Wet tissue response type hydrogel powder adhesive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of medical biological materials, in particular to a wet tissue response type hydrogel powder adhesive as well as a preparation method and application thereof. The wet tissue response type hydrogel powder adhesive is a silk fibroin / ethyl lauroyl arginate hydrochloride / acrylic acid / N-hydroxysuccinimide acrylate polymerization system, and physical crosslinking is formed by means of hydrogen bonds and beta folding of silk fibroin; the hydrogel powder adhesive is powdery, and the particle size of the hydrogel powder adhesive is 180-280 [mu] m. The concept of a hydrogel powder adhesive is introduced, an additional chemical cross-linking agent is not needed, the hydrogel adhesive can be recombined only by delivering hydrogel powder to a humid biological tissue interface, introduction of a small molecule chemical cross-linking agent is avoided, and meanwhile the biocompatibility of the hydrogel adhesive is improved.

Description

Technical Field

[0001] This invention relates to the field of medical biomaterials technology, specifically to a wet tissue-responsive hydrogel powder binder, its preparation method, and its application. Background Technology

[0002] Hydrogels are a class of polymeric materials with a hydrophilic three-dimensional network structure. Due to their good biocompatibility and tunable mechanical properties, they have shown broad application potential in the biomedical field. Compared to traditional adhesives, hydrogels, with their moderate interfacial adhesion strength, flexibility, and strong adhesion to moist tissues, have become a promising wound sealing material in the biomedical field.

[0003] In clinical practice, tissue adhesives are widely used in wound repair, surgical suturing, and wound closure. However, existing bioadhesive materials lack adaptability to dynamic physiological environments: on the one hand, traditional hydrogels are mostly prefabricated block forms, making it difficult to adapt to complex wound morphologies and the needs of minimally invasive surgery; on the other hand, chemically cross-linked adhesives may cause biocompatibility issues, while physically cross-linked adhesives often suffer from insufficient wet adhesion. Especially on moist tissue surfaces, the interfacial adhesion strength, curing speed, and mechanical properties of existing adhesive materials are often difficult to balance, which limits their application effectiveness in various medical scenarios. Therefore, developing a hydrogel adhesive that can rapidly cure and form a stable bond on moist tissue surfaces is of great significance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a wet tissue-responsive hydrogel powder binder that can spontaneously reorganize in response to a wet tissue environment. This invention introduces the concept of a hydrogel powder binder that eliminates the need for additional chemical cross-linking agents. Reorganization of the hydrogel binder is achieved simply by delivering the hydrogel powder to the interface of moist biological tissue, avoiding the introduction of small-molecule chemical cross-linking agents and simultaneously improving the biocompatibility of the hydrogel binder.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A wet tissue-responsive hydrogel powder binder, wherein the wet tissue-responsive hydrogel powder binder is a silk fibroin (SF) / lauroyl arginate ethyl ester hydrochloride (LAE) / polyacrylic acid (PAA) / poly(acrylic acid N-hydroxysuccinimide ester) (PAA-NHS) polymerization system, which relies on hydrogen bonds and the β-sheet of silk fibroin to form physical cross-links; the hydrogel powder binder is in powder form with a particle size of 180-280 μm.

[0006] This invention also provides a method for preparing a wet tissue-responsive hydrogel powder binder, the method comprising: Lauroyl arginine ethyl ester hydrochloride and silk fibroin were dissolved in an aqueous solution, and the silk fibroin was induced to form β-sheets by lauroyl arginine ethyl ester hydrochloride. Acrylic acid (AA) and N-hydroxysuccinimide ester (AA-NHS) were then added to the mixed solution, and the hydrogel was prepared by polymerization initiated by a photoinitiator under ultraviolet light irradiation. The hydrogel was freeze-dried and pulverized to obtain a wet tissue responsive hydrogel powder binder.

[0007] The steps of the above preparation method include: Step 1: Dissolve SF and LAE in deionized water and heat until completely dissolved. Mix the two together and place them in a water bath for a certain period of time. Add AA-NHS and AA, and then add a photoinitiator to initiate polymerization to obtain SF / LAE / PAA / PAA-NHS hydrogel. Step 2: Freeze the SF / LAE / PAA / PAA-NHS hydrogel at -80~-150℃, freeze-dry it, grind and pulverize it, and then sieve it to obtain the SF / LAE / PAA / PAA-NHS wet tissue responsive hydrogel powder binder.

