JP6397781B2 - Concentrator - Google Patents

Description

  The present invention relates to a concentrator for body cavity fluid such as ascites, pleural effusion and pericardial fluid.

  For example, as a treatment for intractable ascites, ascites is collected from a patient, and the ascites is filtered to remove pathogenic substances such as cancer cells and bacteria to produce a protein aqueous solution composed of albumin and the like, and then the protein aqueous solution is concentrated. In addition, there is a cell-free and concentrated ascites reinfusion therapy in which the concentrate is reinjected into the body.

  For the concentration of the protein aqueous solution, a concentrator connected to an ascites treatment circuit is usually used (see Patent Documents 1 and 2). This concentrator has a separation membrane such as a hollow fiber membrane inside the main body, and concentrates the aqueous protein solution by separating the water of the aqueous protein solution through the separation membrane.

Japanese Patent Laid-Open No. 5-220219 JP-A-5-168699

  However, an aqueous protein solution produced by filtration from ascites or the like has high viscosity and high protein adhesion. Therefore, even when concentrated in a small amount of about 1 L, the protein adheres to the separation membrane and clogging begins to occur in the separation membrane. There are many cases. When clogging starts to occur, it becomes difficult for moisture to pass through the pores of the separation membrane, so that the moisture is not sufficiently removed from the protein aqueous solution, and it becomes difficult to achieve concentration at a high magnification of about 5 times. Here, the concentration ratio refers to a value obtained by dividing the amount of protein aqueous solution before concentration by the amount of concentrated solution. On the other hand, if the porosity of the separation membrane is increased in order to suppress clogging, protein will leak through the pores of the separation membrane this time along with moisture. As a result, the protein recovery rate in the concentrated protein solution (concentrated solution) is lowered.

  The present application has been made in view of such points, and in a concentrator that concentrates an aqueous protein solution produced by filtering body cavity fluid such as ascites, it achieves a high protein recovery rate while achieving high-concentration concentration. Its purpose is to ensure.

The present inventors have found that by adjusting the porosity and hydrophilicity of the separation membrane of the concentrator to a predetermined range, it is possible to realize a high protein recovery rate while realizing high-concentration concentration. It came to complete.
That is, the aspect of this invention contains the following.
(A) A concentrator for concentrating a protein aqueous solution produced by filtering body cavity fluid with a separation membrane, wherein the separation membrane has a porosity of 60% or more and 80% or less, and the separation membrane measured by a capillary ascending method. When the liquid level rise value is converted into a hollow fiber membrane having an inner diameter of 200 μm, it is 60 mm to 150 mm, and a protein aqueous solution solution having a concentration of 3 g / dL is passed at a flow rate of 50 mL / min to carry out a concentration step to obtain a concentrated solution of the protein aqueous solution. In some cases, the concentrator is configured to satisfy the following conditions (1) and (2).
(1) The maximum transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 5 L is 500 mmHg or less,
(2) When the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 2 L is A and the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 5 L is B, B / A ≦ 1.6.
(B) The concentrator according to (a), wherein the separation membrane is configured to further satisfy the following conditions (3) and (4) when the concentration step is performed.
(3) The protein recovery rate of the concentrate obtained when 2 L of the aqueous protein solution stock is concentrated is 40% or more,
(4) The protein recovery rate of the concentrate obtained when 5 L of the protein aqueous solution stock is concentrated is 70% or more.
(C) The concentrator according to (b), wherein the albumin recovery rate of the concentrated solution obtained when 5 L of the aqueous protein solution is concentrated in the condition (4) is 80% or more.
(D) The concentrator according to any one of (a) to (c), wherein the separation membrane is configured to satisfy the following (5) when the concentration step is performed.
(5) When the transmembrane pressure difference when 2 L of the protein aqueous solution stock is concentrated is A and the transmembrane pressure difference when 10 L of the protein aqueous solution is concentrated is C, C / A ≦ 1.5.
(E) The substrate used for the separation membrane is polysulfone, ethylene vinyl alcohol, cellulose acetate, polyethylene, polyester polymer alloy (PEPA), polymethyl methacrylate (PMMA), or polyacrylonitrile. , (A) to (d).
(F) The concentrator according to any one of (a) to (e), wherein the separation membrane is a hollow fiber membrane.
(G) The concentrator according to (f), wherein the separation membrane is a polysulfone-based hollow fiber membrane.

