A two-component gastrointestinal mucosa protective composition and use thereof

Abstract

The application discloses a kind of two-component digestive tract mucosa protective composition and application thereof, belong to the technical field of biomedical materials.The composition includes first component and second component: the first component includes 0.2%~8% alginate, 0.2%~5% chitosan polymer, 0.05%~2% cationic polymer, toughening agent 0.05%~2%;Second component includes polyvalent metal ion salt crosslinking agent 0.3%~10%.After two components are mixed, by ion crosslinking, electrostatic complexing and hydrogen bond synergistic effect, in situ formation has strong wet state adhesion hydrogel.The application significantly improves the mechanical strength and wet state adhesion performance of gel through triple crosslinking mechanism, stably exists in gastric acid environment, has physical barrier, rapid hemostasis and repair promoting function;Can be accurately delivered by endoscope, in situ forming, completely degradable absorption, applicable to digestive tract ulcer, postoperative wound protection and digestive tract hemorrhage and the like scene.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials technology, specifically relating to a two-component digestive tract mucosal protection composition and its application, particularly suitable for hemostasis and in-situ protection of endoscopic digestive tract wounds. Background Technology

[0002] The digestive tract mucosa is an important physiological barrier for the body to defend against external pathogens and harmful substances. The gastric mucosa is directly exposed to multiple adverse factors, including gastric acid (pH 1.5-3.5), pepsin, and the shearing force generated by gastric peristalsis. Diseases such as peptic ulcers, endoscopic submucosal dissection (ESD), and endoscopic mucosal resection (EMR), as well as gastric perforation, anastomotic leakage, and other iatrogenic procedures can lead to large-area defects in the gastric mucosa. Under the continuous erosion of acidic digestive juices and mechanical stimulation, these wounds are prone to serious complications such as delayed bleeding (incidence 5%-15%), perforation enlargement, and scar stenosis. Currently, proton pump inhibitors are mainly used in clinical practice to suppress gastric acid secretion and indirectly protect the wound, but they cannot provide an immediate physical barrier. Although endoscopic metal clip closure can mechanically clamp the wound, it is not strong enough for irregular, edematous, or fibrotic tissues, and is prone to falling off, requiring secondary removal. Absorbable hemostatic materials, such as alginate, chitosan, and oxidized regenerated cellulose, have good biocompatibility and biodegradability, but they are mostly pre-formed solids, which have poor adhesion to irregular wounds and lack the ability to adhere to wet tissues, and are prone to displacement and detachment under the flushing of gastric juice.

[0003] In-situ molding hydrogels have become a research hotspot in the field of tissue engineering in recent years. By delivering a liquid solution to the wound surface, it cross-links under physiological conditions to form a gel, achieving perfect adhesion to irregular wounds. The sodium alginate-calcium ion cross-linking system is one of the most extensively studied systems in this field: after mixing sodium alginate solution with calcium ions, Ca²⁺… + It specifically chelates with guluronic acid (G unit) in sodium alginate molecules to form a classic "eggbox" structure, gelling within seconds to minutes. However, this system exhibits the following prominent problems when practically applied to gastric mucosal wounds: insufficient adhesion; the interfacial binding force between calcium alginate gel and moist gastric mucosal tissue is weak (typically <3 kPa), easily detaching from the wound under gastric peristalsis and gastric juice flushing, failing to provide sustained protection. Poor gastric acid stability; calcium alginate gel is unstable in acidic environments (pH < 4.0), and Ca²⁺… + Easily H + Displacement causes the gel network to disintegrate, the material rapidly swells and disintegrates, and loses its barrier function. Lacking hemostatic activity, simple calcium alginate gel relies on physical occlusion for hemostasis and lacks the ability to actively activate the coagulation system, resulting in unsatisfactory hemostatic effects for active bleeding.

[0004] Therefore, developing a gastric mucosal wound protection material that combines strong wet adhesion, gastric acid stability, rapid hemostasis, and can be precisely delivered endoscopically, formed in situ, and completely degraded and absorbed is of great clinical significance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to provide a two-component gastrointestinal mucosal protective composition. Through an in-situ cross-linking reaction of the two components, a hydrogel protective layer with strong wet adhesion, environmental stability, and excellent hemostatic function is formed on the gastrointestinal wound surface. This solves the problems of insufficient adhesion, poor stability, and limited hemostatic effect of existing materials in the complex environment of the gastrointestinal tract. The two-component gastrointestinal mucosal protective composition of this invention is a gastric mucosal wound protection material that can be precisely delivered endoscopically, formed in situ, and completely degraded and absorbed, and has significant clinical implications.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a two-component digestive tract mucosal protective composition, the composition comprising a first component and a second component, wherein: The first component comprises: 0.2%–8% (w / v) alginate, 0.2%–5% (w / v) chitosan polymer, 0.05%–2% (w / v) cationic polymer, and 0.05%–2% (w / v) toughening agent; The second component includes: 0.3% to 10% (w / v) of a polyvalent metal ion salt crosslinking agent. The volume ratio of the first component to the second component is 1:0.5 to 1:2.