[0008] Furthermore, in step 1, the molecular weight of SF is 0.1 kDa to 80 kDa, preferably 0.1 to 10 kDa; Furthermore, the dissolution temperature of SF and LAE in step 1 is 37℃~60℃, preferably 42℃; Furthermore, in the mixed solution of SF and LAE in step 1, the mass ratio of LAE to SF is (1:0.5) to (1:1.5), and the mass ratio of AA to SF is (1:1) to (2:1).

[0009] Furthermore, the heating and mixing time of the SF and LAE mixture in step 1 is 2-8 minutes, preferably 5 minutes; Furthermore, in step 1, the mass ratio of AA to AA-NHS is 100:1; Further, in step 1, the photoinitiator is an ultraviolet photoinitiator selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropanone, and benzoyl peroxide, preferably 2-hydroxy-2-methyl-1-phenyl-1-propanone; the amount of photoinitiator is 0.1 mol% to 1 mol% of the total molar amount of AA and AA-NHS, preferably 0.1 mol%; the polymerization temperature is 20 to 50 °C, preferably 25 °C; the polymerization time is 2400 to 4800 s, preferably 2400 s; SF, LAE, AA, and AA-NHS account for 10 to 30 wt% of the total initial hydrogel mass, preferably 30 wt%. Furthermore, in step 2, the particle size of the SF / LAE / PAA / PAA-NHS wet tissue responsive hydrogel powder is 180~280μm.

[0010] The present invention also provides the application of the above-mentioned wet tissue responsive hydrogel powder binder in the preparation of wound dressings and sealants for use in endoscopic delivery scenarios.

[0011] The wound dressing and sealant are adhesives that promote the healing of gastrointestinal perforations. The SF / LAE / PAA / PAA-NHS wet tissue responsive hydrogel powder adhesive is applied to the surface of moist tissue.

[0012] This invention prepares hydrogel powders with different adhesion effects by controlling the proportions of SF, LAE, AA, and AA-NHS in the reaction system, and by adjusting the powder particle size after freeze-drying and pulverization. The products are easy to store and suitable for minimally invasive surgical instruments such as endoscopes. The hydrogel powder forms physical cross-links through hydrogen bonds and the β-sheet of SF, solving the problem of leakage of small-molecule chemical cross-linking agents in vivo. The hydrogel powder absorbs interfacial water in humid environments, solving the problem of weak adhesion of hydrogel excipients in humid environments. In summary, the adhesive properties of the hydrogel of this invention can be modified according to actual usage needs, and the prepared hydrogel powder has endoscopic delivery capabilities.

[0013] Compared to traditional pre-formed block hydrogels, the powder form of the adhesive of this invention facilitates delivery via minimally invasive instruments such as endoscopes, improving the convenience of storage and transportation. Furthermore, compared to traditional hydrogels, the powder has a larger specific surface area, a stronger ability to absorb water at the interface of the tissue to be adhered, and stronger wet adhesion, enabling it to effectively serve as a wound dressing and sealant to promote the healing of wounds such as gastrointestinal perforations.

[0014] SF is a natural polymer with good biocompatibility. After LAE induction, a large number of hydrophobic structures are formed in the SF molecular chain, which serve as physical cross-linking points to enhance the mechanical properties of the hydrogel. PAA is non-toxic and contains a large number of carboxyl groups in its molecular chain, which can adhere to tissues through hydrogen bonds. To improve the adhesion strength, AA-NHS is added, which forms covalent bond-based adhesion through the Schiff base reaction of AA-NHS with amino groups on the tissue surface. In addition, SF contains a large number of hydrophobic structures, which can aggregate in humid environments, exposing more of the carboxyl groups on the PAA molecular chain and forming a stronger adhesion. This powder has broad application prospects in the field of hydrogel adhesives, especially in endoscopic delivery scenarios such as minimally invasive gastrointestinal surgery.

[0015] Compared with the prior art, the advantages of the present invention are: 1. Powdered adhesive design. Traditional hydrogel adhesives are in block form, making them difficult to apply in minimally invasive surgery. The hydrogel adhesive in this invention is in powder form, suitable for various endoscopic scenarios, easy to store for extended periods, and convenient to carry and transport.

[0016] 2. No external stimulation required; gel forms spontaneously upon contact with wet tissue. Traditional hydrogel adhesives typically require additional stimulation in application scenarios, such as ultraviolet light or the addition of crosslinking agents, increasing the difficulty of application. The hydrogel adhesive of this invention requires no additional external stimulation and spontaneously forms a gel upon contact with a moist interface.

