Biological adhesive as well as preparation method and application thereof in prevention of postoperative stenosis of early esophageal cancer

Abstract

The invention relates to biological adhesive powder for preventing stenosis after endoscopic mucosal dissection of esophageal premature cancer. The biological adhesive powder comprises a silk fibroin-polyphenol cross-linked network and an adhesive layer, wherein the silk fibroin-polyphenol cross-linked network is formed by cross-linking a silk fibroin solution and a polyphenol solution through phenolic hydroxyl groups; the mass ratio of the glucocorticoid carried in the cross-linked network to the adhesive powder is (1: 40)-(1: 50); the structural characteristic is that the content of beta-sheet conformation in Fourier infrared spectroscopy is greater than or equal to 20%. The preparation method comprises the following steps: mixing the silk fibroin-polyphenol basic powder with the therapeutic drug, activating the mixture into gel by using a 20-50% ethanol aqueous solution, and then performing secondary freeze drying. In a miniature pig esophageal ESD operation model, after being sprayed to a wound surface and activated into hydrogel, the powder can be stably attached to the wound surface for more than 14 days, is gradually degraded and releases glucocorticoid, and can continuously release more than or equal to 80% of medicine within 72 hours, so that esophageal stenosis is effectively inhibited.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biological medicine, and relates to a biological adhesive, a preparation method thereof and application thereof in preventing postoperative stenosis of early esophageal cancer. BACKGROUND

[0002] The overall incidence of postoperative esophageal stenosis after ESD of early esophageal cancer is 11.6%, but the incidence of stenosis in the case of mucosal defect range > 3 / 4 circumference is as high as 88%-100%, which is mainly caused by excessive activation of fibroblasts by factors such as TGF-β during wound repair, leading to contraction of scar tissue. Esophageal stenosis can cause dysphagia, malnutrition, psychological diseases and the like in patients, and seriously reduces the quality of life of patients. The existing prevention and treatment means have some shortcomings: the process of hormone injection can injure the muscularis to cause complications such as delayed perforation, and the method needs to be performed multiple times under endoscopy; the effect of single dilation is quite limited, and in addition to increasing the risk of complications such as perforation and bleeding, repeated dilation also increases the economic burden of patients; the existing wet adhesive hydrogel chitosan / gelatin-based and the like generally have problems such as insufficient mechanical strength, uncontrollable degradation and poor drug release performance, and are difficult to maintain long-acting adhesion and anti-stenosis function in a wet wound.

[0003] Therefore, it is urgent to develop a biological adhesive with high wet-state adhesion, controllable drug release and anti-fibrosis function to synergistically inhibit excessive formation of scar, and achieve the effect of preventing esophageal stenosis. SUMMARY

[0004] To solve the above problems, the present application provides a biological adhesive for preventing postoperative stenosis of early esophageal cancer, which is prepared by cross-linking silk fibroin and polyphenol compounds to prepare a hydrogel, and then carrying a therapeutic drug such as glucocorticoid after freeze-drying, and then activating with an ethanol aqueous solution to prepare a powder by secondary freeze-drying. The powder can be sprayed to the esophageal wound, activated with an ethanol aqueous solution to form a gel, so as to provide a physical barrier for the wound and adjacent tissues, release the drug, inhibit the excessive formation and contraction of scar tissue, and achieve the effect of preventing esophageal stenosis.

[0005] In a first aspect, the present application provides a biological adhesive for preventing postoperative stenosis of early esophageal cancer, comprising: a silk fibroin-polyphenol cross-linking network formed by cross-linking a silk fibroin solution and a polyphenol solution through phenolic hydroxyl groups, the polyphenol being selected from at least one of tannic acid, chlorogenic acid, catechin, quercetin and curcumin; and a therapeutic drug, which is a glucocorticoid carried in the cross-linking network, and the mass ratio of the drug to the adhesive powder is 1:40-1:50.

[0006] Structural features: the content of beta-sheet conformation in the Fourier infrared spectrum of the powder is ≥20%.

