A kind of double protein elastic hydrogel with biological activity and preparation method thereof

Abstract

The present invention provides a dual-protein elastic hydrogel, which includes sericin modified by methacrylic anhydride and collagen modified by methacrylic anhydride, the swelling degree of the hydrogel is ≥1.42, and the compression modulus is ≥180.25kPa; the mass concentration of the sericin modified by methacrylic anhydride is 5-20%, and the mass concentration of the collagen modified by methacrylic anhydride is 2-6%. The swelling degree and compression modulus of the hydrogel can be adjusted by adjusting the mass concentrations of sericin and collagen within a certain concentration range, and the maximum swelling degree can reach 2.13, and the maximum compression modulus can reach 253.10kPa. At the same time, the hydrogel also contains a bioactive factor - platelet-rich plasma, which gives the hydrogel repair activity, and is used to repair chronic non-healing wounds. It can be used as a tissue repair material or a tissue engineering scaffold in the field of tissue engineering.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer hydrogels, and specifically relates to a dual-protein elastic hydrogel with biological activity and a preparation method thereof. Background Art

[0002] Although transplantation techniques have made great progress in skin wound care, the availability of donor skin for large wounds may be limited, and the resulting severe scarring, deformity, and ineffective vascularization remain a challenge. In addition, for people over 65 years old, the circulatory system declines with age, which can affect the skin's ability to heal. Topical application of growth factors is a clinically challenging potential therapy that can promote a normal healing process and improve vascularization.

[0003] A number of animal studies have demonstrated the feasibility of this approach, showing that topical application of growth factors such as transforming growth factor beta (TGF-b), platelet-derived growth factor (PDGF), basic fibroblast growth factor (BFGF), and epidermal growth factor (EGF) can accelerate wound closure. However, with the exception of PDGF, human studies evaluating the topical application of individual growth factors have been largely disappointing, suggesting that wound healing may rely on the “synergistic effects” of multiple growth factors. Furthermore, both the exudative and proteolytic environment of wounds may result in rapid degradation of topically applied growth factors, which would necessitate multiple reapplications.

[0004] Traditional dressings are loaded with a single growth factor, and the growth factor degrades quickly in the dressing. Traditional natural hydrogel dressings have poor mechanical properties and cannot be flexibly applied to the wound surface. Therefore, a more effective wound healing therapy may be to promote healing by providing a combination of multiple growth factors. Summary of the invention

[0005] To solve the above technical problems, the present invention provides a bioactive dual-protein elastic hydrogel and a preparation method thereof. The dual-protein elastic hydrogel of the present invention can be closer to manufacturing a structure similar to a natural cytoplasmic matrix and can more effectively achieve the sustained release of growth factors in PRP.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A dual-protein elastic hydrogel comprises sericin modified by methacrylic anhydride and collagen modified by methacrylic anhydride, wherein the hydrogel has a degree of inflation of ≥1.42 and a compression modulus of ≥180.25 kPa.

[0008] Preferably, the hydrogel has a swelling degree of 1.42 to 2.13 and a compression modulus of 180.25 to 253.40 kPa.

[0009] Preferably, the mass concentration of the methacrylic anhydride-modified sericin is 5-20%, and the mass concentration of the methacrylic anhydride-modified collagen is 2-6%. More preferably, the mass concentration of the methacrylic anhydride-modified sericin is 15%, and the mass concentration of the methacrylic anhydride-modified collagen is 4%. The inventors have demonstrated through examples that the swelling degree and compression modulus of the hydrogel can be adjusted by adjusting the mass concentrations of sericin and collagen within this concentration range, especially when the mass concentration of sericin is 15% and the mass concentration of collagen is 4%, a hydrogel with the best swelling degree and compression modulus is obtained.

[0010] Preferably, the hydrogel further comprises cell growth factors.

[0011] Preferably, the cell growth factor is platelet-rich plasma. The present invention selects platelet-rich plasma (PRP) as the active substance because the fibrin matrix produced after platelet activation can provide a scaffold for tissue growth to help tissue repair.

