JP2009125265A - Cytokine absorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent for cytokine which is useful as an absorbent for removing cytokine from liquid containing physiological substance such as body fluid and/or cells, and is composed of cross-linked polymer particles. <P>SOLUTION: The cross-linked polymer particles contain a vinyl alcohol unit and a compound unit containing nitrogen as structural elements. In the cytokine absorbent comprising cross-linked polymer particles, a nitrogen content against particle gross weight in dry weight specified by an ultimate analysis ranges from 7.0 to 30.0 wt.% and a surface nitrogen density specified by an X-ray photoelectro spectroscopy analysis with respect to a particle surface ranges from 9.0 to 30.0 at%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a crosslinked polymer particle that adsorbs and removes cytokines from a liquid containing physiological substances and / or cells, particularly from a culture medium and / or body fluid such as blood and plasma.

  Cytokines are a general term for proteins secreted from cells and transmitting information to specific cells. Cytokines are classified according to their functions, interleukins (secreted by leukocytes and functioning to regulate the immune system), chemokines (inducing leukocyte migration), interferons (having viral growth inhibition and cell growth suppression functions), hematopoiesis Factors (promoting blood cell differentiation / proliferation), cell growth factors (promoting proliferation of specific cells), tumor necrosis factors (inducing cell death of specific cells), etc.

  In recent years, anti-cytokine therapy that inhibits the function of specific cytokines has been widely used as a treatment method for intractable autoimmune diseases and the like that cannot be sufficiently treated by ordinary drug therapy. The most representative of this anti-cytokine therapy is a treatment method by administering an antibody against a cytokine present in the blood of a patient, and its effect has already been recognized for several intractable diseases. However, antibody preparations such as those described above have safety problems such as an increased risk of infectious diseases, and currently there is no treatment in which a plurality of antibody preparations are administered simultaneously. On the other hand, the cytokine network in the blood is composed of very many types of cytokines, and there is a disease that does not lead to a therapeutic effect when the physiological action of one type of cytokine is inhibited (Non-patent Document 1).

Patent Documents 1 and 2 describe adsorbents that adsorb and remove multiple types of cytokines from body fluids. However, the production process of the adsorbent includes a complicated process such as immobilization of a ligand used for adsorption, and has a problem that its production is difficult.
Internal medicine vol. 98, no. 2,313-317 (2006) JP 08-257398 A JP 08-257115 A

  An object of the present invention is to provide an adsorbent for cytokine comprising crosslinked polymer particles, which is useful as an adsorbent for removing cytokine from a fluid containing physiological substances such as body fluids and / or cells.

  As a result of intensive investigations to solve the problems in production of the adsorbent, the present inventors have surprisingly performed treatment such as ligand immobilization by using the crosslinked polymer particles of the present invention. It was clarified that inflammatory cytokines can be adsorbed without performing treatment.

  That is, the present invention is a crosslinked polymer particle comprising vinyl alcohol units and nitrogen-containing polymer units as constituents, and the nitrogen content relative to the total weight of the particles in a dry weight specified by elemental analysis is 7.0 to 7.0. The present invention relates to a cytokine adsorbent comprising 30.0 wt% of crosslinked polymer particles having a surface nitrogen concentration of 9.0 to 30.0 at% specified by X-ray photoelectron spectroscopy on the particle surface.

  Further, the present invention is a crosslinked polymer particle comprising a synthetic polymer containing vinyl alcohol units and nitrogen-containing polymer units as constituents, and the ratio of polymer units containing nitrogen to all polymer units constituting the cross-linked polymer particles 40.0 to 100.0% by weight, and relates to an adsorbent for cytokines comprising crosslinked polymer particles in which the ratio of nitrogen-containing polymerized units on the surface of the crosslinked polymer particles is 55.0 to 100.0% by weight.

  Further, a part of the carboxylic acid vinyl ester unit of the crosslinked polymer containing a carboxylic acid vinyl ester unit obtained by polymerization of a monomer mixture containing a vinyl alcohol unit and a vinyl compound having a carboxylic acid vinyl ester and a triazine ring, or The present invention relates to a cytokine adsorbent comprising the above-mentioned crosslinked polymer particles formed by hydrolysis and / or transesterification.

  Further, the present invention is directed to adsorption of a cytokine comprising the above-mentioned crosslinked polymer particles having a polymerization conversion rate of 10 to 80% in the polymerization of a monomer mixture containing a vinyl compound having a carboxylic acid vinyl ester and a triazine ring. Regarding materials.

  The present invention also relates to a cytokine adsorbent comprising the crosslinked polymer particles, wherein the crosslinked polymer particles have a volume average particle diameter of 50 to 3000 μm.

  The present invention also relates to a cytokine adsorbent comprising the above-mentioned crosslinked polymer particles having a volume average particle size of 150 to 3000 μm and particles having a particle size of less than 100 μm of 5% by volume or less.

  In the present invention, the liquid column of the monomer mixture ejected from the nozzle hole into the dispersion medium is regularly vibrated to form droplets having a uniform diameter in the dispersion medium. The present invention relates to an adsorbent for cytokine comprising the above-mentioned crosslinked polymer particles by polymerizing them under conditions that do not cause coalescence or additional dispersion.

  The present invention also relates to a body fluid treatment material comprising the cytokine adsorbent.

  Provided is a cytokine-adsorbing material using crosslinked polymer particles that can be removed from a liquid containing physiological substances such as body fluids and / or cells, which can be produced without complicated processes such as ligand immobilization.