  ADVANTAGE OF THE INVENTION According to this invention, in the concentrator which concentrates the protein aqueous solution produced | generated by filtering body cavity fluid, it is possible to ensure a high protein recovery rate while realizing high-concentration concentration.

It is explanatory drawing which shows the outline of a structure of an ascites processing system. It is explanatory drawing of the longitudinal cross-section of a concentrator. It is a graph which shows the fluctuation | variation of the transmembrane pressure difference with respect to stock solution concentration. It is the schematic diagram which expanded the separation membrane. It is explanatory drawing which shows the outline of the ascites processing system of an Example.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the positional relationship such as up, down, left, and right in the drawing is based on the positional relationship shown in the drawing unless otherwise specified. The dimensional ratios in the drawings are not limited to the illustrated ratios. Furthermore, the following embodiment is an illustration for explaining the present invention, and is not intended to limit the present invention only to the embodiment. The present invention can be variously modified without departing from the gist thereof.

  FIG. 1 is an explanatory diagram showing an outline of the configuration of an ascites treatment system 1 as a body cavity fluid treatment system provided with a concentrator 22 according to the present embodiment.

  As shown in FIG. 1, the ascites treatment system 1 includes an ascites treatment circuit 10 as a liquid circuit, for example. The ascites treatment circuit 10 connects the ascites bag 20 as a body cavity fluid reservoir, a filter 21, a concentrator 22, a concentrated ascites bag 23 as a concentrate reservoir, and the ascites bag 20 and the filter 21. 1 channel 24, second channel 25 connecting filter 21 and concentrator 22, and third channel 26 connecting concentrator 22 and concentrated ascites bag 23.

  The ascites bag 20 is a container made of a soft resin such as polyvinyl chloride, and can store ascites as a body cavity fluid collected from a patient.

  The filter 21 has a filtration membrane 30 made of a hollow fiber membrane that removes predetermined pathogens such as cancer cells and bacteria from ascites and allows other protein aqueous solutions (filtrate) containing proteins such as albumin to pass therethrough. ing. In the filter 21, for example, ascites is supplied from the inlet of the primary side of the filtration membrane 30 (inside the hollow fiber membrane), and the ascites passes through the filtration membrane 30 to the secondary side of the filtration membrane 30 (outside of the hollow fiber membrane). Ascites can be filtered. The outlet on the primary side of the filtration membrane 30 of the filter 21 communicates with a drainage unit (not shown) from which components that do not pass through the filtration membrane 30 are drained. Further, for example, ascites is supplied from the inlet of the secondary side of the filtration membrane 30 (outside of the hollow fiber membrane), and the ascites passes through the filtration membrane 30 and is discharged to the primary side of the filtration membrane 30 (outside of the hollow fiber membrane). By doing so, ascites can also be filtered.

  The first flow path 24 is a soft tube such as polyvinyl chloride, and is connected from the outlet of the ascites bag 20 to the inlet on the primary side of the filtration membrane 30 of the filter 21. For example, a tube pump 40 is provided in the first flow path 24, and the ascites in the ascites bag 20 can be sent to the filter 21. Note that the ascites in the ascites bag 20 may be supplied to the filter 21 by gravity drop without providing the tube pump 40.

  The concentrator 22 has a separation membrane 60 made of a hollow fiber membrane that removes and concentrates water in the filtrate that has passed through the filter 21. The concentrator 22 has a cylindrical container 50, and a separation membrane 60 is disposed inside the cylindrical container 50 along the longitudinal direction thereof. Ports 51 and 52 that communicate with the inside (space) of the separation membrane 60 are provided in the upper and lower portions of the cylindrical container 50, and 2 that communicate with the outside (space) of the separation membrane 60 on the side surface of the cylindrical container 50. Two ports 53 and 54 are provided. An upper port 51 of the concentrator 22 communicates with the filter 21 via the second flow path 25. The lower port 52 of the concentrator 22 communicates with the concentrated ascites bag 23 via the third flow path 26. The port 53 on the side surface of the concentrator 22 communicates with a drainage unit (not shown) from which the removed water is drained. Further, the port 54 of the filter 22 is closed, for example. In the concentrator 22, for example, an aqueous protein solution is supplied from the inlet of the primary side (inside the hollow fiber membrane) of the separation membrane 60, and moisture contained in the aqueous protein solution passes through the separation membrane 60 to the secondary side (hollow). The protein aqueous solution can be concentrated by slipping outside the thread membrane. Details of the configuration of the concentrator 22 will be described later.