[0007] The drug carried in the adhesive meets the therapeutic dosage, and the drug is too little to achieve good therapeutic effect; the drug is too much to occupy too many cross-linking sites, so that the adhesive has less active sites with the tissue and the adhesion effect is reduced. Silk fibroin is a protein extracted from natural silk, which has good biocompatibility, degradability and mechanical properties. The silk fibroin molecule is rich in amino acid sequences such as serine (Serine), glycine (Glycine) and tyrosine (Tyrosine), which can have physical or chemical interactions with other molecules or matrices. Therefore, using the properties of tannic acid and silk fibroin, a hydrogel is prepared using the two as raw materials to enhance the adhesion performance.

[0008] In some embodiments, the polyphenol is tannic acid, and the volume ratio of the silk fibroin solution to the tannic acid solution is 3:2.

[0009] Tannic acid is a polyphenolic compound with multiple hydroxyl functional groups, which can form hydrogen bonds, hydrophobic interactions and metal ion chelation with various molecules or materials. These properties make tannic acid exhibit excellent performance in adhesion, antioxidant, antibacterial and other aspects.

[0010] In some embodiments, the drug is triamcinolone acetonide.

[0011] In some embodiments, the content of the β-sheet conformation is 20%-25%.

[0012] In a second aspect, the present application provides a preparation method of the biological adhesive powder, comprising:

[0013] (1) Mix cocoon with 0.02 mol / L sodium carbonate solution at a ratio of 1 g: 50-150 mL, degum at 100°C for 1-3 hours, wash and dry;

[0014] (2) Mix degummed silk fibroin with a ternary solution of CaCl2 / absolute ethanol / deionized water at a molar ratio of 1:(1-3):(5-10) at a mass ratio of 1:5-15, dissolve at 70-90°C for 1-4 hours, and filter to obtain a silk fibroin solution;

[0015] (3) Mix 3-8% silk fibroin solution with 3-8% polyphenol solution at a volume ratio of 1:1 to 3:2, freeze-dry and grind into a base powder;

[0016] (4) Physically mix the base powder with the therapeutic drug at a mass ratio of 40-50:1, activate into a gel with 20-50% ethanol aqueous solution, and then freeze-dry again.

[0017] In some embodiments, the degummed silk fibroin in step (1) is dried at 50-80°C for 1-12 hours.

[0018] In some embodiments, the mass fraction of the polyphenol solution in step (3) is 6.25%.

[0019] In some embodiments, the volume concentration of the aqueous ethanol solution in step (4) is 50%.

[0020] In the third aspect, the application provides use of the bioadhesive powder in the preparation of a drug for preventing postoperative stenosis of early esophageal cancer.

[0021] In some embodiments, the drug is continuously released by ≥80% within 72 hours after the powder is activated into a hydrogel.

[0022] The principle of the technical solution of the application is mainly as follows:

[0023] The polyphenol hydroxyl groups of tannic acid form a hydrogen bond network with the amino groups / carboxyl groups of silk fibroin, and the hydrophobic structure cooperates with the hydrophobic region of silk fibroin, and the silk fibroin has a rich β-sheet structure, which can form a stable three-dimensional porous network to provide physical wrapping space for the drug, and the hydrophobic properties of the glucocorticoid (such as triamcinolone acetonide) can cooperate with the hydrophobic region of the silk fibroin. By adjusting the cross-linking density of tannic acid combined with the enzymatic or hydrolytic properties of silk fibroin, the wet adhesion can be enhanced, and the slow release of the drug can be realized, thereby prolonging the therapeutic effect.

[0024] In summary, the application has the following beneficial effects:

[0025] The application first provides use of a bioadhesive powder in the prevention of postoperative stenosis of early esophageal cancer in biological medicine. The bioadhesive powder has obvious effects on preventing esophageal stenosis and scar hyperplasia. At the same time, when the mass ratio of the drug to the bioadhesive powder is 1:40-1:50, the adhesion performance and the drug slow-release effect are synergistically improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Effect of triamcinolone acetonide on the content of β-sheet in the bioadhesive powder;

[0027] Figure 2 Test results of the mechanical properties of the bioadhesive powder, including lap shear strength;

