Acid-initiated biological tissue adhesive as well as preparation method and application thereof

Abstract

The invention discloses an acid-initiated biological tissue adhesive as well as a preparation method and application thereof, and belongs to the field of medical polymer materials. The acid-initiated biological tissue adhesive disclosed by the invention comprises a supramolecular system which is obtained by triggering and condensing a mixed component consisting of (a) and (b) when meeting acid, wherein (a) phenylalanine functionalized natural polymer; (b) biological polyphenol and polyphenol functional polypeptide, and the mass ratio of the component (a) to the component (b) is 1: (0.5-2). The acid-initiated biological tissue adhesive disclosed by the invention has excellent injectability, can be delivered through a minimally invasive way of an endoscope, and is simple to operate; the hydrogel also has the interface water removal capability and the characteristic of triggering hydrophilic-hydrophobic conversion and rapid condensation when meeting acid, and can effectively achieve rapid blocking of ulcer wounds; meanwhile, the acid-initiated biological tissue adhesive can be in wet adhesion with biological tissues through hydrogen bonds, pi-pi accumulation, hydrophobicity and other acting forces, shows excellent self-healing performance, can reside in the stomach environment for a long time and provides the adhesion strength as high as 34.3 kPa.

Description

Technical Field

[0001] This application belongs to the field of medical polymer materials technology, and specifically relates to an acid-initiated biological tissue adhesive, its preparation method and application. Background Technology

[0002] Biological tissue adhesives possess excellent bonding capabilities and good biocompatibility, showing great promise for applications in tissue sealing, wound repair, and hemostasis. However, traditional biological tissue adhesives are fixed in shape, making them unsuitable for delivery to tissue interfaces via minimally invasive methods such as endoscopy, and also unsuitable for sealing irregularly shaped tissue surfaces. In particular, the mucus on the surface of gastric tissue easily reduces adhesive strength, limiting the performance of biological tissue adhesives to mild physiological environments and severely restricting their application in the acidic liquid environment of the stomach. Therefore, developing biological tissue adhesives suitable for the gastric tissue microenvironment is of great significance.

[0003] Currently, hydrogel-type biological tissue adhesives have been designed and developed in related technologies, achieving delivery via minimally invasive endoscopic routes while effectively solving the problem of insufficient contact between the adhesive and the gastric tissue surface. For example, Guo Baolin et al. developed an injectable pH-responsive self-healing adhesive hydrogel based on acryloyl-6-aminohexanoic acid (AA) and AA-gN-hydroxysuccinimide (AA-NHS), which effectively achieved adhesive treatment of gastric wounds.

[0004] However, hydrogel-type biological tissue adhesives such as those mentioned above still have shortcomings. For example, their bonding strength in the moist, closed, and extremely acidic gastric tissue environment is generally less than 10 kPa, which is insufficient to meet the clinical needs of dynamic gastric tissue bonding and repair. Summary of the Invention

[0005] This application discloses an acid-initiated biological tissue adhesive, its preparation method, and its application, aiming to solve the technical problem of insufficient bonding strength of existing hydrogel-type biological tissue adhesives in the gastric tissue environment.

[0006] To achieve the above objectives, the technical solution provided in this application is as follows:

[0007] The first aspect of this application provides an acid-initiated biological tissue adhesive comprising a supramolecular system obtained by acid-triggered aggregation of a mixture of components (a) and (b).

[0008] (a) Phenylalanine-functionalized natural polymers;

[0009] (b) Biopolyphenols and polyphenol-functionalized peptides;

[0010] The mass ratio of (a) to (b) is 1:(0.5~2).

[0011] According to the disclosure of the first aspect, the phenylalanine-functionalized natural polymer is selected from one of phenylalanine-functionalized dextran, phenylalanine-functionalized sodium alginate, phenylalanine-functionalized chitosan, phenylalanine-functionalized hyaluronic acid, phenylalanine-functionalized γ-polyglutamic acid, phenylalanine-functionalized polyaspartic acid, and phenylalanine-functionalized ε-polylysine.

