JPH10328295A - White blood cell separating filter and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity and performance by fixing organo silicone quaternary ammonium salt to the surface of a base material formed of an organic polymer. SOLUTION: A base material is formed of an organic polymer such as polyethylene, polypropylene, polyurethan. Especially three-dimensional mesh-like porous body of polyurethane or the like or non-woven fabric is preferable. Organo silicone quaternary ammonium salt such as 3-(trimethoxyl) propyl dimethyl-alkyl ammonium chloride is fixed to the surface of the base material. This fixation can be favorably achieved by processing using a liquid containing organo silicone quaternary ammonium salt and a sulfate surfactant. Thus, cation is remarkably shown so that the filter can have favorable white blood cell removal and platelet removal rate at a practical bloodstream speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for separating leukocytes which has a stable capturing ability for leukocytes and is excellent in platelet removal performance, and a method for producing the same.

[0002]

2. Description of the Related Art It has been a long time since the form of blood transfusion has changed from a conventional whole blood transfusion to a component blood collection in which only the components required by the patient are transfused. The challenge is how to increase the cost.

[0003] Among them, in the case of concentrated red blood cells (CRC), high-purity red blood cells from which not only white blood cells but also platelets have been removed in order to suppress the production of antibodies against white blood cells and platelets and prevent transfusion side effects. Needless to say, is good.

Many attempts have been made to achieve this, such as a gravity centrifugation method using the difference in specific gravity of blood cells, and a filter method using the action of blood cell adhesion.

Above all, the filter method is widely used because of its high leukocyte removal efficiency and simplicity of the procedure. The structure of the filter portion is formed by packing ultra-fine fibers in a column or secondary processing into a nonwoven fabric or the like. Stuff, sponge-like 3
A typical example thereof is a continuous porous body having a three-dimensional network.

In order to remove white blood cells and platelets from concentrated red blood cells by the filter method, some contrivance is required. In other words, it is natural that the separation ability of blood cells can be enhanced by reducing the pore size of the filter, but when the pore size becomes large enough to remove platelets, clogged blood cells are more likely to be clogged, A requirement is to be able to remove both white blood cells and platelets while using a filter with a large pore size.

A solution is to make the zeta potential of the surface of the filter substrate positive (positive). Specifically, a cationic group, that is, a quaternary ammonium salt is added to the surface of the substrate. It is known that it is good to fix to.

In particular, at least one kind of functional group (acid halide group, isocyanate group, epoxy group, etc.) is introduced by a plasma-initiated graft polymerization method disclosed in JP-A-5-245198, The method of bonding a cationic substance having a site (an amino group, a carboxyl group, a hydroxyl group, or the like) capable of reacting with a polymer is excellent in that the cationic group can be stably fixed to the surface of the filter substrate.

However, in this method, it is necessary to go through two steps of introducing a functional group by plasma grafting and bonding a cationic substance having a site capable of reacting with the functional group. Further, the plasma grafting process requires a large-scale apparatus and its operation is complicated, so that there is no denying that there is a problem in productivity.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems relating to the filter method having excellent performance in removing leukocytes and platelets, and has an excellent productivity and good performance. It is an object to provide a filter having the same.

[0011]

A first aspect of the present invention is a filter for separating leukocytes, wherein an organosilicone quaternary ammonium salt is fixed on the surface of a substrate made of an organic polymer.

A second aspect of the present invention is to treat the surface of a substrate made of an organic polymer with a solution containing an organosilicone quaternary ammonium salt and a sulfate surfactant, and to remove the organosilicone quaternary ammonium salt. A method for producing a leukocyte separation filter, wherein the filter is fixed to the surface of a substrate.

[0013] By adopting such a configuration or method, a filter for separating leukocytes which has good performance in removing leukocytes and platelets and is excellent in productivity can be obtained.

In the present invention, the substrate composed of an organic polymer is made of an organic polymer which can be used as a filter such as polyethylene, polypropylene, polyurethane, polysulfone, polyethersulfone, polyamide polyether block copolymer, polyester polyether block copolymer, ethylene vinyl alcohol copolymer and the like. And the shape is porous, flat membrane, hollow fiber, non-woven fabric,
Woven fabrics, knitted fabrics, or composites thereof are exemplified.

