Protein adsorption inhibition material including amphoteric copolymer

Abstract

To provide a protein adsorption inhibition material excellent in protein adsorption inhibition performance, with a higher degree of freedom in a service condition and in a morphological aspect, capable of imparting the protein adsorption inhibition performance to various kinds of materials or a surface thereof, while having a higher degree of design freedom and capable of controlling the protein adsorption inhibition performance to a desired degree.SOLUTION: A protein adsorption inhibition material includes an amphoteric copolymer (I) having a cationic constitutional unit (1) including an amino group in a structure and an anionic constitutional unit (2). At least part of the cationic constitutional unit (1) is a constitutional unit (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer or a structure being an inorganic acid salt or organic acid salt thereof. At least part of the anionic constitutional unit (2) is a constitutional unit (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a protein adsorption-inhibiting material, and more specifically to a protein adsorption-inhibiting material that contains a specific amphoteric copolymer and thereby is capable of achieving excellent properties such as high protein adsorption-inhibiting performance. [Background technology]

[0002] In various technical and industrial fields, such as medical devices, life sciences, and analytical devices, protein-containing substances such as biological fluids, cells, and viruses are often handled, and in such cases, components that come into contact with such protein-containing substances may adsorb the proteins, resulting in problems such as contamination, deterioration, and reduced analytical accuracy. For this reason, materials that can effectively suppress protein adsorption have been investigated.

[0003] For example, Patent Document 1 proposes a material that inhibits adsorption of biological fluid components, characterized in that the surface is formed from a polyelectrolyte complex obtained by reacting a cationic polyelectrolyte with an anionic polyelectrolyte.

[0004] However, the polymer electrolyte complex described in Patent Document 1 requires a complicated synthesis process because the cationic polymer electrolyte and the anionic polymer electrolyte must be synthesized separately and then mixed together. Furthermore, because the polymers are not bonded via strong covalent bonds, the structure may be partially altered depending on the pH or charge balance, which can significantly change the performance, and this may limit the conditions of use and the form. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-261936 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above-mentioned prior art, an object of the present invention is to provide a protein adsorption-inhibiting material that has excellent protein adsorption-inhibiting performance, has a high degree of freedom in terms of usage conditions and form, is capable of imparting protein adsorption-inhibiting performance to various materials and their surfaces, and has a high degree of design freedom that allows the protein adsorption-inhibiting performance to be controlled to a desired level. [Means for solving the problem]

[0007] As a result of extensive research, the inventors discovered that by using an amphoteric copolymer having a specific structure as a protein adsorption-inhibiting material, it is possible to achieve excellent protein adsorption-inhibiting performance, high usage conditions, freedom in shape, high freedom in design, and the like, and thus completed the present invention. That is, the present invention is [1] A protein adsorption-inhibiting material containing an amphoteric copolymer having a cationic structural unit (1) containing an amino group in its structure and an anionic structural unit (2), The present invention relates to the protein adsorption-inhibiting material, wherein at least a portion of the cationic structural units (1) are structural units (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure of an inorganic acid salt or organic acid salt thereof, and at least a portion of the anionic structural units (2) are structural units (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof.

[0008] Below, [2] to [9] are each a preferred aspect or embodiment of the present invention. [2] The protein adsorption-inhibiting material according to [1], wherein the molar ratio of the cationic structural units (1) to the anionic structural units (2) in the amphoteric copolymer (I) is 4:1 to 1:4. [3] The protein adsorption-inhibiting material according to [1] or [2], wherein at least a portion of the structural units (i) are structural units having a structure derived from an allylamine-based monomer or diallylamine-based monomer having at least one amino group selected from the group consisting of a secondary amino group, a tertiary amino group, and a quaternary amino group, or a structure which is an inorganic acid salt or an organic acid salt thereof. [4] The protein adsorption-inhibiting material according to at least one of [1] to [3], wherein at least a portion of the structural units (i) have a structure that is an inorganic acid salt or an organic acid salt derived from an allylamine-based monomer or a diallylamine-based monomer. [5] The protein adsorption-inhibiting material according to any one of [1] to [4], wherein at least a portion of the structural units (ii) are structural units having a structure derived from allylsulfonic acid or acrylamidosulfonic acid, or a salt thereof. [6] The protein adsorption-inhibiting material according to [5], wherein at least a portion of the structural units (ii) are structural units having a structure derived from acrylamidoalkylsulfonic acid. [7] The protein adsorption-inhibiting material according to any one of [1] to [6], which is used to prevent adsorption of proteins having an isoelectric point of 4 to 12. [8] A biological component adsorption-inhibiting material, a surface protective agent for medical devices, or an antifouling coating agent for transparent materials, which uses the protein adsorption-inhibiting material according to any one of [1] to [6]. [9] The antifouling coating agent for transparent materials according to [8], which is used for transparent materials such as window glass or touch panels. [Effects of the Invention]

[0009] The present invention provides a protein adsorption-inhibiting material that has excellent properties that are of great practical value, such as excellent protein adsorption-inhibiting performance, high flexibility in terms of usage conditions and form, which can be imparted to various materials and their surfaces, and high design freedom that allows the protein adsorption-inhibiting performance to be controlled to a desired level. DETAILED DESCRIPTION OF THE INVENTION

[0010] The protein adsorption-inhibiting material of the present invention contains an amphoteric copolymer (hereinafter also referred to as "amphoteric copolymer (I)") having a cationic structural unit (1) and an anionic structural unit (2), each of which has a specific structure. In the amphoteric copolymer (I), the cationic structural units (1) are structural units having an amino group in their structure. At least a portion of the cationic structural units (1) in the amphoteric copolymer (I) are structural units (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure of an inorganic acid salt or an organic acid salt thereof. In the amphoteric copolymer (I), at least a portion of the anionic structural units (2) are structural units (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof. By containing the amphoteric copolymer (I), the protein adsorption-inhibiting material of the present invention can achieve excellent technical effects, such as high protein adsorption-inhibiting performance. The protein adsorption-inhibiting material of the present invention may contain only one type of amphoteric copolymer (I), or may contain a combination of two or more types.

