JP2007054212A - Quantification method of anionic electric charge and blood treatment filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quantification method of anionic electric charges, which enables the proper evaluation of the production capacity of bradykinin for a filter base material by the accurate quantification of the anionic electric charges on the surface of the filter base material. <P>SOLUTION: The surface of the filter base material having an ionized substance with a cationic electric charge held by the surface of a nonwoven fabric having an anionic electric charge is dyed using a dye agent comprising a pigment having a cationic electric charge and the reflectance absorbance of the surface of the filter base material is measured to quantify the anionic electric charge. In the dyeing of the surface of the filter base material, the dye agent is adsorbed by the surface of the filter base material using a dyeing assistant. After the surface of the filter base material is dyed, the surface of the filter base material is kept in contact with a dye mordant to fix the dye agent on the surface of the filter base material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an anionic charge quantification method and a blood treatment filter.

  In recent years, blood and the like from which only necessary components have been separated and blood from which unnecessary components have been removed have been used in the field of clinical blood transfusion. Examples thereof include blood from which leukocytes have been removed in order to prevent side effects such as alloantigen sensitization and non-hemolytic fever reaction.

  For separating such necessary components and removing unnecessary components, a blood treatment filter having a filter made of polyester non-woven fabric or cotton cotton is often used.

  However, although the unnecessary components and the like are filtered and removed using a blood treatment filter, side effects different from the above may occur due to the use of blood after treatment.

  For example, when a blood treatment filter having a filter made of a material having an anionic charge on the surface is used for filtration, bradykinin may be produced in a large amount in the blood after filtration. Since this bradykinin is a substance having a blood pressure lowering effect, it is not preferable to produce it in a large amount.

  Bradykinin is produced (increased) when an anionically charged material comes into contact with blood and blood coagulation factor XII is activated, and activated blood coagulation factor XII generates kallikrein from prekallikrein, Furthermore, this is because bradykinin is produced (produced) by limited decomposition of high molecular weight kininogen by kallikrein.

For example, Patent Document 1 discloses that the absorbance of the supernatant of an aqueous solution after immersing the blood filtration material in an aqueous solution of a dye having a cationic charge and adsorbing the dye to the blood filtration material is the same without adding the blood filtration material. The surface to measure the negative charge amount from the amount of the dye adsorbed on the blood filtration material by preparing the calibration curve with the material whose negative charge amount is known in advance and measuring the absorbance when not adsorbed A negative charge measurement method is described.
In addition, the negative charge amount obtained here is positive charge amount plus (+), negative charge amount is represented by minus (-) charge amount after both charges are canceled, that is, from the positive charge amount This is the charge amount minus the negative charge amount.
Japanese Patent No. 3176852

  However, in the surface negative charge measurement method based on the absorbance measurement of an aqueous solution described in Patent Document 1 based on the research of the present inventor, after a substance having a cationic charge is held on the surface of the filter base, the filter base It was found that the amount of anionic charge remaining on the surface of the film cannot be accurately grasped.

That is, the surface negative charge measurement method by measuring the absorbance of an aqueous solution can determine whether or not a substance having a cationic charge is retained on the surface of the filter substrate, but it has been found that there is no accuracy to predict the production of bradykinin. .
Further, in the surface negative charge measurement method by measuring the absorbance of an aqueous solution, when the blood filtration material (filter base material) is low in hydrophilicity, it is difficult to immerse in the aqueous solution, resulting in variations in the absorbance measurement results of the aqueous solution. There is also a problem.
For this reason, it is extremely difficult to appropriately evaluate the bradykinin producing ability of the filter base material by blood filtration in the surface negative charge measuring method by measuring the absorbance of the aqueous solution.

Therefore, an object of the present invention is to provide an anionic charge quantification method capable of appropriately evaluating the bradykinin-producing ability of a filter base material by accurately quantifying the anionic charge amount on the surface of the filter base material. It is.
Another object of the present invention is to provide a blood treatment filter having a filter base material with a low production amount of bradykinin in blood after filtration.
In the present invention, “blood” means a blood component or whole blood containing at least one selected from the group consisting of plasma, white blood cells, red blood cells, and platelets.

The present inventor has found a method for measuring only the anionic charge even in the presence of the cationic charge amount, not the total charge amount of the filter substrate.
In addition, the present inventors have found that a blood treatment filter having a filter base material whose surface anionic charge amount measured by this method is in a specific range has a low ability to produce bradykinin.
The said subject is solved by this invention of (1)-(8) shown below.

