JP2003265596A - Leukocyte selective adsorbent and evaluation and selection method thereof - Google Patents

Abstract

[PROBLEMS] To provide a polymer composition having high leukocyte selective adsorption and to provide a method for selecting a polymer composition having high leukocyte selective adsorption. SOLUTION: A polymer composition suitable for a leukocyte selective adsorbent is evaluated and selected by salt concentration change liquid chromatography. Specifically, salt concentration change liquid chromatography measurement was performed using the polymer composition as a sample, and the salt concentration was 1
It is possible to select a polymer composition having excellent leukocyte selective adsorption characteristics using as an index that the recovery rate of the sample that has been desorbed and recovered from the chromatographic separation agent before reaching mM is 85% or more. it can. According to the present invention, it is possible to select a polymer composition having a high leukocyte selective adsorptivity without measuring the number of passing blood cells or the number of adsorbed blood cells of leukocytes and platelets of the filter structure using the polymer composition. it can.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer composition suitable for a leukocyte-selective adsorbent that selectively removes leukocytes from blood and allows platelets to pass through. The present invention also relates to a method for selectively evaluating a polymer composition suitable for such a leukocyte-selective adsorbent. More specifically, the present invention relates to a leukocyte-selective adsorbent for selectively removing leukocytes in blood during blood transfusion or extracorporeal circulation, or for selectively removing leukocytes in the process of producing concentrated platelet plasma from blood, and a selective evaluation method thereof. .

[0002]

2. Description of the Related Art In recent years, component transfusion for transfecting only necessary components in blood for the treatment of various diseases has become popular. Blood products used for component transfusion, such as concentrated red blood cells, concentrated platelets, and platelet poor plasma, are prepared by centrifuging whole blood. However, blood products prepared by centrifugation contain many white blood cells, and these white blood cells cause side effects after blood transfusion, such as headache in minor cases and white blood cells in nausea to severe cases. It has been clarified that infection by the virus present in the. Removing leukocytes contaminated in plasma products is effective in preventing posttransfusion side effects. Normally, whole blood contains 10 million white blood cells per ml, and in order to prevent minor side effects such as headache, the number of white blood cells infused into a patient in a single blood transfusion is about 100 million. It is said that the leukocyte residual rate in blood products (based on whole blood) needs to be 1/10 to 1/100 or less. Further, if this residual rate can be set to 1/10000 to 1/100000, it is expected that serious side effects can be prevented.

As industrial means for removing leukocytes from blood products, there are a centrifugal separation method and a filtration method using a filter having a fibrous structure such as a non-woven fabric, a mesh structure or a sponge structure. Hereinafter, a filter having a fibrous structure such as a non-woven fabric, a mesh structure or a sponge structure is generically called a filter material. Many of the filter materials used in the filtration method adsorb not only leukocytes but also highly adhesive platelets and remove them from blood products and blood. Selectively remove leukocytes and allow platelets to pass through. The filter material is coveted.

In order to meet such demands, the physical structure of the filter material, the physical structure of the surface of the filter material (unevenness, etc.) and the chemical structure (concentration of surface functional group and surface composition,
Efforts have been made to devise the surface charge density). For example, a porous membrane or non-woven fabric forming the filter material may be composed of a polymer composition having high leukocyte selectivity, or a polymer composition having high leukocyte selectivity may be formed on the surface of the porous membrane or non-woven fabric constituting the filter material. Methods such as coating to give leukocyte selectivity to the surface of the filter material have been investigated.

The chemical structure of the surface of the filter material is such that, if the polymer composition is a copolymer, the copolymerization ratio and block property (for example, block chain length, ratio of chain length of various blocks,
The number of block chains is greatly affected, and if the polymer composition is a blend of polymers having different compositions,
It is greatly influenced by the composition and blending ratio of each polymer substance to be mixed. However, in general, measuring the copolymerization ratio and block property of a copolymer, the blending ratio of a blend, or confirming the uniformity of the composition of a copolymer or a blend generally means that a polymer composition has a molecular weight distribution or It is extremely difficult because it is a complex composition in which different components such as composition distribution are mixed. Even if a polymer is polymerized or a polymer composition is prepared based on a certain design, it is very difficult to clarify the molecular structure and detailed composition of the polymer composition that actually exists. is there. Even if the composition ratio and the molecular weight as an average value of such a complicated polymer composition are known, it is not possible to explain the relevance of whether or not the polymer composition has expected properties such as leukocyte selective adsorption. In many cases.