[0012] The present invention also provides a method for preparing the double protein hydrogel, which comprises the following steps:

[0013] S1: preparing modified sericin: chopping silkworm cocoons, soaking and boiling them in a Na2CO3 solution, removing impurities, and obtaining a sericin stock solution; dropping methacrylic anhydride into the sericin stock solution, stirring, centrifuging, removing impurities, dialyzing the solution, and finally freeze-drying the dialyzed solution to obtain methacrylated sericin;

[0014] S2: preparing modified collagen: after the collagen powder is dissolved, methacrylic anhydride is added to react, followed by dialysis, and finally the dialyzed solution is freeze-dried to obtain methacrylated sericin;

[0015] S3: preparing modified sericin / collagen hydrogel: dissolving the methacrylated sericin prepared in step S1, the methacrylated collagen prepared in step S2 and the LAP photoinitiator in water, and irradiating with ultraviolet light to obtain methacrylated modified sericin / collagen dual protein hydrogel.

[0016] Preferably, the dialysis bag used in step S1 has a molecular weight cut-off of 3500 Da.

[0017] Preferably, the dialysis bag used in step S2 has a molecular weight cut-off of 1000 Da.

[0018] Preferably, the ultraviolet irradiation time is 30s; and the mass concentration of the photoinitiator is 0.1%.

[0019] The present invention also provides a method for preparing a dual-protein hydrogel having biological activity, the method comprising the following steps:

[0020] S1: preparing modified sericin: chopping silkworm cocoons, soaking and boiling them in a Na2CO3 solution, removing impurities, and obtaining a sericin stock solution; dropping methacrylic anhydride into the sericin stock solution, stirring, centrifuging, removing impurities, dialyzing the solution, and finally freeze-drying the dialyzed solution to obtain methacrylated sericin;

[0021] S2: preparing modified collagen: after the collagen powder is dissolved, methacrylic anhydride is added to react, followed by dialysis, and finally the dialyzed solution is freeze-dried to obtain methacrylated collagen;

[0022] S3: dissolving the methacrylated sericin prepared in step S1, the methacrylated collagen prepared in step S2 and a photoinitiator in deionized water, adding platelet-rich plasma, and irradiating with ultraviolet light to obtain a dual-protein hydrogel with biological activity.

[0023] The present invention also provides the use of the hydrogel as a tissue repair material or a tissue engineering scaffold in the field of tissue engineering.

[0024] The beneficial effects of the present invention are as follows: the present invention provides a dual-protein elastic hydrogel and a preparation method thereof, wherein the swelling degree and compression modulus of the hydrogel can be adjusted by adjusting the mass concentrations of sericin and collagen within a certain concentration range, and the maximum swelling degree can reach 2.13, and the maximum compression modulus can reach 253.10 kPa. At the same time, the hydrogel also contains a bioactive factor-platelet-rich plasma, which gives the hydrogel repair activity and is used to repair chronic non-healing wounds. The hydrogel can be used as a tissue repair material or a tissue engineering scaffold in the field of tissue engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the H-NMR spectrum of the polymer of modified sericin (SerMA).

[0026] Figure 2 This is the H-NMR spectrum of the polymer of modified collagen (ColMA).

[0027] Figure 3 These are scanning electron microscope images of the hydrogels prepared in Comparative Example 1 and Example 8; wherein A is a scanning electron microscope image of the hydrogel prepared in Comparative Example 1, and B is a scanning electron microscope image of the hydrogel prepared in Example 8.

[0028] Figure 4 This is a schematic diagram of the in vitro growth factor release performance of Example 13.

[0029] Figure 5 Schematic diagram of cell survival rate of Examples 8, 13 and Comparative Example 1. DETAILED DESCRIPTION

[0030] In order to more concisely and clearly demonstrate the technical solution, purpose and advantages of the present invention, the technical solution of the present invention is described in detail below in conjunction with specific embodiments and drawings.

