Tissue adhesives and methods of making and using the same

Abstract

The present application provides a kind of tissue adhesive and its preparation method and purposes.The tissue adhesive includes hydrophobic matrix and adhesive microparticles, wherein the adhesive microparticles are derived from crosslinking agent and polymer with carboxyl.The tissue adhesive of the present application can first remove the blood on the wound surface by hydrophobic matrix when applied to the bleeding site, obtain a transient dry tissue environment, and after a few seconds of pressing, the adhesive microparticles can absorb the remaining blood on the wound surface and interact between components to quickly form a gel and adhere to the tissue.In addition, the tissue adhesive can also react with iron ions in the blood to form a blood clot, which can seal and stop bleeding.

Description

Technical Field

[0001] This invention relates to a tissue adhesive, its preparation method, and its uses, belonging to the field of medical materials. Background Technology

[0002] Bleeding is a major problem following surgery and severe trauma, and uncontrolled bleeding poses a significant risk of death. Bleeding associated with tissues and organs is highly time-sensitive and complex, making it challenging to treat; uncontrolled bleeding is one of the leading causes of death worldwide. Most existing topical hemostatic agents aim to enhance and accelerate intrinsic blood clotting to achieve hemostasis, either through rapid water absorption to concentrate clotting factors or through local delivery of procoagulants. In contrast, adhesive sealing of the bleeding tissue offers a promising alternative for achieving hemostasis.

[0003] Current emergency hemostasis methods are far from ideal, and existing tissue adhesives also have significant limitations. Many commercially available tissue adhesives currently employ a multi-component in-situ gelation method, where the components are sprayed onto the wound surface via a spraying device for in-situ gelation. When applied to blood-covered tissue, the components are diluted by the blood, affecting the gelation effect. The gel, also affected by blood, struggles to adhere tightly to the bleeding site, providing only weak or slow adhesion. The large amount of water in blood interacts with the cementing groups, reducing interfacial interactions and severely weakening the adhesive's adhesion and hemostatic effect. Although some blood-resistant tissue adhesives with improved adhesion properties have been developed, these adhesives require ultraviolet irradiation to trigger a cross-linking reaction to adhere to the tissue, introducing new risks to the user.

[0004] Reference 1 discloses a method for preparing a biological tissue adhesive and its product. The method for preparing the biological tissue adhesive includes the following steps: (1) adding γ-polyglutamic acid and deionized water to a container and stirring at room temperature until completely dissolved; (2) after the γ-polyglutamic acid is completely dissolved, adding tyramine hydrochloride and tannic acid, and continuing to stir to obtain component A solution; (3) dissolving 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride in deionized water to obtain component B solution; (4) mixing component A solution and component B solution, stirring evenly to obtain biological tissue adhesive. In actual production and sales, after preparing the raw materials into component A and component B solutions, they can be stored at room temperature, are resistant to storage and transportation, and can be used by mixing the two components for in-situ molding. The biological tissue adhesive prepared by this method is an in-situ gelling type. Although it has a certain degree of moisture-resistant adhesion, the two components will be diluted by blood on tissue surfaces covered by blood (such as areas with continuous bleeding or large amounts of bleeding), affecting the in-situ gelling effect. The gel is also difficult to adhere tightly to the bleeding site due to the influence of blood, and can only provide weak or slow adhesion.

[0005] Reference 2 discloses a polyglutamic acid-resistant hemostatic adhesive. The preparation method of this hemostatic adhesive includes functionalizing polyglutamic acid, introducing tannic acid, and preparing a hemostatic tissue adhesive through physical cross-linking methods such as hydrogen bonding. The hemostatic tissue adhesive prepared by this invention has excellent adhesive strength and can be used for bonding wet tissues. However, this hemostatic tissue adhesive requires dialysis purification in dialysate using a dialysis bag, which is costly, time-consuming, and has unsatisfactory hemostatic effect.

