JP2001310917A - Filter material for removing thrombocyte and leukocyte, and polymer for the filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter material permeating erythrocytes and plasmas and efficiently removing leukocytes and thrombocytes from a liquid containing leukocytes and thrombocytes such as whole blood, and to provide a new polymer useful for the same. SOLUTION: The filter for removing thrombocyte and leukocyte is characterized by the graft or block copolymer having a polymer segment of monomer with a basic nitrogen functional group and a polymer segment of monomer with a no-ionic hydrophilic group on the surface of the base material of the filter at least. The graft or block copolymer consists of the polymer segment of monomer with the non-ionic hydrophilic group and the polymer segment of monomer with the basic nitrogen functional group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter material for removing leukocytes. More specifically, the present invention relates to a leukocyte-removing filter material for permeating erythrocytes and plasma from a leukocyte- and platelet-containing liquid represented by whole blood and efficiently removing leukocytes and platelets. The invention also relates to novel polymers useful for such filter media.

[0002]

2. Description of the Related Art Conventionally, in the field of blood transfusion, in addition to so-called whole blood transfusion, a blood donor obtained by adding an anticoagulant to blood collected from a blood donor, the need for a donor from a whole blood product is required. What is called component blood transfusion is generally performed in which a blood component is separated and the blood component is transfused. Component transfusions include erythrocyte transfusions, platelet transfusions, plasma transfusions, etc., depending on the type of blood component required by the recipient.The blood component preparations used for these transfusions include erythrocyte preparations, platelet preparations, and plasma preparations. and so on. In recent years, so-called leukocyte-removal transfusion, in which a blood product is transfused after removing leukocytes mixed in the blood product, has become widespread.
These include relatively minor side effects such as headache, nausea, chills, and non-hemolytic fever response associated with blood transfusion, alloantigen sensitization that has a serious effect on the recipient, GVHD after blood transfusion, and serious infections such as viral infection. It has been clarified that such adverse side effects are mainly caused by leukocytes mixed in blood products used for blood transfusion. In addition, in the case of a whole blood product used for supplying red blood cells to a recipient, it is desired to efficiently remove platelets whose life span is significantly shorter than that of red blood cells together with white blood cells.

[0003] Methods for removing leukocytes from blood products include:
Broadly classified, centrifugation using the difference in specific gravity of blood components,
There are two types of filter methods using a fiber material or a porous body having continuous pores as a filter medium.The filter method is widely used because of its high leukocyte removal ability, simple operation, and low cost. Have been.

It is considered that the main mechanism of the leukocyte removal by the filter material using the fiber material or the porous material is that the leukocytes in contact with the surface of the fiber or the porous material are adsorbed on the surface of the material. . Therefore, as a means for improving the leukocyte removal ability of the conventional filter material, the frequency of collision between the filter material and leukocytes is increased, that is, the fiber diameter or the pore size of the filter material is reduced, or the filter material is filled in the filter device. Consideration has been given to increasing the density. However, for a preparation containing a high proportion of red blood cells in the preparation, such as a whole blood preparation or a concentrated red blood cell, there is a limit in improving the leukocyte removal ability using only the above-mentioned means. That is, as the frequency of contact of white blood cells with the filter material increases, the frequency of contact of red blood cells present at a high concentration in the preparation with the filter material and the resistance to liquid passage also increase, resulting in prolonged treatment time and hemolysis associated with the destruction of the red blood cell membrane. There were problems such as the occurrence of.

[0005] On the other hand, studies have been made focusing on the surface chemical properties of filter materials. WO 87/05812,
A filter material having a nonionic hydrophilic group and a basic nitrogen-containing functional group is disclosed. It is stated that when the content of the nitrogen atom of the basic nitrogen-containing functional group exceeds 4.0% by weight, both platelets and leukocytes are easily adsorbed. However, when a random copolymer (80:20 mol composition) composed of 2-hydroxyethyl methacrylate and diethylaminoethyl methacrylate or a diethylaminoethyl methacrylate homopolymer is used, both the leukocyte removal rate and platelet removal rate show insufficient values. However, there was a problem that red blood cells adhered.

[0006] In the technique disclosed in EP0500472-A2, when removing leukocytes and platelets from an erythrocyte preparation, a filter material having a positive zeta potential is used to maintain a good erythrocyte permeability and to remove platelets. This technique does not improve the leukocyte removal rate. Also, JP-A-11-206
No. 876 discloses a technique for removing white blood cells and platelets from an erythrocyte preparation, which comprises at least three or more types of porous base materials having different concentrations of quaternary ammonium salts. A technique aimed at increasing the platelet removal rate while maintaining good red blood cell permeability by using a filter with a high ammonium salt concentration, but not improving the leukocyte removal rate. .