[0031] Example 1

[0032] This embodiment provides a method for preparing a dual-protein elastic hydrogel, comprising the following steps:

[0033] S1: Preparation of modified sericin (SerMA), the specific operation is as follows:

[0034] Cut 40g of silk cocoons into small pieces and wash with deionized water. Then soak the cocoons in 400mL of 0.02M Na2CO3 solution and boil for 1h. Take out the boiled solution every half an hour, then filter through filter cloth to remove impurities to obtain sericin stock solution. Take 300mL of sericin solution and slowly add 6mL of methacrylic anhydride to the sericin solution with a burette. After stirring at room temperature for 6h, centrifuge at 6000r / min for 8min to take the supernatant, and then filter through filter cloth (22-25μm) again to remove impurities. Dialyze in a dialysis bag (molecular weight 3500Da) for 3-5 days. Finally, freeze-dry to obtain methacrylated sericin protein (SerMA).

[0035] S2: Prepare modified collagen (ColMA), the specific operation is as follows:

[0036] Weigh 10g of collagen and dissolve it in 200mL of distilled water. After dissolving at 37℃, add 6mL of methacrylic anhydride and react at 37℃ for 5h. Dialyze with distilled water for 2-3 days. The molecular weight cutoff of the dialysis bag is 1000Da. Freeze-dry at -80℃ to obtain methacrylated collagen (ColMA).

[0037] S3: Preparation of SerMA / ColMA dual protein hydrogel. The specific steps are as follows:

[0038] The SerMA prepared in step S1, the ColMA prepared in step S2, and the LAP photoinitiator were dissolved in deionized water and irradiated with ultraviolet light for 30 seconds to obtain a methacrylated SerMA / ColMA dual-protein hydrogel, wherein the mass concentration of SerMA was 5%, the mass concentration of ColMA was 2%, and the mass concentration of the LAP photoinitiator was 0.1%.

[0039] Example 2

[0040] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 2, the mass concentration of SerMA is 5%, and the mass concentration of ColMA is 4%.

[0041] Example 3

[0042] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 3, the mass concentration of SerMA is 5%, and the mass concentration of ColMA is 6%.

[0043] Example 4

[0044] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 4, the mass concentration of SerMA is 10%, and the mass concentration of ColMA is 2%.

[0045] Example 5

[0046] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 5, the mass concentration of SerMA is 10%, and the mass concentration of ColMA is 4%.

[0047] Example 6

[0048] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 6, the mass concentration of SerMA is 10%, and the mass concentration of ColMA is 6%.

[0049] Example 7

[0050] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 7, the mass concentration of SerMA is 15%, and the mass concentration of ColMA is 2%.

[0051] Example 8

[0052] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 8, the mass concentration of SerMA is 15%, and the mass concentration of ColMA is 4%.

[0053] Example 9

[0054] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 9, the mass concentration of SerMA is 10%, and the mass concentration of ColMA is 6%.

[0055] Example 10

[0056] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 10, the mass concentration of SerMA is 20%, and the mass concentration of ColMA is 2%.

[0057] Embodiment 11

[0058] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 11, the mass concentration of SerMA is 20%, and the mass concentration of ColMA is 4%.

[0059] Example 12

[0060] The only difference between this example and Example 1 is that in the methacrylated SerMA / ColMA dual-protein hydrogel prepared in Example 12, the mass concentration of SerMA is 20%, and the mass concentration of ColMA is 6%.

[0061] Comparative Example 1

[0062] The only difference between Comparative Example 1 and Example 8 is that Comparative Example 1 contains only SerMA but no ColMA, and the total mass of the hydrogel prepared in Comparative Example 1 is the same.

[0063] Comparative Example 2

[0064] The only difference between Comparative Example 2 and Example 8 is that Comparative Example 2 contains only ColMA but no SerMA, and the total mass of the hydrogel prepared in Comparative Example 2 is the same.