[0006] References:

[0007] Reference 1: CN113209356A

[0008] Reference 2: CN114344553A Summary of the Invention

[0009] The problem the invention aims to solve

[0010] Currently, although various hydrogel hemostatic products are available on the market, their tissue adhesion and hemostatic effect remain limited in different hemostatic situations. In the moist environment of the human body (such as tissue surfaces covered with blood), the adhesion of hydrogels is severely weakened, which is the main problem affecting hemostatic efficacy. To address this issue, this invention first provides a tissue adhesive comprising a hydrophobic matrix and viscous microparticles. The hydrophobic matrix enhances the hydrophobicity of the material. When the adhesive is applied to the bleeding site, the hydrophobic matrix first helps to drain a large amount of blood from the wound surface, providing a temporarily relatively dry tissue environment, promoting adhesion between the material and the tissue, forming a tissue adhesive with wet-living tissue adhesion force that is independent of coagulation, thus avoiding the influence of blood on its adhesive hemostatic effect.

[0011] Furthermore, the present invention also provides a method for preparing a tissue adhesive, which is simple, has a mild material crosslinking mechanism, and the resulting tissue adhesive has a short hemostasis time.

[0012] Solution for solving the problem

[0013] The present invention provides a tissue adhesive, wherein the tissue adhesive comprises a hydrophobic matrix and adhesive microparticles, wherein the adhesive microparticles are derived from a crosslinking agent and a polymer having carboxyl groups, and the polymer having carboxyl groups contains two or more carboxyl groups.

[0014] Further, the hydrophobic matrix comprises polysiloxane and / or vegetable oil; preferably, the polysiloxane comprises one or more of dimethyl silicone oil, cyclomethylsiloxane, aminosiloxane, polymethylphenylsiloxane, and polyether polysiloxane copolymer; the vegetable oil comprises one or more of sesame oil, olive oil, rapeseed oil, soybean oil, peanut oil, sunflower oil, and corn oil.

[0015] Furthermore, the polymer having carboxyl groups includes one or more of the following: polyamino acids having two or more repeating amino acid units, gelatin, and collagen.

[0016] Further, the crosslinking agent includes tannic acid and a metal salt; preferably, the mass ratio of tannic acid to metal salt is (2-20):1, more preferably (2-10):1.

[0017] Furthermore, the particle size of the viscous microparticles is no greater than 500 μm.

[0018] Furthermore, in the tissue adhesive, the ratio of the viscous microparticles to the hydrophobic matrix is ​​1g:(0.5-5)mL, preferably 1g:(0.8-3)mL.

[0019] Furthermore, in the tissue adhesive, the mass ratio of the carboxyl-containing polymer to the crosslinking agent is 100:(15-75), preferably 100:(30-60).

[0020] The present invention also provides a method for preparing a tissue adhesive according to the present invention, which includes the step of mixing the components of the tissue adhesive;

[0021] Preferably, the preparation method includes the following steps:

[0022] A crosslinking agent and a polymer with carboxyl groups are mixed to obtain a mixed powder;

[0023] The mixed powder is mixed with a hydrophobic matrix to obtain a tissue adhesive.

[0024] Furthermore, the process also includes a step of grinding the mixed powder, preferably by cryogenic ball milling, to obtain viscous microparticles with a particle size of no more than 500 μm.

[0025] The present invention further provides the use of the tissue adhesive described in the present invention in the preparation of hemostatic products.

[0026] The effects of the invention

[0027] When applied to a bleeding site, the tissue adhesive of this invention first repels blood from the wound surface through a hydrophobic matrix, creating a rapidly drying tissue environment. After a few seconds of pressing, the viscous microparticles absorb remaining blood on the wound surface and interact with each other to quickly form a gel, adhering to the tissue. Furthermore, this tissue adhesive can react with iron ions in the blood to form a blood clot, effectively sealing and stopping the bleeding. This blood-hydrophobic repulsion cross-linking adhesion mechanism features rapid hemostasis and independence from coagulation function, potentially providing an effective hemostasis solution for individuals with coagulation disorders.

[0028] Furthermore, the preparation method of the tissue adhesive of the present invention is simple, the material crosslinking mode is mild, and the obtained tissue adhesive has a short hemostasis time, making it suitable for mass production and applicable in the field of tissue engineering. Attached Figure Description

[0029] Figure 1 A schematic diagram illustrating the hemostatic effect of the tissue adhesive of Embodiment 1 of the present invention on the liver of an animal is shown. Detailed Implementation

[0030] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0031] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0032] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0033] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0034] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0035] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0036] In addition, the term "water" in this specification includes any usable water such as deionized water, distilled water, ion-exchanged water, double-distilled water, high-purity water, and purified water.