  The second flow path 25 is a flexible tube such as polyvinyl chloride, and is connected from the outlet on the secondary side of the filtration membrane 30 of the filter 21 to the port 51 on the primary side of the separation membrane 60 of the concentrator 22. Yes. For example, a tube pump 70 is provided in the second flow path 25, and the filtrate filtered by the filter 21 can be sent to the concentrator 22.

  The third flow path 26 is a flexible tube such as polyvinyl chloride, and is connected to the concentrated ascites bag 23 from the port 52 on the primary side of the separation membrane 60 of the concentrator 22.

  The concentrated ascites bag 23 is a container made of a soft resin such as polyvinyl chloride, for example, and can store a concentrated liquid containing the protein concentrated by the concentrator 22.

  Next, the configuration of the concentrator 22 will be described. FIG. 2 is an explanatory view of a longitudinal section showing an outline of the configuration of the concentrator 22.

  The concentrator 22 has the cylindrical container 50 as described above, and the separation membrane 60 that is a hollow fiber membrane is disposed along the longitudinal direction inside the cylindrical container 50. The cylindrical container 50 includes a cylindrical container body 50a and a header 50b that closes both end openings of the container body 50a. The ports 51 and 52 are formed in the header 50b, and the ports 53 and 54 are formed in the container body 50a.

  Both ends of the separation membrane 60 are potted with a potting material 80 of a curable resin at both ends of the cylindrical container 50. As a result, both end portions of the separation membrane 60 are fixed to the cylindrical container 50, and open end surfaces 81 where the inner sides of the hollow fiber membranes of the separation membrane 60 open are formed at both end portions of the cylindrical container 50. The outer space of the hollow fiber membrane of the separation membrane 60 inside the cylindrical container 50 communicates with the ports 53 and 54 on the side surface of the cylindrical container 50. The space inside the hollow fiber membrane of the separation membrane 60 communicates with the ports 51 and 52 through the open end surface 81. With this configuration, the protein aqueous solution that is the filtrate flows into the inner space of the separation membrane 60 from the port 51, and the moisture of the protein aqueous solution flows out to the outer space of the separation membrane 60 through the separation membrane 60, It can be concentrated by removing moisture from the aqueous solution. Moisture flowing into the outer space of the separation membrane 60 can be discharged from the port 53. The protein aqueous solution from which moisture has been removed after passing through the inner space of the separation membrane 60 is discharged from the port 52 to the concentrated ascites bag 23 as a concentrated solution.

The separation membrane 60 has a porosity of 60% or more and 80% or less and the separation membrane liquid level rise value measured by the capillary rise method is 60 mm to 150 mm when converted to a hollow fiber membrane having an inner diameter of 200 μm, and the concentration is 3 g / dL. When the concentration step P in which the protein aqueous solution stock solution is passed at a flow rate of 50 mL / min to obtain a concentrated solution of the protein aqueous solution is performed, the following conditions (1) and (2) are satisfied.
(1) The maximum transmembrane pressure difference when 5 L of the protein aqueous solution stock solution is concentrated is 500 mmHg or less.
(2) When the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 2 L is A and the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 5 L is B, B / A ≦ 1.6.

  That is, as shown in FIG. 3, the separation membrane 60 has a concentration of 3 g / dL of a protein aqueous solution stock solution passed through the separation membrane 60 at a flow rate of 50 mL / min and is concentrated. Maximum transmembrane pressure difference (maximum difference between primary side pressure and secondary side pressure of separation membrane 60) is 500 mmHg or less, and B (transmembrane pressure difference when 5 L of protein aqueous solution is concentrated) / A The porosity and the hydrophilicity are adjusted so that (the intermembrane pressure difference when 2 L of the protein aqueous solution is concentrated) is 1.6 or less. Curves S1, S2, and S3 in FIG. 3 indicate separation membranes that satisfy the conditions (1) and (2), and curves S4 and S5 indicate separation membranes that do not satisfy the conditions (1) and (2).