Japanese Patent Application Laid-Open No. Hei 6-247682 has a basic functional group and a nonionic hydrophilic group, wherein the molar ratio of the basic functional group to the nonionic hydrophilic group is in the range of 0.6 to 6, and A filter material having a basic functional group on the surface at a density of 5 × 10 ^{−5 to} 0.1 meq / m ² is disclosed. However, this filter material is not sufficiently effective in suppressing red blood cell adhesion, and it has been difficult to stably improve the ability to remove white blood cells.

[0008] Further, as a prior art relating to the interaction between a graft copolymer and blood cells, there is a document Biomateria.
ls, vol 6, p409 (1985) report on the adsorption behavior of leukocytes by coating glass beads with a copolymer obtained by grafting 2-diethylaminoethyl methacrylate on nylon-6. 10
It is stated that the introduction of 31 parts by weight of polyamine with respect to 0 parts suppresses the adsorption of leukocytes.

JP-A-60-119955 to 11995
No. 7 synthesizes a polyamine macromonomer composed of N, N'-diethyl-N- (p-vinylphenethyl) ethylenediamine, and copolymerizes it with 2-hydroxyethyl methacrylate to form microdomains. Although molecular bodies have been obtained, they relate to the effect of making platelets less likely to adhere, and no disclosure is made regarding the behavior of leukocytes.

[0010]

DISCLOSURE OF THE INVENTION The present invention relates to a filter material for removing leukocytes for efficiently transmitting leukocytes and platelets and efficiently removing leukocytes and platelets from a liquid containing leukocytes and platelets represented by whole blood. An object is to provide a novel polymer useful for that purpose.

[0011]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer segment containing a monomer having a nonionic hydrophilic group as a main component and a basic nitrogen-containing functional group. When a graft or block copolymer consisting of a polymer segment having a monomer as a main component was present on the surface of the filter substrate, surprisingly, from a leukocyte- and platelet-containing liquid represented by whole blood,
The present inventors have found that they permeate erythrocytes and plasma and efficiently remove leukocytes and platelets, and have accomplished the present invention.

That is, the present invention provides a graft or block copolymer having a polymer segment composed of a monomer having a nonionic hydrophilic group and a polymer segment composed of a monomer having a basic nitrogen-containing functional group. The present invention relates to a filter material for removing platelets and leukocytes, which is provided at least on the surface. Also, the present invention
The present invention relates to a graft or block copolymer having a polymer segment composed of a monomer having a nonionic hydrophilic group and a polymer segment composed of a monomer having a basic nitrogen-containing functional group. The polymer of the present invention can be widely used not only for filter materials for removing platelets and leukocytes, but also for medical materials such as cell adhesion membranes and permselective membranes.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The leukocyte removal filter of the present invention is a filter for permeating red blood cells and plasma and efficiently removing white blood cells and platelets from a liquid containing white blood cells and platelets represented by whole blood.

The monomer having a nonionic hydrophilic group of the present invention is a monomer containing a hydroxyl group and an amide group, for example, 2-hydroxyethyl (meth) acrylate,
-Hydroxypropyl (meth) acrylate, vinyl alcohol (polymerized as vinyl acetate and then hydrolyzed), (meth) acrylamide, N-vinylpyrrolidone and the like. Here, the description of (meth) acrylate means acrylate or methacrylate. Also,
Examples of the nonionic hydrophilic group include a polyethylene oxide chain in addition to the hydroxyl group and the amide group. These monomers may be used in a mixture. Among the above monomers, 2-hydroxyethyl (meth) acrylate is preferably used from the viewpoints of availability, ease of handling during polymerization, and performance when bleeding blood.

The monomer having a basic nitrogen-containing functional group of the present invention is allylamine; N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl ( Derivatives of (meth) acrylic acid such as (meth) acrylate and 3-dimethylamino-2-hydroxypropyl (meth) acrylate; derivatives of (meth) acrylamide such as 3-dimethylaminopropyl (meth) acrylamide, wherein (meth) Description of acrylamide means acrylamide or methacrylamide; styrene derivatives such as p-dimethylaminomethylstyrene and p-diethylaminoethylstyrene; and nitrogen-containing aromatic compounds such as 2-vinylpyridine, 4-vinylpyridine and 4-vinylimidazole. Vinyl induction ; And it can be exemplified derivatives and quaternary ammonium salts by an alkyl halide such as the vinyl compound. They may also be used in a mixture. Among the above monomers, N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate are preferred because of their availability, ease of handling during polymerization, and performance when bleeding blood. Is preferably used.