The zeta-potential and wettability of a filter material composed of a polymer composition or a base material coated with a polymer composition can be used as an index of leukocyte selective adsorption. The index of is only an average characteristic value on the surface of the filter material and is not directly related to the affinity or adsorptivity with blood cells, so even if it can be an index of the adsorptivity of leukocytes, it does not affect the selective adsorptivity of leukocytes and platelets. It does not serve as an indicator.

Under these circumstances, conventionally, in order to evaluate the leukocyte selectivity of a certain polymer composition, the polymer composition is actually used to construct the structure itself, or the structure serving as a substrate is used. There was no method other than to prepare a filter material by means such as coating a polymer composition on the above and to measure the number of leukocytes or blood platelets passing through or adsorbed blood cells individually by flowing blood or a blood product.

[0008]

The problem to be solved by the present invention is to provide a polymer composition having a high leukocyte selective adsorption property. Another object of the present invention is to provide a method for selecting a polymer composition having high leukocyte selective adsorption.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a polymer recovered when a certain salt concentration is exceeded in salt concentration change liquid chromatography measurement. The inventors have found that the platelet recovery rate of the composition decreases sharply, and have reached the present invention. The present invention performs a salt concentration change liquid chromatography measurement using a polymer composition as a sample, and the recovery rate of the sample that can be eluted and recovered by desorption from the chromatographic separation agent until the salt concentration reaches 1 mM is 85% or more. By using the above as an index, a polymer composition having excellent leukocyte selective adsorption properties is provided.

That is, the present invention provides (1) a method for evaluating and selecting a polymer composition suitable for a leukocyte selective adsorbent by salt concentration change liquid chromatography, and (2) a salt concentration dissolved in a mobile phase of 0 to a predetermined value. A method comprising measuring the amount of polymeric composition recovered before increasing to a concentration.
The evaluation and selection method described above, (3) selecting a polymer composition having a recovery rate of 85% or more by the time the salt concentration dissolved in the mobile phase reaches 1 mM in liquid chromatography with salt concentration change described above ( The evaluation selection method described in 2),
(4) The mobile phase in liquid chromatography is a water-soluble polar organic solvent or a mixed solution of an organic solvent containing a water-soluble polar organic solvent, as described above in (1) to
The evaluation and selection method according to any one of (3) and (5) above, wherein the polar organic solvent is methanol.
(6) The evaluation and selection method described in (6) above, wherein the salts dissolved in the mobile phase have no ultraviolet absorption, and the solubility of the salts in the mobile phase at 25 ° C. is 1 mM or more. Evaluation selection method according to any one of 2) to (5), (7) Evaluation selection method according to any one of (1) to (6) above, wherein the salt is hypophosphite ,
(8) Change in salt concentration In a separation by liquid chromatography, a leukocyte-selective adsorbent consisting of a polymer composition having a recovery rate of 85% or more until the concentration of salt dissolved in the mobile phase reaches 1 mM, (9) The mobile phase in liquid chromatography is a water-soluble polar organic solvent or a mixed liquid of organic solvents containing a water-soluble polar organic solvent, and the leukocyte-selective adsorbent according to (8) above, (10) polar organic solvent (9) The white blood cell selective adsorbent according to (9) above, wherein (11) the salts dissolved in the mobile phase have no absorption in the ultraviolet region, and 25
The white blood cell selective adsorbent according to any one of (8) to (10) above, wherein the solubility at 1 ° C is 1 mM or more, and (12) the salt is hypophosphite. Any of the above (8) to (12), wherein the leukocyte selective adsorbent according to any of (8) to (11), and (13) the polymer composition is a polymer compound having a polar group. (14) The leukocyte-selective adsorbent according to (13), wherein the polar groups are a hydroxyl group and an amide group, and both have in the molecule at the same time.
It is about. According to the present invention, it is possible to select a polymer composition having a high leukocyte-selective adsorption property without measuring the number of passing blood cells or the number of adsorbed blood cells of leukocytes and platelets of a filter structure using the polymer composition. it can.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The salt concentration change liquid chromatography of the present invention refers to a method in which an organic solvent is used as a mobile phase of liquid chromatography and is passed through a column packed with a chromatographic separation agent or a capillary coated with the chromatographic separation agent. In this state, a sample solution of the polymer composition was injected into the column or the capillary and adsorbed on the chromatographic separation agent, and then the mobile phase was changed to a solution in which salts were dissolved in the organic solvent, It refers to liquid chromatography in which the polymer composition adsorbed on the chromatographic separation agent is eluted and recovered by changing the concentration of salts. The applicant has previously filed a patent application for this novel liquid chromatography method (Japanese Patent Application No. 2001-3).
77786).