[0012] According to the disclosure of the first aspect, the bio-polyphenol is selected as tannic acid;

[0013] The polyphenol-functionalized polypeptide is selected from one of gallic acid-functionalized ε-polylysine, ferulic acid-functionalized ε-polylysine, dopamine-functionalized γ-polyglutamic acid, and dopamine-functionalized gelatin.

[0014] According to the disclosure of the first aspect, the total concentration of components (a) and (b) is 5 to 30 w / v.

[0015] According to the disclosure of the first aspect, the grafting rate of the phenylalanine-functionalized natural polymer is 30-50%.

[0016] The second aspect of this application also discloses a method for preparing the acid-initiated biological tissue adhesive described above, comprising the following steps:

[0017] Provide aqueous solutions containing components (a) and (b) respectively;

[0018] Mix the two aqueous solutions from the previous step to prepare the precursor solution;

[0019] The precursor solution is brought into contact with an acidic medium to aggregate and form a supramolecular system.

[0020] According to the disclosure of the second aspect, the pH range of the acidic medium is 1.2 to 1.8.

[0021] According to the disclosure of the second aspect, the acidic medium comprises gastric juice.

[0022] The third aspect of this application also discloses the application of the acid-initiated biological tissue adhesive of the present invention in the preparation of acid-sensitive wound adhesive materials.

[0023] According to the disclosure of the third aspect, the acid-involved wound includes a gastric ulcer wound.

[0024] Compared with the prior art, the advantages or beneficial effects of this application include at least the following:

[0025] This application establishes a supramolecular system based on these two components, achieving several advantages: First, it endows the biological tissue adhesive with the ability to expel water from the interface and the characteristic of rapid coagulation triggered by a hydrophilic-hydrophobic transition upon acid exposure, effectively achieving rapid sealing of ulcer wounds. Second, it endows the adhesive with the tissue interface through hydrogen bonds, hydrophobic interactions, π-π stacking, and other forces, providing excellent self-healing properties. This allows for an adhesion strength of up to 34.3 kPa in the cyclically peristaltic gastric environment, and enables rapid self-healing of damaged structures to maintain structural integrity, extending its in vivo application period. Third, the precursor solution is injectable and can be delivered to the gastric tissue surface via a minimally invasive endoscopic approach for adhesion, making the operation simple and convenient. Fourth, the raw materials are inexpensive, readily available, biocompatible, and biodegradable, and do not require exogenous initiation conditions, effectively avoiding the potential toxic side effects of initiators. It possesses excellent biosafety, has promising clinical translation prospects, and can provide a new option for the clinical treatment of gastric ulcers. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 1H NMR spectra of phenylalanine-functionalized dextran with different phenylalanine grafting amounts provided for this application;

[0028] Figure 2 The 1H NMR spectra of phenylalanine-functionalized γ-polyglutamic acid with different phenylalanine grafting amounts provided in this application;

[0029] Figure 3 Gelation test diagram of DP-501TA1 provided in this application;

[0030] Figure 4 The DP-501TA0 and DP-501TA provided in this application 0.5 DP-501TA1, DP-501TA 1.5 Bond strength test diagram of DP-501TA2;

[0031] Figure 5 Bond strength test diagrams for DP-201TA1, DP-301TA1 and DP-401TA1 provided in this application;

[0032] Figure 6 The wet adhesion test diagram of DP-501TA1 provided in this application;

[0033] Figure 7 Degradation curve of DP-501TA1 provided for this application in simulated gastric juice containing pepsin;

[0034] Figure 8 Test diagram of the self-healing performance of DP-501TA1 provided in this application;

[0035] Figure 9 The DP-501TA0 and DP-501TA provided in this application 0.5 DP-501TA1, DP-501TA 1.5 Antioxidant capacity test chart of DP-501TA2;

[0036] Figure 10 The in vivo adhesion test diagram of DP-501TA1 provided in this application. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort are within the scope of protection of this application.

[0038] In the following description of this specification, the term "and / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and both A and B existing simultaneously. A and B can be singular or plural; the symbol " / " means "or".