  In the crosslinked polymer particle containing the vinyl alcohol unit and the nitrogen-containing polymer unit as constituents in the present invention, the nitrogen content in the dry weight specified by elemental analysis is preferably 7.0 to 30.0% by weight. Yes, more preferably 10.0 to 30.0% by weight, still more preferably 10 to 20% by weight.

  In the crosslinked polymer particles, the surface nitrogen concentration specified by X-ray photoelectron spectroscopy (XPS) is preferably 9.0 to 30.0 at%, more preferably 10.0 to 30.0 at%, More preferably, it is 10-20 at%.

  In the crosslinked polymer particle containing the vinyl alcohol unit and nitrogen-containing polymer unit of the present invention as constituent elements, the ratio of the polymer unit containing nitrogen to the total polymer units constituting the polymer particle is preferably 40.0 to 100. 0.0 wt%, more preferably 65.0 to 100.0 wt%.

  In the crosslinked polymer particle, the ratio of the polymerized units containing nitrogen on the particle surface is preferably 55.0 to 100.0% by weight, more preferably 60.0 to 100.0% by weight.

  Here, when the ratio of the nitrogen-containing polymerized units on the particle surface is less than 55.0 wt%, or when the surface nitrogen concentration specified by XPS is less than 9.0 at%, the cytokine adsorption ability Tends to be low, which is not preferable. On the other hand, when the nitrogen content in the dry weight specified by elemental analysis is less than 7.0% by weight, or the ratio of polymerized units containing nitrogen to all polymerized units constituting the crosslinked polymer particles is 60.0% by weight. If it is less than%, the cytokine adsorption ability is lowered, which is not preferable. On the other hand, when the nitrogen content in the dry weight specified by elemental analysis exceeds 20.0% by weight, or when the surface nitrogen concentration specified by XPS exceeds 20.0 at%, the crosslinked polymer particles tend to become brittle. Is not preferable.

  Although the crosslinked polymer particles of the present invention are usually used in an aqueous medium, the surface nitrogen concentration specified by X-ray photoelectron spectroscopy (XPS) referred to in the present invention is the t-butyl alcohol freeze-drying method, etc. Is the nitrogen concentration on the surface of the crosslinked polymer particles identified by conducting surface elemental analysis by XPS on the crosslinked polymer particles substantially completely dried while maintaining the particle structure in water.

  In the crosslinked polymer particle of the present invention, when the polymerized unit constituting the crosslinked polymer particle is known, nitrogen on the surface of the crosslinked polymer particle is contained from the surface nitrogen concentration specified by the surface element analysis by XPS. It is possible to calculate the proportion of polymerized units.

  In the present invention, the nitrogen content in the dry weight specified by elemental analysis means that the cross-linked polymer particles that have been sufficiently washed are substantially completely dried by vacuum drying or the like, and then the element is obtained by a CHN coder or the like. It is the nitrogen content in the dry weight of the crosslinked polymer particle specified by performing the analysis. Synthetic polymers containing vinyl alcohol units are water-absorbing and moisture-absorbing and require attention to water content, but the presence or absence of water content in the sample can be confirmed by the Karl Fischer method or the like.

  In the crosslinked polymer particle of the present invention, when the polymerized unit constituting the crosslinked polymer particle is known, the total polymerization constituting the crosslinked polymer particle is determined from the nitrogen content in the dry weight specified by elemental analysis. It is possible to calculate the ratio of polymerized units containing nitrogen to units.

  For example, even when a certain polymerization unit is introduced by copolymerization, the composition of the copolymer to be produced does not necessarily match the charged composition of the monomer when the polymerization conversion is less than 100%. Therefore, it is necessary to determine the nitrogen content or the proportion of polymerized units containing nitrogen for those actually used as the adsorbent / treatment material.

  The cross-linked polymer particles of the present invention are obtained by polymerizing a monomer mixture containing at least a monomer that gives a vinyl alcohol unit and a monomer containing nitrogen to form a cross-linked polymer, and then a single amount that gives a vinyl alcohol unit. From the viewpoint of the design of polymer particles, crosslinked polymer particles in which a part or all of the body units are vinyl alcohol units by a chemical reaction or the like are preferable. The monomer mixture may contain other monomers, a non-polymerizable liquid, a linear polymer, a polymerization initiator and the like as necessary.

  Preferred examples of the monomer that gives a vinyl alcohol unit include carboxylic acid vinyl esters. Examples of carboxylic acid vinyl esters preferably used in the present invention include aliphatic carboxylic acid vinyl ester compounds such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl caproate, and divinyl adipate, vinyl benzoate, and phthalate. Examples thereof include aromatic carboxylic acid vinyl ester compounds such as vinyl acid. Of these, aliphatic carboxylic acid vinyl ester compounds such as vinyl acetate and vinyl propionate are more preferable, and vinyl acetate is most preferable from the viewpoint of ease of polymerization and saponification / ester exchange reaction and economical efficiency. One type of carboxylic acid vinyl ester may be used, or two or more types may be used in combination.

  As the nitrogen-containing monomer of the present invention, a monomer having a triazine ring is preferable because of its high ability to adsorb cytokines. Preferable examples of the nitrogen-containing monomer include vinyl compounds having a triazine ring such as triallyl cyanurate, triallyl isocyanurate, and trimethallyl isocyanurate. From the viewpoint of good physical or chemical stability. Isocyanurates such as triallyl isocyanurate and trimethallyl isocyanurate are particularly preferred, and triallyl isocyanurate is most preferred from the viewpoint of ease of handling. One type of monomer containing nitrogen may be used, or two or more types may be used in combination.