In the present invention, a method for evaluating and selecting a polymer composition suitable for a leukocyte selective adsorbent is to select a composition having an excellent function of selectively removing leukocytes from various polymer compositions. Or evaluating the ability of the polymer composition to selectively remove leukocytes.

The recovery rate in the chromatography of the present invention means the polymer composition eluted and recovered with respect to the dry weight Wi of the polymer composition injected into the column or the capillary in the salt concentration change liquid chromatography. The ratio (percentage) of the dry weight Wr of the product, that is, (Wr /
Wi) means 100.

The polymer composition of the present invention may be any polymer substance having various adsorbability to white blood cells, red blood cells and platelets. In order to impart selectivity to different types of blood cells, the polymer substance that constitutes the polymer composition has a polar functional group showing hydrophilicity or ionicity in the molecule, and the hydrophobic functional group is a molecule. It is desirable to have a molecular structure that coexists at an arbitrary ratio. Examples of the polar functional group include a hydroxyl group, an amino group, an amide group, a sulfone group, a carboxyl group and a nitro group, but are not limited thereto. The polar structure also includes an ether bond such as that in 2-methoxyethyl (meth) acrylate. It is essential that the polymer composition has polar functional groups, but the proportion of hydrophobic functional groups is arbitrary. The distribution of these functional groups in the molecular chain may be regular or not regular. That is, it may be a homopolymer consisting of a polar functional group, may be a random copolymer of a polar functional group and a hydrophobic functional group or a block copolymer, and the constituent elements of the copolymer are Any number is acceptable. It may or may not have stereoregularity. Further, it may be a mixture in which two or more different polymer compositions are mixed at an arbitrary ratio. The polar group existing in the molecule is not limited to one type, and a plurality of polar groups may exist in the molecule. For example, a combination of polar groups capable of forming a hydrogen bond, such as a hydroxyl group and an amide group, is preferable for improving the selectivity.

Examples of the polymer composition include a binary copolymer of 2-hydroxyethyl (meth) acrylate and dimethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and dimethylaminoethyl (meth). ) Acrylate, terpolymer of methyl (meth) acrylate, binary copolymer of 2-hydroxypropyl (meth) acrylate and dimethylaminoethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, dimethyl Examples thereof include, but are not limited to, terpolymers with aminoethyl (meth) acrylate and methyl (meth) acrylate. In addition, (meth) acrylate here means an acrylate and / or a methacrylate.