[0039] In the following description of this specification, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions mean any combination of such items, including any combination of single or plural items. For example, "at least one of A, B or C", or "at least one of A, B and C", can mean any one of A, B, C, or A+B, or A+C, or B+C, or A+B+C, where A, B, and C can be single or multiple.

[0040] In the following description of this specification, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and does not constitute any limitation on the execution process of this embodiment.

[0041] In the following description of this specification, numerical ranges should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Any intermediate value within a stated range, as well as any other stated value or each smaller range between intermediate values ​​within a stated range, are also included in this embodiment, and the upper and lower limits of the smaller ranges may be independently included or excluded from the range.

[0042] Unless otherwise stated, the technical / scientific terms used in this specification have the meanings commonly understood by one of ordinary skill in the art. While this specification describes only preferred materials and methods, any similar or equivalent methods and materials may be used in specific embodiments or test examples. All references to this specification are incorporated by way of citation to disclose and describe the methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0043] To address the problem that existing hydrogel-type biological tissue adhesives cannot meet the adhesion and repair requirements in dynamic gastric tissue, a first aspect of this application provides an acid-initiated biological tissue adhesive comprising a supramolecular system obtained by acid-triggered aggregation of a mixture of components (a) and (b):

[0044] (a) Phenylalanine-functionalized natural polymers;

[0045] (b) Biopolyphenols and polyphenol-functionalized peptides;

[0046] The mass ratio of (a) to (b) is 1:(0.5~2).

[0047] This application embodiment utilizes a supramolecular biological tissue adhesive based on phenylalanine-functionalized natural polymers and bio-polyphenols and polyphenol-functionalized peptides. The phenylalanine-functionalized natural polymers effectively remove interfacial water through hydrophobic aggregation, thus providing the biological tissue adhesive with an interfacial water removal mechanism. The bio-polyphenols and polyphenol-functionalized peptides provide hydrophilic effects as well as hydrogen bonding and π-π stacking forces. The mixture of these two components can rapidly aggregate upon acid-triggered hydrophilic-hydrophobic transition, effectively achieving rapid sealing of ulcer wounds. It also provides adhesion to the tissue interface through hydrogen bonding, hydrophobicity, and π-π stacking forces, offering excellent self-healing properties. This allows the precursor solution to provide an adhesion strength of up to 34.3 kPa within the cyclically peristaltic microenvironment of the stomach tissue. Furthermore, any damaged adhesion structures can rapidly self-heal to maintain structural integrity and prolong the in vivo residence period. Simultaneously, the precursor solution containing these two components is injectable and can be delivered to the stomach tissue surface via a minimally invasive endoscopic approach for adhesion, making the procedure simple and convenient. In addition, the raw materials for these components are inexpensive, readily available, biocompatible, and biodegradable, requiring no additional initiation conditions and effectively avoiding the potential toxic side effects of initiators. It possesses excellent biosafety and promising clinical translation prospects, providing a new option for the clinical treatment of gastric ulcers.

[0048] In possible public examples, the phenylalanine-functionalized natural polymer is selected from one of phenylalanine-functionalized dextran (DP), phenylalanine-functionalized sodium alginate (SP), phenylalanine-functionalized chitosan (CP), phenylalanine-functionalized hyaluronic acid (HP), phenylalanine-functionalized γ-polyglutamic acid (PP), phenylalanine-functionalized polyaspartic acid (AP), and phenylalanine-functionalized ε-polylysine (LP).

[0049] It should be noted that this application does not specifically limit the synthetic method of phenylalanine-functionalized natural polymers. They can be prepared by reaction with condensation reagents such as N,N′-carbonyldiimidazole (CDI), 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), and dicyclohexylcarbodiimide (DCC). For example, this invention provides, by way of example, the synthesis of phenylalanine-functionalized dextran (DP), phenylalanine-functionalized γ-polyglutamic acid (PP), and phenylalanine-functionalized polyaspartic acid (AP), and the specific synthetic process is as follows:

[0050] (1) Synthesis of phenylalanine-functionalized dextran (DP):

[0051] S101: Dissolve 3.24g of dextran in 80mL of anhydrous DMSO at 60℃, then cool to room temperature;

[0052] S102: Dissolve 3.24g CDI in 20mL of anhydrous DMSO, and then add it dropwise to the dextran solution of S101 above under N2 protection, and activate the hydroxyl groups for 5h;

[0053] S103: Under a N2 atmosphere, (6.47 g, 8.62 g, 10.78 g and 12.94 g) L-phenylalanine methyl ester hydrochloride were added to the above S102 activated dextran solution and dissolved completely. Then, 8.3 mL of triethylamine was added and the mixture was placed in an oil bath at 80 °C for 48 h.

