according to claim 1, characterized in that: In step (2), the mass ratio of N,N-methylenebenzene (acrylamide) to acrylamide is 0.05:100-0.1:100, and a gel-like hydrogel is obtained.

4. The method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin according to claim 1, characterized in that: In step (2), the mass ratio of N,N-methylenebenzene (acrylamide) to acrylamide is 0.2:100-1:100, and a solid block hydrogel is obtained.

5. The method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin according to claim 1, characterized in that: In the hydrogel system in step (2), silk fibroin / acrylamide = 2-5 wt.%; PDA / acrylamide = 0.1-0.4 wt.%.

6. The method for preparing a biomimetic high-adhesion tissue repair hydrogel based on silk fibroin according to claim 1, characterized in that: In step (2), ammonium persulfate / acrylamide = 8 wt %.

7. Use of the hydrogel material prepared by the method of claim 1 in preparing tissue repair products.

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