The graft copolymer of the present invention is prepared by a chain transfer method in which a monomer is polymerized in the presence of a backbone polymer to introduce a graft chain, a macromonomer having a polymerizable group is synthesized in advance, and reacted with the monomer. A macromonomer method in which a trunk polymer is formed, an initiator method in which an initiator is introduced into the trunk polymer in advance, and a monomer is polymerized from the macromonomer method,
It is synthesized by a coupling method in which a macromonomer having a functional group synthesized separately in advance and a polymer having a functional group capable of reacting with the functional group are reacted. In addition, the block copolymer of the present invention can be obtained by a sequential growth method in which polymerization of another monomer is started from a growth terminal of one component polymer, a coupling method in which growing terminals are reacted with each other, and a start portion is previously introduced into a trunk polymer. In addition, it is synthesized by a polymer initiator method in which a polymer chain is cleaved in the presence of a monomer and polymerized therefrom, and the like. A preferred method is graft copolymerization due to simplicity of synthesis and the like, and a more preferred method is a macromonomer method and a coupling method due to easy control of molecular weight and distribution thereof, hydrophobicity and hydrophilicity, and the like.

For the synthesis of the macromonomer in the macromonomer method, a method of introducing a polymerizable group using a start reaction or termination reaction, and / or a method of converting a terminal functional group into a polymerizable group are used. Preferably, a functional group is introduced into the polymer terminal using an initiator having a functional group, and then the terminal functional group is converted into a polymerizable terminal group, or polymerization is carried out in the presence of a chain transfer agent having a functional group. And then converting the terminal functional group to a polymerizable terminal group. The initiator having a functional group is preferably an azo initiator having a functional group, for example, 4,4′-azobis (4
An initiator for introducing a carboxylic acid such as -cyanovaleric acid);
An initiator for introducing a hydroxyl group such as 2,2′-azobis {2-methyl-N- (2-hydroxyethyl) propionamide} is exemplified. As the chain transfer agent having the functional group, a sulfur-containing compound is preferable, and for example, thioglycolic acid, thiomalic acid, α-thioglycerin, 2-mercaptoethanol, 2-mercaptoethylamine hydrochloride, and the like are used. A known method can be used for converting the terminal functional group into a polymerizable terminal group. For example, the reaction can be carried out using glycidyl (meth) acrylate, 2-isocyanatoethyl (meth) acrylate, (meth) acryloyl chloride or the like to introduce a (meth) acryloyl group at the terminal. These reactions are selected such that side reactions with nonionic hydrophilic groups or basic nitrogen-containing functional groups contained in the macromonomer are not preferred.

The macromonomer in the coupling method is prepared by using the above-mentioned macromonomer synthesis method,
It has a functional group at the terminal. The functional group is preferably a primary or secondary amino group. The polymer having a functional group capable of reacting with the functional group is obtained by, for example, copolymerizing glycidyl (meth) acrylate or the like.

In the polymer segment mainly comprising a monomer having a basic nitrogen-containing functional group according to the present invention,
The repeating number of the monomer having the basic nitrogen-containing functional group,
Preferably 40 or more, more preferably 70 or more,
Most preferably, it is 100 or more. The upper limit of the number of repetitions is preferably 1,000 or less, more preferably 80.
0 or less, most preferably 500 or less. When the number of repetitions of the polymer segment containing a monomer having a basic nitrogen-containing functional group as a main component is less than 40, the improvement in the removal rate of leukocytes and platelets is insufficient, and the base is kept at a low number of repetitions. Increasing the content of the polymer segment containing a monomer having a functional nitrogen-containing functional group as a main component may cause red blood cells to adhere while the removal rate of leukocytes and platelets is not sufficiently improved. When the number of repetitions is large, a portion having a high concentration of the basic nitrogen-containing functional group is localized in the copolymer, and / or the mobility of the basic nitrogen-containing functional group is improved. Thus, it is thought that, as compared with conventional random copolymers and homopolymers of monomers having a basic nitrogen-containing functional group, more effective leukocyte and platelet adsorption ability could be obtained. If the number of repetitions is 1,
If it exceeds 000, there is a possibility that red blood cells may adhere to the white blood cells and platelets while the improvement of the removal rate is insufficient.
Further, polymerization becomes difficult.