  As the monomer other than the monomer used in the present invention, a monomer that can be directly or indirectly copolymerized with the monomer can be used, and may be used as necessary. It is not necessary to use it.

  Such monomers include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, alkyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, polyoxyethylene Acrylic acid such as monoacrylate and polyoxypropylene monoacrylate and esters thereof, methacrylic acid, methyl methacrylate, butyl methacrylate, alkyl methacrylate, t-butyl methacrylate, methoxyethyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, glycerol monomethacrylate, polyethylene glycol Methacrylic acid and its esters such as nonmethacrylate and tetrahydrofurfuryl methacrylate, aromatic vinyl compounds such as styrene, methylstyrene, ethylstyrene and styrenesulfonate, and vinyl compounds such as vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. can give. And / or a polyfunctional vinyl compound such as the following can be used. These monomers can be used alone or in combination of two or more as required.

  The crosslinked structure in the crosslinked polymer particle of the present invention can be obtained, for example, by copolymerizing a polyfunctional vinyl compound. Examples of the polyfunctional vinyl compound include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyalkylene glycol diacrylate, polyalkylene glycol dimethacrylate, 1.3-butylene glycol dimethacrylate, 1 .6-Hexanediol diacrylate, glycerol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, acrylates and methacrylates such as pentaerythritol triacrylate, dipentaerythritol hexaacrylate, butanediol divinyl ether, diethylene glycol divinyl ether Divinyl A Le ethers, divinyl benzene, aromatics such as divinyl naphthalene, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, allyl compounds such as diallyl phthalate and the like. Among them, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate are easy to obtain high mechanical strength and dense pore structure. A compound having a trifunctional or higher functional crosslinkable vinyl group such as the above is more preferable. Furthermore, when the crosslinked structure in the crosslinked polymer particle of the present invention is formed from polymerized units containing nitrogen, it is particularly preferable because of its large ability to adsorb pathogenic substances in blood. Therefore, as described above, polyfunctional vinyl compounds having a triazine ring such as triallyl cyanurate, triallyl isocyanurate, and trimethallyl isocyanurate are particularly preferred, and triallyl isocyanurate is most preferred. One kind of these crosslinkable monomers may be used, or two or more kinds may be used in combination.

  In polymerizing a monomer mixture containing at least a vinyl compound having a carboxylic acid vinyl ester and a triazine ring, 20 to 200 weight parts of a vinyl compound having a triazine ring is used for particle formation with respect to 100 parts by weight of the carboxylic acid vinyl ester. It is preferable to use parts. More preferably, it is 50-200 weight part. When the amount of the vinyl compound having a triazine ring is less than 40 parts by weight with respect to 100 parts by weight of the carboxylic acid vinyl ester for forming the core particle, the adsorbing ability of cytokine tends to be lowered, which is not preferable. On the other hand, when the amount of the vinyl compound having a triazine ring exceeds 200 parts by weight, the particles become brittle, which is not preferable.

  Examples of the polymerization initiator used in the present invention include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2- Azo compounds such as methylbutyronitrile), 2,2′-azobis (2-methylpropionamidine) dihydrochloride, benzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate, t-butyl perpivalate, Organic peroxides such as t-butylperoxyisopropyl carbonate, t-butylperoxyacetate, t-butylperoxy-3,3,5-trimethylcyclohexane, and the like can be mentioned, but are not limited to the above. Absent. A polymerization initiator that is soluble in the monomer mixture is preferable because the polymerization reaction proceeds smoothly. In addition, those that are insoluble in the dispersion medium or have low solubility in the dispersion medium are preferable because they produce less fine particles.

  Here, the polymerization initiator is designed so as to obtain a predetermined polymerization conversion rate in consideration of the characteristics as a polymerization initiator such as reactivity with the monomer and the decomposition rate, and reaction conditions such as polymerization time and polymerization temperature. The amount and type of use are preferably selected for the core and shell portions, and can be used alone or as a mixture of two or more. The polymerization temperature is preferably in the range of 0 to 180 ° C., more preferably 20 to 120 ° C., further preferably 40 to 90 ° C., and most preferably 50 to 70 ° C. from the viewpoint of control of the polymerization reaction. is there. It is preferable to select a polymerization temperature suitable for the core particle formation and the shell formation.

  The crosslinked polymer particles of the present invention can adopt a porous structure. Due to the porous structure, the contact area with the liquid to be treated can be greatly increased, and the target substance can be treated more efficiently. Bulk specific gravity can be used as a porous index, and the bulk specific gravity is preferably 0.05 to 0.40 g / mL, and more preferably 0.10 to 0.30 g / mL. Specifically, the measurement of bulk specific gravity is the dry solid weight per 1 mL of sedimentation volume of particles that are uniformly settled in water by tapping or the like.

  In the crosslinked polymer particles of the present invention, a non-polymerizable liquid can be used in the monomer mixture for introducing a porous structure. In order to obtain a uniform porous structure, the non-polymerizable liquid is preferably soluble in the monomer mixture and insoluble or hardly soluble in the dispersion medium. Specific examples include aromatic hydrocarbons such as toluene, xylene and benzene, aliphatic hydrocarbons such as hexane, heptane, pentane and octane, ester compounds such as ethyl acetate, n-butyl acetate and n-hexyl acetate, dibutyl ether and the like Ethers, alcohols such as n-heptanol and amyl alcohol, ketones such as methyl isobutyl ketone, and the like, but are not limited thereto.