[0011] Amphoteric Copolymer (I) The amphoteric copolymer (I) has cationic constituent units (1) containing an amino group in its structure and anionic constituent units (2), and is not particularly limited as long as at least a portion of the cationic constituent units (1) are constituent units (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure of an inorganic acid salt or an organic acid salt thereof, and at least a portion of the anionic constituent units (2) are constituent units (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof. Therefore, the amphoteric copolymer (I) may contain structural units other than the cationic structural unit (1) and the anionic structural unit (2), or may be composed only of the cationic structural unit (1) and the anionic structural unit (2).

[0012] There are no particular restrictions on the proportion of the cationic structural unit (1) and the anionic structural unit (2) in all structural units of the amphoteric copolymer (I), but it is preferably 30 mol % or more, more preferably 50 to 100 mol %, and particularly preferably 70 to 100 mol %. There are no particular restrictions on the ratio of the cationic structural unit (1) to the anionic structural unit (2) in the amphoteric copolymer (I), and by appropriately adjusting this molar ratio, the high design freedom of the present invention can be exhibited, such as controlling the protein adsorption inhibitory performance to a desired level. The ratio of the cationic structural unit (1) to the anionic structural unit (2) is usually 4:1 to 1:4 (molar ratio), preferably 3:1 to 1:3 (molar ratio), and particularly preferably 2:1 to 1:2 (molar ratio).

[0013] The cationic structural unit (1) may be a structural unit (i) having a structure in which all of the structural unit (1) is derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure in which the structural unit (1) is an inorganic acid salt or an organic acid salt thereof, or may also contain a cationic structural unit having a structure other than the structural unit (i). Similarly, the anionic structural unit (2) may be a structural unit (ii) having a structure derived entirely from a monomer having a sulfonic acid group or a salt thereof, or may include an anionic structural unit having a structure other than structural unit (ii).

[0014] It is sufficient for the amphoteric copolymer (I) to have only one constituent unit (ii) as the cationic constituent unit (1) and one constituent unit (ii) as the anionic constituent unit (2) in its molecule, but from the viewpoint of protein adsorption suppression performance, etc., it is preferable for the amphoteric copolymer (I) to have a plurality of constituent units (i) and a plurality of constituent units (ii). More specifically, the proportion of the total of the constituent units (i) and the constituent units (ii) in the total constituent units of the amphoteric copolymer (I) is preferably 30 mol% or more, more preferably 50 to 100 mol%, and particularly preferably 70 to 100 mol%. The proportion of the structural unit (i) in all structural units of the amphoteric copolymer (I) is preferably at least 6 mol %, more preferably 10 to 80 mol %, and particularly preferably 14 to 80 mol %. The proportion of the total of the structural units (ii) in all the structural units of the amphoteric copolymer (I) is preferably at least 6 mol %, more preferably 10 to 80 mol %, and particularly preferably 14 to 80 mol %.

[0015] The amphoteric copolymer (I) may have only one type of the structural unit (i) in its molecule, or may have two or more types of structural units (i). When two or more types of structural units (i) are contained, the proportion of the structural unit (i) to all structural units of the amphoteric copolymer (I) is calculated based on the total number of moles of the two or more types of structural units (i). The amphoteric copolymer (I) may have only one type of the structural unit (ii) in its molecule, or may have two or more types of structural unit (ii). When two or more types of structural unit (ii) are present, the proportion of the structural unit (ii) in the total structural units of the specific (co)copolymer is calculated based on the total number of moles of the two or more types of structural unit (ii).

[0016] Cationic Building Block (1) The cationic structural units (1) constituting the amphoteric copolymer (I) may be structural units containing an amino group within their structure, and are not otherwise particularly limited. However, as described above, at least a portion of the cationic structural units (1) in the amphoteric copolymer (I) are structural units (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure of an inorganic or organic acid salt thereof. That is, in the amphoteric copolymer (I), all of the cationic structural units (1) may be structural units (i), or only a portion of the cationic structural units (1) may be structural units (i), with other cationic structural units present. The proportion of structural units (i) in the cationic structural units (1) is preferably 10 mol% or more, more preferably 50 mol% or more, and particularly preferably 70 mol% or more.

[0017] Structural unit (i) The structural unit (i), which accounts for at least a portion of the cationic structural unit (1), has a structure derived from an allylamine monomer or a diallylamine monomer, or a structure which is an inorganic acid salt or an organic acid salt thereof, and specific examples thereof include structures corresponding to the following structural unit (i-1), structural unit (i-2), or structural unit (i-3). Here, the structural unit (i-1) and the structural unit (i-2) correspond to structural units having a structure derived from a diallylamine monomer or a structure which is an inorganic acid salt or an organic acid salt thereof, and the structural unit (i-3) corresponds to a structural unit having a structure derived from an allylamine monomer or a structure which is an inorganic acid salt or an organic acid salt thereof. The amphoteric copolymer (I) may contain only one type of structural unit (i) as the cationic structural unit (1), or may contain two or more types of structural units (i). When two or more types of structural units (i) are contained, the two or more types of cationic structural units (1) may be a combination of structural units that are both classified as structural units (i-1), a combination of structural units that are both classified as structural units (i-2), or a combination of structural units that are both classified as structural units (i-3), or may be a combination of structural units that are classified as different structural units from the structural units (i-1) to (i-3). From the viewpoint of polymerization reactivity and the like, the structural unit (i) is preferably a structural unit having a structure derived from an allylamine-based monomer or diallylamine-based monomer having at least one amino group selected from the group consisting of a secondary amino group, a tertiary amino group, and a quaternary amino group, or a structure which is an inorganic acid salt or organic acid salt thereof, more preferably having a secondary amino group or a quaternary amino group, and particularly preferably having a quaternary amino group.