The number of repetitions is determined by gel permeation chromatography (hereinafter abbreviated as GPC) at the macromonomer stage, using polymethyl methacrylate as a sample to determine the number average molecular weight, and dividing the value by the monomer unit molecular weight. Required by

The content of the polymer segment containing a monomer having a basic nitrogen-containing functional group as a main component relative to the graft or block copolymer of the present invention is 0.5% by weight or more;
It is less than 30% by weight, preferably 0.5% by weight or more and less than 20% by weight, more preferably 0.5% by weight or more and less than 10% by weight. If the content is less than 0.5% by weight, it is not suitable because sufficient leukocyte removal and platelet removal efficiency cannot be obtained. On the other hand, if it exceeds 30% by weight, the red blood cells tend to be damaged, which is not suitable. The content was determined by ¹ H-nuclear magnetic resonance spectroscopy (hereinafter referred to as NM).
R).

As a method for allowing the copolymer of the present invention to exist on the surface of a filter substrate, a coating method is preferably used. The polymer may be crosslinked using a known method after coating in order to prevent elution from the surface of the filter substrate.

The surface abundance of the graft copolymer with respect to the filter material is preferably 0.001 g /
m ² or more and less than 0.50 g / m ² , more preferably 0.1 g / m ^{2 or} less.
005 g / m ² or more and less than 0.40 g / m ² , most preferably 0.01 g / m ² or more and less than 0.30 g / m ² . If the abundance is less than 0.001 g / m ² , the leukocyte and platelet removal rate may be inferior, and the abundance may be reduced to 0.
If it is more than 50 g / m ² , the pore size will decrease and the pore structure will change greatly due to swelling when it comes into contact with blood from a dry state, and the removal rate of white blood cells and platelets may become unstable.

The surface abundance of the graft copolymer with respect to the filter material can be determined by the following method. First, the amount of the graft copolymer per unit weight of the filter material is determined by the difference between the weight before and after the coating, or the polymer present on the substrate surface is extracted using an appropriate method, and the weight of the extracted polymer is measured. Required by Next, the total pore surface area per unit weight of the filter material was measured by a mercury intrusion method, and this value was used to divide the abundance of the graft copolymer per unit weight of the filter material. calculate.

The measurement of the total pore surface area per unit weight of the filter material by the mercury intrusion method is performed by the following method. A part of the filter material is sampled and its weight (W) is measured. The total pore surface area (A) of the sample is measured with a mercury porosimeter in a pressure range of 0.1 to 210 psia, and the total pore surface area per unit weight is determined from the following equation. Total pore surface area per unit weight = A / W In order to determine the total pore surface area per unit weight, it is preferable to sample three or more locations of the filter material and determine the average value. Such materials should be considered to be included in the scope of the present patent if, as a result of the measurement, some portions fall within the range defined by the present invention and the remaining portions deviate from the range.

The filter substrate of the present invention is preferably a fibrous medium such as a nonwoven fabric or a porous body having continuous pores. Also,
These may be used in combination. It is known that the structure of the filter substrate greatly contributes to the capture of leukocytes, and selection of the filter substrate is also an important factor for further improving the leukocyte removal rate.

That is, a fibrous medium such as a nonwoven fabric is filtered.
-When used as a substrate, the average fiber diameter is 0.3 μm or more,
Less than 3.0 μm, more preferably 1.0 μm or more,
Desirably less than 2.0 μm. Also, the fibrous medium is placed in a container.
The packing density when filling the body is 0.1 g / cm^Threethat's all,
0.3g / cm^ThreeLess than is preferred. Average fiber diameter is 0.3
less than μm, packing density 0.3g / cm^ThreeThat is all
May cause clogging of blood cells and increased pressure loss
The average fiber diameter is 3.0 μm or more, and the packing density is
0.1 g / cm ^ThreeIf it is less than this, the leukocyte removal rate may decrease.
This is because

The average fiber diameter of the present invention is a value determined according to the following procedure. That is, a part of the filter substrate, which is regarded as substantially uniform, constituting the filter substrate is sampled and photographed using a scanning electron microscope or the like. At the time of sampling, the effective filtration cross-section area of the filter substrate is 0.5 to 1 cm on one side.
, And random sampling is performed at three or more, preferably five or more locations. In order to perform random sampling, for example, after designating an address to each of the sections, a section at a necessary place or more may be selected by a method such as using a random number table. For each sampled section, three or more, preferably five or more locations are photographed.
The diameter of all the fibers in the photograph thus obtained is measured. Here, the diameter refers to the width of the fiber in a direction perpendicular to the fiber axis. The value obtained by dividing the sum of the diameters of all the measured fibers by the number of fibers is defined as the average fiber diameter. However, when multiple fibers are overlapped and the width cannot be measured due to the shadow of other fibers, or when multiple fibers are melted, etc., and become thicker, fibers with significantly different diameters If these are mixed, etc., these data are deleted. By the above method, 1
The average fiber diameter is determined from data of 00 or more, preferably 1,000 or more.

