Adhesive, wound dressing material, adhesion preventive material, hemostatic material, sealant, spray kit, and cured adhesive product

Abstract

To provide an adhesive that exhibits shrinkage of its cured product in a moist environment (e.g. in water, in physiological saline, or in buffer solution).SOLUTION: An adhesive comprising a first agent containing a gelatin derivative in which a hydrophobic group is introduced into gelatin and cyclodextrin, and a second agent containing a crosslinking agent for the gelatin derivative, wherein the gelatin derivative has a structure represented by the following formula (1), the introduction ratio of the hydrophobic group is 20 mol% to 80 mol%, and the weight-average molecular weight of the crosslinking agent is 1,000 to 12,000. In formula (1), Gltn represents a residue of the gelatin, L represents a single bond or a divalent linking group, and R1 represents the hydrophobic group and is an alkyl group having 8 to 16 carbon atoms.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an adhesive, a wound dressing, an adhesion preventing material, a hemostatic material, a sealant, a spray kit, and a cured adhesive product. [Background technology]

[0002] Tissue adhesives using gelatin derivatives obtained by introducing hydrophobic groups into gelatin are known. For example, the present inventors have reported a two-component adhesive comprising a first component containing a gelatin derivative in which a hydrophobic group is bonded to gelatin via an imino group and cyclodextrin, and a second component containing a crosslinker for the gelatin derivative (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 026586 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the area where a surgical adhesive is applied is rich in moisture, such as exudate and blood. If the adhesive (and its cured product) absorbs the moisture and swells, there is a risk that it may peel off from the application site, for example, a closed wound. The cured adhesive of Patent Document 1 is characterized by being resistant to swelling in physiological saline, and is resistant to peeling and exhibits excellent adhesive properties even in the body where there is a large amount of exudate, blood, etc., so there are high expectations for its future applications.

[0005] On the other hand, if the cured adhesive could shrink rather than swell in the moist environment of the body, various applications could be considered. For example, in the digestive tract, which has been sutured (anastomotic) following the resection of colon cancer, peristaltic movements can cause the sutures to open (resulting in anastomosis), which is a problem (Figure 8(a)). If an adhesive that shrinks in a moist environment (shrinkable adhesive) could be applied to such anastomotic sites in the digestive tract, the adhesive would shrink and exert a force in the direction of closing the sutures, reducing the incidence of anastomotic leakage (Figure 8(b)).

[0006] An object of the present invention is to solve the above-mentioned problems. That is, an object of the present invention is to provide an adhesive that, when cured, shrinks in a humid environment (e.g., water, saline, buffer solution, etc.). [Means for solving the problem]

[0007] As a result of extensive research into achieving the above object, the present inventors have found that the above object can be achieved by the following configuration.

[0008] [1] An adhesive, a first agent containing a gelatin derivative in which a hydrophobic group has been introduced into gelatin and cyclodextrin; a second agent containing a crosslinking agent for the gelatin derivative, The gelatin derivative has a structure represented by the formula (1) described below, and the introduction rate of the hydrophobic group is 20 mol % to 80 mol %; The adhesive, wherein the crosslinking agent has a weight average molecular weight of 1,000 to 12,000. [2] In the first agent, the introduction rate of the hydrophobic group is 35 mol% to 75 mol%, In formula (1), R 1 is an alkyl group having 10 to 16 carbon atoms. [3] In the first agent, the introduction rate of the hydrophobic group is 40 mol% to 55 mol%, In formula (1), R 1 is an alkyl group having 12 to 16 carbon atoms. [4] In equation (1), R 1 is a linear alkyl group. [5] The adhesive according to any one of [1] to [4], wherein the cyclodextrin is α-cyclodextrin or a derivative thereof. [6] The adhesive according to any one of [1] to [5], wherein the crosslinking agent has a weight average molecular weight of 5,000 to 10,000. [7] The adhesive according to any one of [1] to [6], wherein the crosslinking agent is a compound having at least two active ester groups. [8] The adhesive according to any one of [1] to [7], wherein the crosslinking agent is an activated polyethylene glycol polybasic acid ester. [9] The adhesive according to any one of [1] to [8], wherein the gelatin is cold-water fish gelatin.

[10] The adhesive according to any one of [1] to [9], wherein the mixture of the first and second parts is a shrinkable adhesive that shrinks in physiological saline when cured.

[11] A wound dressing comprising the adhesive according to any one of [1] to

[10] .

[12] An anti-adhesion material comprising the adhesive according to any one of [1] to

[10] .

[13] A hemostatic material comprising the adhesive according to any one of [1] to

[10] .

[14] A sealant comprising the adhesive according to any one of [1] to

[10] .

[15] A spray kit comprising the adhesive according to any one of [1] to

[10] and a sprayer for the adhesive.

[16] A cured adhesive product obtained by curing the adhesive according to any one of [1] to

[10] . [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an adhesive that, when cured, shrinks in a wet environment (for example, in water, physiological saline, buffer solution, etc.). [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 2 is an explanatory diagram of components of a sprayer included in a spray kit according to an embodiment. [Figure 2] FIG. 1 is an illustration of an assembled spray kit. [Figure 3] 10 is a flow chart illustrating a method of applying adhesive to target tissue with a spray kit. [Figure 4] 4(a) and 4(b) are graphs showing evaluation results of adhesive properties (compression strength, evaluation method 1) of cured adhesive materials prepared in the examples before and after immersion in D-PBS (Dulbecco's phosphate buffered saline). Fig. 4(a) shows the evaluation results of an adhesive using a crosslinker with a weight-average molecular weight of 5,000, and Fig. 4(b) shows the evaluation results of an adhesive using a crosslinker with a weight-average molecular weight of 10,000. [Figure 5] FIG. 1 shows the results of evaluating the adhesiveness (compression strength, evaluation method 2) of cured adhesive materials produced in the examples before and after immersion in D-PBS. [Figure 6] 1 is a graph in which adhesives prepared in the examples are plotted with respect to the number of carbon atoms in the hydrophobic group of the gelatin derivative and the introduction rate. [Figure 7A] 7A and 7B show the mechanical properties of the cured adhesives prepared in the examples before and after immersion in D-PBS. Figure 7A shows the SS curves (stress-strain curves) obtained in the tensile tests. The shapes and sizes of the samples used in the tensile tests are also shown. [Figure 7B] 7A and 7B show the results of evaluation of the mechanical properties of the cured adhesive materials produced in the examples before and after immersion in D-PBS, with strain, tensile strength, and Young's modulus shown. [Figure 8] Figure 8(a) is a diagram explaining anastomosis of the digestive tract after suture (anastomosis) following resection of colon cancer, and Figure 8(b) is a diagram explaining the mechanism by which the application of a contractile adhesive reduces the incidence of anastomosis of the digestive tract. [Figure 9] 1A to 1C are diagrams illustrating the curing (crosslinking) of the adhesive of the present embodiment and its behavior in a humid environment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] In the description of groups (atomic groups) in this specification, when a notation does not specify whether they are substituted or unsubstituted, it encompasses both unsubstituted and substituted groups, as long as it does not impair the effects of the present invention. For example, the term "alkyl group" encompasses not only alkyl groups without substituents (unsubstituted alkyl groups), but also alkyl groups with substituents (substituted alkyl groups). This also applies to each compound.

[0013] [glue] The adhesive according to an embodiment of the present invention comprises a first agent containing a gelatin derivative in which a hydrophobic group has been introduced into gelatin and cyclodextrin, and a second agent containing a crosslinking agent for the gelatin derivative. The gelatin derivative contained in the first agent has a structure represented by formula (1) described below.