  (1) A method for quantifying an anionic charge, wherein the surface of a filter base material is dyed with a staining agent comprising a dye having a cationic charge, and the reflection absorbance of the surface of the filter base material is measured.

  (2) The anionic charge quantification method according to the above (1), wherein the filter base material is a non-woven cloth having an anionic charge held by a substance having a cationic charge.

  (3) The anionic charge quantification method according to the above (1) or (2), wherein the dyeing agent is adsorbed on the surface of the filter base material using a dyeing assistant when dyeing the surface of the filter base material. .

  (4) After dyeing the surface of the filter base material, the surface of the filter base material is brought into contact with a mordant to fix the dyeing agent on the surface of the filter base material. The anionic charge quantification method as described.

  (5) A blood treatment filter comprising a filter substrate having a reflected absorbance of 0.26 or less measured by the anionic charge quantification method according to any one of (1) to (4) above.

  (6) The blood processing filter according to (5), wherein the filter base is a non-woven fabric having an anionic charge and a substance having a cationic charge is held on the surface.

  (7) The blood treatment filter according to (5) or (6), wherein the filter base has a zeta potential of 6 to 30 mV.

  (8) The blood processing filter according to any one of (5) to (7), which is a leukocyte capturing filter or an aggregate capturing filter.

The anionic charge quantification method of the present invention can accurately quantify the amount of anionic charge on the surface of a filter substrate. In particular, it is possible to accurately quantify the amount of anionic charge remaining on the surface of the filter substrate after a substance having a cationic charge is retained on the surface of the filter substrate made of nonwoven fabric. In addition, the degree of bradykinin production of the filter substrate can be appropriately evaluated.
Moreover, the blood treatment filter of the present invention has a low bradykinin-producing ability of the filter base material by blood filtration since the reflection absorbance of the filter base material measured by the anionic charge quantification method is in a specific range.

  Hereinafter, an anionic charge quantification method and a blood treatment filter according to an embodiment of the present invention will be described in detail.

  The anionic charge quantification method of the present invention is characterized in that the surface of a filter substrate is dyed with a staining agent comprising a dye having a cationic charge, and the reflected absorbance of the surface of the filter substrate is measured. To do.

  This filter substrate can be used as a filter medium for a blood treatment filter. As described above, it is known that blood treatment filters have a large amount of bradykinin in blood after filtration if they have an anionic charge on the surface of the filter substrate. It is necessary to grasp (quantify) the amount of anionic charge existing on the surface.

Therefore, the anionic charge quantification method according to the embodiment of the present invention is a method for quantifying the amount of anionic charge present on the surface of a filter substrate used in a blood treatment filter.
In addition, the filter base material is obtained by holding a substance having a cationic charge (hereinafter also referred to as a cationized substance) on the surface of a nonwoven fabric having an anionic charge (hereinafter also referred to as an anionic nonwoven cloth).

That is, the anionic charge quantification method of the present embodiment uses a staining agent composed of a dye having a cationic charge on the surface of a filter base (blood treatment filter) in which a cationized substance is held on an anionic nonwoven fabric. It is dyed and the reflection absorbance on the surface of the filter substrate is measured.
Here, the wavelength at which the reflected absorbance is measured is determined by the type of the staining agent, that is, the dye having a cationic charge.

The staining agent is not particularly limited as long as it is a substance having a cationic charge in a neutral solution, but a basic dye having an amino group (—NH ₂ ) is preferable. Specific examples include safranin, methylene blue, magenta, malachite green, auramin, methyl violet, bismarck brown, and the like.

  In the anionic charge quantification method of this embodiment, when dyeing the surface of the filter base material, it is preferable to adsorb the dyeing agent on the surface of the filter base material using a dyeing assistant.

  The dyeing assistant is a dyeing agent that promotes the action of adsorbing the dye on the surface of the filter substrate. Specifically, for example, the salt is not particularly limited as long as it is a salt such as a sodium salt, a phosphate, or a potassium salt. The concentration of the dyeing aid is appropriate to be about 1 to 5% by weight, and preferably about 1% by weight. If it is less than this, a sufficiently expected effect cannot be obtained, and if it is more than this, the color of the staining agent may be discolored. Therefore, the amount of anionic charge can be measured (quantified) more accurately by using a dyeing assistant having an appropriate concentration.

  Further, in the anionic charge quantification method of the present embodiment, after staining the surface of the filter base, the surface of the filter base may be contacted with a mordant to fix the stain on the surface of the filter base. preferable.