[0065] Table 1: Mass concentration ratio of SerMA and ColMA in hydrogels prepared in Examples 1 to 12 and Comparative Examples 1 and 2

[0066]

[0067]

[0068] The performance of the hydrogels prepared in Examples 1 to 12 and Comparative Examples 1 and 2 was tested as follows:

[0069] 1. MRI test

[0070] 3-5 mg of the methacrylated sericin obtained in step S1 and the methacrylated collagen obtained in step S2 of Example 1 were weighed respectively, dissolved in an appropriate amount of deuterated heavy water, and then placed in a clean NMR tube. The NMR structures were determined at room temperature using a NMR spectrometer, and the spectrum was analyzed using MestReNova software.

[0071] from Figure 1 and Figure 2 The comparative analysis of NMR showed that the characteristic functional groups of methacrylate (δ=5.5 and 5.8 ppm) appeared on the products of step S1 and step S2, thus proving that SerMA and ColMA were successfully prepared.

[0072] 2. Scanning electron microscope test

[0073] The prepared hydrogels in Comparative Example 1 and Example 8 were freeze-dried and sprayed with gold, and then observed under a scanning electron microscope. The test conditions were: 5 kV electron beam.

[0074] from Figure 3 It can be seen that Comparative Example 1 ( Figure 3 -A) and Example 8 ( Figure 3 -B) The prepared hydrogel presents a three-dimensional porous network structure. Compared with the pure 15% SerMA hydrogel, the pore size of the 15% SerMA / 4% ColMA in Example 8 is reduced and the pore density is increased. The results show that the addition of ColMA promotes the densification of the hydrogel.

[0075] 3. Swelling rate test

[0076] The hydrogel was placed in a 37°C water bath for 15 min and then demolded. Its initial weight was weighed and recorded as W0. The hydrogel was immersed in a PBS buffer solution with a pH of 7.4. The hydrogel was taken out at regular intervals and the water on the surface of the hydrogel was quickly absorbed with a slightly moistened filter paper. The weight of the hydrogel was then weighed until the weight of the hydrogel remained basically unchanged. The weight of the hydrogel when it was saturated with water was recorded as W. t , the swelling rate of hydrogel was calculated according to the formula.

[0077]

[0078] When the hydrogel is used as a wound dressing, it can absorb the tissue fluid flowing out of the wound through the water absorption and swelling performance, and can keep the wound surface moist. Appropriate swelling performance can avoid excessive accumulation of secretions leading to wound infection and inflammation, and can also provide nutrients for cells, which is beneficial to cell growth and reproduction and promotes wound healing. The swelling degree results of the hydrogels of Comparative Example 1 and Examples 1 to 12 are shown in Table 2.

[0079] Table 2: Swelling degree of hydrogels prepared in Examples 1 to 12 and Comparative Examples 1 and 2

[0080] Grouping Swelling degree Example 1 1.52 Example 2 1.65 Example 3 1.58 Example 4 1.65 Example 5 1.76 Example 6 1.72 Example 7 1.78 Example 8 2.13 Example 9 1.62 Example 10 1.43 Embodiment 11 1.58 Example 12 1.42 Comparative Example 1 1.13 Comparative Example 2 1.02

[0081] As shown in Table 2, the swelling degree of the hydrogel containing only SerMA in Comparative Example 1 is 1.13, the swelling degree of the hydrogel containing only ColMA in Comparative Example 2 is 1.02, and the swelling degree of the hydrogels of Examples 1 to 12 is ≥1.42, of which Example 8 can reach up to 2.13. It can be seen that the compounding of SerMA and ColMA can significantly improve the swelling degree of the hydrogel. At the same time, it can be seen from Examples 1 to 12 that the concentration ratio of SerMA to ColMA can affect the swelling degree of the hydrogel. In Examples 1 to 12, when the concentration of SerMA is constant, the swelling degree of the double protein hydrogel increases with the increase of the concentration of ColMA, but when the concentration of ColMA increases to 4%, the swelling degree of the hydrogel has a turning point, and then there is no increase in the concentration of ColMA. When the concentration of ColMA increases to 6%, the swelling degree is reduced instead. In addition, it can be seen from Table 2 that when the concentration of ColMA is constant, the swelling degree of the double protein hydrogel increases with the increase of the concentration of SerMA, but when the concentration of SerMA increases to 20%, the swelling degree of the hydrogel has a turning point, and then there is no increase with the increase of the concentration of SerMA. When the concentration of SerMA increases to 20%, the swelling degree decreases instead. This shows that the concentrations of SerMA and ColMA in the double protein hydrogel of the present invention can affect the swelling degree of the hydrogel, and the swelling degree of the hydrogel can only be increased within a certain concentration range.