Japanese Patent Application Laid-Open No. 11-42406 discloses a method for improving the leukocyte removal ability in which a porous element having an average pore diameter of 1.0 μm or more and less than 100 μm and an average fiber diameter of 0. A filter material comprising a fiber structure of not less than 03 μm and less than 1.0 μm, wherein the porosity of the filter material is 50% or more and less than 95%, and the holding amount of the fiber structure with respect to the filter material is 0.01% by weight. %
A leukocyte removal filter in which the ratio of the average pore diameter of the porous element to the average fiber diameter of the fibrous structure is 2 or more and less than 2000, and the fibrous structure forms a network structure. Is disclosed, but it is also preferable to use a filter substrate in which such fine fibers and ultrafine fibers are mixed, as long as clogging of blood cells and increase in pressure loss are not caused.

When the filter substrate is made of fiber, examples of the fiber material include polyamide, aromatic polyamide, polyester, polyacrylonitrile, polytrifluorochloroethylene, polymethyl methacrylate, and the like.
Synthetic fibers such as polystyrene, polyethylene and polypropylene, and recycled fibers such as cellulose acetate, cupra ammonium rayon, viscose rayon, hemp,
Natural fibers such as cotton, silk and wool fibers can be mentioned.
Among them, synthetic fibers such as polyester, polyethylene, and polypropylene are more preferable materials because of their ease of production and handling.

When the filter substrate of the present invention is a porous polymer having continuous pores, the average pore size of the porous polymer is preferably 1 μm or more and less than 20 μm, more preferably 1 μm or more. The thickness is more preferably less than 15 μm, and more preferably 2 μm or more and less than 8 μm. If the average pore size is less than 1 μm, it may be difficult to pass red blood cells, which is not preferable.
If it is not less than μm, the frequency of contact between the surface of the porous body and the leukocytes is too low, so that the leukocytes may not be sufficiently removed.

Further, the average porosity of the polymer porous material is 4
It is preferably 5% or more and less than 95%, more preferably 70% or more and less than 95%, and more preferably 80% or less.
More preferably, it is less than 95%. If the average porosity is less than 45%, there is a possibility that a space through which red blood cells can pass cannot be sufficiently provided. On the contrary, if the average porosity is 95% or more, the mechanical strength of the filter substrate tends to be insufficient. Therefore, it is not preferable. The average pore diameter and average porosity of the present invention are values determined by the mercury porosimetry described below. That is, 3
A portion is sampled at a constant area (S), and each thickness (t) is measured using a film thickness meter (for example, Peacock thickness meter). From these values, the apparent volume (V
₁ = S × T). The total pore volume (V) measured for each sample in the pressure range of 0.1 to 210 psia
₂ ) and the total pore surface area (A) are determined. Using these values, the porosity and the average pore size are determined from the following equation. The porosity _{= (V 2 / V 1)} × 100 (%), the average value of the void ratio of the three, this is the average porosity of the porous body.
Average pore diameter = (4 × V ₂ ) / A The average value of the three average pore diameters is determined, and this is defined as the average pore diameter of the porous body.

When the filter substrate is made of a porous polymer, examples of the porous substrate include polyacrylonitrile, polysulfone, cellulose, cellulose acetate, polyvinyl acetal, polyester, polymethacrylate, and polyurethane. Can be