[0054] S104: After the reaction was completed and cooled to room temperature, 180 mL of 1 M LiOH solution was added. After the deesterification and hydrolysis reaction was carried out for 12 h, the pH of the solution was adjusted to 7-8 using 6 M HCl. The reaction solution was then transferred to a dialysis bag with a molecular weight cutoff of 3500 Da and dialyzed with deionized water for 5 days. The dialysate was then passed through a 0.45 μm filter membrane to obtain a clear dialysate. After vacuum freeze-drying, phenylalanine-functionalized dextran (DP) with different grafting rates was obtained.

[0055] (2) Synthesis of phenylalanine-functionalized γ-polyglutamic acid (PP):

[0056] S201: Dissolve 1.47g of γ-polyglutamic acid and (1.08g, 2.16g, 3.23g and 4.31g) of L-phenylalanine methyl ester hydrochloride in 100mL of deionized water, respectively;

[0057] S202: After the reactants have fully dissolved, add 2.88g of EDC·HCl to the solution and react at room temperature for 6 hours;

[0058] S203: After the reaction is complete, the reaction solution is filtered and the precipitate is collected. 20 mL of 1 M LiOH solution is added to the precipitate. After deesterification and hydrolysis at room temperature for 12 h, the pH of the solution is adjusted to 7-8 using 6 M HCl. The reaction solution is then transferred to a dialysis bag with a molecular weight cutoff of 3500 Da. Dialysis is performed using deionized water for 5 days. The dialysate is then freeze-dried under vacuum to obtain phenylalanine-functionalized γ-polyglutamic acid (PP) with different grafting rates.

[0059] (3) Synthesis of phenylalanine-functionalized polyaspartic acid (AP):

[0060] S301: Dissolve 0.97g of polysuccinimide and 4.31g of L-phenylalanine methyl ester hydrochloride thoroughly in 10mL of DMSO solution;

[0061] S302: Add 2.8 mL of TEA solution to the solution of S301 and perform ring-opening ammonolysis at 80 °C for 24 h; after the reaction is completed and cooled to room temperature, add 40 mL of 1 M NaOH solution to continue hydrolysis for 4 h.

[0062] S303: After the reaction is complete, adjust the pH of the solution to 7-8 using 6M HCl, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 5 days, and freeze-dry the dialysate under vacuum to obtain phenylalanine-functionalized polyaspartic acid (AP).

[0063] In possible public examples, the polyphenol-functionalized polypeptide is selected from one of gallic acid-functionalized ε-polylysine (PG), ferulic acid-functionalized ε-polylysine (PF), dopamine-functionalized γ-polyglutamic acid (PD), and dopamine-functionalized gelatin (GD).

[0064] It should be noted that this application does not specifically limit the synthesis method of polyphenol-functionalized peptides, which can be prepared by reaction using condensation reagents such as N,N′-carbonyldiimidazole (CDI), 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), and dicyclohexylcarbodiimide (DCC). For example, this invention provides an exemplary synthesis of gallic acid-functionalized ε-polylysine (PG), and the specific synthesis process is as follows:

[0065] S401: Under a N2 atmosphere, 1 g of gallic acid and 1.13 g of EDC·HCl were dissolved in 50 mL of 0.1 M morpholine ethanesulfonic acid (MES) solution and activated for 30 min to obtain gallic acid activated solution;

[0066] S402: Dissolve 1g of ε-polylysine in 50mL of 0.1M MES, then add the resulting ε-polylysine solution dropwise to the gallic acid activation solution and react in the dark for 24h.