The porosity is defined by the following formula.
Porosity = (Y−X) × 100 / Y
X: Weight of a certain amount of film Y: Weight when it is assumed that a certain amount of film of X is filled with the substrate (when there is no void).
In the present invention, the porosity needs to be 60% or more and 80% or less. More preferably, it is 65% or more and 80% or less, and more preferably 65% or more and 75% or less. If it is less than 60%, clogging tends to occur during concentration, which is not preferable. On the other hand, if it is larger than 80%, the amount of protein leakage during concentration is undesirably large. Even when the separation membrane is not a hollow fiber membrane but a flat membrane, the porosity is calculated by the above formula.

In the present invention, the degree of hydrophilicity is measured by a capillary rise method. The capillary ascending method referred to in the present invention is a method in which one end of a hollow opening of a hollow fiber membrane (one side of a flat membrane in the case of a flat membrane) is immersed in an aqueous solution, and the liquid level that has risen by capillary action after a certain time is increased from the water surface. This is a method of measuring the thickness. Specifically, the following pretreatments (P) and (Q), that is, the separation membrane is washed with distilled water for injection (P), the separation membrane is sufficiently dried (Q), and then dried. This is a method in which one end of a membrane is immersed in an aqueous solution, and the height of the liquid level rising by capillary action after a certain time is measured from the water surface.
In the case of a tubular separation membrane, it is generally known that there is the following relational expression regarding capillary rise.
h = 2γ cos θ / rρg
h: Ascending position from liquid surface γ: Surface tension of liquid θ: Contact angle (angle from contact surface of solid and liquid to contact surface of liquid and gas)
r: tube radius ρ: liquid density g: gravitational acceleration That is, the surface tension of the liquid can be measured by measuring r (tube radius), ρ (liquid density), and h (rising position from the liquid surface). From this relational expression, it is possible to evaluate the ease of wetting of the surface of the tubular structure body with respect to the liquid, that is, the degree of hydrophilicity and hydrophobicity, by the degree of rise in the liquid level in the capillary.
Therefore, also in the case of a separation membrane, the ease of wetting of the inner surface of the hollow fiber with respect to the aqueous solution, that is, the degree of hydrophilicity (hydrophobicity) can be measured by the above-described capillary ascent method. In addition, even for separation membranes with different inner diameters, the liquid level rise value and inner diameter in each capillary are measured, and each of the separation membranes is corrected by converting to the reference separation membrane inner diameter from the above equation. The degree of hydrophilicity (hydrophobicity) can be absolutely compared as the liquid level rise value of the separation membrane having a reference inner diameter. In the present invention, a correction value obtained by converting the inner diameter of the hollow fiber membrane to 200 μm is used as the liquid level rise value. When measuring the capillary rise value of the separation membrane, the moisture content and the inner diameter of the separation membrane affect the measurement value, so it is necessary to measure the moisture content and the inner diameter. The moisture content of the separation membrane needs to be 5% or less. If the moisture content is greater than 5%, the hydrophobic nature of the inner surface inherent to the separation membrane is less likely to appear, and the capillary rises. The value shows a large measured value, and accurate measurement cannot be performed.
When measuring the level rise of an aqueous solution due to capillary action, the measurement time is also important. When the separation membrane is more hydrophilic, the speed of the rising aqueous solution increases, and the measurement value varies in a short time measurement. Moreover, it becomes difficult to measure many samples at once. Practical measurement time is preferably the time when 5 seconds or more have passed since the separation membrane was immersed in the aqueous solution, and more practically, it is preferably set to an appropriate time within 3 minutes. In the present invention, the value after 1 minute is shown.
When the separation membrane is a flat membrane, the degree of hydrophilicity is determined by the contact angle (chemical handbook, etc.), or the liquid level rise value by the capillary rise method in a hollow fiber membrane with an inner diameter of 200 μm using the same material and composition. To do.
In the present invention, the correction value obtained by converting the inner diameter of the hollow fiber membrane to 200 μm of the increased value of the aqueous solution measured by the capillary ascending method needs to be 60 mm or more and 150 mm or less. More preferably, it is 65 mm or more and 145 mm or less, and more preferably 70 mm or more and 140 mm or less. As will be described later, even when the hydrophilicity is lower than 60 mm, that is, when the hydrophilicity is too low, and when higher than 150 mm, that is, when the hydrophilicity is too high, the bound protein layer F1 on the surface of the separation membrane becomes too thick. This is not preferable because the concentration factor is lowered.