[0007] Preferably, the first component contains 1% to 5% (w / v) alginate, 0.5% to 3% (w / v) chitosan polymer, 0.1% to 1% (w / v) cationic polymer, and 0.1% to 1% (w / v) toughening agent.

[0008] Preferably, the content of the polyvalent metal ion salt crosslinking agent in the second component is 0.6% to 8% (w / v).

[0009] In a preferred embodiment of the present invention, the alginate is a linear anionic polysaccharide composed of β-D-mannuronic acid (M unit) and α-L-guluronic acid (G unit), wherein the G unit can react with polyvalent metal ions (especially Ca²⁺). + The ion-crosslinked network that forms the "egg-box" structure is the core component for constructing the gel framework. Preferably, it is selected from one or more of sodium alginate, potassium alginate, ammonium alginate, propylene glycol alginate, and oxidized sodium alginate; more preferably, it is sodium alginate or potassium alginate.

[0010] Preferably, the alginate contains ≥60% G units and has a molecular weight of 50,000 to 500,000 Da.

[0011] Preferably, when the alginate is sodium oxidized alginate, its oxidation degree is 30% to 50%.

[0012] In a preferred embodiment of the present invention, the chitosan polymer is a natural cationic polysaccharide possessing multiple biological activities, including hemostasis and wound healing promotion. Under acidic conditions, the amino groups on its molecular chain protonate to form -NH3. + It can electrostatically recombine with negatively charged alginate, enhancing the network density and mechanical properties of the gel. The chitosan polymer is selected from one or more of carboxymethyl chitosan, hydroxypropyl chitosan, chitosan hydrochloride, chitosan lactate, chitosan glutamate, N-succinyl chitosan, and carboxyethyl chitosan; preferably carboxymethyl chitosan and / or hydroxypropyl chitosan.

[0013] Preferably, the degree of substitution of the chitosan polymer is 0.5 to 1.0, and the molecular weight is not less than 10,000 Da; more preferably, the degree of substitution is 0.6 to 1.0, and the molecular weight is 10,000 to 500,000 Da.

[0014] In a preferred embodiment of the present invention, the cationic polymer, through its abundant positively charged groups (amino, quaternary ammonium, imino, etc.), undergoes electrostatic adsorption and hydrogen bonding with tissue surface proteins, significantly enhancing the adhesion strength of the material to wet tissues. Simultaneously, the cationic polymer can form a polyelectrolyte complex with negatively charged alginate, further crosslinking and strengthening the gel network. The cationic polymer is selected from one or more of polyethyleneimine (PEI), polyethyleneamine, polyallylamine, polyamino acids, polyamide-amine dendrimers (PAMAM), and poly(2-dimethylaminoethyl methacrylate); preferably polyethyleneimine and / or polylysine.

[0015] Preferably, the molecular weight of the polyethyleneimine is 1,000–70,000 Da; the molecular weight of the polyethyleneamine is 5,000–100,000 Da; the molecular weight of the polyallylamine is 1,000–50,000 Da; the molecular weight of the polyamino acid is 3,000–50,000 Da; the molecular weight of the polyamide-amine dendritic polymer is 1,000–50,000 Da; and the molecular weight of the poly(2-dimethylaminoethyl methacrylate) is 5,000–100,000 Da.

[0016] As a preferred embodiment of the present invention, the toughening agent is selected from one or more of glycerol, mannitol, sorbitol, and polyethylene glycol 400.

[0017] In a preferred embodiment of the present invention, the multivalent metal ion crosslinking agent acts as an ionic crosslinking initiator, coordinating with the G units of the alginate to form a three-dimensional network. The metal ions in the multivalent metal ion salt are selected from Ca²⁺. + Mg² + Ba² + Zn² + Fe³ + Al³ + One or more of the following; the anion is selected from Cl. - One or more of lactate ions, gluconate ions, and citrate ions; preferably calcium chloride and / or calcium lactate.