[0037] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be between 10-40℃.

[0038] <First Aspect>

[0039] A first aspect of the present invention provides a tissue adhesive comprising a hydrophobic matrix and adhesive microparticles, wherein the adhesive microparticles are derived from a crosslinking agent and a polymer having carboxyl groups, the polymer having carboxyl groups containing two or more carboxyl groups.

[0040] The hydrophobic matrix and viscous microparticles of this invention can form a blood-hydrophobic repulsive cross-linking adhesive mechanism. This blood-hydrophobic repulsive cross-linking adhesive mechanism has rapid hemostatic ability independent of coagulation function. The tissue adhesive of this invention is helpful in treating severe bleeding, and can even achieve good hemostasis in patients with coagulation disorders.

[0041] When the tissue adhesive of this invention is applied to the bleeding site, it first dissipates a large amount of blood from the wound surface through a hydrophobic matrix, creating an instantly dry tissue environment. After a few seconds of pressing, the carboxyl-containing polymer in the adhesive microparticles exhibits good hydrophilicity, allowing it to absorb remaining blood from the wound surface. Once the adhesive microparticles are in full contact with the tissue, metal complexation and hydrogen bonding occur between the carboxyl-containing polymer and the crosslinking agent, rapidly forming a gel. The phenolic hydroxyl groups of tannic acid in the crosslinking agent react with the amino and carboxyl groups on the tissue surface, resulting in tissue adhesion. Furthermore, the carboxyl groups in the polymer react with iron ions in the blood to form a blood clot, effectively sealing and stopping the bleeding.

[0042] hydrophobic matrix

[0043] The presence of a hydrophobic matrix allows the tissue adhesive of this invention to form an injectable paste. By using a hydrophobic matrix to enhance the hydrophobicity of the material, this invention helps to drain large amounts of blood from the wound surface, provides a rapidly drying tissue environment, promotes adhesion between the material and tissue, and forms a hemostatic adhesive with wet-living tissue adhesion that is independent of coagulation, thus preventing its adhesive hemostatic effect from being affected by blood.

[0044] In some specific embodiments, the hydrophobic matrix comprises polysiloxane and / or vegetable oil; preferably, the polysiloxane comprises one or more of dimethyl silicone oil, cyclomethylsiloxane, aminosiloxane, polymethylphenylsiloxane, and polyether polysiloxane copolymer; the vegetable oil comprises one or more of sesame oil, olive oil, rapeseed oil, soybean oil, peanut oil, sunflower oil, and corn oil.

[0045] In some specific embodiments, the tissue adhesive can have its flowability arbitrarily adjusted by regulating the ratio of viscous microparticles and hydrophobic matrix, enabling its use on irregular wounds. It can also be administered via syringe injection or tubing. Specifically, in this invention, the ratio of the viscous microparticles to the hydrophobic matrix in the tissue adhesive is 1 g:(0.5–5) mL, preferably 1 g:(0.8–3) mL.

[0046] sticky particles

[0047] The viscous microparticles of this invention can absorb residual blood and undergo intermolecular interactions, rapidly forming adhesion on tissue surfaces without the need for additional aids such as ultraviolet irradiation or coagulants. Specifically, in this invention, the viscous microparticles are derived from crosslinking agents and polymers containing carboxyl groups.

[0048] The carboxyl groups in the polymer of the present invention can react with iron ions in the blood to form blood clots, thereby achieving the effect of blocking and stopping bleeding. In some specific embodiments, the polymer containing carboxyl groups contains more than two carboxyl groups, including one or more combinations of polyamino acids having more than two amino acid repeating units, gelatin, and collagen. The present invention does not particularly limit the amino acids; any feasible amino acid that can be used in the art is acceptable. Specifically, the amino acids can be glycine, alanine, valine, leucine, isoleucine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine, histidine, etc. Preferably, the polymer containing carboxyl groups of the present invention includes polyglutamic acid having more than two glutamic acid repeating units or polyaspartic acid having more than two aspartic acid repeating units.