[0018] Structural unit (i-1) The structural unit (i-1), which is a preferred example of the structural unit (i), is a structural unit having a structure represented by the following general formula (Ia) or general formula (Ib), or a structure that is an inorganic acid salt or organic acid salt thereof: [ka] In the formula, R 1 R is a hydrogen atom or a monovalent hydrocarbon group, and preferably represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, a cycloalkyl group having 5 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. 1 is more preferably a hydrogen atom, a methyl group, an ethyl group, or a benzyl group, and particularly preferably a hydrogen atom or a methyl group. R 1is a hydrogen atom or a monovalent hydrocarbon group, the structural unit (i-1) becomes a structural unit having a secondary amino group or a tertiary amino group, which is preferable from the standpoint of polymerization reactivity, etc., and R 1 When is a hydrogen atom, the structural unit (i-1) becomes a structural unit having a secondary amino group, which is more preferable from the standpoint of polymerization reactivity and the like.

[0019] The structural unit (i-1) may have a structure that is an inorganic acid salt or organic acid salt of the structure represented by the above structural formula (Ia) or (Ib), that is, a structure that is an acid addition salt. When the amphoteric copolymer (I) has the structural unit (i-1), it is preferable to use a diallylamine monomer having an addition salt in producing the amphoteric copolymer (I) from the viewpoint of production costs, etc. The process of removing the addition salt such as HCl from the polymer is complicated and can cause an increase in costs, so using the addition salt type structural unit (i-1), which can be produced without such a process, is a preferred embodiment from the viewpoint of costs, etc. From the viewpoints of availability and reaction controllability, the inorganic acid salt or organic acid salt in the structural unit (i-1) of this embodiment is preferably a hydrochloride, a carboxylate, a sulfonate, or an alkyl sulfate salt, and is particularly preferably a hydrochloride.

[0020] Structural unit (i-2) The structural unit (i-2), which is a preferred example of the structural unit (i), is a structural unit having a structure represented by the following general formula (Ic) or general formula (Id). [ka] In the formula, R 2 and R 3 are each independently a hydrogen atom or a monovalent hydrocarbon group, preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, a cycloalkyl group having 5 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms; X a- represents a counter ion, and a represents the valence of the counter ion. R 2 and R 3 are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or a benzyl group, and particularly preferably a methyl group or an ethyl group. R 2 and R 3 are each independently a hydrogen atom or a monovalent hydrocarbon group, so that the structural unit (i-2) becomes a structural unit having a secondary amino group, tertiary amino group, or quaternary amino group, which is preferable from the standpoint of polymerization reactivity, etc., and R 2 and R 3 are both hydrogen atoms or monovalent hydrocarbon groups, the structural unit (i-2) becomes a structural unit having a secondary amino group or a quaternary amino group, which is more preferable from the standpoint of polymerization reactivity, etc., and R 2 and R 3 When both are monovalent hydrocarbon groups, the structural unit (i-2) becomes a structural unit having a quaternary amino group, which is particularly preferable from the standpoint of polymerization reactivity and the like.

[0021] Counter Ion X a- Although there are no particular limitations on the ion, from the viewpoints of availability and reaction controllability, a chloride ion, a carboxylate ion, a sulfonate ion, or an alkyl sulfate ion is preferred, and a chloride ion or an ethyl sulfate ion is particularly preferred. In producing the amphoteric copolymer (I), it is preferable to use a diallylamine monomer having a counter ion from the viewpoint of production costs, etc. The process of removing the counter ion from the polymer is complicated and can increase costs, so using the amphoteric copolymer (I) having a counter ion type structural unit (1-2), which can be produced without such a process, is a preferred embodiment from the viewpoint of costs, etc.

[0022] Structural unit (i-3) The structural unit (i-3) is a structural unit having a structure represented by the following general formula (Ie) or a structure that is an acid addition salt thereof. [ka] In the formula, R 4 and R 5 are each independently a hydrogen atom or a monovalent hydrocarbon group, and preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a hydroxyl group, an aralkyl group having 7 to 12 carbon atoms, or a cycloalkyl group having 5 to 6 carbon atoms. R 4 and R 5 The alkyl or aralkyl group having 1 to 12 carbon atoms is preferably a straight-chain or branched group. Examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and a benzyl group. 4 and R 5 Preferred cycloalkyl groups having 5 to 6 carbon atoms include, but are not limited to, a cyclopentyl group and a cyclohexyl group. R 4 and R 5 are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or a benzyl group, and particularly preferably a hydrogen atom or a methyl group. R 4 and R 5 When at least one of R is a monovalent hydrocarbon group, the structural unit (i-3) becomes a structural unit having a secondary amino group or a tertiary amino group, which is preferable from the standpoint of polymerization reactivity, etc., and R 4 and R 5 When one of the groups is hydrogen and the other is a monovalent hydrocarbon group, the structural unit (i-3) becomes a structural unit having a secondary amino group, which is more preferable from the standpoint of polymerization reactivity and the like.

[0023] When the structural unit (i-3) is an acid addition salt having a structure represented by general formula (Ie), there are no particular restrictions on the type of addition salt. However, from the standpoint of availability and ease of reaction control, for example, hydrochlorides, sulfates, phosphates, nitrates, sulfites, phosphites, nitrites, hydrobromides, acetates, amidosulfates, methanesulfonates, trifluoroacetates, p-toluenesulfonates, and the like can be used. Among these, hydrochlorides, sulfates, phosphates, and amidosulfates are preferred, and hydrochlorides, sulfates, phosphates, and amidosulfates having a structure derived from monoallylamine are particularly preferred.

