Fibroin-based platelet-rich plasma composite hydrogel as well as preparation method and application thereof

Abstract

The invention relates to the technical field of hydrogel, in particular to fibroin-based platelet-rich plasma composite hydrogel as well as a preparation method and application thereof. The composition comprises platelet-rich plasma (including plasma, platelet lysis buffer, platelet-rich fibrin and fibrin of high-concentration concentrated growth factors), fibroin, a tannic acid solution and a functional metal ion solution (zinc ions). The platelet-rich plasma can be applied to the tissue repair process in the field of biomedicine, and the problems that in the prior art, platelet-rich plasma is poor in mechanical property, difficult to be completely attached to the wound surface and poor in anti-inflammatory and anti-oxidation performance are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogels, and particularly relates to a silk protein-based platelet-rich plasma composite hydrogel, a preparation method thereof, and an application thereof. Background Art

[0002] Tissue injury is a complex phenomenon, usually caused by multiple factors, including mechanical injury, physical injury, chemical injury, and biological injury. Tissue repair is the natural process by which the body repairs and restores these injuries. This process is traditionally divided into three stages: the inflammatory phase, which is the initial stage of wound healing and involves blood clotting and the aggregation of inflammatory cells; the granulation tissue formation phase, during which new blood vessels and connective tissues begin to form to fill the wound; and the tissue remodeling phase, which involves the rearrangement of collagen fibers and the enhancement of wound strength.

[0003] During the process of tissue trauma repair, many challenges and problems may be encountered. For example, excessive inflammatory responses may lead to increased tissue damage, while excessive oxidative stress may damage cells and tissues, affecting normal wound healing. These factors may all delay the process of wound healing, increase the risk of infection, and may lead to the formation of chronic wounds. Chronic wounds not only affect the quality of life of patients but may also cause systemic complications. Therefore, the management and treatment of these problems are crucial. Thus, it is very important to achieve rapid and effective tissue treatment.

[0004] Platelet-Rich Plasma (PRP for short) is a plasma product containing a high concentration of platelets obtained by centrifuging whole blood. PRP contains a large number of growth factors, cytokines, and proteins, which play a crucial role in the process of tissue repair and regeneration. After being activated in PRP, platelets can release a variety of bioactive molecules, such as platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), insulin-like growth factor (IGF), epidermal growth factor (EGF), etc. These factors can promote cell proliferation, differentiation, and matrix synthesis, thus accelerating wound healing and tissue repair. PRP treatment has been widely used in a variety of medical fields, including oral and maxillofacial surgery, plastic surgery, sports medicine, dermatology, etc., due to its advantages of promoting tissue healing, reducing inflammation, and improving biocompatibility. In oral medicine, PRP is used to promote periodontal tissue regeneration, accelerate implant integration, improve the quality of osseointegration, and treat chronic refractory wounds, etc.

[0005] Although PRP treatment demonstrates significant potential and advantages, its efficacy is influenced by various factors, such as the preparation technology of PRP, the concentration of platelets, the selection of activators, the timing and methods of treatment, etc. In oral medicine, PRP is mainly used for tissue repair, usually by making PRP into a gel-like form and applying it to the wound. This PRP gel is activated and formed by adding a specific proportion of thrombin and calcium gluconate to liquid PRP. As an autologous, sterile, and non-allergenic regenerative medicine product, PRP gel shows important clinical application value in the treatment of various wounds.

[0006] However, in practical applications, this PRP gel faces some challenges, such as insufficient mechanical properties, difficulty in adapting to irregular wound surfaces, easy flushing and shedding, and relatively weak anti-inflammatory and antioxidant properties. Therefore, although PRP gel has great potential in promoting tissue repair and tissue regeneration, due to its poor mechanical properties and limited utilization efficiency of single biological functions, these factors limit the application scope of PRP in the medical field.

[0007] Silk protein materials mainly include sericin and fibroin. Among them, sericin is a colloidal protein that wraps around fibroin, has a relatively low molecular weight and high water solubility, and has historically been mainly used for protection and gluing in the silk processing process. Due to its good biocompatibility, moisturizing property, and antioxidant characteristics, sericin has attracted attention as an active ingredient for promoting cell growth and skin regeneration in the field of modern biomaterials, especially in skin care, drug delivery systems, and tissue engineering. With the further understanding of the unique biological properties of sericin, its application potential in healthcare and biotechnology is being continuously explored and utilized.