The leukocyte selective adsorbent of the present invention is a polymer composition having a function of selectively removing leukocytes from blood and allowing red blood cells and platelets to pass through. Generally, if the adsorbent has a high leukocyte adsorbing ability, the adsorbability for platelets also tends to be high at the same time, and the leukocyte selective adsorbability is lowered. The leukocyte-selective adsorbent provided by the present invention is non-adsorptive of platelets,
That is, it is a leukocyte adsorbent having a high platelet recovery rate. The leukocyte selective adsorbent of the present invention is an adsorbent having a low leukocyte residual rate and a high platelet recovery rate. The leukocyte residual rate and platelet recovery rate are not necessarily constant depending on the size and volume of the filter material used for measurement, the filtration pressure, the amount of blood to be processed, and the origin of the blood used, but the source blood and the filtered blood obtained by filtration The number of white blood cells and the number of platelets are measured, and the white blood cell adsorption coefficient and the platelet recovery rate can be obtained using the equations (1) and (2). Strictly speaking, it is possible to compare only in the evaluation results using the same blood by the same evaluation method, but the white blood cell selection coefficient is defined as in the formula (3) and used as a standard for relatively comparing performances. be able to. Leukocyte adsorption coefficient = −log {(white blood cell concentration in the collected liquid after filtration) / (white blood cell concentration in the blood before filtration)} (1) Platelet recovery rate (%) = {(platelet concentration in the collected liquid after filtration) / (Platelet concentration in blood before filtration) × 100 (2) White blood cell selection coefficient = (white blood cell adsorption coefficient) × (platelet recovery rate) / 100 (3)

Change in Salt Concentration The recovery rate of the polymer composition in the liquid chromatography separation increases as the salt concentration increases. That is, as the salt concentration increases, the polymer composition strongly adsorbed on the separating agent gradually elutes. Since the strongly adsorbed polymer composition exhibits strong adsorbability to blood cells, it also adsorbs leukocytes and firmly adsorbs platelets. Therefore, it is not preferable that the leukocyte-selective adsorbent contains a component of the polymer composition that is eluted under the condition of high salt concentration, in order to achieve high leukocyte selectivity. As a result of intensive studies on the relationship between the selective removal ability of leukocytes and the recovery rate of the polymer composition by the salt concentration change liquid chromatography separation of the present invention, the inventors have found that the recovery rate is 85% or more by the time the salt concentration reaches 1 mM. The present invention has been completed, and it was found that the polymer composition having the above-mentioned composition exhibits excellent leukocyte selective adsorption.

In blood cell adsorption using blood, the values of the white blood cell selection coefficient, the platelet recovery rate, and the white blood cell selection coefficient vary depending on the individual blood properties, the device for performing the adsorption experiment, and the blood cell evaluation method. If the experimental conditions shown in the examples of the present invention, leukocyte adsorption coefficient is 3.
5 or more, Platelet recovery rate is 30% or more, White blood cell selection coefficient is 1.0
If it is 5 or more, it can be said that it has the performance as a leukocyte selective adsorbent.

For example, as shown in Example 1, the recovery rate is
The polymer composition copolymer B of 85% or less had a leukocyte selectivity coefficient of 1 or less, and was inferior in performance as a leukocyte selective adsorbent. As shown in Example 2, the copolymer B * obtained by removing the components strongly adsorbed to the separating agent from the polymer composition contained in the copolymer B had a white blood cell selectivity coefficient of
It was 1.05 or more, and the recovery rate of the high-molecular component by the liquid chromatography measurement with salt concentration change was 85%, which showed excellent performance as a leukocyte-selective adsorbent.

The organic solvent of the present invention may be any water-soluble polar organic solvent. Preferred solvents include alcohols such as methanol, ethanol and propanol, amines such as propylamine, diethylamine and triethylamine, ketones such as methyl ethyl ketone and acetone, ethers such as diethyl ether, N, N-
Examples thereof include amides such as dimethylformamide and N, N-dimethylacetamide, cyclic ethers such as tetrahydrofuran, nitrogen-containing cyclic compounds such as pyridine, and acetonitrile. Among these water-soluble polar organic solvents, those having a boiling point of 100 ° C. or less are more preferable because of the ease of removing the solvent after separating the components. The organic solvent used for the mobile phase is
One kind may be used, or a mixed solution of a plurality of organic solvents may be used.