  As the polymerization proceeds, the non-polymerizable liquid and the residual monomer are phase-separated from the generated crosslinked polymer and particles to form pores. Therefore, the structure and size of the pores are greatly affected by the amount of non-polymerizable liquid used and the difference in affinity between the non-polymerizable liquid and the resulting crosslinked polymer. For example, if a non-polymerizable liquid having a lower affinity with the produced polymer is selected, the porous structure formed in the crosslinked polymer particles has a larger pore size. One type of non-polymerizable liquid may be used, or two or more different types may be mixed, and the affinity with the produced polymer is changed depending on the type and mixing ratio, and the porous structure such as pore diameter is adjusted. It is possible. Furthermore, it is possible to adjust the porous structure such as the pore volume by changing the amount of the non-polymerizable liquid used.

  The preferred use amount of the non-polymerizable liquid is 50 to 400 parts by weight, and more preferably 100 to 300 parts by weight or less. If the amount of the non-polymerizable liquid used exceeds 400 parts by weight, the strength tends to be insufficient, and if it is less than 50 parts by weight, it is difficult to become porous.

  In addition, a linear polymer can be used for the crosslinked polymer particles of the present invention in order to introduce a porous structure. The linear polymer referred to in the present invention refers to a polymer that is substantially non-crosslinked, may contain a branched structure, and may contain some crosslinked structure as long as it is soluble in a solvent. The linear polymer used in the present invention is an important component that determines the structure of the pore portion along with the non-polymerizable liquid. For example, the pore diameter of the crosslinked polymer particles obtained by increasing the amount of the linear polymer used increases, and the pore diameter of the crosslinked polymer particles obtained by increasing the average degree of polymerization of the linear polymer increases. By using a combination of a non-polymerizable liquid and a linear polymer, it becomes easier to control the porous structure of the crosslinked polymer particles.

  Specific examples of the linear polymer include ester resins such as polyvinyl acetate, acrylic resins such as polymethyl methacrylate and polyacrylonitrile, aromatic resins such as polystyrene, halogen resins such as polyvinyl chloride, and polybutadiene. Examples thereof include diene resins, and copolymers and blends thereof, but there are no particular restrictions as long as they are soluble in the monomer mixture, and polymers other than these can also be used.

  The preferred use amount of the linear polymer is 1 to 100 parts by weight, more preferably 2 to 40 parts by weight for forming the core particles, and more preferably 0 to 100 parts by weight for forming the shell. Is 0 to 40 parts by weight.

  Moreover, the preferable average degree of polymerization of a linear polymer is 100-5000, More preferably, it is 150-3000, Especially preferably, it is 200-1500, Most preferably, it is 300-1000.

  When the amount of the linear polymer used exceeds 100 parts by weight or when the average degree of polymerization exceeds 5000, the viscosity of the monomer mixture increases and handling becomes difficult. In addition, agglomerates are easily formed during the polymerization.

  For the formation of the crosslinked polymer particles of the present invention, general suspension polymerization can be used, but in suspension polymerization, droplets of the monomer mixture are dispersed in the dispersion medium by mechanical stirring using a stirring blade or the like. At that time, the droplets are divided by stirring and become smaller or become larger together with other droplets. Therefore, the obtained polymer particles have a wide particle size distribution including a large amount of large particles and small particles. The particles having a wide particle size distribution obtained by suspension polymerization or the like are preferably used by removing large particles and small particles by classification operation such as sieving.

  More preferably, after droplets of a uniform diameter of the monomer mixture are formed in the dispersion medium, the droplets are polymerized under conditions that do not cause coalescence or additional dispersion, and are processed, modified, and modified. The crosslinked polymer particles obtained by polishing.

  In the present invention, the conditions that do not cause coalescence or additional dispersion are the case where the droplets of the monomer mixture merge with other droplets to form larger droplets, or vice versa. It means a condition that does not generally occur such that it is divided into smaller droplets.

  The uniform diameter referred to in the present invention means that most of the particles have substantially the same diameter as follows and do not contain a large amount of large particles and small particles.

  That is, the polymer particle of the present invention is the above polymer particle in which 80% by volume or more of the particle is in the range of 0.8 to 1.2 times the volume average particle diameter. Here, 80% by volume or more of the particles are preferably in the range of 0.9 to 1.1 times the volume average particle diameter, and 90% by volume or more of the particles have a volume average particle diameter of the particle diameter. More preferably, it is in the range of 0.9 to 1.1 times, and 95% by volume or more of the particles are in the range of 0.9 to 1.1 times the volume average particle size of the particle size. Is particularly preferred, and most preferably has a substantially single particle size.

  When the particle size distribution is wide and small particles less than 0.8 times the volume average particle size or large particles exceeding 1.2 times exceed 20% by volume, even if the volume average particle size is the same The particle gap that becomes the flow path of the liquid to be treated is narrowed. For example, when the adsorbent is packed in a column, the pressure loss during liquid passage tends to increase. Further, when the liquid to be treated contains a cell component, the cell is likely to be activated non-specifically, the permeability of the cell is lowered, or the column is likely to be clogged.

  The crosslinked polymer particles of the present invention having such a uniform diameter give a regular vibration disturbance to the liquid column of the monomer mixture ejected from the nozzle holes into the dispersion medium, thereby causing the liquid droplets of the uniform diameter to be dispersed in the dispersion medium. Once formed therein, polymer particles can be obtained by polymerizing the droplets under conditions that do not substantially cause coalescence or additional dispersion. The crosslinked polymer particles thus obtained have the advantage that the number of large particles and small particles is extremely small and the classification loss can be greatly reduced.