  The mordant mediates between the stain and the filter base material, makes it easy to fix the stain adsorbed on the filter base material, and makes the color development clearer. Specifically, for example, calcium carbonate, calcium hydroxide, quicklime, copper sulfate, copper acetate, cuprous chloride, citric acid, potassium sodium tartrate, acetic acid, vinegar, sodium citrate, sodium chloride, potassium aluminum sulfate, sulfuric acid Aluminum ammonium, aluminum chloride, aluminum acetate, sodium stannate, stannous chloride, chromium acetate, ferrous chloride, ferrous sulfate, iron pyroacetate solution, hydrogen peroxide, ammonia, potassium dichromate, etc. Various metal salts, chlorides, acids and the like can be mentioned.

  The concentration of the dyeing assistant is appropriate to be about 1 to 5% by weight, and preferably about 1% by weight. If it is less than that, a sufficient expected effect cannot be obtained, and if it is more than that, the dyed color may be discolored. Accordingly, by using a mordant having an appropriate concentration, it becomes difficult for the stain to be detached from the surface of the filter base material, so that the amount of anionic charge can be measured more accurately.

Next, the blood processing filter according to the embodiment of the present invention will be further described.
The blood treatment filter of the present invention is characterized in that the reflection absorbance measured by the above-described anionic charge quantification method is 0.26 or less.
As described above, the blood treatment filter according to the embodiment of the present invention includes a filter substrate in which a substance having a cationic charge (cationized substance) is held on the surface of a nonwoven fabric having an anionic charge (anionic nonwoven cloth). It is what you have.

  Anionic charge is negative at neutral pH such as carboxyl group, phosphate group, phosphite group, sulfonate group, sulfate ester group, sulfite group, hyposulfite group, sulfide group, phenol group, hydroxyl group. Refers to an acidic functional group. This acidic functional group is an example and is not limited thereto.

  This anionic charge is hydrolyzed by, for example, heat, chemicals such as oxides, acids, alkaline solutions, radiation, etc. in the process of producing the negative functional group inherent to the anionic nonwoven material itself and the anionic nonwoven material. Including those produced by decomposition.

  As long as the anionic nonwoven fabric is an nonwoven fabric having an anionic charge, the average fiber diameter, the basis weight, the material (material), etc. are not particularly limited, and may be selected according to the application.

  For example, when the blood treatment filter of the present invention is used as a leukocyte capture filter, the average fiber diameter of the anionic nonwoven fabric is about 1 to 20 μm, preferably about 1.5 to 15 μm.

The basis weight per 0.1 mm thickness is about 10 to 60 g / m ² , preferably about ²⁰ to 50 g / m ² .

  In addition, for example, when the blood treatment filter of the present invention is used as an agglomeration capturing filter, the average fiber diameter of the anionic nonwoven fabric is about 5 to 30 μm, preferably about 8 to 20 μm.

The basis weight per thickness of 0.3 mm is about 30 to 120 g / m ² , preferably about 40 to 100 g / m ² .

  The aggregate capturing filter can be used alone, but can also be used as a prefilter for the leukocyte capturing filter.

  The material used for producing the anionic nonwoven fabric may be any material that generates the anionic charge on the surface of the anionic nonwoven fabric produced using the anionic nonwoven fabric.

  Examples of such materials include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyoxyethylene terephthalate, polyacrylonitrile, and the like.

  Among these, polyester-based synthetic polymer materials such as polyethylene terephthalate and polybutylene terephthalate are particularly preferable. In addition, the formability to the nonwoven fabric, the fiber diameter of the resulting nonwoven fabric, the state of pores formed by the fibers, etc. are easy to control, and it is possible because it is possible to produce an optimal blood treatment filter that matches the substance to be removed such as leukocytes. . Furthermore, this polyester-based synthetic polymer material is also preferable from the viewpoint of blood wettability.

An anionic nonwoven fabric can be manufactured by the following method using the above materials.
First, for example, a nonwoven fabric is manufactured by applying conventional methods such as a spunbond method, a melt blow method, a centrifugal force method, a flash spinning method, a high voltage dry spinning method, a film method, an air lay method, a card method, a garnet machine method, etc. .

  In addition, for example, conventionally, melt-spun fibers are bonded by an adhesive method, a thermal fusion method (thermal bond method), an ultrasonic bonding method, a needle punch method, a spunlace method (a hydroentanglement method), a stitch bond method, or the like. It can also be manufactured by the method.