[0049] Furthermore, in order to effectively achieve the effect of occlusion and hemostasis, when polyglutamic acid is used, its weight-average molecular weight range can be 700,000 kDa to 2,000,000 kDa, and its degree of polymerization is about 5,000 to 15,000; when polyaspartic acid is used, its weight-average molecular weight ranges from 1 kDa to 100 kDa, and its degree of polymerization is about 7 to 800.

[0050] Furthermore, the carboxyl-containing polymers of the present invention can also be natural polymers, such as gelatin, collagen, etc.

[0051] In some specific embodiments, to maximize the effectiveness of the function of the carboxyl-containing polymer and the crosslinking agent in the tissue adhesive of the present invention, the mass ratio of the carboxyl-containing polymer to the crosslinking agent is 100:(15-75), preferably 100:(30-60). The mass ratio of the carboxyl-containing polymer to the crosslinking agent affects the gelling effect of the tissue adhesive during use. When the mass ratio is in the range of 100:(15-75), preferably in the range of 100:(30-60), the combined adhesive can rapidly form a hydrogel with good mechanical strength between the carboxyl-containing polymer and the crosslinking agent during use.

[0052] In some specific embodiments, the crosslinking agent includes tannic acid and a metal salt; the polymer with carboxyl groups, tannic acid, and metal salt are combined, and the multiple ortho-phenolic hydroxyl structures of tannic acid undergo a complexation reaction with metal ions. The multiple ortho-phenolic hydroxyl structures of tannic acid form a multi-point hydrogen bond crosslinking polymer network structure with the amino and carboxyl groups on the tissue surface and the carboxyl groups on the polymer chain with carboxyl groups. This enables the tissue adhesive of the present invention to form metal complexes and hydrogen bond crosslinks between molecules after contact with water or blood, quickly forming a gel and rapidly adhering to the tissue surface without the need for additional auxiliary materials such as ultraviolet irradiation or coagulants.

[0053] Furthermore, in some specific embodiments, in order to maximize the function of the crosslinking agent in the tissue adhesive of the present invention while also having better safety, the mass ratio of tannic acid to metal salt is (2-20):1, preferably (2-10):1.

[0054] The present invention does not specifically limit the metal salts used; any metal salt that can be implemented in the art can be used. Specifically, the metal salts can be copper salts, zinc salts, iron salts, calcium salts, etc. For copper salts, they can be CuCl2, Cu(NO3)2, CuCO3, etc.; for zinc salts, they can be ZnCl2, Zn(NO3)2, ZnCO3, etc.; for iron salts, they can be FeCl3, Fe(NO3)3, Fe2(CO3)3, etc.; for calcium salts, they can be CaCl2, Ca(NO3)2, etc. Preferably, in the present invention, the metal salt can be FeCl3, CaCl2, etc., and most preferably FeCl3, etc.

[0055] In some specific embodiments, the particle size of the adhesive microparticles is no greater than 500 μm. The adhesive microparticles of the present invention exist in the form of particles, and the particle size of the adhesive microparticles is no greater than 500 μm, to ensure that the microparticles have a large specific surface area to contact with blood and maintain a fast gelation rate.

[0056] <Second aspect>

[0057] A second aspect of the present invention provides a method for preparing a tissue adhesive according to the first aspect of the present invention, comprising the step of mixing the components of the tissue adhesive. The present invention does not particularly limit the mixing method, and it can be a commonly used mixing method, such as physical mixing. The preparation method of the present invention is simple in process, has a mild crosslinking mechanism, and is suitable for mass production.

[0058] Specifically, the preparation method includes the following steps:

[0059] A crosslinking agent and a polymer with carboxyl groups are mixed to obtain a mixed powder;

[0060] The mixed powder is mixed with a hydrophobic matrix to obtain a tissue adhesive.

[0061] Furthermore, in some specific embodiments, a step of reducing the particle size of the mixed powder is included before mixing the mixed powder with the hydrophobic matrix. The present invention does not particularly limit the method for reducing the particle size of the mixed powder, but grinding is preferred.

[0062] Specifically, the preparation method of the present invention further includes a step of grinding the mixed powder, preferably by cryogenic ball milling, to obtain viscous microparticles with a particle size not greater than 500 μm. Generally, to ensure that all particle sizes of the viscous microparticles are not greater than 500 μm, sieving can be used to obtain viscous microparticles with a particle size not greater than 500 μm. When all particle sizes of the viscous microparticles are not greater than 500 μm, it can be ensured that the microparticles have a large specific surface area to contact with blood, maintaining a faster gelation rate.