  Hereinafter, the process for forming the crosslinked polymer particles of the present invention will be described. First, droplets of uniform diameter for particle formation are generated in a dispersion medium. As an example of a droplet generator, a nozzle that ejects a monomer mixture is inserted into a column filled with a dispersion medium, and at least one small hole is arranged in the nozzle, and a mechanism for transmitting vibration is installed. Etc. An introduction pipe for supplying a dispersion medium from a dispersion medium tank can be connected to the column, and an introduction pipe for supplying a monomer mixture from a monomer mixture tank can be connected to the nozzle. In order to produce uniform droplets, it is preferable to use a metering pump with as little pulsation as possible to supply the monomer mixture.

  The particle size of the droplet is determined by the nozzle pore size, the nozzle passing speed of the monomer mixture, the viscosity of the monomer mixture and the dispersion medium, and the vibration disturbance applied to the liquid column generated by the monomer mixture passing through the nozzle. It is determined by factors such as type, frequency, and amplitude, and droplets having a desired particle size can be obtained by these factors or a combination thereof. Moreover, the droplet group which has desired particle diameter distribution can be obtained by changing combining one or more of these.

  The nozzle that can be used for droplet formation is not particularly limited, and for example, an orifice having at least one small hole can be used. Such nozzles can be used alone or in combination. As a method of giving vibration disturbance, a method of ejecting the monomer mixture from the nozzle while applying mechanical vibration to the monomer mixture, a method of ejecting the monomer mixture from the nozzle while applying mechanical vibration to the dispersion medium, Although the method etc. which apply mechanical vibration to the nozzle which a monomer mixture ejects can be illustrated, it is not limited to this.

  This is a step of polymerizing the formed droplets of uniform diameter under conditions that do not cause coalescence or additional dispersion. Here, the condition that does not cause coalescence or additional dispersion means that the droplets of the monomer mixture formed by jetting into the dispersion medium from the nozzle holes and being subjected to vibrational disturbance are the other droplets. It means a condition in which it does not substantially occur that the droplets are combined to form a larger droplet, or conversely divided into smaller droplets.

  As a method of polymerizing droplets for forming polymer particles, for example, a method of introducing the previous droplets into the reactor and performing a polymerization reaction while gently stirring the dispersion medium containing the droplets is adopted. You can also. However, if the stirring is insufficient, the droplets are likely to coalesce. Conversely, if the stirring is excessive, additional dispersion is likely to occur. Therefore, the stirring method and conditions need to be appropriately set. For example, when stirring is performed using a stirring blade, it is preferable to select a relatively low shear and high discharge type and adjust the stirring speed. In order to reduce the coalescence and additional dispersion of the droplets, it is preferable to introduce the droplet group into a dispersion medium preliminarily existing in the polymerization reactor, and the droplet generator is used as the polymerization reactor. It is more preferable to connect to the lower part of this through an introduction pipe or the like.

  A dispersion medium that forms a continuous phase is not miscible with a monomer mixture that forms droplets, and an aqueous medium is preferably used in terms of safety, economy, and environment. The dispersion medium can contain a dispersion stabilizer. The dispersion stabilizer is not particularly limited, and those commonly used in suspension polymerization can be used. For example, a dispersion stabilizer soluble in a dispersion medium, a fine solid dispersion stabilizer, an interface, and the like. An activator or the like can be used. These may be used alone, but a greater effect can be obtained by using them in combination. Moreover, you may use an adjuvant together. In addition, if dispersion stability is insufficient, droplet coalescence tends to occur, and conversely, if dispersion stability is excessive, additional dispersion is likely to occur. It is necessary to pay attention to the usage. A more preferable method is to form a droplet group of the monomer mixture in the dispersion medium in the presence of a dispersion stabilizer soluble in the dispersion medium. In this method, a fine particle solid dispersion stabilizer is added and / or the droplet group is polymerized in the presence of a salt.

  As the dispersion stabilizer soluble in the dispersion medium, a polymer protective colloid is preferably used. Specific examples include water-soluble synthetic polymers such as polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone, and sodium polyacrylate, water-soluble cellulose derivatives such as methyl cellulose, carboxymethyl cellulose, and hydroxyethyl cellulose, and water-soluble natural polymers such as starch and gelatin. Can give. These may be used alone or in combination of two or more. A preferable amount of the dispersion stabilizer soluble in the dispersion medium is 0.001 to 10% by weight, more preferably 0.005 to 5% by weight, based on the dispersion medium. When the amount of the dispersion stabilizer soluble in the dispersion medium exceeds 10% by weight, it is not preferable because additional dispersion of droplets is likely to occur or new particles are formed by emulsion polymerization or the like.

  Examples of the particulate solid dispersion stabilizer include sparingly soluble inorganic substances such as calcium phosphate, calcium carbonate, and magnesium pyrophosphate, and tertiary calcium phosphate is particularly effective. These may be used alone or in combination of two or more. A preferable amount of the fine particle solid dispersion stabilizer is 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, based on the dispersion medium. By using an appropriate amount of the fine particle solid dispersion stabilizer, the effect of preventing secondary aggregation of the polymer particles is increased.

  Nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene derivative, sorbitan fatty acid ester, glycerin fatty acid ester Agents, alkyl sulfate salts, alkylbenzene sulfonates, alkyl naphthalene sulfonates, alpha olefin sulfonates, dialkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl phosphates, poly Anionic surfactants such as oxyethylene alkyl sulfate salts and polyoxyethylene alkyl allyl sulfate salts can be exemplified.These surfactants may be used alone or in combination of two or more. Dispersion stability can be further improved by using these surfactants together with the dispersion stabilizer. In particular, when a particulate solid dispersion stabilizer is used, it is effective to use an anionic surfactant in combination. A preferred amount of the surfactant used is 0.0001 to 5% by weight, more preferably 0.0005 to 0.5% by weight, based on the dispersion medium. When the amount of the surfactant used exceeds 5% by weight, it is not preferable because additional dispersion of droplets is likely to occur or new particles are easily formed by emulsion polymerization or the like.