Next, a cationized substance (a substance having a cationic charge) will be described.
The cationized substance is a compound having a basic nitrogen-containing functional group, and a basic nitrogen-containing compound having a primary amino group, a secondary amino group, a tertiary amino group or a quaternary ammonium salt, or pyridyl Group, a basic nitrogen-containing compound having a nitrogen-containing aromatic ring group such as an imidazolyl group.

  Examples of basic nitrogen-containing compounds having a quaternary nitrogen atom in the main chain or side chain include a (meth) acrylic acid polymer having a quaternary ammonium ion represented by the following general formula (1) as an ester group Alternatively, a compound having an alkyl sulfonate (alkyl sulfonate ion) as a counter ion may be used.

Here, in the general formula (1), R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² and R ⁷ each independently represent a methyl group or a hydrogen atom, and R ³ represents 1 to 4 carbon atoms. R ^{4 to} R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, n and m represent an integer (n> m), and preferably n and m are a total 20 to 4000.

  Here, the cationized substance is not particularly limited, but is preferably an alkyl sulfonate (alkyl sulfone) of a (meth) acrylic acid polymer having a quaternary ammonium ion represented by the above general formula (1) as an ester group. It is a cationic compound having an acid ion as a counter ion.

  For example, a copolymer of (meth) acrylic acid- (meth) acryloyloxyethyl diethylmethylammonium methyl sulfate, a copolymer of (meth) acrylic acid- (meth) acryloyloxypropyl diethylmethylammonium methyl sulfate, etc. It is done.

  The compound represented by the general formula (1) may have a molecular weight of about several thousand to several hundred thousand, and is preferably 2,000 to 500,000. When the molecular weight is in the above range, workability when the anionic nonwoven fabric is immersed in a solution containing a cationized substance is good, and it is not easily detached from the anionic nonwoven fabric.

  The method for retaining such a cationized substance on the surface of the anionic nonwoven fabric is not particularly limited as long as the cationized substance can be uniformly retained on the surface of the anionic nonwoven fabric. However, by coating, dipping, spraying or spin coating. It is preferable to hold the cationized substance on the surface of the anionic nonwoven fabric by coating the surface of the anionic nonwoven fabric with a coating solution in which the cationized substance is dissolved and then drying by heating at 60 to 100 ° C.

In addition, the method of retaining a cationized substance on the surface of an anionic nonwoven fabric is to apply a quaternary amine ester of a compound mainly composed of polyacrylic acid to the surface of a leukocyte removal filter substrate, and heat-dry the alkyl sulfonic acid. It may be treated with a sodium solution.
Further, it is more preferable to wash the anionic nonwoven fabric with water after drying by heating and wash out the eluted material.

By such a method, the cationized nonwoven fabric provided with the said cationized substance can be obtained on the surface of the anionic nonwoven fabric mentioned above.
And the blood processing filter which concerns on embodiment of this invention has a filter base material which consists of such a cationized nonwoven fabric.

  A method for obtaining a filter substrate from this cationized nonwoven fabric (a method for converting the cationized nonwoven fabric into a filter medium) is not particularly limited, and conventional methods can be applied. For example, the cationized non-woven fabric is press-compressed or heat-shrinked, and is laminated so as to have a total thickness as will be described later, depending on its application, and is set to an optimum size at the time of use (for example, in a housing to be used) Can be cited as a method of punching out to a suitable size).

  The filter substrate preferably has a zeta potential of 6 to 30 mV. The reason is that if the zeta potential is within this range, the ability to produce bradykinin can be suppressed.

  This zeta potential is based on the streaming potential method. Specifically, using a streaming potential measuring device (cylindrical polytetrafluoroethylene cell: diameter 13 mm, length 5 mm), pressure range 0-50 KPa, 0.001 M KCl solution (temperature: 25 as fluid). (° C.).

Further, the average pore diameter and the total wall thickness of the filter base material are not particularly limited, and may be selected according to the application.
For example, when the blood treatment filter is used as a leukocyte capture filter, the total thickness is about 3 to 9 mm, preferably about 5 to 7 mm.
Further, for example, when a blood treatment filter is used as an aggregate capturing filter, the total thickness is about 0.3 to 6 mm, preferably about 0.6 to 4.8 mm, and more preferably 0.8 to 3. It is about 6 mm.

  As described above, the blood treatment filter of the present invention can be used as a leukocyte capturing filter or an aggregate capturing filter. There are a platelet capturing type and a platelet passing type in the leukocyte capturing filter, and in particular, it can be suitably used as a platelet capturing type leukocyte capturing filter.

Hereinafter, the anionic charge quantification method according to the embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a perspective sectional view of a blood processing filter device according to an embodiment of the present invention.
As illustrated, the blood processing filter device 1 includes a housing 2 having an inflow port 3 and an outflow port 4, and a filter base 5.