The chromatographic separating agent of the present invention is insoluble and stable in the mobile phase of liquid chromatography, and has the ability to adsorb the copolymerized polymer to be separated in the mobile phase containing no salts. Anything is acceptable as long as it exists. In order to perform more precise separation, a specific homopolymer (for example, having a blood cell adsorbing ability) among homopolymers of monomers constituting the copolymer to be separated in a mobile phase containing no salt Preferred is a separating agent which is capable of strongly adsorbing a homopolymer of a monomer which has a strong influence on the expression of leukocyte selective adsorption ability.

The mobile phase of the present invention is the mobile phase of liquid chromatography, and is an organic solvent or a mixture of organic solvents in which the polymer composition to be separated is soluble, and the organic solvent or organic solvent. It is prepared by dissolving salts in a mixed solution of solvents.

The salt of the present invention may be any salt as long as it is soluble in a water-soluble polar organic solvent used as a mobile phase or a polar organic solvent. However, salts that are not detected by the detection method used for chromatography are preferable. In the present invention, since the salt concentration of the mobile phase is changed, the refractive index method is not suitable, and since the salts are generally non-volatile, the solvent evaporation light scattering method cannot be used as a detection method, so that the ultraviolet absorption detection is performed. It is appropriate to use a vessel. Therefore, as the salts, salts having no ultraviolet absorption such as hypophosphite such as sodium hypophosphite are preferable.

In the salt concentration change liquid chromatography of the present invention, first, a sample of the polymer composition of interest is adsorbed on the surface of the separating agent by a mobile phase containing no salt, and then gradually or stepwise. By increasing the concentration of salts in the organic solvent, the components are separated due to the difference in adsorption power. When using a mobile phase in which salts are dissolved,
Blocking of the column due to salt precipitation and contamination of the detection part pose problems. Therefore, the higher the solubility of the salt to be dissolved, the less the risk of blockage of the column and the contamination of the detection section, the easier the preparation of the mobile phase, and the expected desorption effect at a high concentration. Salts having a solubility in an organic solvent of 1 mM or less at 25 ° C are not preferable because there is a risk of blockage of the column and contamination of the detection part. If the solubility of the salt in the organic solvent is 1 mM or more at 25 ° C, the effect as a releasing agent can be expected. If the solubility of the salt in the organic solvent at 25 ° C is 5 mM or more,
The area of concentration change is widened and high desorption effect can be expected,
More preferable.

The concentration range for changing the salt concentration in the mobile phase can be set according to the solubility of the salt used.
When focusing on the selectivity of leukocytes and platelets as in the present invention, the recovery rate of the polymer composition eluted to a salt concentration of up to 1 mM is preferably 85% or more, but the principle of the present invention is white blood cells and platelets. It is not limited only to the selective adsorption of. That is, as the performance of the polymer composition, the type of white blood cells such as neutrophils, monocytes, and lymphocytes is distinguished to evaluate the selective adsorption property with platelets, for example, the selective adsorption property with red blood cells and platelets is evaluated. When assessing selective adsorption between various blood cell combinations, or blood cell components and proteins, or between multiple proteins, the upper limit salt concentration to be eluted is not limited to 1 mM, and the polymer composition The recovery rate in the salt concentration change liquid chromatography separation is not limited to 85% or more, and it is possible to determine by determining the salt concentration and the recovery rate according to each condition. When desalting is required after separating the components, it is preferable to change the salt concentration at 0 to 10 mM.

The change in salt concentration in the present invention is
It is carried out by preparing an organic solvent or a mixed solution of the organic solvent and a solution of salts dissolved in the organic solvent or the mixed solution of the organic solvent in separate bottles, and changing the mixing ratio thereof.
These liquids are mixed by using a pump and a mixer, and then flowed on the column as a mobile phase. The salt concentration may be increased gradually or stepwise. When increasing the salt concentration stepwise, the peak is sharpened to improve the peak separability, and in order to eliminate the influence of the salt adsorbed on the surface of the separating agent, the salt is not added before changing the concentration. It is desirable to pass the mobile phase through the column once. The salt concentration may be gradually or stepwise reduced, but the effect cannot be expected because the sample polymer has been desorbed from the surface of the separating agent by the mobile phase containing a high concentration of salt.