[0067] S403: After the reaction is complete, the reaction solution is transferred to a dialysis bag with a molecular weight cutoff of 500 Da, dialyzed with deionized water for 5 days, and the dialysate is then freeze-dried under vacuum to obtain gallic acid-functionalized ε-polylysine (PG).

[0068] In possible disclosed examples, the total concentration of components (a) and (b) in the hydrogel system is preferably 5-30 w / v%, and can be 5 w / v%, 7 w / v%, 10 w / v%, 12 w / v%, 15 w / v%, 18 w / v%, 20 w / v%, or any one within the range described above. The total concentration refers to the percentage by volume of the total mass of components (a) and (b) to the water solvent.

[0069] In possible disclosed examples, the grafting rate of the phenylalanine-functionalized polysaccharide or polypeptide is preferably 30-50%, and can be 30%, 35%, 40%, 45%, 50%, or any one of the above ranges.

[0070] In a second aspect, embodiments of this application also provide a method for preparing the acid-initiated biological tissue adhesive, comprising the steps of:

[0071] Provide aqueous solutions containing components (a) and (b) respectively;

[0072] Mix the two aqueous solutions from the previous step to prepare the precursor solution;

[0073] The precursor solution is brought into contact with an acidic medium to aggregate and form a supramolecular system.

[0074] In possible public examples, the pH range of the acidic medium is 1.2 to 1.8.

[0075] In a possible disclosed example, the acidic medium contains gastric juice.

[0076] In a third aspect, embodiments of this application also provide the application of the acid-initiated biological tissue adhesive, specifically the application of the acid-initiated biological tissue adhesive in the preparation of adhesive materials for acid-related wounds, such as gastric ulcer wounds.

[0077] The technical solution of the present invention will be further described below with reference to specific embodiments. In the following embodiments, the acid-initiated biological tissue adhesive prepared is denoted as Az. x B y A includes, but is not limited to, DP, PP, AP, etc.; B includes, but is not limited to, tannic acid (TA), PG, etc.; x and y represent mass percentages; z represents the grafting rate of phenylalanine.

[0078] Example 1

[0079] This example provides an experimental preparation method for acid-initiated biological tissue adhesive DP-501TA1. The specific steps are as follows:

[0080] TA and DP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare TA solution and DP solution with a concentration of 10w / v% respectively.

[0081] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive DP-501TA1 precursor solution.

[0082] Example 2

[0083] This example provides an acid-initiated biological tissue adhesive DP-501TA.0.5 The preparation experiment is carried out in the following steps:

[0084] TA and DP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare TA solution with a concentration of 5 w / v% and DP solution with a concentration of 10 w / v% respectively.

[0085] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortexing and sonication to obtain a homogeneous and clear biological tissue adhesive DP-501TA. 0.5 Precursor fluid.

[0086] Example 3

[0087] This example provides an acid-initiated biological tissue adhesive DP-501TA. 1.5 The preparation experiment is carried out in the following steps:

[0088] TA and DP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare TA solution with a concentration of 15 w / v% and DP solution with a concentration of 10 w / v% respectively.

[0089] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortexing and sonication to obtain a homogeneous and clear biological tissue adhesive DP-501TA. 1.5 Precursor fluid.

[0090] Example 4

[0091] This example provides an experimental preparation method for acid-initiated biological tissue adhesive DP-501TA2. The specific steps are as follows:

[0092] TA and DP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare TA solution with a concentration of 20 w / v% and DP solution with a concentration of 10 w / v% respectively.

[0093] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive DP-501TA2 precursor solution.

[0094] Example 5

[0095] This example provides an experimental preparation method for acid-initiated biological tissue adhesive DP-301TA1. The specific steps are as follows:

[0096] TA and DP with a phenylalanine grafting rate of 30% were dissolved in deionized water to prepare TA solution and DP solution with a concentration of 10w / v% respectively.

[0097] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive DP-301TA1 precursor solution.

