Preparation method and application of high-stability sterile liquid dressing containing silk fibroin

Abstract

The invention belongs to the technical field of dressings. The invention provides a preparation method and application of a high-stability sterile liquid dressing containing silk fibroin. The preparation method comprises the following steps: (1) dissolving silk fibroin with water to obtain a silk fibroin solution; (2) dissolving a nonionic thickening agent in water until the nonionic thickening agent is completely dissolved, then adding the silk fibroin solution, and stirring and mixing to obtain a mixed solution; and (3) sterilizing the mixed solution to obtain the silk fibroin liquid dressing. The obtained sterile liquid dressing containing the silk fibroin still has high stability after being subjected to high heat and freezing treatment, and can form a film on the skin surface, maintain a wet healing environment and promote wound repair and tissue regeneration; the preparation method is free of preservatives, cross-linking agents and inducers, so that the irritation of the product is greatly reduced, and the safety is high; the method has the advantages of few raw materials, simplicity in operation, easiness in rapid batch production and the like, and has a good industrialization prospect.

Description

Technical Field

[0001] This invention belongs to the field of dressing technology, specifically relating to the preparation method and application of a highly stable sterile liquid dressing containing silk fibroin. Background Technology

[0002] As the body's largest barrier organ, the skin is susceptible to complications such as infection, prolonged inflammation, scar hyperplasia, and even tissue necrosis if its integrity is compromised, especially in cases of wounds (e.g., trauma, burns, chronic ulcers, and cosmetic surgery wounds). Improper repair of these wounds can severely impact patients' quality of life and increase the burden on the healthcare system. With the global incidence of chronic wounds (such as diabetic foot ulcers, venous ulcers, and pressure ulcers) continuing to rise, and with increasing demands for wound repair quality in fields like cosmetic medicine and surgery, the development of wound repair dressings that combine safety, bioactivity, and clinical suitability has become a research hotspot in regenerative medicine.

[0003] Natural polymeric liquids possess excellent biocompatibility and biodegradability, making them a promising biomedical material with increasing application potential and attracting growing attention. Among them, silk fibroin exhibits good biodegradability and biocompatibility, and was recognized as a biomaterial by the U.S. Food and Drug Administration (FDA) as early as 1993. It is widely used in surgical scaffold materials, vocal cord filling materials, drug carriers, and structural engineering repairs. As an ordered fibrous protein, silk fibroin has numerous hydrophobic groups and charges on its surface. Its regular network structure with a certain physical strength promotes orderly and rapid cell growth, while its hydrophilic and lipophilic properties help maintain the skin's water-oil balance. These properties give it significant advantages for use in dressings.

[0004] However, silk fibroin exhibits strong self-aggregation properties, readily transforming from a soluble, uncoiled structure into a more stable SIlk I or SIlk II structure. This self-assembly property is particularly pronounced under shearing, ultrasonic, thermal, and radiation exposure. Medical dressings commonly employ moist heat sterilization and irradiation sterilization. These sterilization methods often cause silk fibroin-containing liquid dressings to separate, precipitate, harden, or clump due to silk fibroin self-aggregation, making it difficult to prepare stable sterile silk fibroin-containing dressings, especially those with high silk fibroin content. Therefore, existing technologies typically employ cross-linking, heat treatment, and inducing agents to transform the silk fibroin structure during preparation, thereby maintaining the stability of the sterilized product.

[0005] Chinese patent publication number CN112546289A discloses a composite biological liquid dressing and its preparation method. This liquid dressing uses a chemical cross-linking agent to form chemical bonds between silk fibroin and other polymers to fix the structure of the silk fibroin, thereby achieving a radiation-sterilizable effect. However, the use of the cross-linking agent affects the product's biocompatibility and increases product safety risks. Chinese patent publication number CN115282324A discloses a silk fibroin liquid dressing, its preparation method, and its application. The preparation method involves swirling shearing of a silk fibroin solution followed by in-situ gelation through heat treatment to obtain a gel dressing. However, the heat treatment time is as long as 12 hours, significantly increasing the risk of microbial infection; simultaneously, due to differences in raw materials, batch-to-batch stability is difficult to control, resulting in poor reproducibility. Chinese patent publication number CN120132038A discloses a silk fibroin gel dressing, its preparation method, and its application, employing a structure-inducing agent to promote the structural transformation of silk fibroin, achieving a sterilizable effect through moist heat or radiation. However, the use of these inducers can also increase the risk to product safety.