The present invention will be described in detail below with reference to examples.
The present invention is not limited to this.

Example 1 A monomer molar ratio of 2-hydroxyethyl methacrylate (hereinafter abbreviated as HEMA) and dimethylaminoethyl methacrylate (hereinafter abbreviated as DM) was HEM.
A monomer mixture of A: DM = 97: 3 was dropped into the reaction vessel, and copolymer A was synthesized by usual solution radical polymerization. Separately, after dropping a monomer mixture having a monomer molar ratio of HEMA: DM = 70: 30 into the reaction vessel,
Only HEMA is added dropwise and the final monomer molar ratio is HEMA: DM
= 97: 3 to prepare a copolymer B. 2,2'-azobis (2,4-dimethylvaleronitrile) as an initiator
0.04 mol / l ethanol solution was added dropwise to the reactor at 0.5 ml / min. The monomer mixture was added dropwise into the reactor at 1.4 ml / min. Polymerization reaction was carried out in an ethanol solvent at 78 ° C. for 8 hours. The average molar fraction of DM in both polymers was confirmed by NMR, and the average molecular weight was confirmed by GPC. The DM mole fractions of copolymer A and copolymer B are 2.5% and 2.6%, respectively,
The weight average molecular weight (Mw) was 480,000 and 410,000, respectively.
Mw is a value converted into polymethylmethacrylate.

Salt concentration change liquid chromatography samples were prepared by dissolving Copolymer A and Copolymer B in methanol to a polymer concentration of 50 mg / 3 ml methanol. The sample solution was injected into the column at a shot amount of 20 μl. Solution concentrations (liquid) (methanol) and solution II (1 mM sodium hypophosphite /
Methanol solution), either individually or by mixing two liquids at a predetermined volume ratio with a low pressure pump and a mixer,
The concentration of sodium hypophosphite was changed in three steps of 0.1, 0.5 and 1.0 mM. Figure 1 shows the change over time in the concentration of sodium hypophosphite in the mobile phase at the column inlet. Asahipak GS-620HQ (manufactured by Showa Denko: crosslinked PVA gel into which a carboxyl group was introduced) packed with a separating agent that easily adsorbs poly-DM in methanol but does not adsorb poly-HEMA was used for the separation column. Mobile phase flow rate 0.5 ml / min, column temperature 40 ° C
And An ultraviolet detector (detection wavelength: 214 nm) was used to detect the eluted polymer. The polymer recovery of each sample was 100% for polymer A and 76% for copolymer B.
The DM fraction of the recovered components was 2.46% for copolymer A.
And almost equal to that of the original copolymer A, this result confirming that the recovery was 100%. The copolymer A with a uniform composition has a high recovery rate of 100%, whereas the copolymer B, which is expected to have a non-uniform composition and a wide composition distribution, has a recovery rate of 76%. Yes,
The DM mole fraction of the recovered component was 2.14%. In the copolymer B, the component having a high DM mole fraction remained adsorbed on the separating agent. The calculated DM mole fraction of the adsorbed component of the copolymer B was 3.8%.

Next, the obtained copolymer A and copolymer B were coated on a filter substrate by the method shown below. Copolymer A 10g and copolymer B 10g each 50wt
% Copolymer of isopropyl alcohol and dissolved at 40 ° C. to prepare a 5 wt% coating solution of each copolymer. A non-woven fabric made of polyethylene terephthalate fiber having an average fiber diameter of 1.2 μm (40 g / m ² basis weight, thickness 0.20 mm, width 150 mm) was continuously dipped in the coating solution, and then passed through by sandwiching it with a nip roll, The different coating solutions were removed. The coated nonwoven fabric was dried overnight at room temperature in a drying chamber equipped with an exhaust duct, and then collected.