[0028] Figure 3 Test results of the mechanical properties of the bioadhesive powder, including interfacial toughness;

[0029] Figure 4 Test results of the mechanical properties of the bioadhesive powder, including adhesion energy;

[0030] Figure 5 Endoscopic observation of postoperative stenosis of early esophageal cancer;

[0031] Figure 6Prevention of early esophageal cancer postoperative stenosis sampling observation;

[0032] Figure 7 Prevention of early esophageal cancer postoperative stenosis stenosis rate statistical results;

[0033] Figure 8 Bioadhesive powder drug release curve. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and advantages of the present application clearer, the following will be described in detail with reference to the drawings and specific embodiments.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. For purposes of interpreting this specification, the following definitions will apply and, unless otherwise indicated, the singular articles "a", "an", and "the" will be read to include the plural unless expressly stated otherwise. The terms "one" and "the" as used herein, including the use of these terms in conjunction with the term "comprising", encompass the singular as well as the plural, unless specifically stated otherwise. Unless otherwise noted, in the examples, routine conditions or manufacturer's recommended conditions were used. All reagents or instruments, unless otherwise noted, are commercially available conventional products.

[0036] Example 1

[0037] A method for preparing a bioadhesive powder:

[0038] (1) First, the cocoon is degummed, and the cut cocoon is mixed with a 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, placed in a water bath pot to maintain a temperature of 100°C and boiled for 2 hours, with stirring every 20 minutes in between. Then wash with pure water, place on gauze, and put into an oven for 6 hours, maintaining a temperature of 75°C until dry. Then prepare a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8, mix the dried silk fibroin obtained with the ternary solution at a mass ratio of 1:10, place in a water bath pot to maintain a temperature of 80°C and cook for 3 hours until the silk fibroin is completely dissolved, then filter with 8 layers of gauze to obtain a silk fibroin solution. Take 1 g of the above silk fibroin solution, dry at 75°C for 1 hour, and measure the silk fibroin mass fraction. Then prepare a silk fibroin solution with a mass fraction of 5%, and a tannic acid solution with a mass fraction of 6.25%. Pour the silk fibroin solution into the tannic acid solution at a volume ratio of 3:2, filter after the reaction is complete, freeze-dry, and grind into powder to obtain the silk fibroin tannic acid adhesive powder.

[0039] (2) Take 0.9 g of silk fibroin tannic acid adhesive powder, physically mix and load 20 mg of triamcinolone acetonide, then activate into a hydrogel with an ethanol aqueous solution containing 50% by volume, and twice freeze-dry to prepare a powder.

[0040] Example 2

[0041] A method for preparing a biological adhesive powder:

[0042] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:50 ml, placed in a water bath pot to keep the temperature at 100°C and boiled for 1 hour, with stirring every 20 minutes. Then it is washed with pure water, placed on gauze, and placed in an oven for 12 hours at a temperature of 75°C until it is dried. Then a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:1:5 is prepared, and the dried silk fibroin is mixed with the ternary solution at a mass ratio of 1:5, placed in a water bath pot to keep the temperature at 70°C and boiled for 1 hour until the silk fibroin is completely dissolved. Then it is filtered with 8 layers of gauze to obtain a silk fibroin solution. 1 g of the above silk fibroin solution is dried at 50°C for 6 hours, and the silk fibroin mass fraction is determined. A silk fibroin solution with a mass fraction of 3% is prepared, and a tannic acid solution with a mass fraction of 3% is also prepared. The silk fibroin solution is poured into the tannic acid solution at a volume ratio of 2:1, and after the reaction is complete, it is filtered, freeze-dried, and ground into powder to obtain a silk fibroin tannic acid adhesive powder.

[0043] (2) 0.8 g of the silk fibroin tannic acid adhesive powder is physically mixed with 18 mg of triamcinolone acetonide, and then activated into a hydrogel with an aqueous solution containing 20% by volume of ethanol. After secondary freeze-drying, a powder is prepared.