[0024] Other cationic constituent units When the amphoteric copolymer (I) has a cationic constituent unit other than the constituent unit (i) as the cationic constituent unit (1), the cationic constituent unit may be any unit having an amino group in its structure, and is not otherwise limited. Specific examples include a constituent unit having a structure corresponding to polyethyleneimine, and a constituent unit having a tertiary amine or quaternary amine structure derived from N-(dimethylaminoalkyl)(meth)acrylamide or dimethylaminoalkyl(meth)acrylate.

[0025] Anionic Building Block (2) The anionic structural units (2) constituting the amphoteric copolymer (I) need only be structural units capable of acquiring a negative charge upon dissociation, and no other limitations are imposed thereon. However, as described above, at least a portion of the anionic structural units (2) in the amphoteric copolymer (I) are occupied by structural units (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof. That is, in the amphoteric copolymer (I), all of the anionic structural units (2) may be occupied by structural units (ii), or only a portion of the anionic structural units (2) may be occupied by structural units (ii), with other anionic structural units present. The proportion of structural units (ii) in the anionic structural units (2) is preferably 10 mol% or more, more preferably 50 mol% or more, and particularly preferably 70 mol% or more.

[0026] Structural unit (ii) The structural unit (ii) that accounts for at least a portion of the anionic structural unit (2) need only have a structure derived from a monomer having a sulfonic acid group or a salt thereof, and is not otherwise limited. Specific examples include structural units having a structure derived from styrene sulfonic acid or a salt thereof, acrylamidosulfonic acid or a salt thereof, such as 2-acrylamido-2-methylpropanesulfonic acid or acrylamide-t-butylsulfonic acid, allyl sulfonate or a salt thereof, styrene sulfonic acid or a salt thereof, vinyl sulfonic acid or a salt thereof, and sulfopropyl methacrylate. Among these, from the viewpoint of the ease with which a copolymerization reaction with the monomer component that leads to the cationic structural unit (1) occurs, structural units having a structure derived from an acrylamide sulfonic acid such as 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, or an allyl sulfonate or a salt thereof can be preferably used. A structural unit having a structure derived from acrylamidosulfonic acid can be particularly preferably used.

[0027] The acrylamidosulfonic acid may be any compound having at least one acrylamide group (including methacrylamide group) and at least one sulfonic acid group, and is not otherwise limited in structure. However, it is preferably a compound having one acrylamide group and one sulfonic acid group, and it is preferably one having a structure in which one acrylamide group and one sulfonic acid group are bonded via an alkyl group (including alkylene group), i.e., it is preferably an acrylamidoalkylsulfonic acid. The structural unit having a structure derived from acrylamidosulfonic acid, preferably acrylamidoalkylsulfonic acid, may be a salt, but from the viewpoint of polymerizability and the like, it preferably has a free sulfonic acid structure.

[0028] The alkyl group (alkylene group) in the acrylamidoalkylsulfonic acid is not particularly limited, and may be either linear or branched, with branched being preferred. The number of carbon atoms in the alkyl group (alkylene group) is also not particularly limited, but preferably has 1 to 7 carbon atoms, more preferably 2 to 6, and particularly preferably 3 to 5. Preferred examples of the alkyl group (alkylene group) in the acrylamidoalkylsulfonic acid include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a 2-methylpropyl group.

[0029] Examples of acrylamidoalkylsulfonic acids include, but are not limited to, acrylamidomethanesulfonic acid, acrylamidoethanesulfonic acid, acrylamidopropanesulfonic acid, 2-acrylamido-n-butanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, methacrylamidomethanesulfonic acid, methacrylamidoethanesulfonic acid, methacrylamidopropanesulfonic acid, 2-methacrylamido-n-butanesulfonic acid, and 2-methacrylamido-2-methylpropanesulfonic acid. Among these, 2-acrylamido-2-methylpropanesulfonic acid is particularly preferred.

[0030] As the allyl sulfonate or a salt thereof, a compound having a structure represented by the following general formula (II) can be preferably used. [ka] In the formula, R 6 represents a hydrogen atom or a monovalent hydrocarbon group, and X represents a hydrogen atom, an alkali metal, or an ammonium group. 6 is preferably a hydrogen atom or a methyl group. Specific examples of the allylsulfonic acid or a salt thereof represented by the general formula (VI) include allylsulfonic acid, methallylsulfonic acid, sodium allylsulfonate, sodium methallylsulfonate, potassium allylsulfonate, potassium methallylsulfonate, ammonium allylsulfonate, and ammonium methallylsulfonate. Of the above allylsulfonic acids or salts thereof, sodium allylsulfonate and the like can be particularly preferably used from the viewpoint of ease of copolymerization reaction with the cationic component. These allylsulfonic acids or salts thereof may be used alone or in combination of two or more.

[0031] Other anionic building blocks When the amphoteric copolymer (I) has an anionic constituent unit other than the constituent unit (ii) as the anionic constituent unit (2), the anionic constituent unit may be any constituent unit that can acquire a negative charge upon dissociation, and is not otherwise limited. Specific examples include constituent units derived from unsaturated carboxylic acids such as acrylic acid and methacrylic acid or salts thereof, constituent units derived from unsaturated dicarboxylic acids such as maleic acid and fumaric acid or salts thereof, and constituent units derived from unsaturated acid anhydrides such as maleic anhydride.

[0032] Other structural units (nonionic structural units) When the amphoteric copolymer (I) contains a structural unit other than the cationic structural unit (1) and the anionic structural unit (2), there are no particular limitations on the structural unit, and structural units derived from nonionic monomers copolymerizable with the cationic structural unit (1) and the anionic structural unit (2) (hereinafter also referred to as "nonionic structural units") can be appropriately incorporated. As the nonionic structural unit, structural units derived from methacrylate monomers, acrylate monomers, methacrylamide monomers, acrylamide monomers, sulfur dioxide, etc. can be preferably used. More specific examples include structural units derived from methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, methacrylamide, N-methylmethacrylamide, dimethylmethacrylamide, N-(3-dimethylaminopropyl)methacrylamide, acrylamide, dimethylacrylamide, hydroxyethylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide methyl chloride quaternary salt, acryloylmorpholine, isopropylacrylamide, 4-t-butylcyclohexyl acrylate, or sulfur dioxide. Structural units derived from methacrylamide-based monomers, acrylamide-based monomers, sulfur dioxide, etc. are particularly preferably incorporated. When the amphoteric copolymer (I) contains nonionic structural units, the proportion of the nonionic structural units in all structural units of the amphoteric copolymer (I) is more preferably 0 to 50 mol %, and particularly preferably 0 to 30 mol %.