[0014] The present inventors discovered that by adjusting the number of carbon atoms and introduction rate of the hydrophobic group of the gelatin derivative in the first part within a specific range (e.g., 8 to 16 carbon atoms, introduction rate of 20 mol% to 80 mol%), and simultaneously adjusting the weight-average molecular weight of the crosslinker in the second part within a specific range (e.g., Mw = 1,000 to 12,000), the cured adhesive shrinks in a humid environment (e.g., water, saline, or buffer solution; hereinafter, sometimes referred to as "water, etc."), leading to the present invention. The cured adhesive of this embodiment is a hydrogel, which generally tends to swell in water, etc., so the discovery of its shrinkage in water, etc. was surprising. The present inventors have previously reported a low-swelling gel-based adhesive that swells only slightly in water, etc. (Patent Document 1), but the adhesive of this embodiment exhibits shrinkage, the exact opposite of swelling. Furthermore, the cured adhesive of this embodiment exhibits adhesive properties (e.g., compressive strength) and mechanical properties (toughness, breaking strain, tensile strength, Young's modulus, etc.) that are equal to or greater than those before shrinkage, even after shrinkage.

[0015] The mechanism by which the present invention achieves the above-mentioned effects is unclear, but is presumed to be as follows. When the first and second components of the present invention are mixed, a curing reaction (chemical crosslinking) immediately occurs, forming a cured product. In the cured product, at least a portion of the hydrophobic groups introduced into the gelatin derivative are included in cyclodextrin. As shown in Figure 9, when this cured product is immersed in water, the cyclodextrin is released from the hydrophobic groups (dissociated), and the entire cured product shrinks due to interactions between the hydrophobic groups (hydrophobic interactions, physical crosslinking). At the same time, the hydrophobic groups interact with biological tissue, resulting in high adhesiveness. Furthermore, the mechanical properties of the cured product after shrinkage are improved due to the formation of physical crosslinks between the hydrophobic groups and the increase in chemical crosslinking density accompanying the shrinkage of the crosslinked product.

[0016] To achieve the above-mentioned effects, the number of carbon atoms and the introduction rate of the hydrophobic groups in the gelatin derivative in the first agent must be within a specific range. If the number of carbon atoms is too low (e.g., less than 8 carbon atoms) or the introduction rate is too low (e.g., less than 20 mol%), the interaction between the hydrophobic groups is insufficient, resulting in swelling of the cured product in water and reduced adhesive strength and pressure resistance. Conversely, if the number of carbon atoms is too high (e.g., more than 16 carbon atoms) or the introduction rate is too high (e.g., more than 80 mol%), the hydrophobic groups strongly aggregate in water, forming particles with the hydrophobic group as a core, and crosslinking these particles causes the cured adhesive to expand. Adhesives containing these particles also have weaker interactions with the hydrophobic groups in biological tissues, resulting in reduced adhesion to biological tissues. Furthermore, to achieve the above-mentioned effects, the weight-average molecular weight of the crosslinker in the second agent must also be within a specific range. If the weight-average molecular weight of the crosslinker is too large (e.g., Mw>12,000), the cured product will tend to spread and swell in water. Conversely, if the weight-average molecular weight of the crosslinker is too small (e.g., Mw<1,000), the gelatin derivative will not be cured sufficiently, resulting in poor adhesion to biological tissue. The mechanism explained above is merely speculation and does not affect the interpretation of the present invention.

[0017] From the viewpoint of more easily achieving the above-mentioned effects, it is preferable that the first part of the adhesive of this embodiment has an introduction rate of hydrophobic groups of 35 mol % to 75 mol % and the number of carbon atoms in the hydrophobic groups is 10 to 16, or 10 to 14. From the same viewpoint, it is more preferable that the introduction rate of hydrophobic groups of the first part is 40 mol % to 55 mol % and the number of carbon atoms in the hydrophobic groups is 12 to 16, or 12 to 14.

[0018] The components contained in the adhesive according to this embodiment (hereinafter also referred to as "the adhesive") will be described in detail below.

[0019] 1. First agent The first agent according to this embodiment contains a gelatin derivative (hydrophobized gelatin) and cyclodextrin, and may further contain a solvent. The first agent is mixed with the second agent described below, and the gelatin derivative is crosslinked by the crosslinking agent to form the skeleton of a cured product. The curing reaction is typically a reaction between the primary amino group of the hydrophobized gelatin and the crosslinkable group (typically an active ester group, etc.) of the second agent.

[0020] In this regard, the content of the first agent in the adhesive is preferably adjusted so that, relative to the content of crosslinkable groups in the second agent described below, 1 equivalent of amino groups in the first agent corresponds to 0.1 to 3.0 equivalents of crosslinkable groups in the second agent, more preferably 0.2 to 2.0 equivalents, even more preferably 0.3 to 1.5 equivalents, and particularly preferably 0.3 to 0.8 equivalents.

[0021] <Gelatin derivatives> The content of the gelatin derivative in the first agent is not particularly limited, but the concentration of the gelatin derivative in the first agent (gelatin derivative / solvent, rounded to three decimal places) is preferably 0.010 to 0.300 g / mL, more preferably more than 0.050 g / mL, even more preferably 0.075 g / mL or more, particularly preferably more than 0.075 g / mL, preferably 0.150 g / mL or less, and more preferably less than 0.150 g / mL. When two or more gelatin derivatives are used in combination, the total content thereof is preferably within the above numerical range.

[0022] When the concentration of the gelatin derivative exceeds 0.050 g / mL, an adhesive with better pressure resistance and shrinkage can be obtained. When the concentration of the gelatin derivative is less than 0.150 g / mL, the cured product is more likely to shrink in water, etc., and an adhesive with better pressure resistance can be obtained. When the concentration of the gelatin derivative is 0.075 g / mL or more, an adhesive with even better pressure resistance can be obtained.

[0023] The gelatin derivative of this embodiment is a hydrophobic gelatin in which a hydrophobic group is introduced into gelatin (sometimes referred to as "raw gelatin"), and has a structure represented by the following formula (1).

[0024] [ka]

[0025] In formula (1), Gltn represents a residue of gelatin (raw material gelatin), and L represents a single bond or a divalent linking group. 1 is a hydrophobic group introduced into gelatin, and represents an alkyl group having 8 to 16 carbon atoms.

[0026] The divalent linking group for L is not particularly limited, but examples thereof include -C(O)-, -C(O)O-, -OC(O)-, -O-, -S-, -N(R)- (wherein R represents a hydrogen atom or a monovalent organic group (preferably a hydrocarbon group having 1 to 20 carbon atoms)), an alkylene group (preferably an alkylene group having 2 to 10 carbon atoms), an alkenylene group (preferably an alkenylene group having 2 to 10 carbon atoms), and combinations thereof, with -C(O)- being preferred. In formula (1), L is preferably a single bond or -C(O)-.

[0027] In equation (1), *-R 1 (* indicates the binding position) is preferably bound to the ε-amino group of the raw material gelatin (raw material gelatin), and more preferably bound to the ε-amino group of lysine (Lys) in the gelatin. *-R is bonded to an amino group, preferably the amino group of lysine, with or without a linking group (in other words, directly). 1 Examples of methods for binding include the so-called reductive amination reaction (a method using an aldehyde or ketone) and the Schotten-Baumann reaction (a method using an acid chloride).

[0028] The -NH- structure of formula (1) can be seen, for example, at 3300 cm in the FT-IR (Fourier transform infrared) spectrum.-1 It can be detected by nearby bands.