[0006] Therefore, developing a sterile liquid dressing containing silk fibroin with good safety, effectiveness and excellent stability is an urgent problem to be solved. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a dressing that does not affect the dressing performance, has fewer additives, is safer and more stable, as well as the resulting dressing and its application.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a highly stable sterile liquid dressing containing silk fibroin, the method comprising the following steps: (1) Dissolve silk fibroin in water to obtain a silk fibroin solution; (2) Dissolve the nonionic thickener in water until completely dissolved, then add the silk fibroin solution and stir to obtain a mixture; (3) The mixture is then sterilized to obtain silk fibroin liquid dressing; The nonionic thickener is xanthan gum, or a combination of xanthan gum with one or more of hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl cellulose, and sodium hyaluronate. The nonionic thickener has a final weight fraction of 1% to 8% in the mixture.

[0009] Preferably, in step (1), 8 to 500 parts by weight of silk fibroin are added to 1,000 to 2,000 parts by weight of water to dissolve and obtain a silk fibroin solution.

[0010] Preferably, the silk fibroin has a final weight fraction of 0.08% to 5% in the mixture.

[0011] Preferably, in step (2), the nonionic thickener is xanthan gum.

[0012] Preferably, in step (2), the xanthan gum has a final weight fraction of 3% in the mixture.

[0013] Preferably, the silk fibroin has a final weight fraction of 3% in the mixture.

[0014] In step (3), the sterilization process includes moist heat sterilization or irradiation sterilization. Preferably, the sterilization process is moist heat sterilization.

[0015] A highly stable sterile liquid dressing containing silk fibroin, said dressing being prepared by the aforementioned preparation method.

[0016] The aforementioned application of a highly stable sterile liquid dressing containing silk fibroin in the preparation of wound healing agents.

[0017] The beneficial effects of this invention are: (1) The present invention uses nonionic thickeners such as xanthan gum, which can play a good role in interpenetrating and fixing the silk fibroin molecular chains, thereby improving the stability of silk fibroin and enabling sterile dressings to be obtained by moist heat or irradiation sterilization.

[0018] (2) The nonionic thickener used in this invention only fixes the silk fibroin molecular chain, without inducing or cross-linking, and does not change the physical properties of the liquid dressing. It will not cause the liquid dressing to separate, precipitate, harden or clump due to changes in silk fibroin concentration, storage conditions, etc. It has good product stability whether it is treated with high heat or freezing.

[0019] (3) This invention contains no preservatives, no cross-linking agents, and no inducing agents, which greatly reduces the irritation of the product and makes it highly safe.

[0020] (4) The raw materials of the present invention are derived from natural compounds, and therefore have good biocompatibility.

[0021] (5) The present invention has advantages such as fewer raw materials, simple operation, and easy rapid mass production, and has good industrialization prospects.

[0022] (6) The sterile liquid dressing containing silk fibroin obtained by the present invention can form a film on the skin surface, maintain a moist healing environment, and promote wound repair and tissue regeneration. Attached Figure Description

[0023] Figure 1This is a diagram showing the general observation results in Experiment Example 2 of the present invention; Figure 2 This is a diagram showing the results of skin pathological histology observation in Experimental Example 2 of this invention; Figure 3 The images show the appearance of the products obtained from each experimental group in Experimental Example 3 of this invention immediately after sterilization. Figure 4 The images show the appearance of the products obtained from each experimental group in Experiment Example 3 after being treated at 80℃ for 3 days. Figure 5 The image shows the appearance of the products obtained from each experimental group in Experiment Example 3 after freeze-thaw treatment at -20℃. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but are only used to illustrate the present invention. Example