[0033] There are no particular restrictions on the molecular weight of the amphoteric copolymer (I), and an amphoteric copolymer (I) with an appropriate molecular weight may be obtained or polymerized depending on the form of use of the protein adsorption-inhibiting material and its relationship with components other than the amphoteric copolymer (I). However, from the viewpoints of viscosity, handleability, etc., an amphoteric copolymer (I) with a weight-average molecular weight (Mw) of 500 or more and 100,000 or less is usually used. The weight average molecular weight (Mw) of the amphoteric copolymer (I) is preferably 100,000 or less, more preferably 80,000 or less, and particularly preferably 60,000 or less, and is preferably 500 or more, more preferably 750 or more, and particularly preferably 1,000 or more. From the viewpoint of carrying out the polymerization within a practically acceptable time and cost, the weight average molecular weight (Mw) of the amphoteric copolymer (I) is preferably 80,000 or less, more preferably 60,000 or less. The weight average molecular weight (Mw) of the amphoteric copolymer (I) can be measured, for example, by gel permeation chromatography (GPC) using a liquid chromatograph. The molecular weight of the amphoteric copolymer (I) can be appropriately adjusted by adjusting the type and composition of the monomer, the presence or absence, type and composition of the comonomer, the temperature, time and pressure in the polymerization step, the type and amount of the radical initiator used in the polymerization step, etc.

[0034] The rotational viscosity [η] of the amphoteric copolymer (I) is not particularly limited and can be set appropriately depending on the form of use of the protein adsorption-inhibiting material and its relationship with components other than the amphoteric copolymer (I), but is preferably 10 to 700 mPa·s (25°C), and particularly preferably 10 to 60 mPa·s (25°C). The rotational viscosity [η] can be measured by a method commonly used in the art, for example, by a digital Brookfield viscometer DV-3T manufactured by AMETEK Brookfield, Inc. For the measurement, a ULA adapter is used, and the measurement can be typically performed at a liquid volume of 16 mL and a liquid temperature of 25°C. The rotational viscosity [η] can also be appropriately adjusted by adjusting the dilution concentration, the type and composition of the monomer, the presence or absence, type and composition of the comonomer, the temperature, time and pressure in the polymerization step, the type and amount of the radical initiator used in the polymerization step, etc.

[0035] Method for producing amphoteric copolymer (I) The method for producing the amphoteric copolymer (I) is not particularly limited, and it can be produced by a method conventionally known in the art. For example, it can be produced by copolymerizing an allylamine-based monomer or a diallylamine-based monomer with a monomer having a sulfonic acid group, or, if desired, by further copolymerizing it with other monomers.

[0036] The solvent used in copolymerizing an allylamine-based monomer or a diallylamine-based monomer with a monomer having a sulfonic acid group, or further copolymerizing the monomer with other monomers, is not particularly limited, and may be an aqueous solvent or an organic solvent such as an alcohol, ether, sulfoxide, or amide, but is preferably an aqueous solvent. When an allylamine-based monomer or diallylamine-based monomer is copolymerized with a monomer having a sulfonic acid group, or when further copolymerized with other monomers, the monomer concentration varies depending on the type of monomer and the type of solvent used in the copolymerization, but is typically 10 to 75% by weight in the case of an aqueous solvent. This copolymerization reaction is typically a radical polymerization reaction and is carried out in the presence of a radical polymerization catalyst. The type of radical polymerization catalyst is not particularly limited, and preferred examples include peroxides such as t-butyl hydroperoxide, persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, and water-soluble azo compounds such as azobis and diazo compounds.

[0037] The amount of radical polymerization catalyst added is generally 0.1 to 20 mol %, preferably 1.0 to 10 mol %, based on the total amount of monomers. The polymerization temperature is generally 0 to 100°C, preferably 5 to 80°C, and the polymerization time is generally 1 to 150 hours, preferably 5 to 100 hours. Although the polymerization can be carried out in air without causing any significant problems in polymerization, it can also be carried out in an atmosphere of an inert gas such as nitrogen.

[0038] Protein adsorption suppression material The protein adsorption-inhibiting material of the present invention contains the above-described amphoteric copolymer (I). This amphoteric copolymer (I) may be used as the protein adsorption-inhibiting material as is, or may be mixed with other components or dissolved in other components before use.

[0039] For example, when the protein adsorption-inhibiting material of the present invention is used as a material for inhibiting the adsorption of biological components, a surface protective agent for medical devices, an antifouling coating agent for transparent materials, etc., it is preferable to prepare an aqueous solution in which the amphoteric copolymer (I) is dissolved in an aqueous solvent, from the viewpoint of ease of application to components, substrates, etc. to which protein adsorption-inhibiting properties should be imparted. As the aqueous solvent, water, saline solution, etc. can be used, but pure water, physiological saline, etc. are preferred from the viewpoint of avoiding adverse effects on components, substrates, etc. and on analysis, etc. In this case, the amount of amphoteric copolymer (I) used is not particularly limited, and may be appropriately determined depending on the form of use, such as a biological component adsorption-inhibiting material, a surface protective agent for medical devices, or an antifouling coating agent for transparent materials, and the type of component or substrate to which protein adsorption-inhibiting performance should be imparted. For example, the amphoteric copolymer (I) can be used in an amount that results in a concentration of 0.1 to 50% by mass, and preferably 0.2 to 40% by mass.