[0029] R in Equation (1) 1 The hydrophobic group introduced into gelatin is not particularly limited as long as it is an alkyl group having 8 to 16 carbon atoms, and may be linear, branched, or cyclic. From the viewpoint of improving the shrinkability and / or adhesiveness of the cured adhesive in water, etc., R in formula (1) 1 From the same viewpoint, R in formula (1) is preferably a linear alkyl group. 1 The alkyl group preferably has 10 to 16 or 10 to 14 carbon atoms, and more preferably has 12 to 16 or 12 to 14 carbon atoms.

[0030] Examples of the linear alkyl group having 8 to 16 carbon atoms include an octyl group (or a capryl group) (8 carbon atoms), a nonyl group (or a pelargoryl group) (9 carbon atoms), a decyl group (10 carbon atoms), an undecyl group (11 carbon atoms), a dodecyl group (or a lauryl group) (12 carbon atoms), a tridecyl group (13 carbon atoms), a tetradecyl group (14 carbon atoms), a pentadecyl group (15 carbon atoms), and a hexadecyl group (16 carbon atoms).

[0031] In terms of obtaining an adhesive having a more excellent effect of the present invention, the gelatin derivative represented by formula (1) is preferably at least one gelatin derivative selected from the group consisting of the following formulas (2) and (3), and the gelatin derivative represented by formula (2) is more preferred.

[0032] [ka]

[0033] [ka]

[0034] Formula (2) is an embodiment of formula (1) in which L is a single bond. In formula (2), a hydrophobic group (R 1Formula (3) is an embodiment in which L is -C(O)- in formula (1). In formula (3), a hydrophobic group (R 1 In formula (2) and formula (3), the meanings of the symbols are the same as those in formula (1) already explained, and the preferred embodiments are also the same.

[0035] The introduction rate of the hydrophobic group in the gelatin derivative is 20 mol % to 80 mol %. From the viewpoint of improving the shrinkability and / or adhesiveness of the cured adhesive in water, the introduction rate of the hydrophobic group is preferably 35 mol % to 75 mol %, more preferably 40 mol % to 55 mol %.

[0036] The "introduction rate of hydrophobic groups" refers to the molar ratio of the content of imino groups (-NH- in formula (1)) to which hydrophobic groups are bonded, introduced into the gelatin derivative, to the content of amino groups in the raw material gelatin. Specifically, the introduction rate of hydrophobic groups is a value defined as the content of imino groups in the first agent / (content of imino groups + content of amino groups), and is a value determined by quantifying the amount of amino groups using the 2,4,6-trinitrobenzenesulfonic acid method (TNBS method).

[0037] <Method of manufacturing gelatin derivatives> The method for producing a gelatin derivative is not particularly limited, and known methods can be used. For example, a method in which an aldehyde or a ketone is reacted with the ε-amino group of gelatin, a hydrophobic group is bonded via a Schiff base, and the Schiff base is reduced to obtain a gelatin derivative is mentioned. This method is described, for example, in paragraphs 0029 to 0031 of JP 2019-216755 A.

[0038] According to the above method, a gelatin derivative (formula: GltnNH-R) in which a hydrophobic group is directly bonded to a gelatin residue via an imino group is obtained. 1 ) is obtained. The hydrophobic group is derived from an aldehyde or ketone.

[0039] Another method is to react the ε-amino group of gelatin with an acid halide or a chloroformate compound in the presence of a base such as triethylamine to obtain an amide, as described in, for example, paragraphs 0072 to 0080 of WO 2014 / 112208.

[0040] According to the above method, a gelatin derivative can be obtained in which a hydrophobic group is bound to a gelatin residue via an amide bond (including an imino group). This hydrophobic group is derived from an acid halide or a chloroformate compound.

[0041] When a large excess of a poor solvent, such as cold ethanol, is added to the reaction solution obtained above, a gelatin derivative precipitates, which can be filtered off and dried to obtain a powdery gelatin derivative. The gelatin derivative may be washed with ethanol or the like before drying.

[0042] The raw material gelatin used to produce gelatin derivatives (hereinafter also referred to as "ORG gelatin") is typically gelatin without hydrophobic groups introduced therein (non-derivatized).

[0043] The molecular weight of ORG gelatin is not particularly limited, and generally, a weight-average molecular weight of 10,000 to 300,000 is preferred. In one embodiment, from the viewpoint of easily suppressing allergic reactions in living bodies, it is preferably less than 50,000. There is no particular lower limit, but from the viewpoint of providing a cured adhesive with superior mechanical strength, it is preferably 10,000 or more.

[0044] ORG gelatin can be any gelatin obtained by natural origin, chemical synthesis, fermentation, genetic recombination, etc., without any particular limitation. Naturally-derived gelatin is preferred. Examples of naturally-derived gelatin include those derived from mammals such as cows and pigs, and those derived from fish such as sea bream, sturgeon, salmon, cod, and Alaska pollock.

[0045] When the adhesive is used as a liquid, it is preferable that it has excellent fluidity at the temperature of use (e.g., living body temperature) from the viewpoint of ease of handling. In this respect, ORG gelatin is preferably fish-derived gelatin, and in particular, gelatin derived from cold-water fish such as salmon and Alaska pollock is preferred. Note that "used as a liquid" refers to cases where either the first agent or the second agent, or both, are liquids containing a solvent, or cases where both the first agent and the second agent are solids and are mixed with a solvent when used.

[0046] Fish-derived gelatin, particularly cold-water fish gelatin, preferably has 80 or fewer hydroxyproline-derived units and / or 110 or fewer proline-derived units per 1000 amino acids as constituent units. Gelatin meeting these conditions has superior fluidity at room temperature, and therefore, when used in the first agent (as a raw material for gelatin derivatives and / or as an additive), an adhesive with excellent handleability can be obtained.

[0047] ORG gelatin may be either acid-processed gelatin or alkali-processed gelatin. The first agent may contain two or more different types of ORG gelatin. "Two or more different types" means that the gelatins differ in one or more of the following: origin, molecular weight, processing method, etc.

[0048] <Cyclodextrin> Cyclodextrin is a cyclic compound in which D-glucose units are bonded in a ring via α-1,4-glucosidic bonds, and is produced by treating starch and / or starch hydrolysates with an enzyme such as cyclodextrin glucanotransferase.

[0049] The content of cyclodextrin in the first agent is not particularly limited, but the concentration of cyclodextrin in the first agent (cyclodextrin / solvent, rounded to the third decimal place) is preferably 0.001 to 0.200 g / mL, more preferably 0.003 to 0.150 g / mL. When two or more types of cyclodextrin are used in combination, the total content thereof is preferably within the above numerical range.

[0050] Furthermore, in order to obtain an adhesive having even better effects of the present invention, the molar ratio of the cyclodextrin content to the hydrophobic group content in the first agent (cyclodextrin / hydrophobic group, "Cy / HBic") is preferably 0.1 or more, more preferably 1.0 or more, even more preferably greater than 1.0, particularly preferably greater than 2.0, most preferably greater than 2.5, and is preferably 10.0 or less, more preferably 8.0 or less, and even more preferably 6.0 or less. The molar ratio (Cy / HBic) may be 4 to 6. When two or more types of cyclodextrin are used in combination, it is preferable that the total content thereof be within the above numerical range.

[0051] When Cy / HBic exceeds 1.0, the viscosity of the first agent tends to be lower, which is preferable for a spray adhesive. When Cy / HBic exceeds 2.0, the viscosity tends to be even lower, and this tendency is particularly noticeable when Cy / HBic exceeds 2.5.