[0025] A method for preparing a highly stable sterile liquid dressing containing silk fibroin, comprising the following steps by weight: (1) Add 300 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 300 parts xanthan gum with 8000 parts water and stir to dissolve for 2 hours. Then add silk fibroin solution and stir evenly to obtain a mixed solution. (3) The mixed solution was sterilized by moist heat (121℃, 15min) to obtain a sterile liquid dressing containing silk fibroin. Example

[0026] A method for preparing a highly stable sterile liquid dressing containing silk fibroin, comprising the following steps by weight: (1) Add 8 parts of silk fibroin to 1000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 200 parts xanthan gum, 200 parts hydroxyethyl cellulose and 9000 parts water, stir and dissolve for 2 hours, then add silk fibroin solution and stir evenly to obtain a mixed solution; (3) The mixed solution was sterilized by moist heat (121℃, 15min) to obtain a sterile liquid dressing containing silk fibroin. Example

[0027] A method for preparing a highly stable sterile liquid dressing containing silk fibroin, comprising the following steps by weight: (1) Add 500 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 300 parts xanthan gum, 200 parts hydroxyethyl cellulose and 8000 parts water, stir and dissolve for 3 hours, then add silk fibroin solution and stir evenly to obtain a mixed solution; (3) The mixed solution was irradiated and sterilized (20kGy) to obtain a sterile liquid dressing containing silk fibroin. Example

[0028] A method for preparing a highly stable sterile liquid dressing containing silk fibroin, comprising the following steps by weight: (1) Add 300 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 100 parts xanthan gum with 8000 parts water and stir to dissolve for 2 hours. Then add silk fibroin solution and stir evenly to obtain a mixed solution. (3) The mixed solution was sterilized by moist heat (121℃, 15min) to obtain a sterile liquid dressing containing silk fibroin. Example

[0029] A method for preparing a highly stable sterile liquid dressing containing silk fibroin, comprising the following steps by weight: (1) Add 300 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 300 parts xanthan gum, 100 parts carboxymethyl cellulose, 200 parts hydroxypropyl methyl cellulose, 200 parts hydroxypropyl cellulose with 8000 parts water, stir and dissolve for 5 hours, then add silk fibroin solution and stir evenly to obtain a mixed solution. (3) The mixed solution was sterilized by moist heat (121℃, 15min) to obtain a sterile liquid dressing containing silk fibroin.

[0030] Comparative Example 1 A method for preparing a dressing, comprising the following steps, by weight: (1) Add 300 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 300 parts of hydroxypropyl methylcellulose with 8000 parts of water, stir to dissolve, then add silk fibroin solution and stir evenly to obtain a mixed solution; (3) Sterilize the mixed solution with moist heat to obtain the dressing.

[0031] Comparative Example 2 A method for preparing a dressing, comprising the following steps, by weight: (1) Add 300 parts of silk fibroin to 2000 parts of water and stir to dissolve for 10 minutes to obtain a silk fibroin solution; (2) Mix 90 parts xanthan gum with 8000 parts water, stir to dissolve, then add silk fibroin solution and stir evenly to obtain a mixed solution; (3) Sterilize the mixed solution with moist heat to obtain the dressing.

[0032] Experimental Example 1 The stability and related properties of the dressings obtained in Examples 1-3 and Comparative Examples 1-2 were investigated, and the results are shown in Tables 1 and 2.

[0033] Table 1

[0034] Table 2

[0035] As shown in Table 1, the sterile liquid dressing containing silk fibroin obtained by this invention exhibits high stability. It maintains a gel-like state for up to 30 days at temperatures as low as -18°C and as high as 40°C, without any flocculent precipitation and remaining internally homogeneous. Meanwhile, as shown in Table 2, the sterile liquid dressing containing silk fibroin obtained by this invention demonstrates good film-forming properties, and its appearance, pH, and viscosity are all within suitable ranges.

[0036] Experimental Example 2 Based on a porcine skin injury model, the wound repair effect of the silk fibroin liquid dressings obtained in Examples 1-3 on the porcine skin injury model was observed.