This filter base material 5 prepares an anionic nonwoven fabric (nonwoven fabric having an anionic charge), and produces the filter base material by the method described above.
And the cationized substance is hold | maintained by the method mentioned above on the surface of a filter base material.

  Such a filter base material 5 is punched out into a circular shape having a diameter of 25 mm and installed between the housings 2 and 2. The effective diameter of the housing 2 is 22 mm.

  Here, the anionic charge quantification method according to the embodiment of the present invention is a method for quantifying the amount of anionic charge present on the surface of the filter base 5 used in the blood treatment filter device 1. The surface of the filter substrate 5 is dyed with a staining agent comprising a dye having a cationic charge, and the reflection absorbance of the surface of the filter substrate 5 is measured.

That is, an anion on the surface of the filter base material 5 is obtained by dyeing a portion where an anionic charge exists on the surface of the filter base material 5 with a staining agent and measuring the reflection absorbance of the surface portion of the dyed filter base material 5. This is a method for quantifying the sexual charge. In other words, the amount of anionic charge present on the surface of the filter substrate 5 is indirectly measured by directly measuring the reflected absorbance of the surface of the filter substrate 5.
Therefore, a method for measuring the reflection absorbance of the filter substrate in the anionic charge quantification method of the present invention will be described.

  First, a dyeing process (dyeing operation) is performed in which the surface of the filter base 5 installed between the housings 2 and 2 is dyed using a dye having a cationic charge as a dyeing agent. During the dyeing process, the dyeing agent is adsorbed on the surface of the filter substrate 5 using a dyeing assistant.

Specifically, 10 mL of 0.01% Safranin O / 1.00% NaCl aqueous solution was prepared using Safranin O as a staining agent and NaCl as a staining aid, and this aqueous solution (mixture of staining agent and staining assistant) was prepared. Liquid) flows into the housings 2 and 2 from the inflow port 3, passes through the filter base 5, and adsorbs the staining agent to the anionic charge on the surface of the filter base 5.
On the other hand, the excess aqueous solution that has passed through the filter base 5 is discharged out of the housings 2 and 2 from the outlet 4.

After the dyeing treatment step, a mordanting treatment step (mordanting treatment operation) is performed in which the surface of the filter base 5 is brought into contact with the mordant and the dyeing agent is fixed on the surface of the filter base 5.
Specifically, 10 mL of a 1.00% sodium citrate aqueous solution is prepared using sodium citrate as a mordant, and this aqueous solution flows into the housings 2 and 2 from the inlet 3 and passes through the filter base 5. The dye on the surface of the filter substrate 5 is fixed.
On the other hand, the excess aqueous solution that has passed through the filter base 5 is discharged out of the housings 2 and 2 from the outlet 4.

After the mordanting process, a cleaning process (cleaning operation) is performed in which the surface of the filter base 5 is cleaned using a cleaning liquid.
Specifically, using 100 mL of RO water as the cleaning liquid, it flows into the housings 2 and 2 from the inlet 3, passes through the filter base 5, and is not adsorbed on the surface (fixed) of the filter base 5. Wash the stains, dyeing assistants and stains.
Note that the RO water subjected to the cleaning is discharged out of the housings 2 and 2 from the outlet 4.
After the washing step, the filter base material 5 on which the staining agent (pigment having a cationic charge) is adsorbed is taken out from the housings 2 and 2 and dried.

  By the dyeing process, the mordanting process, and the washing process as described above, the filter base material 5 having a dye adsorbed on the surface, which is a sample for measuring the reflection absorbance, is obtained.

Next, the reflected absorbance is measured using an absorptiometer (trade name: dual wavelength chromatographic scanner CS-930, manufactured by Shimadzu Corporation).
The wavelength for measuring the reflection absorbance is 535 nm in accordance with the safranin O used as the staining agent. In the present embodiment, this reflected absorbance is also referred to as a residual anion amount.

The blood treatment filter of the present invention has a reflection absorbance (residual anion amount) determined by such a method of 0.26 or less, preferably about 0.15 to 0.23.
The reflection absorbance should be low, but depending on the pore size and total wall thickness of the filter substrate 5, there is a risk of impairing the performance as a blood treatment filter. For example, when the blood treatment filter of the present invention is used as a leukocyte removal filter, not only leukocytes and platelets but also red blood cells may be captured. On the other hand, when the reflected absorbance exceeds this range, the production ability of bradykinin cannot be sufficiently reduced.