[0052] It is believed that cyclodextrin also encapsulates gelatin residues other than hydrophobic groups, and that there is a negative correlation between the concentration of cyclodextrin in the first agent and the viscosity of the first agent. From the viewpoint of achieving a more pronounced viscosity-reducing effect on the added cyclodextrin, Cy / HBic, in one form, is preferably 10.0 or less, more preferably 8.0 or less, and even more preferably 6.0 or less.

[0053] The cyclodextrin may be one having six glucose units (α-type), seven glucose units (β-type), or eight glucose units (γ-type), and its derivatives may also be used (or used in combination). Of these, α-cyclodextrin or its derivatives are preferred because the size of the cavity is more suitable for encapsulating hydrophobic groups.

[0054] Examples of α-cyclodextrin derivatives include methyl α-cyclodextrin, butyl α-cyclodextrin, 2-hydroxypropyl α-cyclodextrin, acetyl α-cyclodextrin, succinyl α-cyclodextrin, glucosyl α-cyclodextrin, maltosyl α-cyclodextrin, α-cyclodextrin carboxymethyl ether, phosphate ester α-cyclodextrin, and carboxymethyl α-cyclodextrin.

[0055] Examples of β-cyclodextrin derivatives include methyl-β-cyclodextrin (MBCD), (2-hydroxypropyl)-β-cyclodextrin (HPBCD), carboxymethyl-β-cyclodextrin, carboxymethyl-ethyl-β-cyclodextrin, diethyl-β-cyclodextrin, dimethyl-β-cyclodextrin, glucosyl-β-cyclodextrin, hydroxybutenyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, maltosyl-β-cyclodextrin, random methyl-β-cyclodextrin, sulfobutylether-β-cyclodextrin, 2-selenium-bridged-β-cyclodextrin, and 2-tellurium-bridged-β-cyclodextrin.

[0056] Examples of γ-cyclodextrin derivatives include 2-hydroxyethyl-γ-cyclodextrin, 2-hydroxypropyl-γ-cyclodextrin, butyl-γ-cyclodextrin, 3A-amino-3A-deoxy-(2AS,3AS)-γ-cyclodextrin, mono-2-O-(p-toluenesulfonyl)-γ-cyclodextrin, mono-6-O-(p-toluenesulfonyl)-γ-cyclodextrin, mono-6-O-mesitylenesulfonyl-γ-cyclodextrin, octakis(2,3,6-tri-O-methyl)-γ-cyclodextrin, octakis(2,6-di-O-phenyl)-γ-cyclodextrin, octakis(6-Ot-butyldimethylsilyl)-γ-cyclodextrin, and octakis(2,3,6-tri-O-acetyl)-γ-cyclodextrin.

[0057] <Solvent> The first agent may further contain a solvent. Examples of the solvent include aqueous solvents, such as ultrapure water; physiological saline; various inorganic salt buffers such as boric acid, phosphate, and carbonate; and mixtures thereof. Among these, the aqueous solvent is preferably a borate buffer solution having a pH of 8 to 13, and more preferably a borate buffer solution having a pH of 9 to 12. The aqueous solvent is preferably used in an amount such that the solid content of the first agent is 0.050 to 0.800 g / mL.

[0058] In addition to the above, the first agent may or may not contain ORG gelatin, which has been explained as raw material gelatin.

[0059] 2. Second agent The second agent contains a crosslinking agent for the gelatin derivative, and may also contain a solvent.

[0060] <Crosslinking agent> The crosslinking agent is typically a compound having at least two substituents (crosslinkable groups) per molecule that can react with the primary amino groups of the gelatin derivative. When the first agent contains ORG gelatin, the crosslinking agent also reacts with the primary amino groups of the ORG gelatin.

[0061] The weight-average molecular weight (Mw) of the crosslinking agent is 1,000 to 12,000, preferably 5,000 to 10,000. If the weight-average molecular weight of the crosslinking agent is too large, the cured product will spread and swell in water. Conversely, if the weight-average molecular weight of the crosslinking agent is too small, the gelatin derivative will not be sufficiently cured, resulting in reduced adhesiveness to biological tissues.

[0062] The crosslinking group of the crosslinking agent is not particularly limited, but an active ester group (activated ester group) is preferred from the viewpoint of being easily selectively reactive under mild conditions with the primary amino group (typically derived from a gelatin derivative) in the first agent. That is, a compound having at least two active ester groups per molecule is preferred as the crosslinking agent. Such crosslinking agents include polybasic acids activated with N-hydroxysuccinimide or N-hydroxysulfosuccinimide.

[0063] Examples of polybasic acids include polycitric acid, polymalic acid, polyglutamic acid, polyaspartic acid, carboxymethylated dextrin, carboxymethylated dextran, carboxymethylated starch, carboxymethylated cellulose, carboxymethylated chitosan, and carboxymethylated pullulan.

[0064] Also available are polybasic acid esters of polyethylene glycol or polyethylene glycol ether, in which at least one carboxyl group in the polybasic acid that has not reacted with polyethylene glycol is converted into an active ester, such as 4,7,10,13,16-pentaoxanonadecanedioic acid di(N-succinimidyl) and polyethylene glycol di(succinimidyl succinate) (SS-PEG-SS) represented by the following formula:

[0065] [ka]

[0066] (n is a number such that the weight average molecular weight (Mw) is 1,000 to 12,000); Furthermore, pentaerythritol-polyethylene glycol ether tetrasuccinimidyl glutarate (4S-PEG) represented by the following formula:

[0067] [ka]

[0068] (n is a number that results in a weight average molecular weight (Mw) of 1,000 to 12,000, preferably 5,000 to 10,000); etc. are also preferred.

[0069] Aldehyde compounds can also be used as crosslinking agents, including formyl group-introduced polysaccharides having two or more formyl groups in one molecule, such as formyl group-introduced starch, formyl group-introduced dextran, formyl group-introduced dextrin, and formyl group-introduced hyaluronic acid.

[0070] As the crosslinking agent, activated polyethylene glycol polybasic acid esters and formyl group-introduced polysaccharides are preferred, with activated polyethylene glycol polybasic acid esters being more preferred.

[0071] The content of the crosslinking agent in the second agent and the content of the second agent in the adhesive may be adjusted appropriately depending on the content of amino groups in the first agent.

[0072] For example, the amount of ester groups activated with N-hydroxysuccinimide (active ester groups) per equivalent of amino groups in the first agent is preferably 0.1 to 3.0 equivalents, more preferably 0.2 to 2.0 equivalents, even more preferably 0.3 to 1.5 equivalents, and particularly preferably 0.3 to 0.8 equivalents. The second agent may contain one type of crosslinking agent alone or two or more types. When the second agent contains two or more types of crosslinking agents, the total content thereof is preferably within the above numerical range.

[0073] <Solvent> The second agent may contain a solvent. The solvent is preferably an aqueous solvent. As the aqueous solution, those already explained as the aqueous solution that may be contained in the first agent can be used.

[0074] Among these, a phosphate buffer solution with a pH of 3 to 8 is preferred, and a phosphate buffer solution with a pH of 4 to 6 is more preferred. It is preferable to adjust the ionic strength of both aqueous solvents so that when equal volumes of a first agent containing a solvent and a second agent containing a solvent are mixed, the pH is about 8 to about 10. For example, by using a borate buffer solution with a pH of 9 and an ionic strength of 0.05 to 0.1 as the first agent and a phosphate buffer solution with a pH of 4 and an ionic strength of 0.01 to 0.03 as the second agent, the pH can be adjusted to within the above range when mixed in equal volumes. Alternatively, the first agent may be a borate buffer solution with a pH of 10 and an ionic strength of 0.05 to 0.1, and the second agent may be a phosphate buffer solution with a pH of 4 and an ionic strength of 0.01 to 0.07.