[0037] 1. Methods: After acclimatization, animals were fasted for 12 hours before surgery, but allowed free access to water. They were given intramuscular injections of 2 mg / kg flunixin meglumine, 0.5 mg / kg atropine sulfate, and 1.6 million units of penicillin sodium for analgesia, to reduce secretions, and to fight infection. Fifteen minutes later, general anesthesia was induced by intravenous injection of 5 mg / kg propofol. The skin on the animal's abdomen and back was prepared, and a gas anesthesia machine was connected. Anesthesia was maintained using 1-3% isoflurane inhalation. The back skin of the pig was divided into multiple 2cm*2cm square grids, and "well" incisions were made using a 20G needle, with each lesion area measuring 2cm*2cm. After the first modeling, the back skin of the animal was treated by applying the treatment to the lesion area using the methods described in the examples and comparative examples, for 30 minutes each time. Sedation was administered to the animal if necessary.

[0038] 2. Observation indicators: 1) General observation The condition of the skin injury was observed, and photos were taken before treatment, immediately after modeling, and before and after each treatment to observe the wound healing process.

[0039] 2) Skin pathological histological observation After the biopsy tissue is fixed in formaldehyde, it is dehydrated, embedded in paraffin, sectioned, and stained with H&E to observe the pathological changes in the skin. After the treatment with repair patch or gel dressing is completed, biopsies are performed on all remaining modeling sites, and the tissues are fixed in formaldehyde and stored for later use.

[0040] 3. Experimental Results: 1) General observation After the skin is scratched with a needle, a regularly shaped red "well"-shaped stripe-like wound appears on the skin surface, with a clearly defined light red wound area visible. For example... Figure 1 As shown, at 7 days after treatment, there were no significant changes in the scratched areas of each group; at 14 days after treatment, the scratched areas of each group decreased in size and the redness lessened.

[0041] 2) Skin pathological histological observation Ten days after treatment, the wound was covered with a large amount of scabs, with underlying epidermal cell proliferation, but large areas remained unhealed, and no significant thickening of the epidermis was observed. Mild local edema, congestion, and hemorrhage were present in the superficial dermis, with a small number of fibroblasts and capillary proliferation in the granulation tissue, indicating inflammatory infiltration. After treatment, the lesions in all groups showed slight improvement. Fifteen days after treatment, the wound was covered with a large amount of scabs, the epidermal cells were still arranged continuously, and there was a thin layer of newly formed epidermal cells in some areas, without significant thickening. Local edema, congestion, and hemorrhage in the superficial dermis decreased, but there were still many fibroblasts and capillary proliferation in the granulation tissue, indicating inflammatory infiltration. After treatment, the lesions in all groups showed significant improvement, with reduced scab size, continuous and neat epidermal arrangement, aging of the granulation tissue, and a decrease in fibroblasts and capillaries. Edema, congestion, hemorrhage, and inflammatory infiltration were reduced. In Example 1, on day 10, a moderate amount of scab (black arrow) was visible covering the wound, indicating significant thermal damage. Extensive epidermal cell loss was observed (red arrow), and the epidermis showed mild to moderate thickening. The superficial dermis exhibited swelling of numerous collagen fibers, very mild edema with congestion, and abundant fibroblasts and capillary proliferation in the granulation tissue, with very mild inflammatory infiltration, primarily composed of lymphocytes. On day 15, all samples showed moderate to abundant scab (black arrow) covering the wound, with varying degrees of epidermal cell loss (red arrow), and mild thickening of the epidermis. The superficial dermis showed very mild localized edema with congestion and hemorrhage. The granulation tissue still showed abundant fibroblasts and capillary proliferation, with very mild inflammatory infiltration, primarily composed of lymphocytes. In Example 2, on day 10, the wound was covered with a large amount of blood clots (black arrows), indicating significant thermal damage. Extensive epidermal cell loss was observed (red arrows), with mild to moderate thickening of the epidermis. The superficial dermis showed significant collagen fiber swelling, mild congestion and hemorrhage, and the granulation tissue contained numerous fibroblasts and capillary proliferations with mild inflammatory infiltration, primarily composed of neutrophils and lymphocytes. On day 15, all samples showed a small to moderate amount of blood clots (black arrows) covering the wound. The samples exhibited extensive epidermal cell loss (red arrows), mild epidermal thickening, mild to moderate localized edema with mild to moderate congestion and hemorrhage in the superficial dermis, and the granulation tissue still showed numerous fibroblasts and capillary proliferations with mild to severe inflammatory infiltration, primarily composed of neutrophils and lymphocytes. In Example 3, on day 10, the wound showed a continuous and orderly arrangement of epidermal cells, with no significant thickening of the epidermis. The superficial dermis showed very mild edema with mild congestion and bleeding. Granulation tissue contained a small number of fibroblasts and capillary proliferations, with mild inflammatory infiltration, primarily composed of lymphocytes. On day 15, the wound showed a very small amount of blood crust (black arrow), with continuous and orderly arrangement of epidermal cells and no significant thickening. The superficial dermis showed very mild edema with very mild to mild congestion and bleeding. Granulation tissue was aged, with reduced fibroblasts and capillaries, and very mild inflammatory infiltration, primarily composed of lymphocytes.In the model group, on day 10, the wound was covered with a large amount of blood scabs (black arrows), with epidermal cells proliferating beneath them, but large areas were still unhealed (red arrows). The epidermis did not show significant thickening, and the superficial dermis showed localized mild edema with congestion and bleeding. The granulation tissue contained a small number of fibroblasts and capillary proliferation, with mild inflammatory infiltration, mainly composed of neutrophils and lymphocytes. On day 15, all samples showed a small to a large amount of blood scabs (black arrows) covering the wound. The epidermal cells were arranged continuously, and the samples locally contained a thin layer of newly formed epidermal cells (red arrows), without significant thickening. The superficial dermis showed very mild to mild edema with very mild congestion and bleeding. The granulation tissue still contained a large number of fibroblasts and capillary proliferation, with very mild to mild inflammatory infiltration, mainly composed of neutrophils and lymphocytes.