[0044] Example 3

[0045] A method for preparing a biological adhesive powder:

[0046] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:150 ml, placed in a water bath pot to keep the temperature at 100°C and boiled for 3 hours, with stirring every 20 minutes. Then it is washed with pure water, placed on gauze, and placed in an oven for 12 hours at a temperature of 75°C until it is dried. Then a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:3:10 is prepared, and the dried silk fibroin is mixed with the ternary solution at a mass ratio of 1:15, placed in a water bath pot to keep the temperature at 90°C and boiled for 4 hours until the silk fibroin is completely dissolved. Then it is filtered with 8 layers of gauze to obtain a silk fibroin solution. 1 g of the above silk fibroin solution is dried at 100°C for 12 hours, and the silk fibroin mass fraction is determined. A silk fibroin solution with a mass fraction of 8% is prepared, and a tannic acid solution with a mass fraction of 8% is also prepared. The silk fibroin solution is poured into the tannic acid solution at a volume ratio of 1:1, and after the reaction is complete, it is filtered, freeze-dried, and ground into powder to obtain a silk fibroin tannic acid adhesive powder.

[0047] (2) Take 0.8 g of silk fibroin tannic acid adhesive powder, physically mix and carry 22.5 mg of triamcinolone acetonide, and then activate into a hydrogel with an aqueous solution containing 20% by volume of ethanol. After secondary freeze-drying, a powder is prepared.

[0048] Example 4

[0049] A method for preparing a biological adhesive powder:

[0050] (1) First, the cocoon is degummed. The cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, placed in a water bath at 100°C and boiled for 2 hours, with stirring every 20 minutes. Then wash with pure water, place on gauze, and put in an oven at 75°C for 6 hours until dry. Then prepare a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8. Mix the dried silk obtained with the ternary solution at a mass ratio of 1:10, place in a water bath at 80°C and cook for 3 hours until the silk is completely dissolved. Then filter with 8 layers of gauze to obtain a silk fibroin solution. Take 1 g of the above silk fibroin solution, dry at 75°C for 1 hour, and measure the silk fibroin mass fraction. Then prepare a silk fibroin solution with a mass fraction of 5%, and a chlorogenic acid solution with a mass fraction of 6.25%. Pour the silk fibroin solution into the chlorogenic acid solution at a volume ratio of 3:2, filter after the reaction is complete, freeze-dry, and grind into powder to obtain silk fibroin chlorogenic acid adhesive powder.

[0051] (2) Take 0.9 g of silk fibroin chlorogenic acid adhesive powder, physically mix and carry 20 mg of prednisolone, and then activate into a hydrogel with an aqueous solution containing 50% by volume of ethanol. After secondary freeze-drying, a powder is prepared.

[0052] Example 5

[0053] A method for preparing a biological adhesive powder:

[0054] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, placed in a water bath pot to keep the temperature at 100°C and boiled for 2 hours, and stirred every 20 minutes. Then, it is washed with pure water, placed on gauze, and placed in an oven for 6 hours at a temperature of 75°C until it is dried. Then, a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8 is prepared, and the dried silk fibroin is mixed with the ternary solution at a mass ratio of 1:10, placed in a water bath pot to keep the temperature at 80°C and boiled for 3 hours until the silk fibroin is completely dissolved. Then, it is filtered with 8 layers of gauze to obtain a silk fibroin solution. 1 g of the silk fibroin solution is dried at 75°C for 1 hour, and the mass fraction of silk fibroin is determined. A silk fibroin solution with a mass fraction of 5% is prepared, and a catechin solution with a mass fraction of 6.25% is also prepared. The silk fibroin solution is poured into the catechin solution at a volume ratio of 3:2, and after the reaction is complete, it is filtered, freeze-dried, and ground into powder to obtain a silk fibroin catechin adhesive powder.

[0055] (2) 0.9 g of the silk fibroin catechin adhesive powder is physically mixed with 20 mg of hydrocortisone, and then activated into a hydrogel with an ethanol aqueous solution containing 50% by volume. The hydrogel is freeze-dried twice to obtain a powder.