[0018] The gel formation mechanism of the two-component digestive tract mucosal protection composition provided by the present invention is as follows: After the first component and the second component are mixed, the following multiple synergistic crosslinking reactions occur: (1) Ionic crosslinking: Multivalent metal ions form coordination bonds with the G units of alginate to form an "egg box" structure, thus constructing a three-dimensional gel framework; (2) Electrostatic composite: -NH3 of chitosan polymers + The cationic groups of the cationic polymer and the -COO of the alginate - Electrostatic attraction occurs, forming a second cross-linked network; (3) Hydrogen bonding: The abundant hydroxyl (-OH), amino (-NH2), and carboxyl (-COOH) groups in each component form intermolecular and intramolecular hydrogen bonds, which further enhance the cohesive force and structural stability of the gel; The synergistic effect of the triple cross-linking mechanism endows the gel with excellent mechanical strength, anti-swelling properties, and wet adhesion ability.

[0019] The gel of this invention has multiple synergistic protective mechanisms: Physical barrier: The dense gel layer formed in situ can effectively isolate gastric acid, bile, pancreatic juice, digestive enzymes and microorganisms from direct contact with the wound; Rapid hemostasis: The positive charge of chitosan polymers can accumulate platelets and red blood cells, Ca² + Isovalent metal ions activate the coagulation cascade reaction, achieving active and rapid hemostasis; Microenvironment regulation: The gel absorbs wound exudate to maintain a moist healing environment, while scavenging free radicals, reducing oxidative stress damage, and accelerating wound healing.

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned two-component digestive tract mucosal protective composition, comprising the following steps: S1. Preparation of the first component: Dissolve the chitosan polymer in an aqueous solvent and stir until completely dissolved; then add alginate and continue stirring until dissolved; add cationic polymer and stir until a homogeneous and transparent solution is obtained; finally add toughening agent and stir to mix well; adjust pH to 5.0–8.0. S2. Preparation of the second component: Dissolve the polyvalent metal ion salt in an aqueous solvent and adjust the pH to 5.0-8.0, preferably to 6.0-7.5; S3. When using the two-component digestive tract mucosal protection composition, the first component is first sprayed onto the digestive tract wound, and then the second component is sprayed onto the digestive tract wound, wherein the volume ratio of the first component and the second component is 1:0.5 to 1:2.

[0021] Preferably, the preparation method further includes a step of dispensing and sterilizing the first component prepared in step S1 and the second component prepared in step S2.

[0022] Preferably, the first component is dispensed into sterile vials or pre-filled syringes and sterilized by high-temperature steam or filtration; the second component is dispensed into sterile vials or pre-filled syringes and sterilized by high-temperature steam.

[0023] Thirdly, the present invention provides the use of the above-mentioned two-component digestive tract mucosal protection composition in the preparation of digestive tract mucosal protection materials.

[0024] Preferably, the digestive tract includes the esophagus, stomach, duodenum, small intestine, and colon and rectum.

[0025] Preferably, the uses include: covering gastrointestinal ulcer wounds, wound protection after endoscopic submucosal dissection (ESD), wound protection after endoscopic mucosal resection (EMR), hemostasis of gastrointestinal bleeding, protection of gastrointestinal anastomoses, and reconstruction of the gastrointestinal mucosal barrier function.

[0026] When using the composition provided by the present invention, the first component is first sprayed onto the digestive tract wound, and then the second component is sprayed onto the digestive tract wound, wherein the volume ratio of the first component and the second component is 1:0.5 to 1:2.

[0027] In a preferred embodiment of the present invention, a double-lumen catheter or spraying catheter is delivered to the gastrointestinal wound via an endoscopic forceps channel. A first component is sprayed onto the gastrointestinal wound, followed by a second component sprayed over the first component. The volume ratio of the first to the second component is 1:0.5 to 1:2. The two components gel within 1 second to 1 minute after mixing and contact. The gel remains stable in the gastrointestinal tract for 3 to 14 days, gradually degrading through hydrolysis and enzymatic degradation. The degradation products are non-toxic and metabolizable, eliminating the need for secondary removal.

[0028] Preferably, the mixing volume ratio of the first component to the second component is 1:1.

[0029] Preferably, the gelation time is 1 to 10 seconds.