[0075] <Additives> The first and / or second agents may further contain various additives in amounts that do not impair the object of the present invention. Examples of additives include colorants, pH adjusters, and preservatives. For example, a colorant (e.g., brilliant blue) may be added to the first and / or second agents to make it easier to see where the adhesive is applied. The amount added may be, for example, 10 to 100 μg / mL.

[0076] Furthermore, since the adhesive of the present invention (particularly the first agent) has a low viscosity, it is preferably used in the form of a mist sprayed from a sprayer and applied; however, by adding a viscosity adjuster, the viscosity can be easily increased and dripping of the coating film before hardening can be suppressed. This also gives the adhesive an advantage in that the viscosity can be adjusted according to the application area and use (the initial viscosity is low, so there is room for thickening).

[0077] The adhesive contains a gelatin derivative in which a hydrophobic group has been introduced into gelatin, but as long as it contains a gelatin derivative, it may also contain "other" gelatin and / or "other" gelatin derivatives. That is, if the first agent contains a derivative of Alaska pollock gelatin, the first agent may contain, for example, Alaska pollock gelatin (ORG), porcine gelatin, and / or porcine gelatin derivatives. The adhesive does not necessarily need to contain "other" gelatin.

[0078] [Adhesive manufacturing method] This adhesive can be obtained by separately preparing the first and second parts. Below, the methods for preparing the first and second parts are described.

[0079] <Preparation method of the first agent> The first agent can be produced by mixing a gelatin derivative, cyclodextrin, and, if necessary, other ingredients. In this case, it is preferable to include a step of including at least a part of the hydrophobic group of the gelatin derivative in the cyclodextrin (forming an inclusion compound).

[0080] The method for including the hydrophobic group of the gelatin derivative with cyclodextrin is not particularly limited, and examples that can be used include a method in which the gelatin derivative is added to a slurry prepared by adding water to cyclodextrin and then mixed, and a method in which the cyclodextrin and the gelatin derivative are dissolved in a solvent and then dried.

[0081] In the case of the method of dissolving cyclodextrin and a gelatin derivative in a solvent and drying it, the resulting first agent is in a powder form. When this is used as a liquid first agent, an aqueous solvent such as a borate buffer solution can be added to the powder first agent. If necessary, additives can be added at this stage.

[0082] The obtained first agent can be filled into a predetermined container, such as a dispenser made of plastic such as polypropylene. When used as a tissue adhesive, it is preferable to fill one of a double syringe dispenser or the like, which is used when applying to tissue and can mix the two agents at the tip, with the aqueous solution of the first agent.

[0083] <Preparation method of second agent> The second agent contains a crosslinking agent. The crosslinking agent may be synthesized by a known method, or a commercially available crosslinking agent may be used. When the second agent is a liquid, the crosslinking agent may be mixed with an aqueous solvent, such as a phosphate buffer solution, for dissolving the crosslinking agent.

[0084] [How to apply this to your organization] This adhesive can be applied to incisions and skin wounds in various surgical procedures, including thoracic surgery, digestive surgery, cardiovascular surgery, neurosurgery, orthopedic surgery, and oral surgery. This adhesive functions as a contractile adhesive, shrinking in the moist environment of the body, where there is a large amount of exudate, blood, etc. The contraction of this adhesive (cured product) exerts a force in the direction of closing surgical incisions, etc. (see Figure 8(b)). In particular, applying this adhesive to anastomotic sites in the digestive tract, where suture failure is likely to occur due to peristalsis, can reduce the incidence of suture failure.

[0085] By mixing the two parts (the first and second parts), a curing reaction immediately occurs to form a cured product. The temperature during the curing reaction is not particularly limited, but generally 15 to 45°C is preferred, and 20 to 42°C is more preferred. The curing time is not particularly limited, but sufficient adhesive strength and film strength can be obtained in a few seconds to 30 minutes.

[0086] The adhesive can be used as a wound dressing for covering wounds in living tissue, and also as an anti-adhesion material for preventing postoperative adhesions.

[0087] Furthermore, because the cured adhesive has both excellent tissue adhesion and flexibility, it can be used, for example, as a hemostatic material to stop bleeding from vascular anastomoses by applying it to vascular anastomoses. Furthermore, as described below, when applied to tissue, the adhesive has excellent pressure resistance, allowing it to withstand blood pressure, and its flexibility allows it to follow the pulsation of blood vessels. Furthermore, because the cured adhesive has excellent adhesive properties as well as excellent absorbability and biocompatibility, it can also be used, for example, as a sealant to fill the gap between the dura mater, the dura mater suture, or the gap between the dura mater and the dura mater during suturing.

[0088] There are no particular limitations on the method of using the adhesive, but it is preferable to apply it to the target site (tissue) using a sprayer, which will be described later, and allow a hardened product (gel) to form on the tissue.

[0089] [Spray kit] A spray kit according to an embodiment of the present invention comprises a sprayer, a first agent, and a second agent, and is used to apply a mist of adhesive, which is a mixture of the first agent and the second agent, to target biological tissue, etc.

[0090] FIG. 1 is an illustration of the sprayer components included in the spray kit, and FIG. 2 is an illustration of the assembled spray kit.

[0091] The sprayer 10 has a first agent syringe consisting of an outer cylinder 15 and a plunger 18 with a gasket at the tip, and a second agent syringe consisting of an outer cylinder 14 and a plunger 17 with a gasket at the tip. Typically, the same amount of a first agent 21 and a second agent 22 are injected into each syringe. In FIG. 2, the first agent 21 is colored and the second agent 22 is not colored, but the second agent 22 may be colored, or neither may be colored.

[0092] Sheath 14 and sheath 15 are supported by syringe holder 16 in a restrained state so as not to move, and applicator 13 is fitted and inserted into the tip. Flow paths (not shown) for first agent 21 and second agent 22 are formed inside applicator 13, respectively, so that the first agent and second agent extruded from each syringe flow to the tip of applicator 13 without being mixed. Note that an internal flow path may be formed so that the first agent and second agent are mixed inside the applicator.

[0093] Plunger caps 19 are fitted to the rear ends of plungers 17 and 18. By pushing plunger cap 19 toward syringe holder 16, the two plungers 17 and 18 can be pushed in as a unit, and the first agent 21 and the second agent 22 in the syringe can be pushed out in equal amounts.

[0094] The first agent and the second agent are pushed out from the syringe and passed through the flow passage in the applicator 13, and then passed through the flow passage in the extender 12, and are then ejected from the spray tip 11 in the form of a mist. Although the sprayer 10 includes an extender 12, the sprayer 10 does not necessarily have to include the extender 12. If the sprayer 10 does not include the extender 12, the spray tip 11 may be connected to the outlet of the applicator 13.

[0095] Next, a method for using the spray kit will be described. Figure 3 is a flow chart illustrating a method for applying adhesive to target tissue using the spray kit. First, in step S30, the first agent and the second agent are prepared. There are no particular limitations on the method for preparing the first agent and the second agent, but examples include a method in which a predetermined amount of solvent is added to the first agent and the second agent, each of which does not contain a solvent, and then the two agents are mixed.

[0096] More specifically, the spray kit may include vials containing powdered first and second agents, into which predetermined amounts of solvents are injected to prepare liquid first and second agents. These solvents may be pre-injected into the first agent syringe and the second agent syringe, respectively.

[0097] Next, in step S31, the prepared liquid first agent and second agent are injected into syringes, respectively, and the sprayer is assembled. Specifically, the mixture prepared in a vial is drawn into each syringe, and then the sprayer is assembled.