[0056] Example 6

[0057] A method for preparing a biological adhesive powder:

[0058] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, placed in a water bath pot to keep the temperature at 100°C and boiled for 2 hours, and stirred every 20 minutes. Then, it is washed with pure water, placed on gauze, and placed in an oven for 6 hours at a temperature of 75°C until it is dried. Then, a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8 is prepared, and the dried silk fibroin is mixed with the ternary solution at a mass ratio of 1:10, placed in a water bath pot to keep the temperature at 80°C and boiled for 3 hours until the silk fibroin is completely dissolved. Then, it is filtered with 8 layers of gauze to obtain a silk fibroin solution. 1 g of the silk fibroin solution is dried at 75°C for 1 hour, and the mass fraction of silk fibroin is determined. A silk fibroin solution with a mass fraction of 5% is prepared, and a catechin solution with a mass fraction of 6.25% is also prepared. The silk fibroin solution is poured into the catechin solution at a volume ratio of 3:2, and after the reaction is complete, it is filtered, freeze-dried, and ground into powder to obtain a silk fibroin catechin adhesive powder.

[0059] (2) Take 0.9 g of silk fibroin catechin adhesive powder, physically mix and load 20 mg of betamethasone, and then activate into a hydrogel with an aqueous solution containing 50% by volume of ethanol, and then re-freeze dry to prepare a powder.

[0060] Example 7

[0061] A method for preparing a biological adhesive powder:

[0062] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, and then placed in a water bath pot to maintain a temperature of 100°C and boiled for 2 hours, with stirring every 20 minutes. Then wash with pure water, place on gauze, and place in an oven for 6 hours at a temperature of 75°C until dry. Then prepare a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8, mix the dried silk fibroin obtained with the ternary solution at a mass ratio of 1:10, and then place in a water bath pot to maintain a temperature of 80°C and boil for 3 hours until the silk fibroin is completely dissolved. Then filter with 8 layers of gauze to obtain a silk fibroin solution. Take 1 g of the above silk fibroin solution, dry at 75°C for 1 hour, and then measure the silk fibroin mass fraction. Then prepare a silk fibroin solution with a mass fraction of 5%, and at the same time prepare a quercetin solution with a mass fraction of 6.25%. Pour the silk fibroin solution into the quercetin solution at a volume ratio of 3:2, and then filter after the reaction is complete, freeze dry, and grind into powder to obtain a silk fibroin quercetin adhesive powder.

[0063] (2) Take 0.9 g of silk fibroin quercetin adhesive powder, physically mix and load 20 mg of methylprednisolone sodium succinate, and then activate into a hydrogel with an aqueous solution containing 50% by volume of ethanol, and then re-freeze dry to prepare a powder.

[0064] Example 8

[0065] A method for preparing a biological adhesive powder:

[0066] (1) First, the cocoon is degummed, and the cut cocoon is mixed with 0.02 mol / L sodium carbonate solution at a ratio of 1 g:100 ml, placed in a water bath pot to keep the temperature at 100°C and boiled for 2 hours, and stirred every 20 minutes. Then wash with pure water, place on gauze, and put into an oven for 6 hours at 75°C until dry. Then configure a ternary solution of calcium chloride, anhydrous ethanol, and deionized water with a molar mass ratio of 1:2:8, mix the dried silk fibroin with the ternary solution at a mass ratio of 1:10, place in a water bath pot to keep the temperature at 80°C for 3 hours until the silk fibroin is completely dissolved, then filter with 8 layers of gauze to obtain a silk fibroin solution. Take 1 g of the above silk fibroin solution, dry at 75°C for 1 hour, and measure the silk fibroin mass fraction. Then configure a silk fibroin solution with a mass fraction of 5%, and a curcumin solution with a mass fraction of 6.25%. Pour the silk fibroin solution into the curcumin solution at a volume ratio of 3:2, filter after the reaction is complete, freeze-dry, and grind into powder to obtain silk fibroin curcumin adhesive powder.

[0067] (2) Take 0.9 g of silk fibroin curcumin adhesive powder, physically mix and load 20 mg of dexamethasone sodium phosphate, then activate into a hydrogel with an ethanol aqueous solution containing 50% by volume, and twice freeze-dry to prepare a powder.

[0068] Comparative Example 1

[0069] Compared with Example 1, the only difference is that no triamcinolone acetonide drug is added in step (2).