[0030] Fourthly, the present invention provides a method for stopping bleeding in the digestive tract, the method comprising the following steps: The first component of the two-component digestive tract mucosal protective composition is sprayed onto the wound site, and then the second component is sprayed onto the first component. The volume ratio of the first component to the second component is 1:0.5 to 1:2 to form a gel.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: Triple synergistic crosslinking enhances mechanical properties: Through a triple synergistic crosslinking mechanism of ionic crosslinking, electrostatic compounding and hydrogen bonding, the gel's resistance to gastrointestinal motility is significantly enhanced, and its mechanical strength and structural stability are superior to those of a single crosslinking system; Strong wet adhesion performance: The introduction of cationic polymers, through their abundant positively charged groups, allows for electrostatic adsorption and hydrogen bonding with tissue surface proteins, significantly enhancing the adhesion strength of the material to wet tissues and effectively solving the clinical pain point of existing materials easily falling off in wet tissues; The adaptive property of "acid-enhanced": Chitosan polymers undergo protonation enhancement under acidic conditions, giving the gel a more stable adaptive property in the gastric acid environment, and it can still maintain its structural integrity in simulated gastric juice at pH 2.0; Triple active hemostasis mechanism: simultaneously achieving physical occlusion, positive charge coagulation, and Ca²⁺. + The triple active hemostasis mechanism that activates the coagulation cascade has a significantly better hemostatic effect than materials with a single mechanism. Minimally invasive and precise delivery: The dual-component design enables minimally invasive and precise delivery via the endoscopic instrument channel. After the two components meet and mix at the wound site, they rapidly cross-link into a gel in situ under physiological conditions. The gel can adapt to the contour of the defective wound and achieve complete and close coverage of irregular wounds. Multifunctional integration: It has multiple functions such as physical barrier, rapid hemostasis, and microenvironment regulation. It is gradually degraded through hydrolysis and enzymatic hydrolysis, eliminating the need for secondary removal and simplifying the clinical operation process.

[0032] In summary, this invention, through a triple synergistic crosslinking mechanism and a two-component in-situ gelation technology, successfully solves the core technical problems of insufficient adhesion, poor acid stability, weak hemostatic activity, and single function of existing materials, and has good clinical application prospects and market value. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is an image showing the gel prepared in Example 1 of this invention used for hemostasis in the gastric tissue wound of a New Zealand rabbit.

[0034] Figure 2 This is an image showing the gel prepared in Example 2 of this invention used for hemostasis in the gastric tissue wound of a New Zealand rabbit. Detailed Implementation

[0035] To more clearly illustrate the overall concept of this application, a detailed description is provided below with reference to the accompanying drawings and embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with the invention.

[0036] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0039] Unless otherwise specified, in the following embodiments, reagents or instruments whose manufacturers are not indicated are all conventional products that can be purchased commercially.

[0040] Example 1: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 0.5g of carboxymethyl chitosan (degree of substitution 0.6, molecular weight 500000Da) in 100mL of 0.9% NaCl solution and stir until completely dissolved; then add 2g of sodium alginate (molecular weight 300000Da) and continue stirring to dissolve; add 0.1g of polylysine (molecular weight 3000Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.05g of glycerol and stir to mix well; adjust the pH to 7.0 with 0.01M dilute hydrochloric acid; dispense into pre-filled syringes and perform moist heat sterilization at 121℃ for 20min to obtain the first component.

[0041] (2) Dissolve 1.2g of calcium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0042] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel. The gel formation time is 5s.

[0043] Example 2: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 1g of carboxypropyl chitosan (degree of substitution 0.5, molecular weight 100000Da) in 100mL of 0.9% NaCl solution and stir until completely dissolved; then add 4g of potassium alginate (molecular weight 200000Da) and continue stirring to dissolve; add 0.05g of polyethyleneimine (molecular weight 10000Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.1g of polyethylene glycol 400 and stir to mix well; adjust the pH to 8 with 0.01M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121℃ for 20min to obtain the first component.

[0044] (2) Dissolve 10g of zinc gluconate in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize at 121℃ for 20min to obtain the second component.

[0045] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1.5 to form a gel, and the gel formation time is 50s.

[0046] Example 3: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 5.0 g of chitosan hydrochloride (molecular weight 100000 Da) in 100 mL of purified water and stir until completely dissolved; then add 0.2 g of ammonium alginate (molecular weight 150000 Da) and continue stirring to dissolve; add 2 g of polyallylamine (molecular weight 8000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 2 g of sorbitol and stir to mix well; adjust the pH to 6 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0047] (2) Dissolve 0.5g of calcium lactate in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0048] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel. The gel formation time is 1 min.

[0049] Example 4: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 4.0 g of chitosan lactate (molecular weight 200,000 Da) in 100 mL of water for injection and stir until completely dissolved; then add 1.0 g of propylene glycol alginate (molecular weight 500,000 Da) and continue stirring to dissolve; add 1 g of polyhistidine (molecular weight 25,000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 1 g of glycerol and stir to mix well; adjust the pH to 7 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0050] (2) Dissolve 4.0g of magnesium citrate in 100mL of water for injection to form a transparent liquid; dispense into pre-filled syringes and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0051] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:0.5 to form a gel, and the gel formation time is 30s.