[0008] Tannic Acid (TA), as a natural organic compound widely present in nature, is particularly well-known for its rich bioactive components in red wine. This polyphenolic substance exhibits strong chemical activity due to the presence of multiple hydroxyl and phenolic hydroxyl groups in its molecular structure, enabling it to form stable cross-linked networks with various metal ions such as iron, copper, and zinc. These properties endow tannic acid with unique value in multiple fields, especially in antibacterial, antioxidant, and anti-inflammatory aspects. It can inhibit the growth of various bacteria, slow down oxidative stress reactions, reduce the damage of free radicals to cells, and alleviate inflammatory responses, protecting tissues from damage. When tannic acid binds to functional metal ions, it can not only exert its powerful antioxidant ability but also release metal ions to perform the functions of metal ions. For example, zinc is a cofactor of many metal enzymes and participates in the activities of hundreds of enzymes, including carbonic anhydrase, lactate dehydrogenase, and alkaline phosphatase, which is crucial for cell metabolism. Zinc ions also have a regulatory effect on the immune system and can inhibit the synthesis and release of inflammasomes within cells, thereby suppressing and alleviating inflammation; silver ions can disrupt the cell walls and cell membranes of bacteria, thus killing bacteria; copper ions can damage the cell membranes and DNA of bacteria, thereby having an inhibitory and killing effect on various microorganisms.

[0009] Tissue dressings are medical products used for treating tissues and play an important role in the field of wound repair. These dressings are designed to provide local treatment to reduce inflammation, control infection, promote the healing of damaged tissues, and potentially promote tissue regeneration. Types of tissue dressings include film dressings, hydrogel dressings, foam dressings, and bioactive dressings containing growth factors and cytokines. However, many tissue dressings currently used clinically have relatively single components and mainly exhibit limited therapeutic effects, being insufficient for enhancing the comprehensive therapeutic effect.

[0010] With the development of biomaterial science and tissue engineering, significant progress has been made in the research and development of tissue dressings. Modern tissue dressings not only focus on controlling infection and promoting healing but also begin to pay attention to how to better simulate and promote the natural regeneration process of periodontal tissues. For example, some dressings combine biocompatible materials and bioactive molecules such as platelet-rich plasma (PRP) or bone morphogenetic proteins (BMPs) to enhance their therapeutic effects and provide more comprehensive treatment plans for patients.

[0011] In view of the above deficiencies, the inventors of the present invention finally obtained the present invention through long-term research and practice. Summary of the Invention

[0012] The object of the present invention is to solve the problems that currently commonly used tissue repair materials face disadvantages such as component residues, limited effects, and high costs, and provides a silk fibroin-based platelet-rich plasma composite hydrogel, a preparation method thereof, and its application.

[0013] To achieve the above object, the present invention discloses a preparation method of a silk protein-based platelet-rich plasma composite hydrogel, comprising the following steps:

[0014] S1, adding freeze-dried silk protein powder into deionized water, stirring and dissolving at 90 °C to form a silk protein solution, and cooling it to obtain a silk protein hydrogel;

[0015] S2, fully mixing and crosslinking the silk protein hydrogel obtained in step S1 with a tannic acid-functional metal ion chelating solution and platelet-rich plasma by the counterflow method to obtain a composite hydrogel.

[0016] In the above step S1, the silk protein solution is any one of a sericin protein solution, a fibroin protein solution, and a sericin protein-fibroin protein mixed solution.

[0017] In the above step S2, the platelet-rich plasma is any one of platelet-rich plasma, platelet lysate, platelet-rich fibrin, and fibrin with high-concentration concentrated growth factor.

[0018] In the above step S2, first fully mix the silk protein solution and the tannic acid-functional metal ion chelating solution by the counterflow method, and then fully mix and crosslink with platelet-rich plasma by the counterflow method to obtain a composite hydrogel.

[0019] In the above step S2, the functional metal ion in the tannic acid-functional metal ion chelating solution is zinc ion.

[0020] In the above step S2, the mass ratio of platelet-rich plasma, silk protein solution, and tannic acid-zinc chelating solution is 1:8:1 - 6:3:1.

[0021] In the above step S2, the mass ratio of platelet-rich plasma, silk protein solution, and tannic acid-functional metal ion chelating solution is 4:5:1.