The coated non-woven fabric thus produced was arbitrarily cut into a circular shape having a diameter of 20 mm, and 32 pieces thereof were filled in a filter holder (filling density 0.2 g / cm ³ ).
Human fresh whole blood prepared by the method described below was added to this column.
Flow at a constant flow rate of 0.74 ml / min using a syringe pump,
The 13.3 ml was collected. Fresh human whole blood is the blood sampled
For 100 ml, filtered CPD solution as anticoagulant (trisodium citrate dihydrate 26.3 g, citric acid monohydrate
3.27 g, glucose 23.2 g, and sodium dihydrogen phosphate dihydrate 2.51 g are dissolved in distilled water for injection 1000 ml,
It was prepared by adding 14 ml of a solution (filtered through a filter having a pore size of 0.2 μm), mixing and storing at 20 ° C. for 3 hours. A fixed amount of blood was collected from the blood before filtration and the collected liquid after filtering the blood, and the leukocyte concentration was measured by the LeucoCOUNT ^™ kit, a reagent system for residual leukocyte measurement.
Flow cytometer FACSCalibur and analysis software CELL Quest (above, BD Bio
(Science, USA). In addition, the platelet concentration is determined by the automatic blood cell counter MAX A / L-Retic.
(BECKMAN COULTER, USA).

The leukocyte adsorption coefficient and the platelet recovery rate were determined by the above equations (1) and (2), respectively. Further, the white blood cell selection coefficient was calculated by the above equation (3). The selection coefficient represented by the equation (3) has a large value when the recovery rate of platelets is high, and thus it can be considered that white blood cells are selectively removed. When the leukocyte adsorption coefficient is almost the same or the platelet recovery rate is almost the same, the relative evaluation of the nonwoven fabric is possible by using the leukocyte selection coefficient.

3 hemofiltration experiments using this filter
I went there. Table 1 shows the average values of the leukocyte adsorption coefficient, the platelet recovery rate, and the leukocyte selection coefficient when the copolymer was used. The leukocyte adsorption coefficients of Copolymer A and Copolymer B were almost the same, but the platelet recovery rate was higher in Copolymer A. This difference could be measured as a difference in white blood cell selection coefficient. The polymer component recovery rate of copolymer A was 100%, but the polymer component recovery rate of copolymer B was as low as 76%, which was 24%.
Was adsorbed on the separating agent and could not be eluted and collected by the liquid chromatography with change in salt concentration.

[0033]

Example 2 9 g of the copolymer B synthesized in Example 1 was added to 300 m
It was dissolved in l of methanol to prepare a sample solution. Asahipak GS-6
The sample solution was injected into a preparative column (inner diameter: 21.5 mm, length: 50 cm) packed with 20HQ in a volume of 3 ml. Salt Concentration Change Liquid I (methanol) and liquid II (1 mM sodium hypophosphite / methanol solution) were used as mobile phases for liquid chromatography, and the concentration of sodium hypophosphite was 1.0 mM.
Varyed in stages. The mobile phase flow rate was 1.5 ml / min, and the column temperature was 40 ° C. An ultraviolet detector (detection wavelength: 214 nm) was used to detect the eluted polymer, and the eluate in which the polymer component was dissolved was collected. Methanol was removed from this eluate by an evaporator, and then distilled water was added to precipitate and collect a polymer component. Further, it was vacuum dried to recover the polymer component as a solid content. Copolymer B recovered by elution with sodium hypophosphite by repeating such operations
About 5 g of ingredient B * of was prepared. When the recovery of the polymer component in the salt concentration change liquid chromatography of the copolymer B * was measured by the same method as in Example 1, it was 85%.

4 g of copolymer B * was dissolved in 76 g of 50 wt% isopropyl alcohol aqueous solution at 40 ° C. to prepare copolymer B *.
A 5 wt% coating solution was prepared and coated on a nonwoven fabric in the same manner as in Example 1. In the same procedure and method as the hemofiltration of Example 1,
Blood was filtered using a non-woven fabric coated with copolymer B * as a filter material to measure the leukocyte adsorption coefficient and the platelet recovery rate. Simultaneously, using the non-woven fabric coated with the copolymer A prepared in Example 1, blood collected from the same person was filtered,
The leukocyte adsorption coefficient and the platelet recovery rate were measured. The results are shown in Table 1.
Shown in. The leukocyte adsorption coefficient of copolymer B * was the same as that of copolymer B, but the leukocyte selectivity coefficient was as high as that of copolymer A because the platelet recovery rate was close to that of copolymer A.