[0070] Comparative Example 2

[0071] Compared with Example 1, the only difference is that 40 mg of triamcinolone acetonide drug is added in step (2).

[0072] Comparative Example 3

[0073] Prepare a hydrogel using the method of CN117547502A patent Example 1.

[0074] Example 1

[0075] This experiment investigates the effect of triamcinolone acetonide on the β-sheet content of the biological adhesive powder

[0076] Test the β-sheet content of the biological adhesive powder prepared in Example 1, Comparative Example 1, and Comparative Example 2. The test process is as follows: use a Fourier infrared spectrometer to measure the spectrum of the biological adhesive powder prepared in Example 1, Comparative Example 1, and Comparative Example 2, perform peak separation by Origin software, calculate the β-sheet content ratio, and the results are shown in Table 1. Figure 1SF@TAS represents Comparative Example 1; SF@TAS-20TA represents Example 1; SF@TAS-40TA represents Comparative Example 2.

[0077] The results show that the β-sheet content of Example 1 is 20.04% higher than that of Comparative Example 1, because triamcinolone acetonide is a hydrophobic drug, which promotes the conformational transition of silk fibroin through hydrophobic interaction or intermolecular hydrogen bond, forming a more compact β-sheet network, thereby enhancing the mechanical properties and adhesion of the gel. The increase of the loading amount of triamcinolone acetonide in Comparative Example 2 leads to a decrease in the β-sheet content, indicating that the appropriate increase of the loading amount of triamcinolone acetonide improves the drug efficacy, and the excessive amount may reduce the drug efficacy, which may be due to the interference of the excessive amount of drug with the crosslinking network.

[0078] Example 2

[0079] This experiment investigates the mechanical properties of the biological adhesive powder

[0080] The biological adhesive powders prepared from Example 1, Comparative Example 1 and Comparative Example 2 were subjected to mechanical property tests in the tensile mode, and the test process was as follows:

[0081] The sample was cut into a cuboid shape with a length of 20 mm, a width of 12.5 mm, and a thickness of 3 mm. The tensile strength (σ) of the sample was measured using an Instron mechanical testing machine (INSTRON5982, USA); and at 0 min and 40 min, the sample was stretched to complete tensile failure at a constant strain rate of 5 mm / min, and each test was repeated 3 times to take the average value. The greater the tensile strength, the more closely the material adheres to the tissue, and the results are shown in Table 2. Figures 2-4 SF@TAS represents Comparative Example 1; SF@TAS-20TA represents Example 1; SF@TAS-40TA represents Comparative Example 2.

[0082] The results show that the lap shear strength, adhesion energy and interfacial toughness of Example 1 are higher than those of Comparative Examples 1 and 2, indicating that the mechanical properties are the best, because the crosslinking network structure formed by multiple physical actions has good elasticity and mechanical stability. The increase of the loading amount of triamcinolone acetonide in Comparative Example 2 leads to a decrease in the mechanical properties, indicating that the appropriate increase of the loading amount of triamcinolone acetonide improves the mechanical properties, and the excessive amount occupies too many crosslinking sites, reducing the active sites of the adhesive and the tissue, thereby affecting the adhesion effect and the mechanical properties.

[0083] Example 3

[0084] This experiment investigates the effect of the biological adhesive powder on the prevention of postoperative stenosis of early esophageal cancer

[0085] Example 1 is the experimental group, and Comparative Example 1 is the control group. The bioadhesive powder prepared from Example 1 and Comparative Example 1 is subjected to a small pig animal experiment test, and the test process is as follows:

[0086] The esophagus of a small pig is subjected to endoscopic submucosal dissection (ESD), and a 3 / 4-week-diameter esophagus model is shaped by annular resection. The bioadhesive powder is activated into a gel by spraying it using an endoscope and the like. After the operation, a gastroscope is rechecked at 1 week, 2 weeks, and 3 weeks, and samples are taken and photographed. The stenosis rate is calculated. The results are shown in Figures 5-7 .