[0082] 4. Compression performance test

[0083] The hydrogel sample is placed directly below the special probe for gel strength. The gel probe squeezes the hydrogel until it breaks. The force required for the hydrogel to break is recorded, which is defined as the compressive strength (or compression modulus) of the hydrogel. An ideal hydrogel should have good mechanical properties to maintain its convenience and integrity during use. The compression properties of the hydrogels prepared in Comparative Examples 1 and 2 and Examples 1 to 12 are shown in Table 3.

[0084] Table 3: Compression modulus of hydrogels prepared in Examples 1 to 12 and Comparative Examples 1 and 2

[0085]

[0086]

[0087] As shown in Table 3, the compressive strength of the hydrogel containing only SerMA in Comparative Example 1 is 150.39 kPa, the compressive strength of the hydrogel containing only ColMA in Comparative Example 2 is 145.25 kPa, and the compressive strength of the hydrogels of Examples 1 to 12 is ≥150.39, wherein Example 8 can reach up to 253.40 kPa. It can be seen that the compounding of SerMA and ColMA can significantly improve the compressive strength of the hydrogel. At the same time, as shown in Examples 1 to 12, the concentration ratio of SerMA to ColMA can affect the compressive strength of the hydrogel. In Examples 1 to 12, when the concentration of SerMA is constant, the compressive strength of the double protein hydrogel increases with the increase of the concentration of ColMA, but when the concentration of ColMA increases to 4%, the compressive strength of the hydrogel has a turning point, and then there is no increase in the concentration of ColMA. When the concentration of ColMA increases to 6%, the compressive strength decreases instead. In addition, it can be seen from Table 3 that when the concentration of ColMA is constant, the compressive strength of the double protein hydrogel increases with the increase of SerMA concentration, but when the concentration of SerMA increases to 20%, the compressive strength of the hydrogel has a turning point, and then there is no increase with the increase of SerMA concentration. When the concentration of SerMA increases to 20%, the compressive strength decreases instead. This shows that the concentrations of SerMA and ColMA in the double protein hydrogel of the present invention can affect the compressive strength of the hydrogel, and the compressive strength of the hydrogel can only be improved within a certain concentration range.

[0088] In summary, it can be seen from Tables 2 and 3 that the compounding of SerMA and ColMA has a synergistic effect. The lack of any one of the comparative examples 1 and 2 cannot achieve the purpose of improving the swelling degree and compression strength of the hydrogel. The concentration ratio of SerMA and ColMA can not only affect the swelling degree of the hydrogel but also its compression strength. The inventors have shown through Examples 1 to 12 that the compression modulus and swelling degree of the SerMA / ColMA double protein hydrogel can be adjusted by adjusting the concentrations of SerMA and ColMA. Therefore, a double protein hydrogel with a maximum compression modulus of ≥180.25 kPa and a swelling degree of ≥1.42 can be obtained in the range of 5 to 20% mass concentration of SerMA and 2 to 4% mass concentration of ColMA, which is a biomaterial with potential biomedical application prospects.