Particularly preferred organic polymers are polyurethane, polyester, polyamide or ethylene vinyl alcohol copolymer, and the shape is preferably a three-dimensional network porous body or nonwoven fabric.

In consideration of the leukocyte or platelet removal rate and the flow rate during filtration, a filter having a mode pore diameter of 1 to 7 microns, more preferably 2 to 6 microns is preferred.

The most frequent pore diameter in the present invention is defined as the diameter obtained by arbitrarily cutting a porous body, measuring the area of each of the pores dispersed in the entire cross section, and converting the area into a circle. When examining the relationship with the number of pores, it shows the place where the diameter converted into a circle is the largest. In other words, the pores dispersed on an arbitrary cut surface of the porous body have various shapes and various diameters, but each pore is converted into a circle having the same area as the cross-sectional area of the pore, and the diameter is converted to a circle. When the abscissa is plotted on the abscissa at intervals of 1 μm and the number of pores (each 1 μm) in the section is plotted on the ordinate, a curve corresponding to the peak is the most frequent pore diameter. In this case, it is preferable to randomly measure 2,000 or more pores in order to secure more accuracy. Therefore, pores having a diameter equal to or greater than the most frequent pore diameter only mean that the number is reduced, and do not represent the pores having the largest diameter, and therefore, particles of larger diameters will pass through. It does not mean not to.

Next, as the organosilicone quaternary ammonium salt in the present invention, 3- (trimethoxyl) propyldimethyl-alkylammonium chloride represented by the following general formula (1) is preferable.

[0019]

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A device is required to immobilize the organosilicone quaternary ammonium salt on the surface of the filter substrate.

That is, it is often difficult to immobilize an organic polymer substrate that does not contain a reactive group such as a hydroxyl group even if it is treated as it is. In order to solve this problem, it is preferable to treat with a liquid containing an organosilicone quaternary ammonium salt and a sulfate surfactant.

Examples of the sulfate surfactant include alkyl sulfates such as sodium lauryl sulfate, triethanolamine lauryl sulfate and ammonium lauryl sulfate, and polyoxyalkylene alkyls such as sodium polyoxyethylene sulfide and sodium polyoxyethylene alkylphenyl ether sulfate. (Aryl) ether sulfates are preferred. The number average degree of polymerization of the polyoxyethylene part is suitably from 2 to 20.

More specifically, the organosilicone quaternary ammonium salt is adjusted to have a concentration of 0.01 to 2% by weight, more preferably 0.03 to 1.5% by weight, and a sulfate surfactant is added. The solution is dissolved in water so as to have a molar ratio of 0.2 to 3 times, more preferably 0.3 to 2 times the amount of the ammonium salt. What is necessary is just to process by usual methods, such as immersion, padding, and spraying, wash with water, and dry.

The temperature of the treatment is 30 to 80 degrees, more preferably 40 to 70 degrees, and the treatment time is about 15 to 120 minutes, more preferably about 20 to 100 minutes.

What should be noted here is the amount of the sulfated surfactant. If the amount of the sulphate surfactant is small, the effect of the organosilicone quaternary ammonium salt sticking to the filter substrate is not exhibited. It is difficult to fix it, probably because it is completely surrounded by the anions of these phenomena (the rationale for these phenomena is not clear).

Here, the "degree of cationization", that is, the amount of ammonium salt fixed is confirmed by the following method.

The treated filter is immersed in a phosphate buffer.

The immersed filter is immersed in a 0.025 mM trypan blue / phosphate buffer for 15 minutes.

After the treatment, the filter is immersed again in a phosphate buffer solution for 10 minutes (all are performed at room temperature).

The filter after immersion was dried at 60 ° C. for 1 hour, and the reflection absorbance of the filter surface was measured at a wavelength of 550 to 600.
Measure in the nm range.

In order to achieve a good leukocyte removal rate and platelet removal rate, the reflection absorbance measured by the above method must be 0.2 to 1.2, more preferably 0.3 to 1.0. Is good.