[0098] Next, in step S32, the plunger cap is pressed in, causing a mist of adhesive to be ejected from the spray tip. This step applies the adhesive to the target tissue and quickly solidifies into a gel. [Example]

[0099] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0100] [Adhesive manufacturing] Adhesives consisting of a first part and a second part shown in Tables 1 and 2 were produced by the method described below.

[0101] (1) Gelatin derivatives (1-1) Synthesis of "43C14" Ten grams of alkali-processed gelatin derived from Alaska pollack (raw gelatin, Mw = 45,000, "B-Matrix Fish Gelatin TA (trade name)" manufactured by Nitta Gelatin, hereafter referred to as "Organic Gelatin") was added to 50 mL of an ultrapure water-ethanol mixed solvent in a pear-shaped flask immersed in an oil bath at 50°C, and dissolved with stirring for approximately 2 hours to prepare a 20% by mass aqueous solution. Next, picoline borane (manufactured by Junsei Chemical Co., Ltd.) was added to the resulting aqueous solution in an amount 1.5 times the equivalent of the tetradecanal added later, followed by the addition of tetradecanal (manufactured by Tokyo Chemical Industry Co., Ltd.) in an amount 1.3 times the equivalent of the amino groups of the gelatin (molar ratio of tetradecanal to 1 mole of amino groups of gelatin).

[0102] Next, a reflux condenser was attached to the eggplant-shaped flask, and the reaction was carried out at 55°C for 18 hours while stirring. The reaction solution was then added dropwise to 1 L of ethanol to cause reprecipitation. After stirring for 1 hour, the solution was left to stand in a freezer for 1 hour, and then filtered through a glass filter. The filter residue was again placed in 1 L of ethanol in a beaker to cause reprecipitation, and after stirring for 1 hour, the solution was left to stand in a freezer for 1 hour. After filtering again through a glass filter, the filter residue was dried overnight or longer in a vacuum dryer, and a gelatin derivative in which a hydrophobic group, a tetradecyl group (C14), was introduced into the gelatin residue via an imino group was obtained in a yield of 96%.

[0103] The introduction rate of tetradecyl groups in the obtained gelatin derivatives was determined using the following method. First, Org gelatin and the gelatin derivatives were each dissolved in a water / DMSO (dimethyl sulfoxide) mixed solvent (volume ratio 1:1, hereinafter the same) at 0.1% by mass / volume, and 100 μL was dispensed into a 48-well plate. 100 μL of 0.1% by volume triethylamine (TEA, manufactured by Nacalai Tesque) dissolved in a water / DMSO mixed solvent was added and the mixture was shaken at 400 rpm for 1 minute on a plate shaker. 100 μL of 0.1% by volume trinitrobenzenesulfonic acid (TNBS, manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in a water / DMSO mixed solvent was then added and the mixture was shaken at 400 rpm for 1 minute on a plate shaker. The mixture was shielded from light with aluminum foil and placed in a 37°C incubator for 2 hours. The reaction was then stopped by adding 50 μL of HCl (6 mol / L) and shaking on a plate shaker at 400 rpm for 1 minute. The mixture was then shielded from light for 10 minutes, after which the absorbance (Abs) at 340 nm was measured using a spectrophotometer (TECAN Spark 10M-NMST). The absorbance of a blank sample, which differed only in that it contained no gelatin, was subtracted from the measured absorbance, and the tetradecyl group introduction rate of the gelatin derivative was calculated to be 43.0 mol% using the following formula: Incorporation rate (mol%) = [Abs(Organic gelatin) - Abs(gelatin derivative)] / [Abs(Organic Gelatin)]×100

[0104] The gelatin derivative obtained by the above method was named "43C14."

[0105] (1-2) Synthesis of gelatin derivatives shown in Tables 1 and 2 Tables 1 and 2 show several gelatin derivatives with different carbon numbers and introduction rates of alkyl groups introduced into raw gelatin. In the notation of gelatin derivatives in Tables 1 and 2, the first half indicates the "alkyl group introduction rate (%)" and the second half indicates the "carbon number" of the alkyl group introduced, similar to the above-mentioned gelatin derivative 43C14. For example, "54C10" in Table 1 means a gelatin derivative with an alkyl group introduction rate of 54% and an alkyl group carbon number of 10. These gelatin derivatives were synthesized by the same method as the above-mentioned gelatin derivative 43C14. Specifically, starting material gelatin (Mw=45,000 or 84,000) was used, and the amount of tetradecanal (carbon number: 14) used was appropriately adjusted. Alternatively, instead of tetradecanal, hexanal (carbon number: 6), octanal (carbon number: 8), decanal (carbon number: 10), dodecanal (carbon number: 12), or octadecanal (carbon number: 18) was used, and the amounts of these used were appropriately changed to synthesize each of the gelatin derivatives shown in Tables 1 and 2.

[0106] (2) Preparation of the first agent The gelatin derivative and α-cyclodextrin were weighed so that the molar ratio (Cy / HBic) of the cyclodextrin content (Cy) to the gelatin derivative hydrophobic group content (HBic) was the value shown in Tables 1 and 2, and 0.075 mol / L borate buffer (pH 9.5) was added to prepare the first agent. The concentration of the gelatin derivative in the first agent was 0.1 g / mL. In the first agents in Tables 1 and 2, "Org" refers to the raw material gelatin itself without alkyl groups introduced. The first agent using Org does not contain cyclodextrin.

[0107] (3) Preparation of the second agent Pentaerythritol-polyethylene glycol ether tetrasuccinimidyl glutarate ("4S-PEG", weight-average molecular weight 5,000, 10,000, or 20,000, manufactured by NOF Corp.) was prepared as a crosslinking agent. This was dissolved in 0.01 mol / L phosphate buffer (pH 4.0) to form the second agent.

[0108] (4) Preparation of adhesive The first and second agents were filled into a W syringe manufactured by ADY Co., Ltd. so that the molar ratio (NHS ester of crosslinking agent) / (primary amino group in the first agent) was (NHS / NH2) = 0.4 (40 mol%). This was extruded and mixed before use.

[0109] [evaluation] (1) Confirmation of inclusion of tetradecyl groups by cyclodextrin The inclusion of the tetradecyl group in 43C14 by α-cyclodextrin was confirmed by two-dimensional nuclear magnetic resonance (2D-NOESY) JNM-AL300; JEOL, Japan). 2D-NOESY is a measurement method that rapidly changes the spin occupancy and observes the process of returning to thermal equilibrium. In 2D-NOESY, NOE phenomena are observed between adjacent protons located within a distance of approximately 5 Å. In the case of α-cyclodextrin and the tetradecyl group in 43C14, peaks due to NOE are observed between the methylene protons of the tetradecyl group and the protons at the 3rd and 5th positions inside α-cyclodextrin, confirming the formation of the inclusion complex.

[0110] α-Cyclodextrin and 43C14 were dissolved in DO so that the concentration of 43C14 was 3 w / v% and the molar ratio of α-cyclodextrin to tetradecyl groups (Cy / HBic) was 4 / 1 (mol / mol) and the measurement was performed (accumulation number: 16, measurement time: 4 hours 56 minutes). NOE was observed between the protons at positions 3 and 5 located inside the α-cyclodextrin and the peak at 1.2-1.5 ppm. This result confirmed that the tetradecyl groups of 43C14 in the first agent solution were included in α-cyclodextrin.