[0035]

[Table 1]

From the results of Examples 1 and 2, when the recovery rate of the high molecular component is 85% or more, the leukocyte selective removal coefficient is
It was found to be 1.05 or more, which is excellent in leukocyte selective removal performance.

[0037]

EFFECTS OF THE INVENTION According to the present invention, it is possible to select a polymer composition having a high leukocyte-selective adsorptivity without measuring the passing blood cell count or the adsorbed blood cell count of the filter structure using the polymer composition. Thus, a polymer composition having excellent leukocyte selective adsorption properties can be provided.

[Brief description of drawings]

FIG. 1 is a time change of the sodium hypophosphite concentration of the mobile phase at the column entrance in Example 1.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01J 20/26 B01J 20/26 H G01N 30/14 G01N 30/14 Z 30/26 30/26 A 30/88 30 / 88 E // A61K 35/14 A61K 35/14 C A61P 7/00 A61P 7/00 7/08 7/08 (72) Inventor Takuya Morikawa 1 No. 2 Samejima, Fuji-shi, Shizuoka Asahi Kasei Corporation F-term ( Reference) 4C077 AA12 BB02 BB03 KK11 LL01 LL23 MM09 NN02 PP10 4C087 AA04 BB38 DA15 DA18 DA21 ZA51 4D017 AA11 BA07 CA13 CB01 DA03 EA05 EB10 4G066 AC17B AD11B AD20B CA20 DA12 EA01

Claims (14)

[Claims] 1. A method for evaluating and selecting a polymer composition suitable for a leukocyte-selective adsorbent by salt concentration change liquid chromatography. 2. The evaluation and selection method according to claim 1, which comprises measuring the amount of the polymer composition recovered until the salt concentration dissolved in the mobile phase is increased to 0 to a predetermined concentration. 3. The evaluation according to claim 2, which comprises selecting a polymer composition having a recovery rate of 85% or more by the time the salt concentration dissolved in the mobile phase reaches 1 mM in the liquid chromatography with varying salt concentration. Selection method. 4. The mobile phase in liquid chromatography is a water-soluble polar organic solvent or a mixed liquid of organic solvents containing a water-soluble polar organic solvent, according to claim 1. Evaluation selection method. 5. The evaluation / selection method according to claim 4, wherein the polar organic solvent is methanol. 6. The salt dissolved in the mobile phase has no ultraviolet absorption, and the solubility of the salt in the mobile phase at 25 ° C. is 1 mM or more.
Evaluation selection method according to any one of 1. 7. The evaluation / selection method according to claim 1, wherein the salt is hypophosphite. 8. A leukocyte-selective adsorbent comprising a polymer composition having a recovery rate of 85% or more until the concentration of the salt dissolved in the mobile phase reaches 1 mM in the separation by salt concentration change liquid chromatography. 9. The leukocyte-selective adsorbent according to claim 8, wherein the mobile phase in liquid chromatography is a water-soluble polar organic solvent or a mixed solution of organic solvents containing a water-soluble polar organic solvent. 10. The leukocyte-selective adsorbent according to claim 9, wherein the polar organic solvent is methanol. 11. The salt dissolved in the mobile phase has no absorption in the ultraviolet region, and the solubility of the salt in the mobile phase at 25 ° C. is 1 mM or more.
10. The leukocyte-selective adsorbent according to any one of 10. 12. The leukocyte-selective adsorbent according to any one of claims 8 to 11, wherein the salt is hypophosphite. 13. The leukocyte-selective adsorbent according to any one of claims 8 to 12, wherein the polymer composition is a polymer compound having a polar group. 14. The leukocyte-selective adsorbent according to claim 13, wherein the polar groups are a hydroxyl group and an amide group, and both have in the molecule at the same time.