[0089] Embodiment 13

[0090] This embodiment provides a dual-protein hydrogel with biological activity, and the specific operation is as follows:

[0091] S1: Preparation of modified sericin (SerMA), the specific operation is as follows:

[0092] Cut 40g of silk cocoons into small pieces and wash with deionized water. Then soak the cocoons in 400mL of 0.02M Na2CO3 solution and boil for 1h. Take out the boiled solution every half an hour, then filter through filter cloth to remove impurities to obtain sericin stock solution. Take 300mL of sericin solution and slowly add 6mL of methacrylic anhydride to the sericin solution with a burette. After stirring at room temperature for 6h, centrifuge at 6000r / min for 8min to take the supernatant, and then filter through filter cloth (22-25μm) again to remove impurities. Dialyze in a dialysis bag (molecular weight 3500Da) for 3-5 days. Finally, freeze-dry to obtain methacrylated sericin protein (SerMA).

[0093] S2: Prepare modified collagen (ColMA), the specific operation is as follows:

[0094] Weigh 10g of collagen and dissolve it in 200mL of distilled water. After dissolving at 37℃, add 6mL of methacrylic anhydride and react at 37℃ for 5h. Dialyze with distilled water for 2-3 days. The molecular weight cutoff of the dialysis bag is 1000Da. Freeze-dry at -80℃ to obtain methacrylated collagen (ColMA).

[0095] S3: Preparation of SerMA / ColMA / PRP hydrogel, the specific operation is as follows:

[0096] The SerMA prepared in step S1, the ColMA prepared in step S2, and the LAP photoinitiator were dissolved in deionized water, and then platelet-rich plasma was added (the volume ratio of PRP to the hydrogel solution was 1:10, and the PDGF-BB, TGF-β1, and EGF in the PRP were 17440.18±82.53 pg / mL, 8643.05±69.72 pg / Ml, and 885.68±5.31 pg / mL, respectively), and irradiated with ultraviolet light for 30 seconds to obtain the SerMA / ColMA / PRP hydrogel, in which the mass concentration of SerMA was 15%, the mass concentration of ColMA was 4%, and the mass concentration of the LAP photoinitiator was 0.1%.

[0097] The hydrogel prepared in Example 13 was tested for its effects, as follows:

[0098] 1. In vitro growth factor release performance

[0099] In the in vitro release study, the hydrogel prepared in Example 13 was placed in 1 mL of PBS solution (pH 7.4) and incubated at 37° C. The PBS supernatant was collected at each time point and replaced with the same volume of fresh PBS. The collected PBS was stored at -80° C. The content of platelet-derived growth factor (PDGF) was detected by enzyme-linked immunosorbent assay (ELISA), and the cumulative release rate was calculated.

[0100] Due to the special spatial structure of hydrogel, different drugs can be loaded and released slowly. Figure 1 It can be seen that in the initial 24h, PDGF was observed to be released faster, probably because PDGF on the surface and shallow layer of the hydrogel was released. After the burst release, PDGF on the surface and shallow layer of the hydrogel was completely released, and the release rate decreased. After 24h, it continued to release slowly. It is speculated that it is due to the following three reasons: first, the internal movement of the hydrogel and the external release balance; then, the slow degradation of the hydrogel leads to the release of PDGF from the hydrogel; as the surface and shallow layer of PDGF are released, the PDGF concentration inside the hydrogel is low, and the release driving force becomes weaker.

[0101] 2. Cell Survival Rate

[0102] Select L929 fibroblasts with spindle or triangular morphology for cell planting. Count the cells using a cell counting plate and dilute them to a certain concentration. The cell planting density for this experiment is 3×10 4 cells / well, and then planted in the corresponding wells of the 24-well culture plate where the hydrogel was placed, and then cultured in a carbon dioxide incubator at 37°C for a certain period of time, the corresponding well plate of the cultured cells was taken out, 50ul of CCK8 solution was added to each well, and a negative control (blank culture medium) was set, and cultured in a cell culture incubator for 30min-60min. According to the color change, the culture plate was taken out and the liquid in the corresponding well was pipetted into a 96-well plate. The absorbance value (OD value) was detected at a wavelength of 450nm on the microplate reader, and the data was recorded and calculated. The cell viability test was performed on the dressings prepared in Example 8, Example 13 and Comparative Example 1, and the test results are as follows. Figure 2 shown.