[0098] Example 6

[0099] This example provides an experimental preparation method for acid-initiated biological tissue adhesive DP-401TA1. The specific steps are as follows:

[0100] TA and DP with a phenylalanine grafting rate of 40% were dissolved in deionized water to prepare TA solution and DP solution with a concentration of 10w / v% respectively.

[0101] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive DP-401TA1 precursor solution.

[0102] Example 7

[0103] This example provides an experimental preparation method for acid-initiated biological tissue adhesive PP-501TA1. The specific steps are as follows:

[0104] TA and PP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare TA solution and PP solution with a concentration of 15w / v% respectively.

[0105] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive PP-501TA1 precursor solution.

[0106] Example 8

[0107] This example provides an experimental preparation method for acid-initiated biological tissue adhesive PP-401TA1. The specific steps are as follows:

[0108] TA and PP with a phenylalanine grafting rate of 40% were dissolved in deionized water to prepare TA solution and PP solution with a concentration of 15w / v% respectively.

[0109] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive PP-401TA1 precursor solution.

[0110] Example 9

[0111] This example provides an experimental preparation method for an acid-initiated biological tissue adhesive, AP-401TA1. The specific steps are as follows:

[0112] TA and AP with a phenylalanine grafting rate of 40% were dissolved in deionized water to prepare TA solution and AP solution with a concentration of 15w / v% respectively.

[0113] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear precursor solution of the biological tissue adhesive AP-401TA1.

[0114] Example 10

[0115] This example provides an experimental preparation method for acid-initiated biological tissue adhesive PP-501PD1. The specific steps are as follows:

[0116] PD and PP with a phenylalanine grafting rate of 50% were dissolved in deionized water to prepare PD solution and PP solution with a concentration of 15w / v% respectively.

[0117] After physically mixing the above PD solution and PP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive PP-501PD1 precursor solution.

[0118] Example 11

[0119] This example provides an experimental preparation method for acid-initiated biological tissue adhesive PP-401PD1. The specific steps are as follows:

[0120] PD and PP with a phenylalanine grafting rate of 40% were dissolved in deionized water to prepare PD solution and PP solution with a concentration of 15w / v% respectively.

[0121] After physically mixing the above PD solution and PP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive PP-401PD1 precursor solution.

[0122] Comparative Example 1

[0123] This example provides an experimental preparation method for the biological tissue adhesive DP-501TA0. The specific steps are as follows:

[0124] DP with a phenylalanine grafting rate of 50% was dissolved in deionized water to prepare a DP solution with a concentration of 10 w / v, which is the precursor solution of biological tissue adhesive DP-501TA0.

[0125] Comparative Example 2

[0126] This example provides an experimental preparation method for acid-initiated biological tissue adhesive DP-201TA1. The specific steps are as follows:

[0127] TA and DP with a phenylalanine grafting rate of 20% were dissolved in deionized water to prepare TA solution and DP solution with a concentration of 10 w / v% respectively.

[0128] After physically mixing the above TA solution and DP solution at a volume ratio of 1:1, the mixture is subjected to vortex oscillation and sonication to obtain a homogeneous and clear biological tissue adhesive DP-201TA1 precursor solution.

[0129] Test Example 1: Characterization by Proton NMR Spectroscopy

[0130] 1.1 The phenylalanine-functionalized dextran (DP) prepared above was characterized by 1H NMR spectroscopy, and the results were as follows: Figure 1 As shown.

[0131] according to Figure 1 It can be seen that phenylalanine-functionalized dextran was successfully prepared, and the grafting rates of phenylalanine were 20%, 30%, 40% and 50%, respectively.

[0132] 1.2 The phenylalanine-functionalized γ-polyglutamic acid (PP) prepared above was characterized by 1H NMR spectroscopy, and the results were as follows: Figure 2 As shown.

[0133] according to Figure 2 It can be seen that phenylalanine-functionalized γ-polyglutamic acid was successfully prepared, and the grafting rates of phenylalanine were 40%, 50%, 60% and 70%, respectively.

[0134] Test Example 2: Gelation Test

[0135] The biological tissue adhesive precursor solution DP-501TA1 was injected into simulated gastric fluid (SGF=1.2) using a syringe to construct the letter "DPTA". The result was... Figure 3 As shown.