[0111] (2) Evaluation of shrinkage and adhesiveness <Method for evaluating shrinkage> Each adhesive listed in Tables 1 and 2 was filled into a W syringe and dispensed to produce a 1 mm thick gel (cured adhesive), which was then punched out with a 10 mm diameter punch to prepare a sample. The sample (cured adhesive) was then transferred to a 50 ml centrifuge tube, 50 ml of saline (containing 25 μ / mL of Acid Blue) was poured over it, and the tube was left to stand in a 37°C incubator. The shrinkage rate (%) was calculated using the following formula: (M0) = (M1) / (M0) / (M1 ...

[0112] Shrinkage rate (%) = (M1 / M0) x 100

[0113] A shrinkage rate of less than 100% means that the sample shrunk after immersion in saline, and a smaller shrinkage rate means that the sample shrunk more. Conversely, a shrinkage rate of more than 100% means that the sample swelled after immersion. The results are shown in Figures 1 and 2.

[0114] <Adhesion (compression resistance) evaluation method 1> As evaluation samples, four types of adhesives, Org-5,000, 20C14-5,000, 43C14-5,000, and 62C14-5,000, which use 4S-PEG with a weight-average molecular weight of 5,000, and four types of adhesives, Org-10,000, 20C14-10,000, 43C14-10,000, and 62C14-10,000, which use 4S-PEG with a weight-average molecular weight of 10,000, were prepared, as shown in Table 1.

[0115] In accordance with ASTM-F2392-04R, adhesion (compression strength) was evaluated using collagen casing (manufactured by Nippi) as a model tissue for evaluating tissue adhesive strength. A 3 mm diameter pinhole was created in a 35 mm diameter collagen casing, and adhesive was applied to a thickness of 1 mm. This was left to stand at room temperature (23-25°C) for 10 minutes, and the compression strength was measured. The test was performed five times, and the average value was calculated. This result was taken as the compression strength of the cured adhesive "before immersion."

[0116] Similarly, the adhesive was applied to a collagen casing, left at room temperature for 10 minutes, and then immersed in D-PBS (Dulbecco's Phosphate Buffered Saline) containing 0.02% sodium azide for 24 hours. The pressure resistance was then measured in the same manner as described in ASTM-F2392-04R. The test was performed five times, and the average value was calculated. This result was used as the pressure resistance of the cured adhesive "after immersion."

[0117] The results for adhesives Org-5,000, 20C14-5,000, 43C14-5,000, and 62C14-5,000, which used 4S-PEG with a weight-average molecular weight of 5,000, are shown in Figure 4(a) as Org, 20C14, 43C14, and 62C14, respectively. The results for adhesives Org-10,000, 20C14-10,000, 43C14-10,000, and 62C14-10,000, which used 4S-PEG with a weight-average molecular weight of 10,000, are shown in Figure 4(b) as Org, 20C14, 43C14, and 62C14, respectively. The compressive strength of each adhesive before and after immersion was tested for significance using Tukey's multiple comparisons test.

[0118] <Adhesion (compression resistance) evaluation method 2> The adhesives Org-10,000 and 43C14-10,000 shown in Table 1 were prepared as evaluation samples.

[0119] In Evaluation Method 2, instead of collagen casing, 50 mm diameter porcine colons (pinhole diameter: 3 mm) were prepared as model tissues. They were pretreated to ensure uniform moisture content among the porcine colons used in each test (five times per evaluation sample). Specifically, before adhesive application, 16 paper wipes (Kimwipes®, manufactured by Nippon Paper Crecia Co., Ltd.) were stacked on the adhesive-coated surface of the porcine colon, and a 50 g weight was placed on top of them and allowed to stand for 3 minutes. The pressure strength of the cured adhesive was measured "before" and "after" immersion in accordance with ASTM-F2392-04R using the same method as in Evaluation Method 1. The results (pressure strength) for Adhesive Org-10,000 are shown as Org, and the results (pressure strength) for Adhesive 43C14-10,000 are shown as 43C14 in Figure 5. The pressure strengths of each adhesive before and after immersion were tested for significance using Tukey's multiple comparisons test.

[0120] [Table 1]

[0121] [Table 2]

[0122] <Relationship between the weight-average molecular weight of the crosslinking agent and the shrinkage and adhesion of the adhesive> As shown in Table 1, all of the adhesive cured products using raw material gelatin (Org) without alkyl groups in the first agent expanded after immersion in saline (shrinkage rate >100%).

[0123] In adhesives using a gelatin derivative with alkyl groups introduced into the first agent, the smaller the weight-average molecular weight of the crosslinking agent (4S-PEG) in the second agent, the greater the shrinkage of the crosslinked adhesive after immersion. When the weight-average molecular weight of the crosslinking agent (4S-PEG) reached 20,000, the cured adhesive expanded after immersion (shrinkage rate >100%), except for the adhesive using gelatin derivative 43C14. From these results, from the viewpoint of improving the shrinkage of the cured adhesive, the weight-average molecular weight of the crosslinking agent is preferably 12,000 or less, and more preferably 10,000 or less.

[0124] On the other hand, in order to sufficiently cure the adhesive and increase its adhesive strength, the curing agent must have a certain size (molecular weight). Comparing Figure 4(a) (4S-PEG Mw = 5,000) with Figure 4(b) (4S-PEG Mw = 10,000), the adhesive shown in Figure 4(b), which has a higher weight-average molecular weight of the crosslinker, exhibited higher adhesive strength (compression strength). From these results, from the perspective of improving the adhesive strength of the adhesive, the weight-average molecular weight of the crosslinker is preferably 1,000 or more, and more preferably 5,000 or more.

[0125] <Relationship between the hydrophobic group (number of carbon atoms and introduction rate) of gelatin derivatives and the shrinkage and adhesive properties of adhesives> The adhesives shown in Table 2 were plotted on the graph shown in Figure 6, focusing on the carbon number of the hydrophobic group of the gelatin derivative and the introduction rate. The horizontal axis of Figure 6 is the carbon number of the hydrophobic group of the gelatin derivative, and the vertical axis is the introduction rate (mol%).

[0126] In Figure 6, adhesives plotted within range (I) where the number of carbon atoms in the hydrophobic group of the gelatin derivative is 8 to 16 and the introduction rate is 20 mol% to 80 mol% showed shrinkage in the cured product after immersion (shrinkage rate <100%). On the other hand, adhesives plotted outside range (I) showed expansion in the cured product after immersion (shrinkage rate >100%). Furthermore, adhesives plotted within range (II) shown in Figure 6 (number of carbon atoms: 10 to 16, introduction rate: 35 mol% to 75 mol%) showed more shrinkage in the cured product after immersion (shrinkage rate <73%), and adhesives plotted within range (III) (number of carbon atoms: 12 to 16, introduction rate: 40 mol% to 55 mol%) showed even more shrinkage in the cured product after immersion (shrinkage rate <69%).

[0127] Next, let us consider Figure 4(a) and (b), which show the results of evaluating the adhesive properties (compression strength). Compared with adhesives using raw gelatin (Org), which are plotted outside range (I) in Figure 6, adhesives using modified gelatin (20C14, 43C14, and 62C14), which are plotted within range (I), had higher compression strength. In particular, adhesives using modified gelatin (43C14), which is plotted within range (III), showed higher compression strength.

[0128] Next, let us consider the adhesive properties before and after immersion, as shown in Figures 4(a) and 4(b). The adhesives using modified gelatins (20C14, 43C14, and 62C14) plotted within range (I) in Figure 6 showed adhesive properties after shrinkage that were equivalent to or even higher than those before shrinkage (no significant change). Among these, the adhesives using modified gelatins (62C14 and 43C14) plotted within range (II) showed improved adhesive properties after shrinkage, while the adhesive using modified gelatin (43C14) plotted within range (III) showed even greater improvement after shrinkage.