[0040] The protein adsorption-inhibiting material of the present invention can also be added to detergents, paints, and the like to impart protein adsorption-inhibiting properties to these materials. In such cases, the amphoteric copolymer (I) can also be used in appropriate combination with solvents, surfactants, pigments, dyes, preservatives, and the like. In this case, the amount of amphoteric copolymer (I) used is not particularly limited and may be appropriately set depending on the form of use such as a cleaning agent, paint, etc. For example, the amphoteric copolymer (I) can be used in an amount such that the concentration thereof becomes 0.1 to 50% by mass, and it is preferably used in an amount such that the concentration becomes 0.2 to 40% by mass.

[0041] The protein-adsorption-inhibiting material of the present invention contains an amphoteric copolymer (I) that has high structural stability due to the cationic structural unit (1) and the anionic structural unit (2) being bonded via a strong covalent bond. This allows for a high degree of freedom in terms of usage conditions and form, and makes it possible to impart protein adsorption-inhibiting properties to a variety of materials and their surfaces. Therefore, the material can be suitably used in a variety of applications, such as a material for inhibiting the adsorption of biological components, a surface protective agent for medical devices, and an antifouling coating agent for transparent materials. The antifouling coating agent for transparent materials, which is one embodiment of the present invention, can be particularly suitably applied to antifouling coatings on various transparent materials such as window glass and touch panels.

[0042] The protein adsorption-inhibiting material of the present invention offers a high degree of freedom in design, and its protein adsorption-inhibiting performance can be controlled to a desired level by appropriately adjusting the structures, copolymerization ratios, etc. of the cationic structural unit (1) and the anionic structural unit (2). Therefore, it can be used to inhibit the adsorption of various proteins, and there are no particular restrictions on the proteins whose adsorption can be inhibited. For example, it can be effectively used to inhibit the adsorption of proteins with an isoelectric point of 4 to 12. It is more preferable that it be particularly effective in inhibiting the adsorption of proteins with an isoelectric point of 6 to 12, and particularly preferably that it is particularly effective in inhibiting the adsorption of proteins with an isoelectric point of 10 to 12.

[0043] More specifically, the protein-adsorption-inhibiting material of the present invention can be preferably used to inhibit the adsorption of proteins contained in blood, blood cells (red blood cells, white blood cells, platelets), plasma, serum, urine, saliva, cells, enzymes, antibodies, nucleic acids (DNA, RNA), viruses, polypeptides, glycoproteins, etc. More specifically, the protein adsorption-inhibiting material of the present invention can be particularly preferably used to inhibit the adsorption of fibrinogen, albumin, (α1, α2, β, and γ) globulin, lysozyme, and the like.

[0044] The ability to inhibit adsorption of proteins with an isoelectric point of 4 to 12 can be evaluated using, for example, bovine serum albumin (isoelectric point: 4.7 to 4.9), bovine plasma fibrinogen (isoelectric point: 6.8 to 8.2), and / or hen egg white lysozyme (isoelectric point: 11.1 to 11.35). More specifically, the ... the method described in the Examples of the present application. [Example]

[0045] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any sense.

[0046] (Production Example 1) A solution containing 74 parts of a 57% by weight aqueous solution of allylamine hydrochloride (AA-HCl), 70 parts of sodium allylsulfonate (SAS), and 126 parts of distilled water was heated to 60°C. After the temperature stabilized, 2.4 parts of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (V-50) was added as a polymerization initiator to initiate polymerization. Subsequently, 2.4 parts of V-50 were added at 3 and 6 hours after the start of the reaction. After adding all the initiator, the mixture was heated and stirred at 60°C overnight. The next day, GPC analysis confirmed that the yield was sufficiently high. The heating was then stopped to terminate the reaction, yielding an AA-HCl·SAS copolymer (AA-HCl:SAS copolymer molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) based on GPC analysis before the end of the reaction was 94%.

[0047] (Production Example 2) Polymerization was carried out in the same manner as in Production Example 1, except that 85 parts by mass of a 66% by mass aqueous solution of diallylamine hydrochloride (hereinafter also referred to as "DAA-HCl") was used instead of 74 parts by mass of the 57% by mass aqueous solution of AA-HCl, to obtain a DAA-HCl·SAS copolymer (DAA-HCl:SAS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 100%.

[0048] (Production Example 3) Polymerization was carried out in the same manner as in Production Example 1, except that 33 parts by mass of a 67% by mass aqueous solution of diallylmethylamine hydrochloride (hereinafter also referred to as "DAMA-HCl") was used instead of 74 parts by mass of the 57% by mass aqueous solution of AA-HCl, to obtain a DAMA-HCl·SAS copolymer (DAMA-HCl:SAS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 95%.

[0049] (Production example 4a) Polymerization was carried out in the same manner as in Production Example 1, except that 87 parts by mass of a 65% by mass aqueous solution of diallyldimethylammonium chloride (hereinafter also referred to as "DADMAC") was used instead of 74 parts by mass of the 57% by mass aqueous solution of AA-HCl, to obtain a DADMAC-SAS copolymer (DADMAC:SAS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) based on GPC analysis before the end of the reaction was 100%.

[0050] (Production example 4b) Polymerization was carried out in the same manner as in Production Example 3a, except that 124 parts by mass of a 65% by mass DADMAC aqueous solution was used, to obtain a DADMAC-SAS copolymer (DADMAC:SAS copolymerization molar ratio 2:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) based on GPC analysis before the end of the reaction was 100%.

[0051] (Production example 4c) Polymerization was carried out in the same manner as in Production Example 3a, except that 62 parts by mass of a 65% by mass DADMAC aqueous solution was used, to obtain a DADMAC-SAS copolymer (DADMAC:SAS copolymerization molar ratio 1:2). The yield (polymer peak area / (polymer peak area + monomer peak area)) based on GPC analysis before the end of the reaction was 100%.