[0042] In summary, based on gross observation and dermatopathological observation, the sterile liquid dressings containing silk fibroin prepared in Examples 1, 2, and 3 all demonstrated a certain effect in promoting wound repair in a porcine skin injury model. Compared with the model group, the wounds treated with the dressings in the examples showed a smaller area and reduced redness at 14 days post-treatment, indicating a better healing trend. In dermatopathological observation, at 15 days post-treatment, the wounds in the examples showed reduced scabs, more continuous and orderly epidermal arrangement, aging granulation tissue, fewer fibroblasts and capillaries, and reduced edema, congestion, hemorrhage, and inflammatory infiltration. These changes all indicate that the dressings in the examples are helpful for wound repair and tissue regeneration. In conclusion, the method for preparing sterile liquid dressings containing silk fibroin provided by this invention can effectively promote skin wound repair and has clinical application potential.

[0043] Experimental Example 3 As described in the background section, existing technologies often use methods such as cross-linking, heat treatment, and inducing agents to transform the structure of silk fibroin in order to maintain product stability. However, this invention does not require such treatment or the addition of other reagents. Example 1 of this invention is now compared with relevant examples of patent CN120132038A (hereinafter referred to as the comparative patent).

[0044] 1. Experimental group design and preparation method: The raw material formulations and preparation schemes for each experimental group are shown in Table 3.

[0045] Table 3

[0046] 2. Performance testing immediately after sterilization: As shown in Table 4 and Figure 3 As shown, immediately after sterilization, the products prepared by the methods in Table 3 all exhibited good pH, viscosity, and shape.

[0047] Table 4

[0048] 3. Thermal stability test: To investigate thermal stability, samples A1, B1, B2, and B3 were placed together in an 80℃ oven and heated for 3 days. After being removed and allowed to cool naturally to room temperature, they were observed and tested. The results are shown in Table 5. Figure 4 As shown.

[0049] The results showed that after being treated at 80℃ for 3 days, sample A1 of Example 1 of this invention still maintained a good translucent pale yellow gel-like consistency, with good fluidity and internal homogeneity, and minimal changes in pH and viscosity, demonstrating excellent thermal stability. In contrast, sample B1 of the comparative patent, although still maintaining a transparent pale yellow gel-like consistency and fluidity, showed a significant increase in pH and a substantial decrease in viscosity, indicating that its thermal stability was inferior to sample A1. Samples B2 and B3 showed significant changes in properties after the thermal stability test; B2 became a yellow paste with no fluidity, and B3 became a yellow block with no fluidity. The pH and viscosity of both could not be measured, indicating extremely poor thermal stability. This is because B1 has a low silk fibroin content of only 0.1%, while B2 and B3 have high silk fibroin content, which further self-aggregates at high temperatures, leading to changes in product state. This comparative result fully demonstrates that this invention can prepare a sterile liquid dressing containing silk fibroin with excellent thermal stability without cross-linking, heat treatment, or the addition of other reagents.