[0063] <Third aspect>

[0064] A third aspect of the invention also provides the use of the tissue adhesive according to the invention in the preparation of hemostatic products.

[0065] The present invention does not impose any particular limitation on the hemostatic products, and any hemostatic product commonly used in the art can be used. Specifically, the hemostatic products of the present invention can be used for hemostasis of accidental injuries or surgical wounds to human or animal tissues or organs.

[0066] The hemostatic products of the present invention can be used for hemostasis and repair of tissue bleeding, capillary bleeding, arterial bleeding, and lacunar bleeding, and / or for hemostasis and repair of burns, trauma, and surgical wounds, and have broad application prospects.

[0067] The hemostatic product of the present invention can be in the form of an injectable tissue adhesive material. When used for hemostasis and repair of oozing blood in cavities, it can be applied to oozing blood in cavities and other areas with the aid of auxiliary instruments such as syringes. The hemostatic product of the present invention can also be in the form of a sheet-like tissue adhesive material, such as forming the tissue adhesive of the present invention with a backing material, which is suitable for bleeding on the skin surface.

[0068] Doctors can also use this product in combination with other commercially available products, such as hemostatic sponges and hemostatic gauze, based on their experience, to achieve better hemostasis.

[0069] The tissue adhesive in the hemostatic product of the present invention has the characteristics of rapid hemostasis and independence from coagulation function, which provides an effective hemostasis solution for people with coagulation disorders.

[0070] Example

[0071] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0072] Example 1

[0073] The tissue adhesive in this embodiment is prepared through the following steps:

[0074] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 10:1 to obtain a tannic acid / FeCl3 mixture;

[0075] S2: Weigh 1g of polyglutamic acid (weight average molecular weight of 2 million kDa) and 0.55g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0076] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0077] S4: Add 1.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0078] Example 2

[0079] The tissue adhesive in this embodiment is prepared through the following steps:

[0080] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 20:1 to obtain a tannic acid / FeCl3 mixture;

[0081] S2: Weigh 1g of polyglutamic acid (weight average molecular weight of 1 million kDa) and 0.525g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0082] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0083] S4: Add 1.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0084] Example 3

[0085] The tissue adhesive in this embodiment is prepared through the following steps:

[0086] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 5:1 to obtain a tannic acid / FeCl3 mixture;

[0087] S2: Weigh 1g of polyglutamic acid (weight average molecular weight of 1 million kDa) and 0.3g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0088] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0089] S4: Add 1.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive;

[0090] Example 4:

[0091] The tissue adhesive in this embodiment is prepared through the following steps:

[0092] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 2:1 to obtain a tannic acid / FeCl3 mixture;

[0093] S2: Weigh 1.0g of polyglutamic acid (weight average molecular weight of 700,000 kDa) and 0.15g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0094] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0095] S4: Add 1.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive;

[0096] Example 5

[0097] The tissue adhesive in this embodiment is prepared through the following steps:

[0098] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 10:1 to obtain a tannic acid / FeCl3 mixture;

[0099] S2: Weigh 3.0g of polyglutamic acid (weight average molecular weight of 700,000 kDa) and 0.55g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0100] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0101] S4: Add 4.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0102] Example 6

[0103] The tissue adhesive in this embodiment is prepared through the following steps:

[0104] S1: Tannic acid and FeCl3 are mixed at a mass ratio of 10:1 to obtain a tannic acid / FeCl3 mixture;

[0105] S2: Weigh 2.0g of polyglutamic acid (weight average molecular weight of 1 million kDa) and 0.55g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0106] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0107] S4: Add 3.0 ml of dimethyl silicone oil to the mixed powder obtained in S3, mix well, and obtain tissue adhesive.