[0052] Example 5: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 3.0 g of chitosan glutamate (molecular weight 250000 Da) in 100 mL of water for injection and stir until completely dissolved; then add 3.0 g of sodium alginate (molecular weight 300000 Da) and continue stirring to dissolve; add 1.5 g of polyethyleneimine (molecular weight 5000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.5 g of mannitol and stir to mix well; adjust the pH to 7.5 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0053] (2) Dissolve 8.0g of calcium gluconate in 100mL of water for injection to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0054] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:2 to form a gel, and the gel formation time is 15s.

[0055] Example 6: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 2.0 g of carboxyethyl chitosan (degree of substitution 0.6, molecular weight 50000 Da) in 100 mL of 0.01 M phosphate buffer and stir until completely dissolved; then add 5.0 g of sodium alginate (molecular weight 200000 Da) and continue stirring to dissolve; add 1.0 g of polyamide-amine dendritic polymer (molecular weight 10000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.05 g of glycerol and stir to mix well; dispense into sterile vials and perform moist heat sterilization at 125 °C for 8 min to obtain the first component.

[0056] (2) Dissolve 0.3g of calcium chloride in 100mL of water for injection to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0057] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:2 to form a gel. The gel formation time is 1 min.

[0058] Example 7: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 0.2 g of N-succinyl chitosan (molecular weight 100000 Da) in 100 mL of 0.01 M phosphate buffer and stir until completely dissolved; then add 8.0 g of sodium oxidized alginate (oxidation degree 40%, molecular weight 20000 Da) and continue stirring to dissolve; add 0.5 g of poly(2-dimethylaminoethyl methacrylate) (molecular weight 30000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 1.0 g of sorbitol and stir to mix well; filter to sterilize and then dispense into pre-filled syringes to obtain the first component.

[0059] (2) Dissolve 1.2g of calcium chloride in 100mL of water for injection to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0060] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel. The gel formation time is 5s.

[0061] Example 8: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 1.0 g of carboxymethyl chitosan (degree of substitution 0.8, molecular weight 250000 Da) in 100 mL of purified water and stir until completely dissolved; then add 3.0 g of sodium alginate (molecular weight 300000 Da) and continue stirring to dissolve; add 0.2 g of polyethyleneimine (molecular weight 8000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 2 g of polyethylene glycol 400 and stir to mix well; adjust the pH to 8.0 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0062] (2) Dissolve 2.0g of calcium chloride in 100mL of water for injection to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0063] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel, and the gel formation time is 1 second.

[0064] Example 9: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 2.0 g of hydroxypropyl chitosan (degree of substitution 1.0, molecular weight 200000 Da) in 100 mL of 0.9% NaCl solution and stir until completely dissolved; then add 2.0 g of potassium alginate (molecular weight 100000 Da) and continue stirring to dissolve; add 1 g of polylysine (molecular weight 10000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.2 g of sorbitol and stir to mix well; adjust the pH to 7.5 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0065] (2) Dissolve 3g of barium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 126℃ for 6min to obtain the second component.

[0066] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:0.5 to form a gel, and the gel formation time is 20s.

[0067] Example 10: Preparation method of a two-component digestive tract mucosal protective composition (1) Dissolve 0.5 g of carboxyethyl chitosan (degree of substitution 0.8, molecular weight 300000 Da) in 100 mL of 0.01 M phosphate buffer and stir until completely dissolved; then add 6 g of sodium alginate (molecular weight 200000 Da) and continue stirring to dissolve; add 0.1 g of polyethyleneimine (molecular weight 10000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.5 g of glycerol and stir to mix well; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0068] (2) Dissolve 1.5g of calcium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 126℃ for 6min to obtain the second component.

[0069] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel, and the gel formation time is 1 second.

[0070] Comparative Example 1: (Comparative example of chitosan-free polymers) (1) Dissolve 3.0 g of sodium alginate (molecular weight 300,000 Da) in 100 mL of purified water and stir until completely dissolved; add 0.2 g of polyethyleneimine (molecular weight 10,000 Da) and stir until a homogeneous and transparent solution is obtained; finally, add 2 g of polyethylene glycol 400 and stir to mix well; adjust the pH to 8.0 with 0.01 M dilute hydrochloric acid. Dispense into sterile vials and sterilize by moist heat at 121 °C for 20 min to obtain the first component.