[0136] according to Figure 3 It can be seen that DP-501TA1 rapidly gelled upon contact with simulated gastric fluid and remained firmly adhered to the plastic disc even under strong water flow, indicating that DP-501TA1 possesses injectability, gastric acid responsiveness, and strong adhesion capabilities.

[0137] Test Example 3: Bond Strength Test

[0138] 3.1 Add 200 μL of DP-501TA0 and DP-501TA respectively. 0.5 DP-501TA1, DP-501TA 1.5The DP-501TA2 precursor solution was evenly applied to the ends of two pig stomachs, and simulated gastric juice was added dropwise to fully displace it. The two pig stomach tissues were then overlapped and sheared. The adhesion strength of the hydrogel to the pig skin was tested using a universal tensile testing machine. The results were as follows: Figure 4 As shown.

[0139] according to Figure 4 It can be known that DP-501TA 0.5 DP-501TA1, DP-501TA 1.5 The adhesion strength of DP-501TA1 and DP-501TA2 to fresh porcine gastric tissue was higher than 10 kPa, with DP-501TA1 reaching a maximum of 34.4 kPa. Furthermore, the adhesion strength showed a trend of first increasing and then decreasing with the increase of TA mass ratio, while the adhesion strength of DP-501TA0 to fresh porcine gastric tissue was far less than 10 kPa. Therefore, the mass ratio of phenylalanine-functionalized natural polymers to bio-polyphenols and polyphenol-functionalized peptides was selected as 1:(0.5~2).

[0140] 3.2 200 μL of DP-201TA1, DP-301TA1, and DP-401TA1 precursor solutions were uniformly applied to the distal ends of two pig stomachs, respectively. Simulated gastric juice was then added dropwise to fully displace the precursor solutions. The two pig stomach tissues were then overlapped and sheared. The adhesion strength of the hydrogel to the pig skin was tested using a universal tensile testing machine. The results were as follows: Figure 5 As shown.

[0141] according to Figure 5 It can be seen that the adhesion strength of DP-301TA1 and DP-401TA1 to fresh porcine gastric tissue is higher than 10 kPa, and the adhesion strength increases with the increase of phenylalanine grafting rate, while the adhesion strength of DP-201TA1 to fresh porcine gastric tissue is far less than 10 kPa. Therefore, the phenylalanine grafting rate of phenylalanine-functionalized natural polymers should be selected as 30-50%.

[0142] Test Example 4: Wet Adhesion Test

[0143] The precursor solution DP-501TA1 for biological tissue adhesive was injected into the gastric lesion to test its wet adhesion ability. The results were as follows: Figure 6 As shown.

[0144] according to Figure 6 It can be seen that after DP-501TA1 is fully gelled in response to gastric acid, it can firmly adhere to the gastric tissue and completely cover the entire wound. Even after being stretched, bent and twisted, it still adheres firmly to the tissue, indicating that the biological tissue adhesive DP-501TA1 has a good physical barrier function.

[0145] Test Example 5: Degradation Capacity Test

[0146] The in vitro degradation capacity of DP-501TA1 was tested by immersing it in simulated gastric fluid containing pepsin. Specifically, freshly prepared DP-501TA1 was wiped dry and weighed, denoted as W0. It was then placed in simulated gastric fluid containing pepsin and incubated in a 37°C constant temperature shaking incubator. Samples were removed at different time points, wiped dry, and weighed, denoted as Wt. The degradation rate of the material was calculated using the following formula. The results are as follows: Figure 7 As shown.

[0147] Degradation rate =

[0148] according to Figure 7 It is known that DP-501TA1 exhibits a continuous degradation trend under the action of pepsin, which can ensure the safety of biological tissue adhesives in vivo.

[0149] Test Example 6: Self-Healing Performance Test

[0150] The self-healing performance of DP-501TA1 was tested. Specifically, the rheological self-healing properties of the hydrogel were characterized using alternating strain scanning spectroscopy. The strain was switched from small strain (1%, 2 minutes) to large strain (150%, 1 minute) for a total of 3 cycles. The results were as follows: Figure 8 As shown.