[0022] The present invention also discloses a silk protein-based platelet-rich plasma composite hydrogel prepared by the above preparation method and the application of this silk protein-based platelet-rich plasma composite hydrogel in the preparation of tissue dressings.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The present invention realizes the mechanical improvement of the platelet-rich plasma-sericin protein composite hydrogel by introducing a sericin protein hydrogel with high mechanical properties and excellent rheological properties;

[0025] 2. The present invention realizes the improvement of the injectability of the platelet-rich plasma-sericin protein composite hydrogel by introducing an injectable sericin protein hydrogel;

[0026] 3. The gel formed by the homogeneous mixing of the sericin hydrogel and the platelet-rich plasma prepared by the present invention is a platelet-rich composite hydrogel. By introducing tannic acid-zinc ions, the biological function of the hydrogel is enhanced, enabling the hydrogel to have anti-inflammatory and antioxidant properties, which is more conducive to tissue repair and healing.

[0027] 4. Most of the platelet-rich plasma in the present invention is collected from autologous blood, containing a variety of growth factors with high concentrations that promote cell proliferation and differentiation. It has no risk of immune rejection and disease transmission, and the infection probability is reduced, being safe and reliable. The sericin is extracted from natural silk and has good biocompatibility.

[0028] 5. The technology for preparing platelet-rich plasma in the present invention is mature and convenient, and has a good clinical application foundation. The sericin extraction process is simple and inexpensive.

[0029] 6. By introducing sericin into platelet-rich plasma, compared with the platelet-rich plasma gel currently used clinically, the mechanical properties of the present invention are improved. The promotion of tissue healing and repair is achieved by loading platelet-rich plasma in the hydrogel, and it has high biological activity. The introduction of sericin significantly improves the injectability of the hydrogel dressing, which can enhance the clinical treatment of the dressing for irregular tissue wounds. The high biosecurity and low-cost characteristics of sericin can realize the low-cost preparation of a new generation of hydrogel dressings with high safety and high treatment quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Scanning electron microscope pictures of the composite materials prepared in Example 3 and Comparative Example 1, (a) Comparative Example 1, (b, c, d, e, f) Example 3;

[0031] Figure 2 Rheological characterizations of the PRP composite hydrogels prepared in Examples 3-7, (a) Examples 3 and 4, 5, (b) Examples 6 and 7;

[0032] Figure 3 Injectability characterizations of Example 3, (a) The force required to inject the hydrogel from a 1 ml syringe through 27, 25, 23G needles at a set flow rate (3.0 mL / min), (b) and the force required to inject the hydrogel from a 1 ml syringe at a speed of 3.0, 2.0, 1.0 mL / min with a set needle aperture (27G);

[0033] Figure 4 In vitro antioxidant performance curves of Example 3 and Comparative Examples 1 and 2, (a) DPPH scavenging rates of Example 3 and Comparative Examples 1 and 2; (b) UV absorption peaks of DPPH of Example 3 and Comparative Examples 1 and 2 at 400-700 nm; (c) Pictures of the DPPH supernatant of Example 3 and Comparative Examples 1 and 2;

[0034] Figure 5 For the safety assessment of the hydrogels prepared in Example 3 and Examples 8 and 9 on cells, (a) cell viability graphs on the 1st, 3rd, and 5th days after co-culture of Example 3 with cells, (b) cell viability graphs on the 1st day after co-culture of Example 3 and Examples 8 and 9 with cells;

[0035] Figure 6 Pictures of the effect of the hydrogels prepared in Example 3 and Comparative Examples 2 and 3 on cell migration 24 hours after treating cells;

[0036] Figure 7 Graph of the content of inflammatory factor (IL-1β) in the cell supernatant after treating cells with the hydrogels prepared in Example 3 and Comparative Examples 2 and 3. Detailed implementation mode

[0037] The following further elaborates on the above and other technical features and advantages of the present invention with reference to the accompanying drawings.

[0038] Example 1

[0039] A preparation method of a 10% sericin aqueous solution, comprising the following steps:

[0040] Since sericin needs to be dissolved in hot water and it is difficult to be fully dissolved by conventional magnetic stirring at room temperature, therefore, this solution adopts the heating and stirring method for preparation. Weigh 0.2 g of sericin powder and 20 g of water in advance and put them into a 50 mL beaker respectively, and heat and stir them in a water bath through a magnetic heating stirrer to make them fully dissolved.