[0050] Table 5

[0051] 4. Freeze-thaw stability test: Samples A1, B1, B2, and B3 were placed together in a -20°C freezer for 24 hours. After being removed and allowed to return to room temperature, they were observed and tested. The results are shown in Table 6. Figure 5 As shown.

[0052] The results showed that after freezing at -20℃ for 24 hours and then naturally returning to room temperature, sample A1 of Example 1 of this invention maintained a translucent pale yellow gel-like consistency, with good fluidity and internal homogeneity. Its pH and viscosity showed minimal changes, demonstrating excellent freeze-thaw stability. In contrast, sample B1 from the comparative patent, while still maintaining a transparent pale yellow gel-like consistency and fluidity, exhibited a significant increase in pH and a substantial decrease in viscosity, indicating inferior freeze-thaw stability compared to sample A1. As for samples B2 and B3, their properties changed significantly after the freeze-thaw stability test. B2 transformed into a yellow paste and lost its fluidity, while B3 became a yellow block and lacked fluidity. The pH and viscosity of both could not be measured, indicating extremely poor freeze-thaw stability. This is also due to the low silk fibroin content of B1 (only 0.1%), while B2 and B3 had higher silk fibroin content, which may have led to self-aggregation during freezing, resulting in a change in product state. This comparative result further confirms that this invention can prepare a sterile liquid dressing containing silk fibroin with excellent freeze-thaw stability without cross-linking, heat treatment, or the addition of other reagents.

[0053] Table 6

Claims

1. A process for the preparation of a high stability sterile liquid silk fibroin containing dressing, characterized in that, The preparation method includes the following steps: (1) Dissolve silk fibroin in water to obtain a silk fibroin solution; (2) Dissolve the nonionic thickener in water until completely dissolved, then add the silk fibroin solution and stir to obtain a mixture; (3) The mixture is then sterilized to obtain silk fibroin liquid dressing; The nonionic thickener is xanthan gum, or a combination of xanthan gum with one or more of hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl cellulose, and sodium hyaluronate. The nonionic thickener has a final weight fraction of 1% to 8% in the mixture.

2. A process for the preparation of a high stable silk fibroin containing sterile liquid dressing according to claim 1, characterized in that, In step (1), 8 to 500 parts by weight of silk fibroin are added to 1,000 to 2,000 parts of water to dissolve and obtain a silk fibroin solution.

3. A process for the preparation of a high stable silk fibroin containing sterile liquid dressing according to claim 1, characterized in that, The silk fibroin has a final weight fraction of 0.08% to 5% in the mixture.

4. The process for preparing a high stable silk fibroin containing aseptic liquid dressing as claimed in claim 1, wherein, In step (2), the nonionic thickener is xanthan gum.

5. The process for preparing a high stable liquid silk fibroin containing sterile dressing according to claim 3, characterized in that, In step (2), the xanthan gum has a final weight fraction of 3% in the mixture.

6. A process for the preparation of a high stable silk fibroin containing sterile liquid dressing according to claim 5, characterized in that, The silk fibroin has a final weight fraction of 3% in the mixture.

7. A method for preparing a highly stable sterile liquid dressing containing silk fibroin according to claim 1 or 6, characterized in that, In step (3), the sterilization process includes moist heat sterilization or irradiation sterilization.

8. The method for preparing a highly stable sterile liquid dressing containing silk fibroin according to claim 7, characterized in that, In step (3), the sterilization process is moist heat sterilization.

9. A high-stability sterile liquid silk fibroin-containing dressing, characterized by, The dressing is prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the highly stable sterile liquid dressing containing silk fibroin as described in claim 9 in the preparation of a wound-healing agent.

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