As shown in FIG. 4, for example, when an aqueous protein solution is passed through the separation membrane 60, if the total volume of the portion 60a, that is, the porosity is high, clogging hardly occurs at the time of separation, and high-magnification can be achieved. On the other hand, the protein also passes with the water, and the protein recovery rate is lowered. It was considered that by adjusting the porosity to an appropriate range, it is possible to ensure the water permeability and not allow the protein to pass through.
Further, it is generally considered that a bound protein layer F1 in which proteins in an aqueous protein solution are irreversibly deposited and a free protein layer F2 in which proteins are reversibly deposited are formed on the surface of the separation membrane 60. When the bound protein layer F1 and the free protein layer F2 are deposited and the thickness is increased, the separation membrane 60 is clogged, the amount of water permeated through the separation membrane 60 is reduced, and the concentration rate is lowered. Here, the inventors of the present application considered reducing the clogging by adjusting the thickness of the constrained protein layer F1 to be thin.

  It has been found that the thickness of the bound protein layer F1 depends on the hydrophilicity of the separation membrane 60. That is, it was found that the protein tends to adhere to the separation membrane 60 and the bound protein layer F1 becomes thick both when the hydrophobicity of the entire membrane is too strong and conversely when the hydrophilicity of the entire membrane is too strong. . Therefore, the present invention adjusts the thickness of the bound protein layer F1 to an appropriate range by adjusting the porosity and hydrophilicity of the separation membrane 60 to appropriate values, thereby ensuring the water permeability of the separation membrane 60. In addition, while realizing a high concentration rate, the leakage of the protein from the separation membrane 60 is suppressed and a high recovery rate of the protein is ensured.

The substrate used for the separation membrane 60 is polysulfone, ethylene vinyl alcohol such as eval, cellulose acetate, polyethylene, polyester polymer alloy (PEPA), polymethyl methacrylate (PMMA), or polyacrylonitrile. In particular, a polysulfone base material is preferred. Further, the degree of hydrophilicity is adjusted by applying a hydrophilization treatment by adding a hydrophilizing agent to the substrate. Examples of the hydrophilizing agent include ethylene such as polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, polypropylene glycol, and eval. -Vinyl alcohol copolymer, polyhydroxyethyl acrylate, etc. are mentioned. The hydrophilicity of the separation membrane 60 is adjusted by adjusting, for example, the type of base material and the amount and type of hydrophilizing agent.
The porosity of the separation membrane 60 is determined by adjusting the stretching temperature, the stretching speed, and the stretching roll diameter, for example, in the case of a separation membrane that opens by thermal stretching. In the case of wet spinning using a double spinning nozzle or the like, it is carried out by adjusting the discharge rate of the polymer stock solution, the composition of the internal solution, and the spinning temperature.

  According to the present embodiment, the value of the maximum transmembrane pressure difference does not become large (in the concentration step P of the predetermined condition, it is maintained at 500 mmHg or less even if 5 L is concentrated), and the increase rate of the transmembrane pressure difference Is small (B / A ≦ 1.6 or less in the concentration step P), and as a result of setting the porosity and hydrophilicity of the separation membrane 60 within a specific value range, the thickness of the bound protein layer F1 is It can be considered that the value is adjusted to an appropriate range. Therefore, in the concentrator for concentrating the protein aqueous solution produced by filtering the ascites, the water permeability of the separation membrane 60 is ensured, and protein leakage from the separation membrane 60 can be suppressed. A high recovery rate of protein can be realized.