[0087] The results show that the stenosis rate of the experimental group is significantly lower than that of the control group, indicating that the bioadhesive agent carrying triamcinolone acetonide has a significant effect on preventing postoperative stenosis of early esophageal cancer.

[0088] Example 4

[0089] This experiment investigates the drug release of the bioadhesive powder

[0090] An equal amount of the hydrogel prepared from Example 1, Comparative Example 2, and Comparative Example 3 is uniformly loaded into a dialysis bag, which is sealed at both ends and immersed in 200 ml of PBS solution. The dialysis bag is stirred on a constant temperature shaker. At 1 hour, 3 hours, 5 hours, 8 hours, 12 hours, 15 hours, 20 hours, 24 hours, 28 hours, 32 hours, 36 hours, 40 hours, 44 hours, 48 hours, 60 hours, and 72 hours, 1 ml of the release medium is taken and immediately supplemented with an equal volume of fresh PBS. The drug concentration is measured, and the results are shown in Figure 8 .

[0091] The results show that Example 1 exhibits a sustained release trend within 72 hours. Compared with Comparative Examples 2 and 3, the initial release rate is not significantly different, but the release rate is significantly lower than that of Comparative Examples 2 and 3 as time increases. This indicates that it has better sustained release performance, and the amount of triamcinolone acetonide carried needs to be appropriate, and excessive amounts may affect the sustained release effect.

[0092] The above describes preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application. These improvements and refinements should also be considered within the scope of the present application.

Claims

1. A biological adhesive powder for preventing postoperative stricture of the esophagus after early esophageal cancer surgery, characterized in that, Contains: a silk fibroin-polyphenol cross-linking network: formed by cross-linking silk fibroin and polyphenols through phenolic hydroxyl groups, wherein the polyphenols are selected from at least one of tannic acid, chlorogenic acid, catechin, quercetin, and curcumin; Therapeutic drug: a glucocorticoid carried in the cross-linked network, wherein the mass ratio of the drug to the adhesive powder is 1:40 to 1:50; Structural characteristics: The content of β-sheet conformation in the Fourier transform infrared spectrum of the powder is ≥20%; Release performance: After the powder is activated into a hydrogel by a 50% ethanol aqueous solution, it continuously releases ≥80% of the drug within 72 hours.

2. The bio-adhesive powder according to claim 1, characterized in that, The polyphenol is tannic acid, and the volume ratio of the silk fibroin solution to the tannic acid solution is 3:

2.

3. The bio-adhesive powder according to claim 1, characterized in that, The drug in question is triamcinolone acetonide.

4. The bio-adhesive powder according to claim 1, characterized in that, The β-sheet conformation content is 20% to 25%.

5. A method for preparing the bio-adhesive powder according to any one of claims 1-4, characterized in that, include: (1) Mix silkworm cocoons with 0.02mol / L sodium carbonate solution at a ratio of 1g:50-150mL, degumm at 100℃ for 1-3 hours, wash and dry at 50-80℃ for 1-12 hours; (2) Mix degummed silk fibroin with a CaCl2 / anhydrous ethanol / deionized water ternary solution with a molar ratio of 1:1~3:5~10 at a mass ratio of 1:5~15, dissolve at 70~90℃ for 1~4 hours, and filter to obtain silk fibroin solution. (3) Mix the silk fibroin solution with the polyphenol solution, freeze dry and grind into a basic powder; (4) Mix the base powder with the therapeutic drug at a mass ratio of 40-50:1, treat with a 20-50% ethanol aqueous solution to form a gel, and then freeze-dry it a second time.

6. The method according to claim 5, characterized in that, In step (3): The silk fibroin solution has a mass fraction of 3-8%; The polyphenol solution has a mass fraction of 3-8%; The volume ratio of silk fibroin solution to polyphenol solution is 1:1 to 3:

2.

7. The method according to claim 6, characterized in that, The mass fraction of the polyphenol solution in step (3) is 6.25%.

8. The method according to claim 5, characterized in that, In step (4), the volume concentration of the ethanol aqueous solution is 50%.

9. The use of the bioadhesive powder as described in any one of claims 1-4 in the preparation of a medicament for preventing postoperative stricture of the esophagus in early cancer patients.

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