[0041] Example 2

[0042] A preparation method of a tannic acid-zinc ion solution, comprising the following steps:

[0043] Fully mix a 0.5 mg / mL tannic acid solution and a 0.338 mg / mL zinc sulfate solution evenly, and then add a 0.05 mol / L sodium bicarbonate solution to consume the excessive H + , and the volume ratio of the three is 10:10:1.

[0044] Example 3

[0045] A preparation method of a 40-PRP-SS-TA / Zn (40-PSTZ) composite hydrogel, comprising the following steps:

[0046] Fully mix a 10% sericin hydrogel and a TA / Zn aqueous solution evenly by the counterflow method, and then add PRP and mix them evenly by the counterflow method, and the mass ratio of the three is 4:5:1.

[0047] Example 4

[0048] Preparation method of 20-PRP-SS-TA / Zn (20-PSTZ) composite hydrogel, comprising the following steps:

[0049] Fully and evenly mix 10% sericin hydrogel with TA / Zn aqueous solution by the counterflush method, and then add PRP and fully mix evenly by the counterflush method. The mass ratio of the three is 2:7:1.

[0050] Example 5

[0051] Preparation method of 50-PRP-SS-TA / Zn (50-PSTZ) composite hydrogel, comprising the following steps:

[0052] Fully and evenly mix 10% sericin hydrogel with TA / Zn aqueous solution by the counterflush method, and then add PRP and fully mix evenly by the counterflush method. The mass ratio of the three is 5:4:1.

[0053] Example 6

[0054] Preparation method of 60-PRP-SS-TA / Zn (10-PSTZ) composite hydrogel, comprising the following steps:

[0055] Fully and evenly mix 10% sericin hydrogel with TA / Zn aqueous solution by the counterflush method, and then add PRP and fully mix evenly by the counterflush method. The mass ratio of the three is 6:3:1.

[0056] Example 7

[0057] Preparation method of 10-PRP-SS-TA / Zn (10-PSTZ) composite hydrogel, comprising the following steps:

[0058] Fully and evenly mix 10% sericin hydrogel with TA / Zn aqueous solution by the counterflush method, and then add PRP and fully mix evenly by the counterflush method. The mass ratio of the three is 1:8:1.

[0059] Example 8

[0060] Preparation method of 40-PL-SS-TA / Zn (40-PL-STZ) composite hydrogel, comprising the following steps:

[0061] Fully and evenly mix 10% sericin hydrogel with TA / Zn aqueous solution by the counterflush method, and then add platelet lysate and fully mix evenly by the counterflush method. The mass ratio of the three is 4:5:1.

[0062] Example 9

[0063] Preparation method of 40-PRF-SS-TA / Zn (40-PRF-STZ) composite hydrogel, comprising the following steps:

[0064] Fully mix 10% sericin hydrogel and TA / Zn aqueous solution evenly by the counterflush method, and then add platelet-rich fibrin and fully mix evenly by the counterflush method. The mass ratio of the three is 4:5:1.

[0065] Comparative example 1

[0066] Preparation of 10% sericin hydrogel: Add 0.1 g of freeze-dried sericin powder to 10 g of deionized water, and stir and dissolve at 90 °C to form sericin hydrogel.

[0067] Comparative example 2

[0068] Preparation of PRP gel: Add 2000 units of freeze-dried thrombin powder to 8 mL of 10% calcium gluconate injection for dilution to prepare a PRP thrombin activator of 250 units / mL. Use a syringe to aspirate PRP and the pre-prepared thrombin activator respectively. The volume ratio of PRP to thrombin activator is 10:1, and PRP gel is prepared through a three-way valve.

[0069] Comparative example 3

[0070] Preparation method of SS-TA / Zn (STZ) composite hydrogel: Fully mix 10% sericin hydrogel and TA / Zn aqueous solution evenly by the counterflush method. The mass ratio of the two is 5:1.

[0071] 1. Observe the porous structure of the material by scanning electron microscope:

[0072] After freeze-drying the prepared samples of Example 3 and Comparative Example 1 respectively, stick the materials on a metal bracket with conductive double-sided tape, spray gold, and then observe the structure of each material under a scanning electron microscope at an accelerating voltage of 20 kV.