[0103]

[0104] Cell activity Figure 2 As shown, the relative survival rate of cells in the SerMA hydrogel group prepared in Comparative Example 1 was comparable to that in the control group, indicating that the SerMA hydrogel group had no cytotoxicity. However, the survival rates of cells in Example 8 (15% SerMA / 4% ColMA) and Example 13 (15% SerMA / 4% ColMA / PRP) hydrogels were significantly higher than those in the control group. This is mainly due to the good biocompatibility of collagen and the three-dimensional porous structure of the hydrogel, which can promote cell proliferation. Moreover, PRP contains a variety of cell growth factors, which can synergistically promote cell proliferation.

[0105] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A dual-protein elastic hydrogel, characterized in that: It comprises sericin modified by methacrylic anhydride and collagen modified by methacrylic anhydride, the swelling degree of the hydrogel is ≥1.42, and the compression modulus is ≥180.25 kPa; the mass concentration of the sericin modified by methacrylic anhydride is 5-20%, and the mass concentration of the collagen modified by methacrylic anhydride is 2-6%; the methacrylic anhydride modified collagen is obtained by dissolving collagen powder, adding methacrylic anhydride, reacting, dialyzing, and finally freeze-drying the dialyzed solution; the dialysis molecular weight cutoff is 1000 Da.

2. The dual-protein elastic hydrogel according to claim 1, characterized in that The hydrogel also includes cell growth factors.

3. The dual-protein elastic hydrogel according to claim 2, characterized in that: The cell growth factor is platelet-rich plasma.

4. A method for preparing the dual-protein elastic hydrogel according to claim 1, characterized in that: The method comprises the following steps: S1: preparing modified sericin: chopping silkworm cocoons, soaking and boiling them in a Na2CO3 solution, removing impurities, and obtaining a sericin stock solution; dropping methacrylic anhydride into the sericin stock solution, stirring, centrifuging, removing impurities, dialyzing the solution, and finally freeze-drying the dialyzed solution to obtain methacrylated sericin; S2: preparing modified collagen: after the collagen powder is dissolved, methacrylic anhydride is added to react, followed by dialysis, and finally the dialyzed solution is freeze-dried to obtain methacrylated collagen; S3: preparing a dual-protein elastic hydrogel: dissolving the methacrylated sericin prepared in step S1, the methacrylated collagen prepared in step S2, and a LAP photoinitiator in water, and irradiating with ultraviolet light to obtain a dual-protein elastic hydrogel.

5. The preparation method according to claim 4, characterized in that: The molecular weight cut-off of the dialysis bag used in step S1 is 3500 Da.

6. The preparation method according to claim 4, characterized in that: The molecular weight cut-off of the dialysis bag used in step S2 is 1000 Da.

7. The preparation method according to claim 4, characterized in that: The ultraviolet irradiation time is 30 s; the mass concentration of the photoinitiator is 0.1%.

8. A method for preparing the dual-protein elastic hydrogel according to any one of claims 2 to 3, characterized in that: The method comprises the following steps: S1: preparing modified sericin: chopping silkworm cocoons, soaking and boiling them in a Na2CO3 solution, removing impurities, and obtaining a sericin stock solution; dropping methacrylic anhydride into the sericin stock solution, stirring, centrifuging, removing impurities, dialyzing the solution, and finally freeze-drying the dialyzed solution to obtain methacrylated sericin; S2: preparing modified collagen: after the collagen powder is dissolved, methacrylic anhydride is added to react, followed by dialysis, and finally the dialyzed solution is freeze-dried to obtain methacrylated collagen; S3: dissolving the methacrylated sericin prepared in step S1, the methacrylated collagen prepared in step S2 and a photoinitiator in deionized water, adding cell growth factors, and irradiating with ultraviolet light to obtain a dual-protein elastic hydrogel with biological activity.

9. Use of the dual-protein elastic hydrogel according to any one of claims 1 to 3 as a tissue repair material or a tissue engineering scaffold in the field of tissue engineering.

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