  A blood treatment filter having a reflection absorbance in such a range has a low ability to produce bradykinin by filtration of blood, and thus does not adversely affect a patient using the blood after treatment.

The anionic charge quantification method and the blood treatment filter according to the embodiment of the present invention have been described above, but the present invention is not limited to this.
Specifically, in this embodiment, the filter substrate 5 is a non-woven fabric having an anionic charge that holds a substance having a cationic charge (cationized substance), but the present invention is limited to this. It is not a thing.
For example, the filter substrate may not be one in which the nonwoven fabric has an anionic charge, and may not have a cationized substance held therein. Moreover, the filter base material may not be a nonwoven fabric.

Furthermore, the filter base material may be fixed with not only a cationized substance but also other surface treatment agents such as a hydrophilic treatment agent.
In the present embodiment, when measuring the amount of anionic charge, the filter substrate 5 is installed between the housings 2 and 2 in the dyeing process, the mordanting process, and the washing process. It is not limited to this.
For example, all steps (operations) may be performed before the filter base material 5 is installed between the housings 2 and 2, that is, without the filter base material 5 being installed between the housings 2 and 2.
Further, only the dyeing process, or the dyeing process and the mordanting process are performed by installing the filter base 5 between the housings 2 and 2, and the subsequent process is performed by removing the filter base 5 from the housings 2 and 2. May be.

Further, in this embodiment, a cationized nonwoven fabric is obtained by holding a cationized substance in an anionic nonwoven fabric, and then the cationized nonwoven fabric is obtained in the form of a filter medium to obtain a filter substrate. It is not limited.
For example, after making an anionic nonwoven fabric into the form of a filter medium, a filter base material may be obtained by holding a cationized substance on the surface of the filter medium (anionic nonwoven fabric) to form a cationized nonwoven fabric.

  The blood processing filter according to the embodiment of the present invention is shown below. In addition, this invention is not limited to this Example.

Example 1
In Example 1, a non-woven fabric made of polyethylene terephthalate having an average fiber diameter of 2 μm and a basis weight per wall thickness of 0.1 was 40 g / m ² .
Polyacrylic acid-poly 2- (acryloyloxy) dimethylmethylammonium methyl sulfate, which is a cationizing substance, was introduced on the surface of this nonwoven fabric.

Specifically, the cationized substance was dissolved in distilled water to make a 10% by mass aqueous solution, and 30 g of nonwoven fabric was immersed in 1000 mL of this aqueous solution with a stainless steel tray. The immersion time was 2 minutes.
And after immersion time progress, it removed from the Erlenmeyer flask and performed the shower washing | cleaning using distilled water immediately. The flow rate for shower cleaning was 4 L / min, and the shower cleaning time was 3 hours.
Further, after the washing time had elapsed, drying was performed at 70 ° C. for 1 hour using a dryer (product number: WTO-1000SD, manufactured by EYELA).

Thus, after obtaining the cationized nonwoven fabric which hold | maintained the cationized substance on the surface of an anionic nonwoven fabric, the filter base material was obtained by making it the form of a filter medium. This is referred to as filter base material a1.
Then, the reflection absorbance, bradykinin production amount, zeta potential, leukocyte removal rate, and platelet removal rate of the filter substrate a1 were measured by the methods described later. Note that the reflection absorbance was measured under three measurement conditions. The results are shown in Tables 1 and 2.

(Example 2)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 1 was set to 5% by mass and all other conditions were the same. The measurement items are the same as in Example 1. The results are shown in Tables 1 and 2. The filter base material used for each measurement in Example 2 is referred to as filter base material a2.

(Example 3)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 1 was set to 1% by mass and all other conditions were the same. The measurement items are the same as in Example 1. The results are shown in Tables 1 and 2. The filter base material used for each measurement in Example 2 is referred to as a filter base material a3.

(Comparative Example 1)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 1 was 0.005% by mass and all other conditions were the same. The measurement items are the same as in Example 1. The results are shown in Tables 1 and 2. The filter base material used for each measurement in Comparative Example 1 is referred to as filter base material a4.

(Comparative Example 2)
About the filter base material a1 obtained in said Example 1, it measured by the light absorbency by the method mentioned later. The results are shown in Table 3.

(Comparative Example 3)
About the filter base material a2 obtained in said Example 2, it measured with the light absorbency by the method of mentioning later. The results are shown in Table 3.

(Comparative Example 4)
About the filter base material a3 obtained in said Example 3, it measured with the light absorbency by the method mentioned later. The results are shown in Table 3.