[0052] (Production Example 5) 33 parts by weight of a 57% by weight aqueous solution of allylamine hydrochloride was dissolved in 42 parts by weight of distilled water and heated to 60°C. After the temperature stabilized, an aqueous solution of 42 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid (hereinafter also referred to as "AMPS") dissolved in 61 parts by weight of distilled water was added dropwise using a metering pump, and 1.1 parts by weight of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (commonly known as "V-50") was added as an initiator to initiate polymerization. Subsequently, 1.1 parts by weight of V-50 was added every 2, 4, and 6 hours after the start of the reaction to continue the polymerization. After the dropwise addition of the AMPS aqueous solution was completed, the mixture was heated and stirred at 60°C overnight. The next day, GPC measurement confirmed a sufficiently high yield, and the heating was stopped to terminate the reaction, yielding an AA-HCl·AMPS copolymer (AA-HCl:AMPS copolymer molar ratio 1:1). The yield (polymer peak area / monomer peak area) according to GPC analysis before the end of the reaction was 94%.

[0053] (Production Example 6) Polymerization was carried out in the same manner as in Production Example 5, except that 41 parts by mass of a 66% by mass DAA-HCl aqueous solution was used instead of 33 parts by mass of the 57% by mass AA-HCl aqueous solution, to obtain a DAA-HCl-AMPS copolymer (DAA-HCl:AMPS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 95%.

[0054] (Production Example 7) Polymerization was carried out in the same manner as in Production Example 5, except that 44 parts by mass of a 67% by mass DAMA-HCl aqueous solution was used instead of 33 parts by mass of the 57% by mass AA-HCl aqueous solution, to obtain a DAMA-HCl-AMPS copolymer (DAMA-HCl:AMPS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 97%.

[0055] (Production example 8a) Polymerization was carried out in the same manner as in Production Example 5, except that 50 parts of a 65% by mass aqueous solution of DADMAC was used instead of 33 parts by mass of the 57% by mass aqueous solution of AA-HCl, to obtain a DADMAC-AMPS copolymer (DADMAC:AMPS copolymerization molar ratio 1:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 95%.

[0056] (Production example 8b) Polymerization was carried out in the same manner as in Production Example 8a, except that 99 parts by mass of a 65% by mass DADMAC aqueous solution was used, to obtain a DADMAC-AMPS copolymer (DADMAC:AMPS copolymerization molar ratio 2:1). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 97%.

[0057] (Production example 8c) Polymerization was carried out in the same manner as in Production Example 8a, except that 25 parts by mass of a 65% by mass DADMAC aqueous solution was used, to obtain a DADMAC-AMPS copolymer (DADMAC:AMPS copolymerization molar ratio 1:2). The yield (polymer peak area / (polymer peak area + monomer peak area)) determined by GPC analysis before the end of the reaction was 96%.

[0058] (Mixed solution 1) A 28% by mass DADMAC homopolymer aqueous solution (PAS-H-5L, manufactured by Nitto-Bo Medical) diluted with ultrapure water to 0.05% by mass was mixed with a 10% by mass AMPS homopolymer aqueous solution (manufactured by Thermo Fisher Scientific Inc.) diluted with ultrapure water to 0.05% by mass in a volume ratio of 8.5:10 to prepare mixed solution 1 (DADMAC:AMPS molar ratio 1:1).

[0059] Example 1 The AA-HCl·SAS copolymer produced in Production Example 1 above was used to evaluate its protein adsorption inhibitory performance according to the following procedure. (Preparation of 0.5 wt% copolymer solution) 1) The AA-HCl·SAS copolymer sample prepared in Preparation Example 1 above was placed in a 10 mL volumetric flask using a micropipette and diluted with ultrapure water to a final concentration of 1.0 wt%. 2) The pH of the polymer sample prepared in 1) above was measured. 3) 500 μL of the 1.0 wt% copolymer solution prepared in 1) above was placed in a 1.5 mL microtube, and 500 μL of ultrapure water was added to prepare a copolymer solution with an ionic strength of 0 μM. Similarly, 500 μL of the 1.0 wt% copolymer solution prepared in 1) above was placed in a 1.5 mL microtube, and 450 μL of ultrapure water and 50 μL of NaCl solution of the corresponding concentration were added to prepare copolymer solutions with ionic strengths of 0.1 μM, 1 μM, 10 μM, and 100 μM. (Coating for water-repellent printed glass) 1) A 24-hole highly water-repellent microslide glass (Matsunami Glass Industry Co., Ltd., TF2404) was treated with ozone for 1.5 hours using a UV ozone cleaner. 2) 10 μL (n=6) of the 0.5 wt % copolymer solution prepared above was applied to each well of the slide glass. 3) The slide glass from 2) above was incubated in a humidified dish at 35°C for 30 minutes. 4) The applied polymer solution was absorbed, and each hole was washed twice with 20 μL of a solution of each ionic strength (ultrapure water for an ionic strength of 0 μM, and NaCl solutions of each concentration for ionic strengths of 0.1 μM, 1 μM, 10 μM, and 100 μM), followed by washing twice with 20 μL of pure water. 5) After the cleaning solution was completely absorbed, the slide glass was placed in a slide glass case and subjected to ultrasonic treatment twice for 5 minutes in pure water (30°C, Hi mode, 43 Hz), and then dried with N2 gas. (Preparation method of fluorescently labeled proteins) Protein (bovine serum albumin (BSA) or hen egg white lysozyme (HEWL)) was dissolved in 50 mM carbonate buffer (pH 10.00), and fluorescein-4-isothiocyanate (FITC, Dojindo Laboratories) was added with stirring under ice bath cooling. After stirring for 1 hour under ice bath cooling and then for 4 hours at room temperature, a fluorescently labeled protein solution was obtained by size exclusion chromatography using Sephadex G-25. (Protein adsorption experiment) 1) The fluorescently labeled protein was adjusted to 1.0 mg / mL in phosphate buffered saline, and the pH was measured. 2) 10 μL of the fluorescently labeled protein solution prepared in 1) was applied to each well of the slide glass that had been contacted with the polymer solution in the above procedure and the uncoated slide glass. 3) The slide glass from 2) above was incubated in a humidified dish at 35°C for 6 hours. 4) The applied fluorescently labeled protein solution was absorbed, and each well was washed twice with 20 μL of phosphate-buffered saline, then twice with pure water, and then dried. 5) The fluorescently labeled proteins adsorbed on the surface of the slide glass were observed using a fluorescence microscope (BX51WI, manufactured by OLIMPUS), and the fluorescence intensity was recorded. The fluorescence intensity of each protein was calculated by dividing the fluorescence intensity when coated by the fluorescence intensity when uncoated. The results are shown in Table 1.