In the above-described embodiment, the separation membrane 60 has a porosity of 60% or more and 80% or less and a liquid level rise value of the separation membrane measured by a capillary ascending method is 60 mm to 150 mm when converted to a hollow fiber membrane having an inner diameter of 200 μm. In addition, when the concentration step P for obtaining a concentrated solution of the protein aqueous solution by passing the protein aqueous solution stock solution with a concentration of 3 g / dL at a flow rate of 50 mL / min, the following conditions (3) and (4) are further satisfied. May be.
(3) The protein recovery rate of the concentrate obtained when 2 L of the protein aqueous solution stock is concentrated is 40% or more.
(4) The protein recovery rate of the concentrate obtained when 5 L of the protein aqueous solution stock is concentrated is 70% or more.

  In such a case, the separation membrane 60 can reduce protein leakage in the separation membrane 60 and set a high protein recovery rate by setting the porosity and hydrophilicity to appropriate values.

  Further, the separation membrane 60 is further set with a porosity and a hydrophilicity so that the albumin recovery rate of the concentrated solution obtained when 5 L of the protein aqueous solution is concentrated under the above condition (4) is 80% or more. May be.

Moreover, in the said embodiment, when the separation membrane 60 is converted into a hollow fiber membrane having a porosity of 60% or more and 80% or less and a liquid level increase value of the separation membrane measured by the capillary ascending method, an inner diameter of 200 μm, 60 mm to 150 mm. When a concentration step P for obtaining a concentrated aqueous solution of protein by passing a 3 g / dL aqueous protein solution at a flow rate of 50 mL / min and carrying out the concentration step P is performed, the following (5) is further satisfied. Also good.
(5) When the transmembrane pressure difference when 2 L of the protein aqueous solution stock is concentrated is A and the transmembrane pressure difference when 10 L of the protein aqueous solution is concentrated is C, C / A ≦ 1.5.

  That is, the separation membrane 60 has a C (transmembrane pressure difference when the protein aqueous solution is concentrated by 10 L) / A (transmembrane pressure difference when the protein aqueous solution stock is concentrated by 2 L) when the concentration step P is performed. The porosity and the hydrophilicity are adjusted so as to be 5 or less.

  In such a case, since the rate of increase in the transmembrane pressure difference when 10 L is concentrated in the concentration step P is suppressed, the transmembrane pressure difference does not increase even if a larger amount of protein aqueous solution is concentrated for a long time. It is thought that the thickness is maintained at an appropriate value. Therefore, in the concentrator for concentrating the protein aqueous solution produced by filtering the ascites, the water permeability of the separation membrane 60 is ensured and the leakage of the protein from the separation membrane 60 is suppressed, so that high-concentration concentration is achieved. High protein recovery rate can be realized.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  For example, the configuration of the concentrator 22 in the above embodiment is not limited to this. Further, the configuration of the ascites treatment system 1 having the concentrator 22 is not limited to this. The separation membrane 60 of the concentrator 22 is a hollow fiber membrane, but may be another type of membrane, for example, a flat membrane, as long as it can separate the water in the protein aqueous solution.

  The present invention can also be applied to a concentrator that concentrates body cavity fluid other than ascites, such as pleural effusion or pericardial fluid.

  In the following Examples, the experimental results verified for the ascites concentration rate and the final protein recovery rate in the present invention are shown. In this example, a solution simulating a protein aqueous solution before concentration is referred to as “original solution”.

  As shown in FIG. 5, the original liquid storage unit 100, the concentrator 101, the concentrated liquid storage unit 102, the pressure gauges 103, 104, and 105 and the pumps 106 and 107 were arranged and connected by a circuit. A manometer (manufactured by Copal Electronics, PG-200-102GP-P) was used as the pressure gauge. The pump used was a roller pump (RP-1000) manufactured by EYELA, the pump 106 was set to have a flow rate of 50 mL / min, and the pump 107 was set to have a flow rate of 40 mL / min.

<Preparation method of the original solution>
A simulated ascites containing blood cell components using bovine blood was prepared. First, bovine blood to which heparin sodium injection (10,000 units / 1 L of bovine blood) was added as an anticoagulant was centrifuged to obtain plasma layer, red blood cell layer and buffy coat layer solutions, which were collected separately. Plasma was obtained. Next, the plasma was filtered through a filter (ascites filter AHF-MO-W manufactured by Asahi Kasei Medical Co., Ltd.), and then mixed with physiological saline to adjust the protein concentration to 3.0 (g / dL) and the albumin concentration. 10 L of the original solution prepared to 1.5 (g / dL) was prepared.