[0151] according to Figure 8 It can be seen that after DP-501TA1 is subjected to a large strain to a small strain, the modulus can quickly return to near the original value, indicating that DP-501TA1 can exhibit excellent self-healing properties at human body temperature, ensuring the stability of biological tissue adhesives in the cyclically peristaltic gastric environment.

[0152] Test Example 7: Antioxidant Capacity Test

[0153] DP-501TA0 and DP-501TA respectively 0.5 DP-501TA1, DP-501TA 1.5 Antioxidant capacity was tested with DP-501TA2 by immersing 5 mg of sample in 5 mL of ABTS. + In the solution, the sample was placed in the dark for 30 minutes and the optical density at 734 nm was recorded. The ABTS+ clearance rate was then calculated using the following formula. Figure 9 As shown.

[0154] ABTS + Clearance rate =

[0155] In the formula, A c A represents the absorbance of the control group. s The absorbance represents the sample group.

[0156] according to Figure 9 It can be known that DP-501TA 0.5 DP-501TA 1.5 Both DP-501TA1 and DP-501TA2 have excellent in vitro free radical scavenging capabilities, which can reduce the damage caused by oxidative stress to organisms, while DP-501TA0 has relatively weak in vitro free radical scavenging capabilities.

[0157] Test Example 8: In vivo adhesion test

[0158] DP-501TA1 precursor solution was delivered endoscopically to the gastric ulcer lesions of miniature pigs, and its adhesion and sealing performance on the gastric ulcer lesions was observed. The results were as follows: Figure 10 As shown.

[0159] according to Figure 10 As shown, the DP-501TA1 precursor solution rapidly gels upon contact with gastric juice, adheres firmly to the tissue, and completely covers the ulcer wound.

[0160] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0161] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. An acid-initiated biological tissue adhesive, characterized in that, A supramolecular system comprising a mixture of components (a) and (b) that undergoes acid-triggered condensation: (a) Phenylalanine-functionalized natural polymers; (b) Biopolyphenols and polyphenol-functionalized peptides; The mass ratio of (a) to (b) is 1:(0.5~2).

2. The acid-initiated biological tissue adhesive according to claim 1, characterized in that, The phenylalanine-functionalized natural polymer is one of the following: phenylalanine-functionalized dextran, phenylalanine-functionalized sodium alginate, phenylalanine-functionalized chitosan, phenylalanine-functionalized hyaluronic acid, phenylalanine-functionalized polyaspartic acid, phenylalanine-functionalized γ-polyglutamic acid, and phenylalanine-functionalized ε-polylysine.

3. The acid-initiated biological tissue adhesive according to claim 1, characterized in that, The bio-polyphenol is tannic acid; And / or, the polyphenol-functionalized polypeptide is one of gallic acid-functionalized ε-polylysine, ferulic acid-functionalized ε-polylysine, dopamine-functionalized γ-polyglutamic acid, and dopamine-functionalized gelatin.

4. The acid-initiated biological tissue adhesive according to claim 1, characterized in that, The total concentration of components (a) and (b) is 5-30 w / v.

5. The acid-initiated biological tissue adhesive according to claim 4, characterized in that, The grafting rate of the phenylalanine-functionalized natural polymer is 30-50%.

6. A method for preparing an acid-initiated biological tissue adhesive according to any one of claims 1 to 5, characterized in that, Includes the following steps: Aqueous solutions containing components (a) and (b) are provided respectively; Mix the two aqueous solutions from the previous step to prepare the precursor solution; and, The precursor solution is brought into contact with an acidic medium to aggregate and form a supramolecular system.

7. The preparation method according to claim 6, characterized in that, The pH range of the acidic medium is 1.2 to 1.

8.

8. The preparation method according to claim 6, characterized in that, The acidic medium contains gastric juice.

9. The use of the acid-initiated biological tissue adhesive according to any one of claims 1 to 5 in the preparation of acid-sensitive wound adhesive materials.

10. The application according to claim 9, characterized in that, The acid-inducing wounds include gastric ulcer wounds.

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