Example 4
Instead of the non-woven fabric a used in Example 1, a non-woven fabric made of polyethylene terephthalate having an average fiber diameter of 11 μm and a basis weight per 0.3 mm of wall thickness of 50 g / m ² was used. Hereinafter, this is referred to as a nonwoven fabric b.
And by the same method as Example 1, the filter base material was obtained by making the cationized nonwoven fabric which hold | maintains a cationization substance on the surface into the form of a filter medium. This filter base material is referred to as b1.
And the reflected light absorbency, bradykinin production amount, zeta potential, and aggregate removal rate of the filter base material b1 were measured by the method mentioned later. The results are shown in Table 4.

(Example 5)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 4 was set to 5% by mass and all other conditions were the same. The measurement items are the same as in Example 4. The results are shown in Table 4. The filter base material used for each measurement in Example 5 is referred to as filter base material b2.

(Example 6)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 4 was set to 1% by mass and all other conditions were the same. The measurement items are the same as in Example 4. The results are shown in Table 4. The filter base material used for each measurement in Example 6 is referred to as filter base material b3.

(Comparative Example 5)
A test was performed in which the aqueous solution concentration of the cationized substance used in Example 4 was 0.005% by mass, and all other conditions were the same. The measurement items are the same as in Example 5. The results are shown in Table 4. The filter base material used for each measurement in Comparative Example 2 is referred to as filter base material b4.

<Reflected absorbance>
Using the filter base materials a1 to a4 and the filter base materials b1 to b4 as samples, the reflection absorbance was measured by the above-described anionic charge quantification method of the present invention.

  Here, with respect to the filter base materials a1 to a4, only the dyeing agent is used (the dyeing agent is not used in the dyeing process, the mordanting process is not performed), the measuring method A, the dyeing agent, and the dyeing assistant are used (dyeing). The reflective absorbance is measured by three measurement methods, measurement method B, which performs the treatment step and does not perform the mordanting treatment step), and measurement method C which uses the dyeing agent, the dyeing assistant and the mordant (which performs the dyeing treatment step and the mordanting treatment step). It was measured.

In Table 1, the measurement results by the measurement method A are shown in the A column, the measurement results by the measurement method B are shown in the B column, and the measurement results by the measurement method C are shown in the C column.
Moreover, about the filter base materials b1-b4, only the measuring method (the above-mentioned measuring method C) which uses a dyeing agent, a dyeing auxiliary agent, and a mordant (performs a dyeing process process and a mordant process process) was performed.

<Brazikinin production>
1 g of each of the filter base materials a1 to a4 and the filter base materials b1 to b4 was prepared and immersed in 6 mL of concentrated red blood cells (CRC-MAP) in a polypropylene test tube. The concentrated erythrocytes are stored at 4 ° C. for 4 days after blood collection and adjustment. After incubation at 25 ° C. for 5 minutes, 5 mL of concentrated erythrocytes was immediately collected from a polypropylene test tube into an inhibitor cocktail for Bradykinin sample (manufactured by SRL). Then, after centrifugation at 4 ° C. and 4.54 × 10 ³ G for 6 minutes, bradykinin was measured by the RIA method.

<Zeta potential>
A sample obtained by punching each of the filter base materials a1 to a4 and the filter base materials b1 to b4 into a circle having a diameter of 13 mm is used as a sample, and using a streaming potential measuring device (ZP-20H type, manufactured by Shimadzu Corporation), zeta The potential was measured. Here, the same 0.001 M KCl solution as described above was used as the fluid.

<Leukocyte removal rate, platelet removal rate>
Each of the above filter base materials a1 to a4 was punched out into a circle having a diameter of 30 mm, and 30 sheets laminated for each sample (total thickness: 3.0 mm) were set in a housing.

The housing used here has the same shape as in FIG. 1, and the mounting portion of the filter base material (blood treatment filter) is cylindrical. The cross section is a circle with a diameter of 30 mm.
Using the blood treatment filter device thus obtained, 60 ml of concentrated red blood cells (CRC-MAP) having a storage period of 4 days were filtered under a drop of 40 cm (upstream 20 cm, downstream 20 cm).

  The mass of blood before and after filtration was measured using an electronic balance. In addition, the platelet concentration before and after filtration and the white blood cell concentration before filtration were measured using a multi-item automatic blood cell analyzer (SYSMEX XE-2100, manufactured by Sysmex Corporation). Then, the leukocyte concentration after filtration was measured using a Najet method. Furthermore, leukocyte and platelet removal rates were determined using the following formula.