  Examples of the salt include chlorides such as sodium chloride and potassium chloride, sulfates such as sodium sulfate and magnesium sulfate, and phosphates such as sodium dihydrogen phosphate and disodium hydrogen phosphate.

  Furthermore, the formation of fine particles can be suppressed by performing the above-described polymerization in the presence of a polymerization inhibitor soluble in the dispersion medium. Examples of the polymerization inhibitor soluble in the dispersion medium include nitrites such as sodium nitrite, hydroquinone, and p-diaminophenylene. A preferable concentration of the polymerization inhibitor is 0.0001 to 1% by weight, more preferably 0.0005 to 0.5% by weight, based on the dispersion medium. If the amount of the polymerization inhibitor used exceeds 1% by weight, the polymerization reaction is difficult to proceed smoothly, which is not preferable.

  The crosslinked polymer particles of the present invention can be used after being treated and modified as necessary. Treatment and modification are performed for the purpose of hydrophilicity, biocompatibility, improvement of physical and chemical properties of polymer particles, improvement of mechanical strength, addition of functions as treatment materials, reduction of eluate, and sterilization. Is called. Examples of treatment and modification include saponification, washing, high temperature treatment and high pressure treatment, radiation treatment, plasma treatment, and other chemical and / or physical treatments and modification. Or after polymerization.

  The polymer particles of the present invention can be used, for example, by a method of mixing and contacting the liquid to be treated in a container and then separating the liquid to be treated from the polymer particles by filtration or centrifugation. More preferably, the polymer particles of the present invention are filled in a container having an inlet and an outlet such as a column, the liquid to be treated is introduced from the inlet, the liquid to be treated is brought into contact with the polymer particles in the container, and the liquid is coated from the outlet. It can be used in such a manner as to cause the processing liquid to flow out. The container may be provided with a mechanism such as a mesh that does not allow the polymer particles to pass but allows the liquid to be processed to pass.

Example 1
A 2 L separable flask having a stirring blade was charged with 378.2 g of water, 1.75 g of a 3 wt% aqueous solution of sodium alpha olefin sulfonate, and 120.0 g of a 10 wt% slurry of particulate calcium triphosphate, and gently stirred. I was allowed to.

As a droplet generator, a nozzle for ejecting a monomer mixture is inserted into a column filled with a dispersion medium, the upper end of the nozzle is made of an orifice plate having 12 small holes with a hole diameter of 0.17 mm, and the lower end is vibrated. A transmitting diaphragm was installed, and a diaphragm connected to a vibrator was used. The column was connected to an introduction pipe for supplying a dispersion medium from a dispersion medium tank, and the nozzle was connected to an introduction pipe for supplying a monomer mixture from a monomer mixture tank for particle formation. A double plunger pump with high quantitativeness and little pulsation was used to supply the monomer mixture.
From the monomer mixture tank for particle formation, 100 parts by weight of vinyl acetate, 50 parts by weight of TAIC, 158 parts by weight of ethyl acetate, 30 parts by weight of heptane, 3.2 parts by weight of polyvinyl acetate (average polymerization degree 400), V- 65. 50 g of the monomer mixture consisting of 5.0 parts by weight was supplied to the nozzle at a rate of 27.6 mL / min, and charged into a separable flask via a droplet generator. At the same time, 500.0 g of a dispersion medium consisting of 133 g of 3 wt% PVA aqueous solution, 7.39 g of 6 wt% NaNO ₂ aqueous solution and 3859 g of water is supplied to the column from the dispersion medium tank, and is separable via a droplet generator. The flask was charged.

  At this time, the monomer mixture was subjected to mechanical vibration with a constant frequency (500 Hz) and an intensity of 0.14 G by a vibrator. The liquid column of the monomer mixture ejected from the nozzle hole is divided by the mechanical vibration to form droplets of uniform diameter in the dispersion medium in the column, and into the separable flask together with the dispersion medium supplied at the same time. Sent. The contents of the separable flask were held at 65 ° C. for 7 hours under a nitrogen atmosphere to polymerize the droplets. The contents of the separable flask were then cooled to room temperature.

  Samples were taken at the column outlet, before and after polymerization, and observed with the OMRON 3D Digital Finescope VC1000. All of the droplets maintained a uniform diameter, resulting in coalescence or additional dispersion. It was confirmed that the polymerization was performed without any problems.

Next, hydrochloric acid was added to the contents of the separable flask to adjust the pH to 2 or less to dissolve the tribasic calcium phosphate, and then washed well with water. After confirming that the pH of the cleaning liquid was close to neutral, water was replaced with acetone, and the polymer was thoroughly washed with acetone. Next, acetone was replaced with water, and then an amount of sodium hydroxide (NaOH) of the following formula was added as an aqueous solution so as to be an excess amount with respect to the vinyl acetate unit.

NaOH (solid weight) = particle dry weight / 86.09 × 40 × 1.5

The amount of water was adjusted so that the NaOH concentration relative to water was 4% by weight. This was saponified with stirring at a reaction temperature of 40 ° C. for 6 hours. Then, it washed with water until pH of the washing | cleaning liquid became neutrality, and also wash | cleaned fully with 80 degreeC warm water. Subsequently, autoclave treatment was performed at 121 ° C. for 20 minutes to obtain clean crosslinked polymer particles having a uniform particle diameter of about 450 μm.