In the filter substrate of the present invention, a fiber filter substrate having a sequentially smaller average fiber diameter and / or a polymer porous body having a sequentially smaller average pore size are arranged from the inlet side to the outlet side of blood. Is preferred. The fiber filter base material having the smallest average fiber diameter or the polymer porous body having the smallest average pore size is the base material part having the highest leukocyte adsorption efficiency, but is therefore liable to be clogged by the leukocytes adsorbed, and thus has the blood Before reaching the preparation, it is preferable that leukocytes are coarsely removed by a fiber filter substrate having a relatively large average fiber diameter and / or a polymer porous material filter substrate having a relatively large average pore diameter. In general, the leukocyte-containing liquid often contains microaggregates. A prefilter can also be used to remove microaggregates from a leukocyte-containing liquid that is rich in such microaggregates. The prefilter base material is preferably a fiber aggregate having an average fiber diameter of 8 μm to 50 μm or a continuous porous body having an average pore size of 20 μm to 200 μm. The prefilter base material is assembled on the blood entry side of a leukocyte removal filter. It is used by embedding. The prefilter may be used in the presence of the polymer of the present invention on the surface.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples. The GPC used for the measurement of molecular weight and the like in the present invention was measured using HLC-8020 manufactured by Tosoh Corporation under the following conditions. The column is TSKgel GMHXL B0032
(7.8 mm ID x 30 cm) and TSKgel α
-Use by connecting MB0011 (7.8 mm ID x 30 cm). As a developing solution, a 1 mM lithium bromide monohydrate / N, N-dimethylformamide solution was used.
The test was performed under a flow rate of 1 mL / min. As the standard polymer, polymethyl methacrylate MM-10 manufactured by GL Sciences (manufactured by Polymer Laboratories) was used.

[0036]

Production Example 1 100 mL of a methanol solution containing 15.7 g of N, N-dimethylaminoethyl methacrylate (hereinafter abbreviated as DMAEMA), 1.13 g of 2-mercaptoethylamine hydrochloride, and 0.164 of azobisisobutyronitrile initiator Was heated to 60 ° C. in a nitrogen atmosphere and reacted for 3 hours. After cooling with ice, the solvent was distilled off under reduced pressure, and the residue was washed with hexane. Next, the obtained oligomer 4.0
g was dissolved in 50 mL of tetrahydrofuran, 1.5 g of 2-methacryloyloxyethyl isocyanate and 0.5 mg of hydroquinone were added, and the mixture was stirred at room temperature for 4 hours to carry out a reaction. The solvent was distilled off under reduced pressure, and the residue was washed with hexane and dried under vacuum. The molecular weight of the obtained macromonomer is a number average molecular weight (hereinafter abbreviated as MN) 21,9.
00 (average number of repetitions: about 140).

Subsequently, 0.5 g of the macromer, 9.5 g of 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA), and 90 mg of 2,2'-azobis (2,4-dimethylvaleronitrile) were dissolved in 100 mL of ethanol, and the mixture was dissolved in a nitrogen atmosphere. Polymerization was performed at 50 ° C. for 4 hours under the following conditions. After cooling, the polymer solution was poured into a buffer solution having a pH of 10 to precipitate a polymer, and the recovered polymer was subjected to vacuum drying. The molecular weight of the obtained graft copolymer was MN67,500, and the segment content of the polymer composed of DMAEMA was 8.6% by weight.

[0038]

[Production Example 2] In the part relating to copolymerization in Production Example 1,
Polymerization was carried out in the same manner except that the amount of the macromer was changed to 0.2 g. The molecular weight of the obtained graft copolymer was MN87,
The segment content of the polymer consisting of 200, DMAEMA was 2.7% by weight.

[0039]

Production Example 3 In the part relating to the synthesis of the macromer in Production Example 1, the amount of 2-mercaptoethylamine hydrochloride was changed to 2.
The same operation was performed except that the amount was 26 g. The MN of the obtained macromonomer was 8,410 (average repetition number: about 50). The copolymerization was carried out in the same manner as in Reference Example 1. The molecular weight of the obtained graft copolymer was MN 74,500, DMA
The segment content of the polymer composed of EMA was 5.5% by weight.

[0040]

Production Example 4 In the part relating to the synthesis of the macromer in Production Example 1, the amount of 2-mercaptoethylamine hydrochloride was changed to 1.
The same operation was performed except that the amount was 70 g. The MN of the obtained macromonomer was 17,410 (average repetition number: about 110). Further, the copolymerization was conducted in Reference Example 1 with HEMA8.
The amount was changed to 5 g and 1.5 g of the macromonomer. The molecular weight of the obtained graft copolymer was MN 67,500,
The segment content of the polymer consisting of DMAEMA is 1
It was 8.5% by weight.

[0041]

[Production Example 5] In Production Example 4, copolymerization was carried out using HEMA7.
The amount was changed to 2 g and 2.8 g of macromonomer. The molecular weight of the obtained graft copolymer was MN81,000,
The segment content of the polymer consisting of DMAEMA is 2
It was 8.0% by weight.

[0042]

Production Example 6 The procedure of Production Example 1 was repeated except that N, N-diethylaminoethyl methacrylate (DEAEMA) was used instead of DMAEMA. The MN of the obtained macromonomer was 19,
900 (average number of repetitions: about 105). The copolymerization was carried out in the same manner as in Production Example 1, except that 2-hydroxypropyl methacrylate (HPMA) was used instead of HEMA. The molecular weight of the obtained graft copolymer is M
The segment content of the polymer consisting of N167,000 and DMAEMA was 5.9% by weight.