[0108] Example 7

[0109] The tissue adhesive in this embodiment is prepared through the following steps:

[0110] S1: Tannic acid and FeCl3 are mixed in a mass ratio of 1:1 to obtain a tannic acid / FeCl3 mixture;

[0111] S2: Weigh 1.0g of polyglutamic acid (weight average molecular weight of 1 million kDa) and 0.2g of tannic acid / FeCl3 mixture and mix them to obtain a mixed powder;

[0112] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0113] S4: Add 1.5 ml of dimethyl silicone oil to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0114] Example 8

[0115] The tissue adhesive in this embodiment is prepared through the following steps:

[0116] S1: Tannic acid and CaCl2 are mixed at a mass ratio of 15:1 to obtain a tannic acid / CaCl2 mixture;

[0117] S2: Weigh 1.0g of polyglutamic acid (weight average molecular weight of 1.5 million kDa) and 0.32g of tannic acid / CaCl2 mixture and mix them to obtain a mixed powder;

[0118] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0119] S4: Add 5.0 ml of polymethylphenylsiloxane to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0120] Example 9

[0121] The tissue adhesive in this embodiment is prepared through the following steps:

[0122] S1: Tannic acid and ZnCl2 are mixed at a mass ratio of 4:1 to obtain a tannic acid / ZnCl2 mixture;

[0123] S2: Weigh 1.0g of polyaspartic acid (weight average molecular weight of 70kDa) and 0.5g of tannic acid / ZnCl2 mixture and mix them to obtain a mixed powder;

[0124] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0125] S4: Add 6 ml of olive oil to the viscous microparticles obtained in S3, mix well, and obtain the tissue adhesive.

[0126] Example 10

[0127] The tissue adhesive in this embodiment is prepared through the following steps:

[0128] S1: Tannic acid and Cu(NO3)2 are mixed at a mass ratio of 4:1 to obtain a tannic acid / Cu(NO3)2 mixture;

[0129] S2: Weigh 1.0g of polyaspartic acid (weight average molecular weight of 30kDa) and 0.75g of tannic acid / Cu(NO3)2 mixture and mix them to obtain a mixed powder;

[0130] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0131] S4: Add 5.2 ml of peanut oil to the viscous microparticles obtained in S3, mix well, and obtain the tissue binder.

[0132] Example 11

[0133] The tissue adhesive in this embodiment is prepared through the following steps:

[0134] S1: Tannic acid and CaCl2 are mixed at a mass ratio of 5:1 to obtain a tannic acid / CaCl2 mixture;

[0135] S2: Weigh 1.0g of gelatin and 0.6g of tannic acid / CaCl2 mixture and mix them to obtain a mixed powder;

[0136] S3: The mixed powder obtained in S2 is placed in a ball mill and ball-milled, and then sieved. The sieve has a mesh size of 35 to obtain viscous microparticles with a particle size of no more than 500 μm.

[0137] S4: Add 2 ml of cyclomethylsiloxane to the viscous microparticles obtained in S3, mix well, and obtain tissue adhesive.

[0138] Performance testing

[0139] 1. In vitro cytotoxicity test

[0140] The tests were conducted in accordance with GB / T 16886.5-2017 Biological Evaluation of Medical Devices Part 5: In Vitro Cytotoxicity Tests.

[0141] Preparation of extract: Add 0.1 g / ml of bovine serum-containing culture medium and extract at 37°C for 24 h.

[0142] Cells: L929 (mouse fibroblasts)

[0143] The cytotoxicity grading criteria are shown in Table 1 below, and the experimental results are shown in Table 2 below:

[0144] Table 1. Cytotoxicity Grading Standards

[0145] Relative growth rate (RGR, %) Cytotoxicity level ≥75％ Level 1 50％～74％ Level 2 25％～49％ Level 3 ≤24％ Level 4

[0146] Table 2. In vitro cytotoxicity results

[0147]

[0148] As shown in Table 2, the cytotoxicity level of the tissue adhesive of this application is no higher than level 2. Furthermore, when the mass ratio of tannic acid to metal salt is in the range of (2–20):1, the prepared tissue adhesive exhibits low cytotoxicity and better safety.

[0149] 2. Animal liver hemostasis test

[0150] Modeling: Using a 0.5cm diameter skin biopsy device, a 0.5cm diameter circular concave wound was created on the liver of a New Zealand white rabbit. The tissue adhesive from the example was injected into the blood-covered wound using a syringe. A stopwatch was used to time the bleeding, and pressure was applied to observe the bleeding. The experimental results are as follows: Figure 1 As shown in Table 3 below. After stopping the bleeding, rinse with running water for 20 seconds and observe for any re-bleeding.