[0073] Result analysis: From Figure 1 It can be seen that the prepared hydrogel presents a three-dimensional porous network structure. Compared with the sericin gel of Comparative Example 1, the pore size of the hydrogel prepared in Example 3 is relatively uniform, and the uniform loading of PRP and TA / Zn can be observed. The results show that sericin, PRP and TA / Zn form an interpenetrating network structure.

[0074] 2. Rheological test:

[0075] Approximately 2 mL of the material sample was evenly placed on the rheometer test bench. At a test temperature of 25 °C and a frequency range of 0.1 - 100 Hz / rad / s, the storage modulus G’ (Pa) and loss modulus G” (Pa) were recorded. In the flow sweep mode at 25 °C, a frequency sweep was performed from 100 - 0.1 Hz / rad / s from high to low.

[0076] Result analysis: From Figure 2 it can be seen that the storage modulus G’ and loss modulus G” were measured in the frequency sweep. The storage modulus measures the ability of the material to store energy and reflects the network cross - link density. The higher the cross - link degree, the greater the storage modulus; while the loss modulus measures the dissipation of the material's energy, that is, the energy lost as heat. The value of G’ provides information on the gel strength. G’ being higher than G” indicates that the gel is more elastic and solid - like. Figure 2 (a) shows the frequency sweep test curves of hydrogels with different ratios. The results all exhibit the typical viscoelastic behavior of hydrogels with G’ higher than G”. When the shear frequency gradually increases, G’ > G” proves that the hydrogel is stable and has good mechanical properties. Figure 2 (b) shows the frequency sweep test curves of the hydrogels with the end - value ratios, indicating that as the proportion of PRP increases, the modulus of the hydrogel gradually decreases.

[0077] 3. Injectability test:

[0078] To study the injectability of the hydrogel, the force required to inject the hydrogel through 27G, 25G, 23G needles from a 1 mL syringe at a set flow rate (3.0 mL / min) and the force required to inject the hydrogel from a 1 mL syringe at a set needle aperture (27G) at speeds of 3.0, 2.0, 1.0 mL / min were measured using a mechanical tester.

[0079] Result analysis: Figure 3 It shows that the force required to inject the PSTZ gel under different conditions is very small (<10 N), indicating good injectability. It can be injected in situ at the wound to achieve complete filling of the wound area with the PSTZ composite material.

[0080] 4. In vitro antioxidant performance test:

[0081] In the in vitro antioxidant study, 0.1 g, 0.05 g, and 0.04 g of the hydrogels prepared in Example 3 and Comparative Example 1 and Comparative Example 2 were accurately weighed and added to 500 μM DPPH solution respectively. After vortex mixing, they were incubated at room temperature in the dark for 30 minutes. The supernatant was taken to measure the ultraviolet absorption peak at 400 - 700 nm and the ultraviolet absorption value at 517 nm.

[0082] Result analysis: From Figure 4It can be seen that there are obvious differences in the scavenging of DPPH between Example 3 and Comparative Example 1 and Comparative Example 2. Example 3 can effectively scavenge most of the DPPH and has good antioxidant performance.

[0083] 5. Cell safety assessment:

[0084] HUVEC angiogenic cells were selected for culture. The cells were counted using a cell counter and diluted to a certain concentration. 100 μL of cell suspension was inoculated into a 96-well cell culture plate at a cell seeding density of 5×10 3 cells / well, and then pre-cultured in a carbon dioxide incubator at 37 °C for 12 h to allow the cells to adhere. After that, 100 μL of the material extract was added to each well of the culture plate. After co-culturing the material extract with the adherent cells for 24, 72, and 120 h, 10 μL of CCK8 solution was added to each well. After culturing in a carbon dioxide incubator at 37 °C for 60 - 120 min, the absorbance value (OD value) was measured at a wavelength of 450 nm using an enzyme-linked immunosorbent assay (ELISA) reader, and the cell viability was recorded and calculated according to the formula.