[0017] 3. Good biocompatibility. Most existing hydrogels are synthetic macromolecules, and their biocompatibility still needs further investigation. This hydrogel adhesive utilizes physical cross-linking during preparation to avoid the biocompatibility issues of chemical cross-linking agents. Furthermore, SF is a natural macromolecule with good biocompatibility. LAE has been approved by the US Food and Drug Administration (FDA) for use in the food and cosmetic fields. PAA is also considered by the FDA to be a polymer with good biocompatibility. Therefore, the hydrogel exhibits good biocompatibility.

[0018] 4. Strong wet adhesion. The adhesion strength of "Veco" and "fibrin glue" used in clinical practice to pigskin is usually 1-2 kPa, while the wet adhesion strength of the hydrogel of this invention can exceed 39 kPa.

[0019] 5. Green and environmentally friendly. The preparation process of this hydrogel is relatively simple, using an aqueous system and prepared at room temperature. It does not involve chemical synthesis or complex organic solvents, making it green and environmentally friendly. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the hydrogel powder adhesive of the present invention used in endoscopic surgical delivery scenarios.

[0021] Figure 2 This is a schematic diagram of the hydrogel powder adhesive of the present invention used in a gastrointestinal endoscopic surgical delivery scenario.

[0022] Figure 3 This is a scanning electron microscope image of the hydrogel powder adhesive of the present invention.

[0023] Figure 4 These are photographs of the hydrogel powder adhesive of the present invention and the hydrogel adhesive formed in situ on the surface of wet animal tissue.

[0024] Figure 5 This is a graph showing the test results of the adhesion performance of the hydrogel powder adhesive of the present invention.

[0025] Figure 6 This is a comparison chart of the adhesion performance of the hydrogel powder adhesive of the present invention and commercial adhesives.

[0026] Figure 7 The photograph shows the hydrogel powder adhesive of the present invention used to seal perforated pig stomach and intestines.

[0027] Figure 8 This is a photograph of the hydrogel powder adhesive of the present invention after it adheres to a pig stomach and is then soaked in simulated gastric juice and phosphate buffer for 12 hours.

[0028] Figure 9 The photograph shows the hydrogel powder adhesive of the present invention adhering to a pig stomach, after being soaked in simulated gastric juice and phosphate buffer for 12 hours and then rinsed with running water.

[0029] Figure 10 This is a graph showing the test results of the in vivo and in vitro biocompatibility of the hydrogel powder adhesive of the present invention. Detailed Implementation

[0030] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0031] The pharmaceuticals used in the embodiments of this invention are shown in the table below:

[0032] Example 1 Preparation of SF / LAE / PAA / PAA-NHS wet tissue responsive hydrogel powder binder.

[0033] 74.72 mg SF and 112.08 mg LAE were dissolved separately in 350 μL of deionized water. The mixture was then vortexed for 30 s and placed in a 42 °C water bath for 5 min. Then, 106.64 μL of AA, 1.12 mg of AA-NHS, and 0.238 μL of photoinitiator 1173 were added, and the mixture was irradiated in a UV crosslinking chamber for 2400 s to obtain a hydrogel.

[0034] The hydrogel was placed in a -80°C freezer for 24 hours, then removed and freeze-dried in a freeze dryer. The dried product was then pulverized and ground into tiny particles, and the freeze-dried powder with a particle size of 180-280 μm was sieved using a standard steel sieve.

[0035] like Figure 1 As shown, the hydrogel powder adhesive obtained by this invention can be directly delivered to internal tissues via an endoscopic tubing, making it particularly suitable for delivery of hydrogel powder adhesives during endoscopic surgery for healing gastrointestinal perforations, such as... Figure 2 As shown.

[0036] Physicochemical property analysis: 1. Scanning electron microscopy analysis, such as Figure 3 As shown.

[0037] The hydrogel powder prepared in Example 1 was analyzed using scanning electron microscopy. Figure 3 As shown in the left image, the hydrogel powder surface has a dense porous structure, which facilitates rapid absorption and recombination of interfacial water. Figure 3 As shown in the right figure, after rehydration to form a hydrogel, the hydrogel still has a three-dimensional network structure.

[0038] 2. Adhesion performance test, such as Figure 4 , 5 As shown in 6, 7, 8, and 9.