  The obtained polymer particles were subjected to the following evaluations, except for large particles on a sieve having an opening of 710 μm and small particles having an opening of 300 μm. In addition, the particle | grains which become a classification loss under the sieve of 710 micrometers of openings and the sieve of 300 micrometers of openings were few.

  In order to observe the obtained crosslinked polymer particles with a scanning electron microscope (SEM) while maintaining the pore structure in water, the water contained in the particles is replaced with t-butyl alcohol and freeze-dried to prepare a sample. did. As a precaution, it was confirmed with the OMRON 3D digital fine scope VC1000 that there was no noticeable shrinkage or expansion of the crosslinked polymer particles during sample preparation. When the surface and cross section of the particles were observed with an SEM, it was confirmed that a large number of fine pores of micron order or less existed in the entire crosslinked polymer particles obtained.

The crosslinked polymer particles were sufficiently dried in vacuum, and then elemental analysis (CHN analysis) was performed using J Science Lab Microcoder JM10 type, and the N content in the dry weight of the crosslinked polymer particles was determined. It was 11.0% by weight. Further, the ratio of TAIC units to the total polymerization units constituting the crosslinked polymer particles was calculated to be 65.2% by weight.

TAIC content = N content × TAIC molecular weight / (N atomic weight × N atom number in TAIC)

After sufficiently additionally drying the sample prepared by t-butyl alcohol freeze-drying method for SEM observation as described above, Phi Quantum 2000 was used as an apparatus, X-ray intensity AIKα / 15 kV · 25 W, X-ray beam diameter 100 μmφ The particle surface was subjected to X-ray photoelectron spectroscopy (XPS) at a pass energy of 187.85 eV (wide spectrum) and 58.70 eV (narrow spectrum). The surface nitrogen (N) concentration (atomic percent: at%) was determined to be 10.5 at%. Also, from the surface N concentration, the ratio of triallyl isocyanurate (TAIC) units on the surface of the crosslinked polymer particles was calculated from the formula (1), and converted to wt% (weight percent: wt%) from the formula (2). However, it was 61.6% by weight.

Surface TAIC = 1 − {(1-6 × Surface N) / (1-5 × Surface N)} (1) Formula Surface TAIC (weight) = 249.27 × Surface TAIC /
{249.27 × surface TAIC + 44.05 × (1-surface TAIC)} (2) Formula

In a batch experiment, the particles were added at a sedimentation volume of 0.5 mL, and human serum was added with cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) to give respective initial concentrations of 859 pg / mL and The adsorbing rate was determined by bringing 3.0 mL of the 898 pg / mL solution into contact with stirring at 37 ° C. for 2 hours. As a result, the adsorption rates for IL-6 and TNF-α were 79.2% and 20.0%, respectively.
The adsorption rate was calculated from (“initial IL-6 / TNF-α concentration” − “IL-6 / TNF-α concentration after contact”) / “initial IL-6 / TNF-α concentration”.

  The characteristics and evaluation results of the crosslinked polymer particles are shown in Tables 1-2.

（実施例２）
撹拌翼を有する２Ｌセパラブルフラスコ中に、水３７８．２５ｇ、アルファオレフィンスルホン酸ナトリウムの３重量％水溶液１．７５ｇ、微粒子状の第三リン酸カルシウムの１０重量％スラリー１２０．０ｇを仕込み、穏やかに撹拌させておいた。

(Example 2)
In a 2 L separable flask equipped with a stirring blade, 378.25 g of water, 1.75 g of a 3 wt% aqueous solution of sodium alpha olefin sulfonate, and 120.0 g of a 10 wt% slurry of fine particulate calcium triphosphate were stirred gently. I was allowed to.

Generation of droplets for particle formation was performed in the same manner as in Example 1. From the monomer mixture tank for particle formation, 100 parts by weight of vinyl acetate, 130 parts by weight of TAIC, 246 parts by weight of ethyl acetate, 46.6 parts by weight of heptane, 5.0 parts by weight of polyvinyl acetate (average polymerization degree 400), V A monomer mixture consisting of −7.7 7.7 parts by weight of 500.0 g was supplied to the nozzle at a rate of 27.6 mL / min, and charged into a separable flask via a droplet generator. At the same time, 500.0 g of a dispersion medium consisting of 133 g of 3 wt% PVA aqueous solution, 7.39 g of 6 wt% NaNO ₂ aqueous solution and 3859 g of water is supplied to the column from the dispersion medium tank, and is separable via a droplet generator. The flask was charged.

  At this time, the monomer mixture was subjected to mechanical vibration with a constant frequency (500 Hz) and an intensity of 0.14 G by a vibrator. The liquid column of the monomer mixture ejected from the nozzle hole is divided by the mechanical vibration to form droplets of uniform diameter in the dispersion medium in the column, and into the separable flask together with the dispersion medium supplied at the same time. Sent. The contents of the separable flask were held at 65 ° C. for 5 hours under a nitrogen atmosphere to polymerize the droplets. Thereafter, the contents of the separable flask were cooled to room temperature.

  Thereafter, the same operation as in Example 1 was performed to obtain clean crosslinked polymer particles having a uniform particle diameter.

  Hereinafter, evaluation of the obtained crosslinked polymer particles was performed in the same manner as in Example 1.