[0071] (2) Dissolve 2.0g of calcium chloride in 100mL of water for injection to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0072] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component and the second component is 1:1 to form a gel. The gel formation time is 1.5 min.

[0073] Comparative Example 2: (Comparative example of chitosan-free polymers and cationic polymers) (1) Dissolve 8.0g of sodium alginate (molecular weight 300000Da) in 100mL of 0.01M phosphate buffer and stir until completely dissolved; add 0.5g of glycerol and stir well; dispense into sterile vials and sterilize at 121℃ for 20min to obtain the first component.

[0074] (2) Dissolve 1.5g of calcium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 126℃ for 6min to obtain the second component.

[0075] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel. The gel formation time is 3 minutes.

[0076] Comparative Example 3: (Comparative example of non-cationic polymers) (1) Dissolve 2.0 g of hydroxypropyl chitosan (degree of substitution 1.0, molecular weight 200000 Da) in 100 mL of 0.9% NaCl solution and stir until completely dissolved; then add 2.0 g of potassium alginate (molecular weight 100000 Da) and continue stirring to dissolve; finally add 0.2 g of sorbitol and stir to mix well; adjust the pH to 7.5 with 0.01 M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0077] (2) Dissolve 3g of barium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 126℃ for 6min to obtain the second component.

[0078] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:0.5 to form a gel. The gel formation time is 2 minutes.

[0079] Comparative Example 4: (Comparative examples of chitosan polymers and alginate at lower mass fractions) (1) Dissolve 0.1 g of carboxymethyl chitosan (degree of substitution 0.8, molecular weight 500,000 Da) in 100 mL of 0.9% NaCl solution and stir until completely dissolved; then add 0.1 g of sodium alginate (molecular weight 300,000 Da) and continue stirring to dissolve; add 0.1 g of polylysine (molecular weight 8,000 Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.05 g of glycerol and stir to mix well; dispense into pre-filled syringes and perform moist heat sterilization at 121 °C for 20 min to obtain the first component.

[0080] (2) Dissolve 1.2g of calcium chloride in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize by moist heat at 121℃ for 20min to obtain the second component.

[0081] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1 to form a gel. The gel formation time is greater than 5 minutes and the gel is not completely cured.

[0082] Comparative Example 5: (Comparative example with chitosan polymers and alginate at higher mass fractions) (1) Dissolve 1g of carboxyethyl chitosan (degree of substitution 0.8, molecular weight 200000Da) in 100mL of 0.9% NaCl solution and stir until completely dissolved; then add 10g of potassium alginate (molecular weight 100000Da) and continue stirring to dissolve; add 0.05g of polyethyleneimine (molecular weight 10000Da) and stir until a homogeneous and transparent solution is obtained; finally add 0.1g of polyethylene glycol 400 and stir to mix well; adjust the pH to 8 with 0.01M dilute hydrochloric acid; dispense into sterile vials and perform moist heat sterilization at 121℃ for 20min to obtain the first component.

[0083] (2) Dissolve 10g of zinc gluconate in 100mL of purified water to form a transparent liquid; dispense into sterile vials and sterilize at 121℃ for 20min to obtain the second component.

[0084] (3) Application method: Spray the first component onto the wound or carrier, and then spray the second component onto the first component. The volume ratio of the first component to the second component is 1:1.5 to form a gel. The gel formation time is greater than 5 minutes and the gel is not completely cured.

[0085] The composition samples of Examples 1-10 and the samples of Comparative Examples 1-5 were tested using test case experiments, and the test results are shown in Table 1. The hemostatic efficacy of the above samples in an animal gastric bleeding model was also studied, and the adhesion of the gel sample to the gastric mucosal wound was observed. The test results are shown in Table 2.

[0086] Test Example 1: Tissue Adhesion Test Fresh gastric tissue was obtained from the normal euthanasia of Bama miniature pigs and used within 24 hours. Fresh gastric tissue was placed in 37°C saline solution, cut open, and the gastric lining was cleaned with saline solution; the cleaned stomach was used within 2 hours. A 2cm × 5cm section of gastric tissue was cut and fixed onto a self-made polyethylene rinsing slope. The gastric mucosa was removed to form a 1cm × 1cm wound. 0.5mL of the first component was evenly applied to the gastric mucosal wound, followed by the application of the second component. The wound was then placed in a constant temperature incubator (relative humidity >90%, temperature 37°C) for 15 minutes. Excess fixative was rinsed off with saline solution, and the rinsing slope was tilted at 60° and fixed to an iron stand. The gastric tissue and gel sample were rinsed with 0.01mol / L hydrochloric acid solution using a peristaltic pump at a rate of 25mL / min for 60 minutes. The rinsing solution was collected in a container of known weight. A blank test was performed simultaneously, with another section of gastric tissue of the same area treated in the same manner, and the rinsing solution collected. The rinsing fluid collected in the container is freeze-dried and weighed. Tissue adhesiveness is expressed as the percentage of mass adhering to the gastric tissue.