[0043]

Production Example 7 (Reference) Polymerization was carried out in the same manner as in Production Example 1 except that DMAEMA was used instead of the macromonomer. The molecular weight of the obtained random copolymer was MN138,500, and the content of DMAEMA was 4.9% by weight.

[0044]

Production Example 8 (Reference) Polymerization was carried out in the same manner as in Production Example 4, except that the content of DMAEMA was changed. The molecular weight of the obtained random copolymer was MN 112,400, DMA
The EMA content was 56.0% by weight.

[0045]

Example 1 (Coating method) Average diameter about 1.2 μm
Non-woven fabric (about 40 g / m ² basis weight, about 190 μm thickness) made of polyethylene terephthalate fiber of 25 mm in diameter
And then immersed in a 3% by weight ethanol solution in which the polymer obtained in Production Example 1 was dissolved at 50 ° C. for 5 minutes, and then set in a filter holder at a flow rate of 5 NL / min. Drying was performed by flowing nitrogen for 5 minutes, followed by vacuum drying at 40 ° C. for 8 hours. The coating amount is 0.
It was 139 g / m ² .

(Evaluation of blood performance) In a holder in which four coated filters were set, 14 mL of a CPD solution (composition: sodium citrate 2
6.3 g / L, citric acid 3.27 g / L, glucose 2
3.2 g / L, sodium dihydrogen phosphate dihydrate 2.5
100 g of blood was collected in a blood bag containing 1 g / L), and 6 mL of whole blood prepared by flowing at a constant flow rate of 2.7 mL / min at room temperature using a syringe pump was collected. The leukocyte removal rate (%) and the platelet removal rate (%) were measured by measuring the leukocyte concentration and the platelet concentration of the pre-filtration solution and the post-filtration solution. A = white blood cell concentration before filtration, B = white blood cell concentration after filtration, C = When the platelet concentration before filtration and D = platelet concentration after filtration, respectively, the leukocyte removal rate = (1-B / A)
x100 (%), platelet removal rate = (1-D / C) x10
It was determined by an equation represented by 0 (%). The leukocyte concentration of the pre-filtration solution was measured by injecting a 10-fold diluted solution by the Turck method into a Bürker-Turk type hemocytometer and measuring the number of leukocytes present in the eight large sections using an optical microscope. did. The leukocyte concentration of the filtered solution was measured using the Nadget method described below. That is, leucop
1 mL of the collected blood was added to 9 mL of late (SOBIODA), mixed, and allowed to stand at room temperature for 20 to 30 minutes, centrifuged, and the supernatant was removed by a decant method. It was added to a calculator and the number of leukocytes was measured using an optical microscope. The platelet concentration was measured with an automatic blood cell counter (Toa Medical Electronics Sysmex K4500).

The leukocyte removal rate was 99.41% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Further, the filter after blood filtration was sufficiently washed with physiological saline, fixed with 0.2% glutaraldehyde, and further freeze-dried. Observation of the pre-treated filter after blood filtration with a scanning electron microscope showed that little attachment of red blood cells was observed.

[0048]

Example 2 Example 1 was repeated except that the polymer of Production Example 2 was used. Coating amount is 0.102g
/ M ² . The leukocyte removal rate was 99.60% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0049]

Example 3 Example 1 was repeated except that the polymer of Production Example 3 was used. 0.130g coat amount
/ M ² . The leukocyte removal rate was 98.74% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0050]

Example 4 The procedure of Example 1 was repeated except that the polymer of Production Example 4 was used. 0.105 g coat
/ M ² . The leukocyte removal rate was 99.24% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0051]

Example 5 The same procedure as in Example 1 was carried out except that the polymer of Production Example 5 was used. 0.084 g coat amount
/ M ² . The leukocyte removal rate was 97.84% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0052]

Example 6 Example 1 was repeated except that the polymer of Production Example 6 was used. The coat weight is 0.124g
/ M ² . The leukocyte removal rate was 98.52% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0053]

Comparative Example 1 The same procedure as in Example 1 was carried out except that the polymer of Production Example 7 was used. 0.096 g coat amount
/ M ² . The leukocyte removal rate was 97.54%, the platelet removal rate was 51.0%, and the leukocyte removal rate and platelet removal rate were inferior. Erythrocyte adhesion was hardly observed.