If the reflection absorbance is lower than 0.2, no good blood cell removal rate is exhibited, and if it is higher than 1.2, clogging is likely to occur because platelets rapidly adhere to the filter surface.

[0033]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto as long as the examples have the effect.

1-1. Experimental Method (Examples 1 to 3, Comparative Examples 1 and 2) Cationization treatment of filter substrate: mode diameter 3 μm,
A three-dimensional mesh-like continuous porous cloth made of polyurethane with a porosity of 90% and a thickness of 1.5 mm (20 cm wide x 100 cm long)
With 3- (trimethoxysilyl) propyldimethyl-lauryl ammonium chloride (A1) (molecular weight of about 41
2) and sodium lauryl sulfate (B1) (molecular weight 28
8) and immersed in 10 L of an aqueous solution containing 50 ° C. for 60 minutes. Next, after boiling in 70 ° pure water, squeeze 70
It dried on the conditions of degree x 12 hours.

Measurement of the degree of cationization (the amount of organosilicone quaternary ammonium salt fixed) of the filter substrate:
A small piece of 2 cm square was sampled from the polyurethane cloth after the treatment, and the degree of cationization was measured based on the method described above.

Evaluation of hemofiltration performance: A circular piece having a diameter of 6 cm was punched out from the cloth obtained in the above, and two pieces (filters) were stacked and filled in a dedicated module. To this module, 0.5 units of CPD-added human erythrocyte concentrate (CRC) obtained by collecting 400 ML blood was flowed. Automatic blood cell counting device (Sys)
After calculation using mex NE-6000 (manufactured by Toa Medical Electronics Co., Ltd.) and a flow cytometer (Cyto-ACE150, manufactured by JASCO Corporation), the absolute number of each blood cell component was determined based on the fluid volume, From this, the leukocyte removal rate, platelet removal rate, and red blood cell recovery rate were determined.

1-2. Experimental Results Table 1 shows the concentration conditions (A ₁ ) and (B ₁ ), the degree of cationization (absorbance) and the state of hemofiltration. As is clear from this table, when (A ₁ ) and (B ₁ ) coexist in the treatment solution, cationization (fixation of ammonium salt) is remarkably observed, and the obtained filter has a practical blood flow rate. Shows good leukocyte removal and platelet removal rates.

It was also confirmed that there was no problem with the red blood cell recovery rate. Not only the case where (A ₁ ) and (B ₁ ) are not contained in the treatment liquid (Comparative Example 1), but also the case where (A) is used alone (Comparative Example 2), the cationization is insufficient, and the leukocytes of the filter Poor in platelet removal performance.

[0039]

[Table 1]

2-1. Experimental Method (Examples 4 to 6, Comparative Examples 3 and 4) Cationization treatment of filter substrate: mode pore diameter 6 μm,
A non-woven fabric (20 cm wide × 100 cm long) made of polyester fiber having an average pore diameter of 1.5 μm was prepared by adding 3- (trimethoxysilyl) propyldimethyl-decyl ammonium chloride (A ₂ ) (molecular weight: about 384) and polyoxyethylene sodium sulfate (B ₂ ) Aqueous solution 1 containing (molecular weight 426)
It was immersed in 0 L and treated under the condition of 50 degrees × 60 minutes. Next, after being immersed in pure water of 70 ° C., it was dried under the condition of squeezing 70 ° × 12 hours.

Measurement of the degree of cationization of the filter substrate (the amount of the organosilicone quaternary ammonium salt fixed):
A small piece of 2 cm square was sampled from the polyurethane cloth after the treatment, and the degree of cationization was measured based on the method described above.

Evaluation of hemofiltration performance: A circular piece having a diameter of 6 cm was punched from the cloth obtained in the above, and three pieces (filters) were stacked and filled in a dedicated module. To this module, 0.5 units of CPD-added human erythrocyte concentrate (CRC) obtained by collecting 400 ML blood was flowed. Automatic blood cell counting device (Sys)
After calculation using mex NE-6000 (manufactured by Toa Medical Electronics Co., Ltd.) and a flow cytometer (Cyto-ACE150, manufactured by JASCO Corporation), the absolute number of each blood cell component was determined based on the fluid volume. From this, the leukocyte removal rate, platelet removal rate, and red blood cell recovery rate were determined.