[0060] Examples 2, 3 and 4a The protein adsorption inhibitory performance was evaluated in the same manner as in Example 1, except that the AA-HCl·SAS copolymer produced in Production Example 1 was replaced with the DAA-HCl·SAS copolymer produced in Production Example 2, the DAMA-HCl·SAS copolymer produced in Production Example 3, and the DADMAC-HCl·SAS copolymer produced in Production Example 4a, respectively. The results are shown in Table 1. [Table 1]

[0061] Examples 4b and 4c The protein adsorption inhibitory performance was evaluated in the same manner as in Example 1, except that the AA-HCl·SAS copolymer produced in Production Example 1 was replaced with the DADMAC-HCl·SAS copolymers produced in Production Examples 4b and 4c, respectively. The results are shown in Table 2 together with the results of Example 4a. [Table 2]

[0062] (Examples 5 to 7, and 8a) The protein adsorption inhibitory performance was evaluated in the same manner as in Example 1, except that the AA-HCl·AMPS copolymer produced in Production Example 5, the DAA-HCl·AMPS copolymer produced in Production Example 6, the DAMA-HCl·AMPS copolymer produced in Production Example 7, and the DADMAC-HCl·AMPS copolymer produced in Production Example 8a were used instead of the AA-HCl·SAS copolymer produced in Production Example 1. The results are shown in Table 3.

[0063] (Comparative Example 1) The protein adsorption inhibitory performance was evaluated in the same manner as in Example 1, except that mixed solution 1 was used instead of the AA-HCl·SAS copolymer produced in Production Example 1. The results are shown in Table 3. [Table 3]

[0064] Examples 8b and 8c The protein adsorption inhibitory performance was evaluated in the same manner as in Example 1, except that the AA-HCl·SAS copolymer produced in Production Example 1 was replaced with the DADMAC·AMPS copolymers produced in Production Examples 8b and 8c, respectively. The results are shown in Table 4 together with the results of Example 8a. [Table 4] [Industrial Applicability]

[0065] The protein adsorption-inhibiting material of the present invention has excellent protein adsorption-inhibiting performance, a high degree of freedom in terms of usage conditions and form, and is capable of imparting protein adsorption-inhibiting performance to a variety of materials and their surfaces. It also has a high degree of design freedom, allowing the protein adsorption-inhibiting performance to be controlled to a desired level, making it highly valuable in practical applications. Therefore, the material can be suitably used in a variety of applications, such as a material for inhibiting the adsorption of biological components, a surface protective agent for medical devices, and an antifouling coating for transparent materials, and is highly applicable in various industrial fields, including medical devices, pharmaceuticals, life sciences, analytical instruments, food, sanitation, and distribution.

Claims

1. A protein adsorption-inhibiting material containing an amphoteric copolymer (I) having a cationic structural unit (1) containing an amino group in its structure and an anionic structural unit (2), The protein adsorption-inhibiting material described above, wherein at least a portion of the cationic structural units (1) are structural units (i) having a structure derived from an allylamine-based monomer or a diallylamine-based monomer, or a structure of an inorganic acid salt or organic acid salt thereof, and at least a portion of the anionic structural units (2) are structural units (ii) having a structure derived from a monomer having a sulfonic acid group or a salt thereof.

2. 2. The protein adsorption-inhibiting material according to claim 1, wherein the molar ratio of the cationic structural units (1) to the anionic structural units (2) in the amphoteric copolymer (I) is from 4:1 to 1:

4.

3. 3. The protein adsorption-inhibiting material according to claim 1 or 2, wherein at least a portion of the structural units (i) are structural units having a structure derived from an allylamine-based monomer or diallylamine-based monomer having at least one amino group selected from the group consisting of a secondary amino group, a tertiary amino group, and a quaternary amino group, or a structure which is an inorganic acid salt or an organic acid salt thereof.

4. 3. The protein adsorption-inhibiting material according to claim 1, wherein at least a portion of the structural units (i) have a structure that is an inorganic acid salt or an organic acid salt derived from an allylamine-based monomer or a diallylamine-based monomer.

5. 3. The protein adsorption-inhibiting material according to claim 1, wherein at least a portion of the structural units (ii) are structural units having a structure derived from allylsulfonic acid or acrylamidosulfonic acid, or a salt thereof.

6. 6. The protein adsorption-inhibiting material according to claim 5, wherein at least a portion of the structural units (ii) are structural units having a structure derived from acrylamidoalkylsulfonic acid.

7. 3. The protein adsorption-inhibiting material according to claim 1, which is used to prevent adsorption of proteins having an isoelectric point of 4 to 12.

8. A biological component adsorption-inhibiting material, a surface protecting agent for medical instruments, or an antifouling coating agent for transparent materials, comprising the protein adsorption-inhibiting material according to claim 1 or 2.

9. The antifouling coating agent for transparent materials according to claim 8, which is used for transparent materials such as window glass or touch panels.

Images