<Method for measuring protein concentration and method for calculating protein recovery>
The protein concentration was measured by the burette method. Automatic analyzer (manufactured by Tokyo Trading Medical System Co., Ltd., Biolis 24i), Iatro TPII (Co., Ltd. L) as a reagent for measurement
SI Medience).
When the amount of protein in the original solution is TP1, and the amount of protein in the concentrate is TP2, the protein recovery rate was calculated using the following equation.
Protein recovery rate = TP2 / TP1 × 100 (%)

<Measurement method of albumin concentration and calculation method of albumin recovery>
The albumin concentration was measured by the BCG method. Automatic analyzer (manufactured by Tokyo Trading Medical System Co., Ltd., Biolis 24i), Iatrofine ALBII (reagent for measurement)
LSI Medience Co., Ltd.) was used.
When the amount of albumin in the original solution was ALB1, and the amount of albumin in the concentrate was ALB2, the albumin recovery rate was calculated using the following equation.
Albumin recovery rate = ALB2 / ALB1 × 100 (%)

<Measurement method of transmembrane pressure difference>
When the pressures indicated by the pressure gauge 103, the pressure gauge 104, and the pressure gauge 105 are P1, P2, and P3, respectively, the transmembrane pressure difference was calculated by the following equation.
Transmembrane pressure difference = (P1 + P2) / 2−P3 (mmHg)

<Calculation method of transmembrane pressure difference ratio (B / A, C / A)>
The transmembrane pressure difference during the original liquid 2L treatment is A (mmHg), the transmembrane pressure difference during the original liquid 5L treatment is B (mmHg), and the transmembrane pressure difference during the original liquid 2L treatment is C (mmHg). The ratio of the transmembrane pressure difference was a value obtained by dividing B and C by A and rounding off to the second decimal place.

<Concentration ratio>
A value obtained by dividing the original liquid volume by 10 L and the concentrated liquid volume X was taken as the concentration ratio, and the following determination was made.
Concentration factor is 5 times ... Yes Concentration factor is less than 5 times ... x
In this embodiment, the flow rate of the pump 106 is 50 mL / min, whereas the flow rate of the pump 107 is 40 mL / min. Therefore, if the total amount can be concentrated without clogging, the amount of the concentrated solution becomes 2 L, and the concentration factor Will be 5 times.

<Final protein recovery rate>
When the protein amount in the original solution is TP1, and the protein amount in the finally obtained concentrated solution is TP3, the final protein recovery rate was calculated using the following equation.
Final protein recovery rate = TP3 / TP1 × 100 (%)
The final protein recovery rate was determined as follows.
Final protein recovery rate is 50% or more 〇 Final protein recovery rate is less than 50% ・ ・ ・ ×

Example 1
As the concentrator, a hollow fiber membrane type concentrator composed of 9000 polysulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 200 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 78%, and a liquid level increase value of 110 mm by the capillary ascending method was used. The results are shown in Table 1.

(Example 2)
As a concentrator, a hollow fiber comprising 10600 polysulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 185 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 73%, and a liquid level rising value of 120 mm (converted as an inner diameter of 200 μm) by the capillary ascending method. The same experiment as in Example 1 was performed except that a membrane concentrator was used. The results are shown in Table 1.

(Example 3)
As a concentrator, a hollow fiber composed of 10600 polysulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 185 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 60%, and a liquid level rising value of 120 mm (converted as an inner diameter of 200 μm) by the capillary ascending method. The same experiment as in Example 1 was performed except that a membrane concentrator was used. The results are shown in Table 1.

(Example 4)
As a concentrator, an ethylene-vinyl alcohol copolymer (EVAL) hollow fiber having an inner diameter of 185 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 72%, and a liquid level increase value of 150 mm (converted as an inner diameter of 200 μm) by the capillary ascending method The same experiment as in Example 1 was performed except that 10600 hollow fiber membrane type concentrators were used. The results are shown in Table 1.