  Elemental analysis was performed in the same manner as in Example 1, and the N content in the dry weight of the crosslinked polymer particles was determined to be 14.0% by weight. Further, the ratio of TAIC units to the total polymerization units constituting the crosslinked polymer particles was calculated to be 82.8% by weight.

XPS analysis was performed in the same manner as in Example 1, and the surface N concentration was determined to be 14.7 at%. Further, the ratio of TAIC units on the surface of the crosslinked polymer particles was determined to be 87.6% by weight.
In a batch experiment, the particles were 0.5 mL in sedimentation volume, and IL-6 and TNF-α, cytokines, were added to human serum to adjust the initial concentrations to 638 pg / mL and 1024 pg / mL, respectively, while stirring 3.0 mL of the solution. The adsorption rate was determined by contacting at 37 ° C. for 2 hours. As a result, the adsorption rates for IL-6 and TNF-α were 86.2% and 33.1%, respectively.

(Comparative Example 1)
In a 2 L separable flask equipped with a stirring blade, 378.25 g of water, 1.75 g of a 3 wt% aqueous solution of sodium alpha olefin sulfonate, and 120.0 g of a 10 wt% slurry of fine particulate calcium triphosphate were stirred gently. I was allowed to.

Generation of droplets for particle formation was performed in the same manner as in Example 1. From the monomer mixture tank for particle formation, 100 parts by weight of vinyl acetate, 31 parts by weight of TAIC, 132 parts by weight of ethyl acetate, 36 parts by weight of heptane, 3.2 parts by weight of polyvinyl acetate (average polymerization degree 400), V- 65. 50 g of the monomer mixture consisting of 5.0 parts by weight was supplied to the nozzle at a rate of 27.6 mL / min, and charged into a separable flask via a droplet generator. At the same time, 500.0 g of a dispersion medium consisting of 133 g of 3 wt% PVA aqueous solution, 7.39 g of 6 wt% NaNO ₂ aqueous solution and 3859 g of water is supplied to the column from the dispersion medium tank, and is separable via a droplet generator. The flask was charged.

  At this time, the monomer mixture was subjected to mechanical vibration with a constant frequency (500 Hz) and an intensity of 0.14 G by a vibrator. The liquid column of the monomer mixture ejected from the nozzle hole is divided by the mechanical vibration to form droplets of uniform diameter in the dispersion medium in the column, and into the separable flask together with the dispersion medium supplied at the same time. Sent. The contents of the separable flask were held at 65 ° C. for 5 hours under a nitrogen atmosphere to polymerize the droplets. Thereafter, the contents of the separable flask were cooled to room temperature.

  Thereafter, the same operation as in Example 1 was performed to obtain clean crosslinked polymer particles having a uniform particle diameter.

  Hereinafter, evaluation of the obtained crosslinked polymer particles was performed in the same manner as in Example 1.

  Elemental analysis was performed in the same manner as in Example 1, and the N content in the dry weight of the crosslinked polymer particles was determined to be 8.4% by weight. The ratio of TAIC units to the total polymer units constituting the crosslinked polymer particles was calculated to be 49.6% by weight.

XPS analysis was performed in the same manner as in Example 1, and the surface N concentration was determined to be 7.3 at%. Further, the ratio of TAIC units on the surface of the crosslinked polymer particles was determined to be 42.4% by weight.
In a batch experiment, the particles were 0.5 mL in sedimentation volume, and IL-6 and TNF-α, cytokines, were added to human serum to adjust the initial concentrations to 859 pg / mL and 898 pg / mL, respectively, while stirring 3.0 mL of the solution. When the adsorption rate was determined by contact at 37 ° C. for 2 hours, the adsorption rate was 0% for any cytokine.

Claims (6)

  Crosslinked polymer particles containing vinyl alcohol units and nitrogen-containing polymerized units as constituents, and having a nitrogen content of 7.0 to 30.0% by weight based on the total weight of the particles in a dry weight specified by elemental analysis A cytokine adsorbent comprising cross-linked polymer particles having a surface nitrogen concentration of 9.0 to 30.0 at% specified by X-ray photoelectron spectroscopy analysis on the particle surface.   Crosslinked polymer particles comprising a synthetic polymer containing vinyl alcohol units and nitrogen-containing polymerized units as constituents, wherein the ratio of polymerized units containing nitrogen to all polymerized units constituting the crosslinked polymer particles is 40.0 to An adsorbent for cytokine comprising 100.0 wt% of crosslinked polymer particles having a nitrogen-containing polymer unit ratio of 55.0 to 100.0 wt% on the surface of the crosslinked polymer particles.   A part or all of the carboxylic acid vinyl ester units of a crosslinked polymer containing a carboxylic acid vinyl ester unit obtained by polymerization of a monomer mixture containing a vinyl compound having a carboxylic acid vinyl ester and a triazine ring. The cytokine adsorbent comprising the crosslinked polymer particles according to claim 1, which is formed by hydrolysis and / or transesterification.   The cytokine adsorbent comprising the crosslinked polymer particles according to any one of claims 1 to 3, wherein 80% by volume or more of the particles have a volume average particle size of 0.8 to 1.2 times the volume average particle size.   A regular vibration disturbance is applied to the liquid column of the monomer mixture ejected from the nozzle hole into the dispersion medium to form droplets of uniform diameter in the dispersion medium, and then the droplets are joined or added. The cytokine adsorbent comprising the crosslinked polymer particles according to claim 1, wherein the polymer particles are polymerized under conditions that do not cause undue dispersion.   A body fluid treatment material comprising the cytokine-adsorbing material according to claim 1.