[0085]

[0086] Result analysis: The cell safety of the hydrogels prepared in Example 3, Example 6, and Example 7 was evaluated, and the test results are as Figure 5 shown. As can be seen from Figure 5 (a), the relative cell viability of the hydrogel group was comparable to that of the control group, indicating that the prepared materials had no cytotoxicity. The cell viability of the composite hydrogel was significantly higher than that of the control group, mainly because PRP contains various cell growth factors that can synergistically promote cell proliferation. It can be seen that the composite hydrogel can effectively promote wound healing. As can be seen from Figure 5 (b), the cell viability of the composite hydrogels prepared from platelet-rich plasma, platelet lysate, and platelet-rich fibrin was comparable, and all were higher than that of the control group. This indicates that the composite hydrogels prepared from platelet-rich plasma, platelet lysate, and platelet-rich fibrin can all promote cell proliferation.

[0087] 6. Cell migration test:

[0088] The HUVEC cell suspension was inoculated into a 96-well culture plate and incubated at 37 °C and 5% CO 2Pre-culture overnight in an incubator. Observe that the cell confluence is about 80%, and use a scriber to make cell scratches. After making the scratches, wash off the detached cells with PBS buffer. Next, add DMEM / F12 medium containing different materials to each well as the treatment group, and use pure DMEM / F12 medium for the control group. Subsequently, use the Incucyte SX5 high-throughput live cell analysis system to take timed photos and count. Finally, use ImageJ software to analyze the images to determine the cell migration rate, and the results are as Figure 6 shown.

[0089] As can be seen Figure 6 from Figure 6 , the hydrogels prepared in Example 3 have a more obvious promoting trend in promoting cell migration compared to Comparative Examples 2 and 3, indicating that Example 3 has a positive effect on promoting wound healing and repair.

[0090] 7. Release test of inflammatory factor (IL-1β):

[0091] Inoculate the THP-1 cell suspension in a 6-well plate, and add 100 nM PMA to the cell suspension. Pre-culture overnight in an incubator at 37 °C and 5% CO 2 . The next day, remove the original medium and replace it with opti-MEM medium supplemented with LPS (100 ng / mL) for 3 hours of inflammatory induction. Add the groups of Example 3 and Comparative Examples 2 and 3 to each well respectively, and continue to culture for 3 hours. Finally, culture with nigericin (5 μM) for 40 minutes, collect the cell supernatant, and use an enzyme-linked immunosorbent assay (ELISA) kit to measure the content of IL-1β in the cell supernatant.

[0092] As can be seen Figure 7 from Figure 7 , the hydrogels prepared in Example 3 have obvious effects in inhibiting the production of inflammatory factor (IL-1β) by cells compared to Comparative Examples 2 and 3, indicating that Example 3 has a positive effect on inhibiting the occurrence and development of inflammation in wounds and is beneficial to tissue repair and healing.

[0093] The above are only the preferred embodiments of the present invention, which are illustrative rather than restrictive to the present invention. Those skilled in the art understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, but all will fall within the protection scope of the present invention.

Claims

1. A method for preparing a silk protein-based platelet-rich plasma composite hydrogel, characterized in that: The following steps are involved: S1, adding lyophilized silk protein powder into deionized water, stirring and dissolving at 90°C to form a silk protein solution, which is cooled to form a silk protein hydrogel; S2, the silk protein hydrogel obtained in step S1 is fully mixed with tannic acid-functional metal ion chelating solution and platelet-rich plasma by a hedge method to obtain a composite hydrogel by cross-linking.

2. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In the step S1, the silk protein solution is any one of a sericin solution, a fibroin solution, and a sericin-fibroin mixed solution.

3. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In step S2, the platelet-rich plasma is any one of platelet-rich plasma, platelet lysate, and platelet-rich fibrin.

4. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In the step S2, the silk protein solution and the tannic acid-functional metal ion chelating solution are firstly fully mixed by the hedge method, and then fully mixed with the platelet-rich plasma by the hedge method to cross-link to obtain the composite hydrogel.

5. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In the step S2, the functional metal ions in the tannic acid-functional metal ion chelating solution are zinc ions.

6. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In the step S2, the mass ratio of platelet-rich plasma, silk protein solution and tannic acid-zinc chelate solution is 1:8:1-6:3:

1.

7. The method for preparing a silk protein-based platelet-rich plasma composite hydrogel according to claim 1, characterized in that: In the step S2, the mass ratio of platelet-rich plasma, silk protein solution and tannic acid-functional metal ions is 4:5:

1.

8. A silk protein-based platelet-rich plasma composite hydrogel prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the silk protein-based platelet-rich plasma composite hydrogel as claimed in claim 8 in the preparation of tissue dressings.

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