[0054]

Comparative Example 2 The same procedure was performed as in Example 1, except that the polymer of Production Example 8 was used. 0.088 g coat
/ M ² . The leukocyte removal rate was 97.33%, the platelet removal rate was 95.0%, and the leukocyte removal rate and platelet removal rate were insufficient. Further, it was observed that a large amount of red blood cells adhered to the filter after filtration.

[0055]

Example 7 In Example 1, the polymer 1 of Production Example 1 was used.
0 parts by weight and 76 parts by weight of commercially available poly-2-hydroxyethyl methacrylate were blended, and the coating was carried out in the same manner except that the coating was performed using a polymer having a DMAEMA content adjusted to 1% by weight. The coating amount was 0.144 g / m ² . The leukocyte removal rate was 99.47% and the platelet removal rate was 100%, indicating that the leukocyte removal rate and the platelet removal rate were excellent. Erythrocyte adhesion was hardly observed.

[0056]

Comparative Example 3 The procedure of Example 1 was repeated except that the commercially available poly-2-hydroxyethyl methacrylate used in Example 7 was used. The coating amount is 0.117 g / m
^{Was 2} . The leukocyte removal rate was 93.45% and the platelet removal rate was 62.1%, which was inferior to the leukocyte removal rate and platelet removal rate. . Erythrocyte adhesion was hardly observed.

[0057]

Comparative Example 4 The same procedure was performed as in Example 1, except that only the nonwoven fabric was used. The leukocyte removal rate was 84.83% and the platelet removal rate was 89.6%, which was inferior to the leukocyte removal rate and platelet removal rate. Erythrocyte adhesion was hardly observed.

Table 1 summarizes the results of Examples 1 to 7 and Comparative Examples 1 to 4.

[Table 1]

[0059]

The leukocyte-removing filter material of the present invention has the effect of transmitting red blood cells and plasma from a leukocyte- and platelet-containing liquid represented by whole blood and efficiently removing white blood cells and platelets.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 71/78 B01D 71/78 71/80 71/80 C08F 291/00 C08F 291/00 293/00 293 / 00 // D06M 15/267 D06M 15/267 (72) Inventor Hirofumi Miura 2111-2, Ojiri, Oita-shi, Oita F-term in Asahi Medical Co., Ltd. (Reference) 4C077 AA12 BB02 BB03 BB03 KK11 LL13 MM07 MM09 NN09 PP02 PP03 PP08 PP10 PP12 PP13 PP19 4D006 GA13 HA41 MA03 MA22 MB09 MC14 MC18 MC22 MC30 MC30X MC37 MC38 MC40 MC45 MC54 MC78 MC81 MC82 MC85 NA46 NA63 NA64 PB09 PB45 PB46 4J026 AA38 AA45 AA48 AA50 AA76 BA06 BA29 BA32 BA39419

Claims (5)

[Claims] 1. A graft or block copolymer having a polymer segment comprising a monomer having a nonionic hydrophilic group and a polymer segment comprising a monomer having a basic nitrogen-containing functional group is provided on at least the surface of a filter substrate. A filter material for removing platelets and leukocytes, comprising: 2. The monomer having a basic nitrogen-containing functional group has a repetition number of 40 or more, and the content of a polymer segment composed of a monomer having a basic nitrogen-containing functional group is 0.5% by weight or more. The filter material for removing platelets and leukocytes according to claim 1, which is less than 30% by weight. 3. The method according to claim 1, wherein the monomer having a nonionic hydrophilic group is 2
-Hydroxyethyl (meth) acrylate, wherein the monomer having a basic nitrogen-containing functional group is N, N-dimethylaminoethyl (meth) acrylate or N, N-diethylaminoethyl (meth) acrylate. Item 3. The filter material for removing platelets and leukocytes according to Item 1 or 2. 4. The number of repetitions of a monomer having a basic nitrogen-containing functional group, comprising a polymer segment comprising a monomer having a nonionic hydrophilic group and a polymer segment comprising a monomer having a basic nitrogen-containing functional group Is 40 or more, and the content of the polymer segment composed of a monomer having a basic nitrogen-containing functional group is 0.5% by weight or more and 30% or more.
Graft or block copolymer that is less than weight percent. 5. The method according to claim 1, wherein the monomer having a nonionic hydrophilic group is 2
The graft according to claim 4, which is -hydroxyethyl (meth) acrylate, and wherein the monomer having a basic nitrogen-containing functional group is N, N-dimethylaminoethyl (meth) acrylate or N, N-diethylaminoethyl (meth) acrylate. Or a block copolymer.