2-2. Experimental Results Table 2 shows the concentration conditions of (A ₂ ) and (B ₂ ), the degree of cationization (absorbance) and the state of hemofiltration. As is clear from this table, when (A ₁ ) and (B ₁ ) coexist in the processing solution, cationization (fixation of ammonium salt) proceeds smoothly, and this is remarkably seen and obtained. The filter shows good leukocyte removal and platelet removal at a practical blood flow rate.

It was also confirmed that there was no problem with the red blood cell recovery rate.

Not only the case where (A ₂ ) and (B ₂ ) are not contained in the treatment liquid (Comparative Example 3), but also the case where (A) is used alone (Comparative Example 4), the cationization is insufficient. The filter is inferior in the performance of removing leukocytes and platelets.

[0046]

[Table 2]

[0047]

As described above in detail, the present invention relates to a leukocyte removal filter comprising an organosilicone quaternary ammonium salt fixed to the surface of a filter substrate and a method for producing the same, which is excellent only in leukocyte removal rate. In addition, the filter has a good platelet removal rate, is excellent in productivity, and has high industrial value.

Claims (16)

[Claims] 1. A leukocyte separation filter, wherein an organosilicone quaternary ammonium salt is immobilized on a surface of a substrate made of an organic polymer. 2. The method according to claim 1, wherein said substrate is selected from the group consisting of polyethylene, polypropylene, polyurethane, polysulfone, polyethersulfone, polyamide polyether block copolymer, polyester polyether block copolymer and ethylene vinyl alcohol copolymer. The leukocyte separation filter according to claim 1, wherein: 3. The leukocyte separation filter according to claim 1, wherein the base material is selected from polyurethane, polyester, polyamide, and an organic polymer of ethylene vinyl alcohol copolymer. 4. The leukocyte separation filter according to claim 1, wherein said substrate is made of a porous material. 5. The leukocyte separation filter according to claim 1, wherein said substrate is made of a hollow fiber. 6. The leukocyte separation filter according to claim 1, wherein the substrate is made of a nonwoven fabric. 7. The leukocyte separation filter according to claim 1, wherein the substrate is made of a woven fabric. 8. The leukocyte separation filter according to claim 1, wherein the substrate is made of a knitted fabric. 9. The leukocyte separation filter according to claim 1, wherein the mode pore diameter of the substrate is 1 to 7 μm. 10. The leukocyte separation filter according to claim 1, wherein the mode pore diameter of the substrate is 2 to 5 μm. 11. The leukocyte separation filter according to claim 1, wherein said organosilicone quaternary ammonium salt is 3- (trimethoxyl) propyldimethyl-alkylammonium chloride. 12. The surface of a substrate made of an organic polymer is treated with a solution containing an organosilicone quaternary ammonium salt and a sulfate surfactant, and the organosilicone quaternary ammonium salt is applied to the surface of the substrate. A method for producing a leukocyte separation filter, which comprises fixing the filter. 13. The sulfate surfactant may be an alkyl sulfate such as sodium lauryl sulfate, triethanolamine lauryl sulfate or ammonium lauryl sulfate, or a polyoxyalkylene such as sodium polyoxyethylene alkyl sulfate or sodium polyoxyethylene alkyl phenyl ether sulfate. 13. The method for producing a leukocyte separation filter according to claim 12, wherein the filter is selected from the group of aryl (aryl) ether sulfates. 14. The method for producing a leukocyte separation filter according to claim 12, wherein the processing temperature of the processing is 30 to 80 degrees. 15. The method for producing a leukocyte separation filter according to claim 12, wherein the treatment is performed for 15 to 120 minutes. 16. A filter immersed in a phosphate buffer is washed with 0.015 mM trypan blue / phosphate buffer.
The filter after immersion in a phosphate buffer for 10 minutes and then dried at 60 ° C. for 1 hour, and when the reflection absorbance of the filter surface is measured in the wavelength range of 550 to 600 nm, the reflection absorbance is 0.2. A filter for separating leukocytes, wherein