[0039] The tensile properties of the reconstituted hydrogels were tested using a universal testing machine. The powder prepared in Example 1 was sprinkled onto the moist stomach, intestines, skin, and liver of mice, as... Figure 4 As shown, the adhesive can effectively adhere. 200 mg was placed on a 2cm x 5cm piece of moist pigskin and immediately subjected to an lap shear test on a universal testing machine at a tensile speed of 50 mm / min. The adhesive strength of powder adhesives prepared with different ratios of SF, LAE, and PAA is shown in the figure. Figure 5 As shown. Zhejiang Seringte Pharmaceutical's "Porcine Fibrin Adhesive" and Yingjian Bio's "Weike Tie" were selected as Commercial Control 1 and Commercial Control 2, respectively. Overlap shear tests were conducted on a universal testing machine at a tensile speed of 50 mm / min. The results are as follows. Figure 6 As shown, the adhesion strength of this hydrogel adhesive to pigskin is superior to that of the commercial control.

[0040] Figure 7This study demonstrates the use of SF / LAE / PAA / PAA-NHS wet tissue-responsive hydrogel powder adhesive to bond perforated porcine stomachs and intestines, achieving a strong seal. Simulated gastric fluid was prepared by dissolving 2g of sodium chloride in 1000mL of deionized water and adjusting the pH to 1.5 using 2M hydrochloric acid. The powder adhesive was poured onto the inner and outer sides of the porcine stomach and immersed in the simulated gastric fluid and phosphate-buffered saline (PBS) for 12 hours, respectively. The adhesive maintained adhesion and resisted rinsing by running water. Figure 8 , 9 ).

[0041] 3. Cell compatibility testing, such as Figure 10 As shown, the cell compatibility of the hydrogel was tested using a CCK-8 assay kit. The powder prepared in Example 1 was soaked in deionized water to remove unreacted initiators and monomers. Hydrogel extracts at concentrations of 0.1, 1, 5, and 10 mg / mL were prepared and cultured into human gastric mucosal cells. The results showed that the cell viability was above 80%, indicating that the hydrogel adhesive has good biocompatibility.

[0042] The upper and lower limits of the process parameters (such as temperature, time, etc.) and the range values ​​of the present invention can all achieve this method, and examples are not listed here.

[0043] All aspects not described in detail in this invention can be covered using conventional technical knowledge in the field.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A wet tissue-responsive hydrogel powder binder, characterized in that, The wet tissue responsive hydrogel powder binder is a silk fibroin / lauroyl arginine ethyl ester hydrochloride / acrylic acid / N-hydroxysuccinimide acrylate polymer system, which relies on hydrogen bonds and the β-sheet of silk fibroin to form physical cross-links; the hydrogel powder binder is in powder form with a particle size of 180~280μm.

2. A method for preparing a wet tissue-responsive hydrogel powder adhesive, the preparation method comprising: Lauroyl arginine ethyl ester hydrochloride and silk fibroin were dissolved in an aqueous solution, and the formation of β-sheets in silk fibroin was induced by lauroyl arginine ethyl ester hydrochloride. Then, acrylic acid and N-hydroxysuccinimide acrylate are added to the mixed solution, and the hydrogel is prepared by photoinitiation polymerization. The hydrogel is freeze-dried and pulverized to obtain a wet tissue responsive hydrogel powder binder.

3. The preparation method according to claim 2, characterized in that, The molecular weight of silk fibroin ranges from 0.1 kDa to 80 kDa.

4. The preparation method according to claim 2, characterized in that, The dissolution temperature of lauroyl arginine ethyl ester hydrochloride and silk fibroin is 37℃~60℃; the dissolution time is 2~8min.

5. The preparation method according to claim 2, characterized in that, The mass ratio of lauroyl arginine ethyl ester hydrochloride to silk fibroin is (1:0.5) to (1:1.5), and the mass ratio of acrylic acid to silk fibroin is (1:1) to (2:1); the mass ratio of acrylic acid to N-hydroxysuccinimide acrylate is 100:

1.

6. The preparation method according to claim 2, characterized in that, The photoinitiator is an ultraviolet photoinitiator selected from one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropanone, and benzoyl peroxide.

7. The preparation method according to claim 2, characterized in that, In the polymerization reaction, the amount of photoinitiator is 0.1 mol% to 1 mol% of the total amount of AA and AA-NHS; the polymerization temperature is 20 to 50℃; the polymerization time is 2400 to 4800 s; SF, LAE, AA, and AA-NHS account for 10 to 30 wt% of the initial total mass of the hydrogel.

8. The preparation method according to claim 2, characterized in that, The freezing temperature during the freeze-drying process is -80 to -150℃.

9. The use of the wet tissue-responsive hydrogel powder binder of claim 1 in the preparation of wound dressings and sealants for use in endoscopic delivery scenarios.

10. The application according to claim 9, characterized in that, The wound dressing and sealant are adhesives that promote the healing of gastrointestinal perforations.

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