[0151] Table 3 Results of animal liver hemostasis test

[0152] sample Hemostasis site Hemostasis time Observe the bleeding effect after rinsing with water for 20 seconds. Example 1 Sample liver 7s No blood was observed flowing out. Example 3 Sample liver 9s No blood was observed flowing out. Example 5 Sample liver 10s No blood was observed flowing out. Example 6 Sample liver 11s No blood was observed flowing out. Example 8 Sample liver 10s No blood was observed flowing out. Example 10 Sample liver 14s No blood was observed flowing out. Example 11 Sample liver 15s No blood was observed flowing out.

[0153] As can be seen from the results in Table 3, the tissue adhesive of the present invention can achieve hemostasis of the liver wound within 15 seconds, and no blood flowed out of the wound after rinsing under running water. This indicates that the tissue adhesive of the present invention still has good adhesion in the humid environment of the human body and can quickly achieve hemostasis of the bleeding site.

[0154] Figure 1 This diagram illustrates the hemostatic effect of the tissue adhesive of Example 1 of the present invention on the liver of an animal. The left image shows the liver wound site bleeding without the use of the tissue adhesive of Example 1; the right image shows the bleeding site sealed by the tissue adhesive after 7 seconds of using the tissue adhesive of Example 1, with no further blood flow. This demonstrates that the tissue adhesive of the present invention has a good sealing and hemostatic effect.

[0155] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0156] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A tissue adhesive, characterized in that, The tissue adhesive comprises a hydrophobic matrix and adhesive microparticles, wherein the adhesive microparticles are composed of a crosslinking agent and a polymer having carboxyl groups, the polymer having carboxyl groups comprises polyamino acids having two or more repeating amino acid units, the crosslinking agent comprises tannic acid and metal salts, and the polymer having carboxyl groups contains two or more carboxyl groups. The mass ratio of the polymer with carboxyl groups to the crosslinking agent is 100:(15~60).

2. The tissue adhesive according to claim 1, characterized in that, The hydrophobic matrix includes polysiloxanes and / or vegetable oils.

3. The tissue adhesive according to claim 2, characterized in that, The polysiloxane includes one or more of dimethyl silicone oil, cyclomethylsiloxane, aminosiloxane, polymethylphenylsiloxane, and polyether polysiloxane copolymer; the vegetable oil includes one or more of sesame oil, olive oil, rapeseed oil, soybean oil, peanut oil, sunflower oil, and corn oil.

4. The tissue adhesive according to any one of claims 1-3, characterized in that, The mass ratio of the tannic acid to the metal salt is (2~20):

1.

5. The tissue adhesive according to claim 4, characterized in that, The mass ratio of the tannic acid to the metal salt is (2~10):

1.

6. The tissue adhesive according to any one of claims 1-3, characterized in that, The particle size of the viscous microparticles is no greater than 500µm.

7. The tissue adhesive according to any one of claims 1-3, characterized in that, In the tissue adhesive, the ratio of the viscous microparticles to the hydrophobic matrix is ​​1 g: (0.5~5) mL.

8. The tissue adhesive according to claim 7, characterized in that, The ratio of the viscous microparticles to the hydrophobic matrix is ​​1 g : (0.8~3) mL.

9. The tissue adhesive according to claim 8, characterized in that, The mass ratio of the polymer with carboxyl groups to the crosslinking agent is 100:(30~60).

10. A method for preparing a tissue adhesive according to any one of claims 1-9, characterized in that, It includes the step of mixing the components of the tissue adhesive.

11. The method for preparing the tissue adhesive according to claim 10, characterized in that, The preparation method includes the following steps: A crosslinking agent and a polymer with carboxyl groups are mixed to obtain a mixed powder; The mixed powder is mixed with a hydrophobic matrix to obtain a tissue adhesive.

12. The preparation method according to claim 11, characterized in that, It also includes the step of grinding the mixed powder.

13. The preparation method according to claim 12, characterized in that, The particles were ground using cryogenic ball milling to obtain viscous microparticles with a particle size of no more than 500 µm.

14. Use of a tissue adhesive according to any one of claims 1-9 in the preparation of hemostatic products.

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