[0087] Calculation method: Percentage of gastric tissue adhesion = {[M-(Aa-m)] / M}x100%.

[0088] In the formula, M is the mass of the protective adhesive (lyophilized under the same conditions); A is the total weight of the container and lyophilized residue; a is the mass of the empty lyophilized rinsing solution container; m is the mass of solids contained in the same volume of rinsing solution in the blank test (blank control); the higher the percentage of gastric tissue adhesion, the better the adhesion of the sample. The test results are shown in Table 1.

[0089] Test Example 2: Adhesion Time Test Fresh pigskin was cleaned by removing the fatty portion to expose the collagen. It was then cut into 2.5cm wide strips, cleaned with detergent to remove grease, washed with 75% ethanol, and then rinsed with purified water. The cleaned pigskin was cut into approximately 2.5cm x 2.5cm pieces. A 0.5mL layer of 0.01mol / L hydrochloric acid solution was applied to the inner surface of the pigskin, and the liquid was drained. 0.5mL of the first component was evenly applied to the wound surface of the pigskin carrier. The second component was then sprayed onto the contact surface of the first component, and the mixture was placed in a constant temperature incubator (relative humidity >90%, temperature 37℃) for 15 minutes. The pigskin covered with gel was then placed in a beaker containing approximately 0.01mol / L hydrochloric acid solution and shaken in a constant temperature shaker (37℃, 60 rpm). The hydrochloric acid solution was changed daily, and the adhesion of the gel to the pigskin was observed until more than 50% of the gel detached. The adhesion time was recorded. The experimental results are shown in Table 1.

[0090] Experimental results: Table 1 shows the percentage of adhesion of each sample to the stomach tissue of Bama miniature pigs and the adhesion time of the pig skin carrier.

[0091] Table 1. Results of gastric tissue adhesion percentage and porcine skin carrier adhesion time for each sample.

[0092] The data in Table 1 show that the product compositions of the Example Group of the two-component digestive tract mucosal protection composition of the present invention have higher adhesion percentage to the gastric tissue and longer adhesion time to the pig skin carrier than the product compositions of the comparative examples. This proves that the two-component digestive tract mucosal protection composition of the present invention can improve the adhesion of the product to the gastric mucosa and the adhesion time to the pig skin carrier. Moreover, the composition of Example 8 has the highest adhesion percentage to the gastric tissue of Bama miniature pigs and the longest gel adhesion time.

[0093] Test Example 3: Animal Hemostasis Experiment for Gastric Mucosal Injury Establishment of a gastric mucosal hemorrhage model: Healthy New Zealand white rabbits weighing 2.0–2.5 kg were selected and fasted for 12 hours before surgery, but allowed free access to water. After anesthesia with sodium pentobarbital (30 mg / kg) via the marginal ear vein, the rabbits were fixed in a supine position. The surgical area of ​​the upper abdomen was shaved, disinfected, and draped. A 3–4 cm longitudinal incision was made along the midline of the abdomen, and the abdominal wall was dissected layer by layer, gently freeing and exposing the greater curvature of the stomach. Using sterile ophthalmic scissors, an elliptical wound of approximately 10 mm × 5 mm was made on the greater curvature of the stomach, aiming to damage only the mucosa and submucosa while maintaining the integrity of the muscle layer, avoiding gastric perforation. The gastric mucosal hemorrhage model was considered successfully established when continuous fresh bleeding without spurting bleeding appeared. Free blood around the wound was gently wiped away with sterile gauze. The qualified experimental animals were randomly divided into a blank control group and a combination group (Examples 1-10, Comparative Examples 1-5).

[0094] Experimental group procedure: Using a disposable sterile syringe, an appropriate amount of the first component (enough to completely cover the wound and adjacent areas) was drawn and evenly applied to the bleeding wound. Immediately afterwards, using another sterile syringe, the second component was drawn and dripped onto and evenly covered over the first component to form a gel. Blank control group: No treatment was performed after modeling.