  Leukocyte removal rate (%) = (1− (leukocyte concentration after filtration × blood volume after filtration) / (leukocyte concentration before filtration × blood volume before filtration)) × 100

  Platelet removal rate (%) = (1− (platelet concentration after filtration × blood volume after filtration) / (platelet concentration before filtration × blood volume before filtration)) × 100

<Absorbance>
Prepare 2g of each of the above filter base materials a1 to a4, immerse them in 5mL of 0.001% Safranin O aqueous solution in a polypropylene test tube, deaerate them with a vacuum pump for 10 minutes, and filter the Safranin O aqueous solution sufficiently. The substrate was infiltrated. Thereafter, the filter substrate was taken out from the safranin O aqueous solution, and the absorbance of the safranin O aqueous solution at a wavelength of 535 nm was measured using an absorptiometer (trade name: Hitachi spectrophotometer U-3010, manufactured by Hitachi Sakusho Co., Ltd.).

<Agglomerate removal rate>
Each of the above filter base materials b1 to b4 was punched into a circle having a diameter of 30 mm, and a laminate (total thickness of 3.0 mm) of these 10 sheets was set in each housing.
The housing used here has the same shape as in FIG. 1, and the filter base (blood treatment filter) mounting portion is cylindrical. The cross section is a circle with a diameter of 30 mm.

Using the blood treatment filter device thus obtained, 60 ml of concentrated red blood cells (CRC-MAP) having a storage day of 21 days were filtered under a drop of 40 cm (upstream 20 cm, downstream 20 cm).
And the mass of the blood before and behind filtration was measured using the electronic balance. The number of aggregates of 15 to 45 μm before and after filtration was measured using a Coulter counter Z2 (manufactured by Beckman Coulter). And the aggregate removal rate was calculated | required using the following formula | equation.

  Aggregate removal rate (%) = (1− (aggregate concentration after filtration × blood volume after filtration) / (aggregate concentration before filtration × blood volume before filtration)) × 100

  Here, the measurement results of bradykinin production amount and zeta potential in Comparative Examples 2 to 4 shown in Table 3 use the same filter base materials a1 to a3 as in Examples 1 to 3 in Comparative Examples 2 to 4. The results were the same as the measurement results of bradykinin production and zeta potential in Examples 1 to 3 shown in Table 1.

From the test results shown in Tables 1 to 4, the filter base materials of Examples 1 to 6, that is, the blood treatment filter according to the examples of the present invention, showed almost no increase in bradykinin, and had the ability to produce bradykinin. Very low. Moreover, it has confirmed that the performance at the time of using as a blood processing filter was also provided.
Moreover, the correlation with the amount of bradykinin production was not able to be confirmed by the result of measuring the amount of anionic charges which existed on the surface of a filter base material indirectly by Comparative Examples 2-4, ie, the light absorbency measurement of aqueous solution. On the other hand, in Examples 1 to 3, that is, as a result of measuring the amount of anionic charge directly present on the filter surface by reflection absorbance measurement, there is a correlation between the measured value of reflected absorbance and the amount of bradykinin production. It was confirmed that the anionic charge can be quantified.

FIG. 1 is a perspective sectional view of a blood processing filter device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blood processing filter apparatus 2 Housing 3 Inlet 4 Outlet 5 Filter base material (blood processing filter)

Claims (8)

  An anionic charge quantification method characterized in that the surface of a filter substrate is dyed with a staining agent comprising a dye having a cationic charge, and the reflection absorbance of the surface of the filter substrate is measured.   The method for quantifying an anionic charge according to claim 1, wherein the filter base material is a non-woven fabric having an anionic charge held by a substance having a cationic charge.   The anionic charge quantification method according to claim 1 or 2, wherein a dyeing agent is adsorbed on the surface of the filter base material by using a dyeing assistant when dyeing the surface of the filter base material.   The anionic charge determination according to any one of claims 1 to 3, wherein after staining the surface of the filter base material, the surface of the filter base material is contacted with a mordant to fix the dyeing agent on the surface of the filter base material. Method.   A blood treatment filter comprising a filter substrate having a reflection absorbance of 0.26 or less measured by the anionic charge quantification method according to claim 1.   The blood processing filter according to claim 5, wherein the filter base material is a non-woven fabric having an anionic charge, on which a substance having a cationic charge is held.   The blood processing filter according to claim 5 or 6, wherein the filter base has a zeta potential of 6 to 30 mV. The blood processing filter according to any one of claims 5 to 7, which is a leukocyte capturing filter or an aggregate capturing filter.

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