[0129] <Adhesion of adhesive to pig large intestine (compression resistance strength)> In evaluation method 2, the moisture content was equalized among the pig large intestines used in each test, which significantly reduced the variation in the results of five tests using the same evaluation sample (cured adhesive), as shown in Figure 5. When comparing the pressure resistance strength before immersion, the cured adhesive using modified gelatin (43C14) had higher pressure resistance strength than the cured adhesive using raw gelatin (Org).

[0130] Next, we compared the adhesive properties before and after immersion. The cured adhesive using raw material gelatin (Org) swelled after immersion (see Table 1), and its pressure resistance decreased to below the maximum internal pressure of the human large intestine (30 mmHg) (see Figure 5). On the other hand, the cured adhesive using the gelatin derivative (43C14) shrunk after immersion (see Table 1), and its pressure resistance increased (see Figure 5).

[0131] (3) Evaluation of mechanical properties Adhesive Org-10,000 and adhesive 43C14-10,000 shown in Table 1 were prepared, and cured materials were produced. Tensile tests were performed before and after immersion in water, etc., to evaluate the mechanical properties.

[0132] <Test method for tensile test> (i) Each adhesive (a mixture of the first and second parts) was poured into a dumbbell-shaped silicone mold (see Figure 7A for each size), a glass plate was placed on top, and the mold was left to stand for 10 minutes to obtain a cured product. (ii) After making sure that there were no air bubbles in the constricted portion of the cured product, the product was removed from the mold, and multiple measurement samples were obtained from each bond. (iii) Some of the obtained measurement samples were subjected to a tensile test as they were, as "before immersion" samples. The measurement results of the five pre-immersion samples of adhesive 43C14-10,000 are shown as "43C14," and the measurement results of the six pre-immersion samples of adhesive Org-10,000 are shown as "Org," and are shown in Figures 7A and 7B. The remaining test specimens were immersed in D-PBS (Dulbecco's Phosphate Buffered Saline) for 24 hours and subjected to tensile testing as "post-immersion" specimens. The measurement results for four specimens of adhesive 43C14-10,000 are shown as "43C14-S," and the measurement results for four specimens of adhesive Org-10,000 after immersion are shown as "Org-S" in Figures 7A and 7B. The cross-sectional area (thickness and width) of the post-immersion specimens was measured using calipers. (iv) Tensile tests were performed using a texture analyzer (TA.XT plus, Stable Micro Systems, Godalming, GB-SRY, UK). First, the top and bottom of the test sample were fixed to a jig (only 43C14-S was fixed with a clip; the other test samples were fixed with a screw). Measurement was started at a tensile speed of 10 mm / min and ended when the test sample broke or when the strain limit of the device was reached. (v) After immersion, the stress of the samples was calculated from the average cross-sectional area. Figure 7A shows the SS curve (stress-strain curve). Young's modulus was calculated from the slope of the linear portion of the SS curve. The strain, tensile strength, and Young's modulus were tested for significance using Tukey's multiple comparisons test. The results are shown in Figure 7B.

[0133] <Tensile test results> As explained below, the cured product of adhesive 43C14-10,000 exhibited improved mechanical properties (toughness, breaking strain, tensile strength, and Young's modulus) after immersion in D-PBS.

[0134] As shown in Figure 7A, the toughness of the cured adhesive Org-10,000 decreased when immersed in D-PBS, whereas the toughness of the cured adhesive 43C14-10,000 increased upon immersion. This is presumably because, in 43C14-S, the cyclodextrin inclusion complex was removed from the hydrophobic groups (dissociation), forming physical crosslinks between the hydrophobic groups. Furthermore, the chemical crosslink density increased with shrinkage of the crosslinked material. Furthermore, in 43C14-S, the physical crosslinks of the hydrophobic groups acted like sacrificial bonds, dissipating the input energy, possibly contributing to the toughness.

[0135] As shown in FIG. 7B, after immersion in D-PBS, the cured product of adhesive Org-10,000 showed no significant changes in breaking strain (elongation) or tensile strength, and the Young's modulus decreased. On the other hand, the breaking strain (elongation), tensile strength, and Young's modulus of the cured adhesive 43C14-10,000 were all significantly improved after immersion in D-PBS compared to before. The increase in tensile strength and Young's modulus for 43C14-S is presumed to be due to the formation of physical crosslinks between hydrophobic groups as the cyclodextrin was removed from the hydrophobic groups, and the increase in chemical crosslink density as the crosslinked material shrunk. Furthermore, the improvement in breaking strain (elongation) for 43C14-S is presumed to be due to the fact that the polymer chains were in a shortened state due to shrinkage at the start of the measurement, resulting in a larger rate of change in strain. [Industrial Applicability]

[0136] The cured adhesive of the present invention shrinks in a moist environment within the body and exhibits excellent adhesion to biological tissue, making it suitable for use in wound dressings, adhesion inhibitors, hemostatic materials, sealants, and the like. [Explanation of symbols]

[0137] 10: sprayer, 11: spray tip, 12: extender, 13: applicator, 14: outer barrel, 15: outer barrel, 16: syringe holder, 17, 18: plunger, 19: plunger cap, 21: first agent, 22: second agent

Claims

1. An adhesive, a first agent containing a gelatin derivative in which a hydrophobic group has been introduced into gelatin and cyclodextrin; a second agent containing a crosslinking agent for the gelatin derivative, The gelatin derivative has a structure represented by the following formula (1), the introduction rate of the hydrophobic group is 20 mol % to 80 mol %, and the weight average molecular weight of the crosslinking agent is 1,000 to 12,000. 【Chemistry 1】 In formula (1), Gltn represents a residue of the gelatin, L represents a single bond or a divalent linking group, and R １ is the hydrophobic group and represents an alkyl group having 8 to 16 carbon atoms.

2. In the first agent, the introduction rate of the hydrophobic group is 35 mol % to 75 mol %; In formula (1), R １ The adhesive according to claim 1, wherein is an alkyl group having 10 to 16 carbon atoms.

3. In the first agent, the introduction rate of the hydrophobic group is 40 mol % to 55 mol %, In formula (1), R １ The adhesive according to claim 1, wherein is an alkyl group having 12 to 16 carbon atoms.

4. In formula (1), R １ The adhesive according to any one of claims 1 to 3, wherein is a linear alkyl group.

5. 5. The adhesive according to claim 1, wherein the cyclodextrin is α-cyclodextrin or a derivative thereof.

6. The adhesive according to any one of claims 1 to 5, wherein the crosslinking agent has a weight average molecular weight of 5,000 to 10,000.

7. The adhesive according to any one of claims 1 to 6, wherein the crosslinking agent is a compound having at least two active ester groups.

8. The adhesive according to any one of claims 1 to 7, wherein the crosslinking agent is an activated polyethylene glycol polybasic acid ester.

9. The adhesive according to any one of claims 1 to 8, wherein the gelatin is cold water fish gelatin.

10. The adhesive according to any one of claims 1 to 9, wherein the mixture of the first and second parts is a shrinkable adhesive that shrinks in physiological saline when cured.

11. A wound dressing comprising the adhesive of any one of claims 1 to 10.

12. An anti-adhesion material comprising the adhesive according to any one of claims 1 to 10.

13. A hemostatic material comprising the adhesive according to any one of claims 1 to 10.

14. A sealant comprising the adhesive according to any one of claims 1 to 10.

15. A spray kit comprising the adhesive according to any one of claims 1 to 10 and a sprayer for said adhesive.

16. A cured adhesive product obtained by curing the adhesive according to any one of claims 1 to 10.

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