(Example 5)
As the concentrator, a hollow fiber membrane type concentrator composed of 9000 polysulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 200 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 80%, and a liquid level increase value of 110 mm by the capillary ascending method was used. Except that, the same experiment as in Example 1 was performed. The results are shown in Table 1.

(Example 6)
As the concentrator, a hollow fiber membrane type concentrator composed of 9000 polyethersulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 200 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 63%, and a liquid level rising value of 70 mm by the capillary ascending method is used. The same experiment as in Example 1 was performed except that it was. The results are shown in Table 1.

(Example 7)
Other than using a hollow fiber membrane type concentrator consisting of 9000 cellulose triacetate hollow fibers having an inner diameter of 200 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 70%, and a liquid level increase value of 60 mm by the capillary ascending method. The same experiment as in Example 1 was performed. The results are shown in Table 1.

(Comparative Example 1)
As a concentrator, a hollow fiber membrane type comprising 9000 ethylene-vinyl alcohol copolymer (EVAL) hollow fibers having an inner diameter of 200 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 52%, and a liquid level rising value of 180 mm by the capillary ascending method. The same experiment as in Example 1 was performed except that a concentrator was used. The results are shown in Table 1.

(Comparative Example 2)
As a concentrator, a hollow fiber comprising 10600 polysulfone / polyvinylpyrrolidone hollow fibers having an inner diameter of 185 μm, a film thickness of 45 μm, a length of 330 mm, a porosity of 55%, and a liquid level rising value of 110 mm (converted as an inner diameter of 200 μm) by the capillary ascending method. The same experiment as in Example 1 was performed except that a membrane concentrator was used. The results are shown in Table 1.

  INDUSTRIAL APPLICABILITY The present invention is useful for securing a high protein recovery rate while achieving high-concentration concentration in a concentrator that concentrates an aqueous protein solution produced by filtering body cavity fluid.

1 Ascites treatment system 22 Concentrator 60 Separation membrane

Claims (7)

A concentrator that concentrates an aqueous protein solution produced by filtering body cavity fluid with a separation membrane,
The separation membrane has a porosity of 60% or more and 80% or less and a liquid level rise value of the separation membrane measured by a capillary rise method is 60 mm to 150 mm when converted to a hollow fiber membrane having an inner diameter of 200 μm, and a concentration of 3 g / dL. A concentrator configured to satisfy the following conditions (1) and (2) when a concentration step of obtaining a concentrated solution of an aqueous protein solution by passing the aqueous protein solution at a flow rate of 50 mL / min is performed.
(1) The maximum transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 5 L is 500 mmHg or less,
(2) When the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 2 L is A and the transmembrane pressure difference when the protein aqueous solution stock solution is concentrated by 5 L is B, B / A ≦ 1.6. The concentrator according to claim 1, wherein the separation membrane is configured to further satisfy the following conditions (3) and (4) when the concentration step is performed.
(3) The protein recovery rate of the concentrate obtained when 2 L of the aqueous protein solution stock is concentrated is 40% or more,
(4) The protein recovery rate of the concentrate obtained when 5 L of the protein aqueous solution stock is concentrated is 70% or more.   The concentrator according to claim 2, wherein the albumin recovery rate of the concentrate obtained when 5 L of the protein aqueous solution is concentrated under the condition (4) is 80% or more. The concentrator according to any one of claims 1 to 3, wherein the separation membrane is configured to satisfy the following (5) when the concentration step is performed.
(5) When the transmembrane pressure difference when 2 L of the protein aqueous solution stock is concentrated is A and the transmembrane pressure difference when 10 L of the protein aqueous solution is concentrated is C, C / A ≦ 1.5.   The base material used for the separation membrane is polysulfone, ethylene vinyl alcohol, cellulose acetate, polyethylene, polyester polymer alloy (PEPA), polymethyl methacrylate (PMMA), or polyacrylonitrile. The concentrator in any one of 1-4.   The concentrator according to any one of claims 1 to 5, wherein the separation membrane is a hollow fiber membrane.   The concentrator according to claim 6, wherein the separation membrane is a polysulfone-based hollow fiber membrane.

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