[0095] Observation and recording: For all groups, 5 minutes after the completion of modeling (or material application), the wound area was gently rinsed with an appropriate amount of physiological saline. The following indicators were observed and recorded: hemostasis time (the time from material application to cessation of bleeding from the wound; more than 5 minutes was recorded as >300 seconds), gel adhesion (complete coverage / partial detachment / complete detachment after rinsing), and rebleeding. The experimental results are shown in Table 2.

[0096] Experimental results: Table 2 shows the hemostasis time, gel adhesion, and rebleeding in animal experiments on gastric mucosal injury in each sample group.

[0097] Table 2 Summary of hemostasis time, gel adhesion, and rebleeding in each sample group

[0098] As can be seen from the data in Table 2, the compositions of each embodiment can effectively stop bleeding on the gastric wall wound, and their hemostasis time is shorter than that of the comparative example and the blank control group. After the wound area was rinsed with physiological saline after hemostasis, the gel still completely covered the wound and there was no further bleeding. This is because the hydrogel formed by the synergistic effect of ionic cross-linking, electrostatic compounding and hydrogen bonding of the composition has strong wet adhesion and strong hemostatic effect. It also proves that the protonation enhancement effect of the two-component digestive tract mucosal protection composition prepared in this invention endows the gel with the adaptive property of "enhanced adhesion when exposed to acid" under acidic conditions.

[0099] The above description is merely an embodiment of the present invention, and the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. A two-component digestive tract mucosal protective composition, characterized in that, The composition comprises a first component and a second component, wherein: The first component comprises: 0.2%–8% (w / v) alginate, 0.2%–5% (w / v) chitosan polymer, 0.05%–2% (w / v) cationic polymer, and 0.05%–2% (w / v) toughening agent; The second component includes: 0.3% to 10% (w / v) of a polyvalent metal ion salt crosslinking agent. The volume ratio of the first component to the second component is 1:0.5 to 1:

2.

2. The two-component digestive tract mucosal protection composition according to claim 1, characterized in that, The alginate is selected from one or more of sodium alginate, potassium alginate, ammonium alginate, propylene glycol alginate, and oxidized sodium alginate.

3. The two-component digestive tract mucosal protection composition according to claim 1, characterized in that, The chitosan polymer is selected from one or more of carboxymethyl chitosan, hydroxypropyl chitosan, chitosan hydrochloride, chitosan lactate, chitosan glutamate, N-succinyl chitosan, and carboxyethyl chitosan.

4. The two-component digestive tract mucosal protection composition according to claim 1, characterized in that, The cationic polymer is selected from one or more of polyethyleneimine, polyethyleneamine, polyallylamine, polyamino acids, polyamide-amine dendritic polymers, and poly(2-dimethylaminoethyl methacrylate).

5. The two-component digestive tract mucosal protection composition according to claim 1, characterized in that, The toughening agent is selected from one or more of glycerol, mannitol, sorbitol, and polyethylene glycol 400.

6. The two-component digestive tract mucosal protection composition according to claim 1, characterized in that, The metal ions in the polyvalent metal ion salt are selected from Ca²⁺. + Mg² + Ba² + Zn² + Fe³ + Al³ + One or more of the following; the anion is selected from Cl. - One or more of lactate ions, gluconate ions, and citrate ions.

7. A method for preparing a two-component digestive tract mucosal protective composition as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation of the first component: Dissolve the chitosan polymer in an aqueous solvent and stir until completely dissolved; then add alginate and continue stirring until dissolved; add cationic polymer and stir until a homogeneous and transparent solution is obtained; finally add toughening agent and stir to mix well; adjust pH to 5.0–8.

0. S2. Preparation of the second component: Dissolve the polyvalent metal ion salt in an aqueous solvent and adjust the pH to 5.0–8.0; S3. When using the two-component digestive tract mucosal protection composition, the first component is first sprayed onto the digestive tract wound, and then the second component is sprayed onto the digestive tract wound, wherein the volume ratio of the first component and the second component is 1:0.5 to 1:

2.

8. The preparation method according to claim 7, characterized in that, The aqueous solvent is selected from one or more of purified water, physiological saline, phosphate buffer, and water for injection.

9. Use of a two-component digestive tract mucosal protective composition as described in any one of claims 1-6 in the preparation of digestive tract mucosal protective materials.

10. The use according to claim 9, characterized in that, The uses include at least one of the following: covering gastrointestinal ulcer wounds, protecting wounds after endoscopic submucosal dissection, protecting wounds after endoscopic mucosal resection, stopping gastrointestinal bleeding, protecting gastrointestinal anastomoses, and reconstructing the gastrointestinal mucosal barrier function.

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