Blood purifier

Abstract

The purpose of the present invention is to provide a blood purifier capable of removing both cytokines and leukocytes. The present invention provides a blood purifier comprising a hollow fiber membrane and a cylindrical case, the blood purifier being configured such that the case is filled with the hollow fiber membrane, and blood comes into direct contact with an outer surface of the hollow fiber membrane, wherein the hollow fiber membrane includes a polymer selected from the group consisting of polymethyl methacrylate, cellulose, cellulose ester, polyethylene, polypropylene, polyarylate, polystyrene, polyethersulfone, polyethylene terephthalate, polytetrafluoroethylene, polyurethane, polycarbonate, polyamide, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, and polyvinylidene fluoride, and copolymers containing repeating units constituting these polymers.

Description

blood purifier

[0001] The present invention relates to a blood purifier.

[0002] Cytokines are a group of proteins that are produced by various cells, including immune cells, in response to stimuli such as infection or trauma, and are released extracellularly to act. Cytokines are immune-related proteins that are normally produced for biological defense, but it has been revealed that excessive production of cytokines in the body is involved in tissue damage and pathology in various inflammatory diseases. Known inflammatory cytokines that cause inflammatory diseases include interleukin (IL), tumor necrosis factor (TNF), and interferons. Among these, IL-6 and IL-8 have attracted attention in recent years. Methods for treating inflammatory diseases include inactivating inflammatory cytokines or suppressing their production using biological preparations such as small molecule drugs and antibodies. However, inflammatory cytokines do not act alone at the site of inflammation; rather, multiple inflammatory cytokines act in combination to cause the onset and progression of inflammatory diseases. Therefore, recently, attention has been focused on extracorporeal circulation therapy, which removes not only inflammatory cytokines but also activated leukocytes, which are the source of inflammatory cytokines, from the body.

[0003] Hollow fiber membranes have been studied as a material for use in extracorporeal circulation therapy. For example, Patent Document 1 discloses a hollow fiber membrane having excellent blood compatibility and high cytokine adsorption performance. Patent Document 2 discloses a device (blood purifier) ​​including a hollow fiber membrane for reducing leukocytes from blood. Patent Document 3 discloses a cartridge (blood purifier) ​​equipped with a solid support such as a hollow fiber (hollow fiber membrane) for separating (isolating) inflammation-related cells and reducing their inflammatory activity. Patent Document 4 discloses a device (blood purifier) ​​including a hollow fiber (hollow fiber membrane) for treating inflammation-related cells.

[0004] Japanese Patent Application Laid-Open No. 2011-62282 Japanese Patent Application Laid-Open No. 2010-515503 Japanese Patent No. 7224329 Japanese Patent Application Laid-Open No. 2017-80400

[0005] However, although the hollow fiber membrane of Patent Document 1 has the ability to adsorb cytokines, there is no disclosure regarding its ability to adsorb leukocytes, which are a source of cytokines.

[0006] The device of Patent Document 2 can remove leukocytes, but does not disclose its ability to adsorb inflammatory cytokines.

[0007] The blood purifiers of Patent Documents 3 and 4 temporarily separate inflammation-related cells, particularly leukocytes, into a hollow fiber membrane, inactivate the leukocytes, and then release them from the hollow fiber membrane. However, the temporarily separated leukocytes continue to release cytokines until they are inactivated. Furthermore, Patent Documents 3 and 4 do not disclose the cytokine adsorption performance of these blood purifiers.

[0008] Therefore, an object of the present invention is to provide a blood purifier that can remove both cytokines and leukocytes.

[0009] As a result of extensive research into solving the above problems, the inventors discovered that both cytokines and leukocytes can be removed in a blood purifier that has a hollow fiber membrane and a cylindrical case, in which the hollow fiber membrane is filled in the cylindrical case and blood comes into contact with the outer surface of the hollow fiber membrane.

[0010] That is, the present invention provides the following [1] to [4]: ​​[1] A blood purifier having a hollow fiber membrane and a cylindrical case, the case being filled with the hollow fiber membrane, and blood being in direct contact with the outer surface of the hollow fiber membrane, the blood purifier having the following configuration (a) or (b), wherein the hollow fiber membrane comprises a polymer selected from the group consisting of polymethyl methacrylate, cellulose, cellulose ester, polyethylene, polypropylene, polyarylate, polystyrene, polyethersulfone, polyethylene terephthalate, polytetrafluoroethylene, polyurethane, polycarbonate, polyamide, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, and polyvinylidene fluoride, and copolymers containing repeating units constituting these polymers. (a) A configuration in which the case has a blood inlet on a side thereof, and one end and the other end of the hollow fiber membrane are embedded in one end and the other end of the case, respectively. (b) A configuration in which both ends of the hollow fiber membrane are closed. [2] The blood purifier according to [1], wherein the hollow fiber membrane comprises polymethyl methacrylate or a copolymer containing a repeating unit constituting polyacrylonitrile and a repeating unit constituting polymethallylsulfonic acid. [3] The blood purifier according to [2], wherein the polymethyl methacrylate is a stereocomplex of isotactic polymethyl methacrylate and syndiotactic polymethyl methacrylate. [4] The blood purifier according to any of [1] to [3], wherein the hollow fiber membrane is a homogeneous membrane.

[0011] The blood purifier of the present invention is capable of removing both cytokines and leukocytes, and can be used to treat inflammatory diseases.

[0012] FIG. 2 is a cross-sectional view of one embodiment of the blood purifier of the present invention, and is a cross-sectional view of the blood purifiers of Examples 1 to 5, Examples 9 and 10, and Comparative Example 2. FIG. 3 is a cross-sectional view of one embodiment of the blood purifier of the present invention, and is a cross-sectional view of the blood purifier of Example 6. FIG. 4 is an enlarged view of a portion of FIG. 2. FIG. 5 is a cross-sectional view of one embodiment of the blood purifier of the present invention, and is a cross-sectional view of the blood purifier of Example 7. FIG. 6 is a cross-sectional view of one embodiment of the blood purifier of the present invention, and is a cross-sectional view of the blood purifier of Example 8. FIG. 7 is a diagram showing a method of winding a hollow fiber membrane around a central pipe member in FIG. 5. FIG. 8 is a cross-sectional view of the blood purifier of Comparative Example 1.

[0013] The present invention will be described in detail below.

[0014] The blood purifier of the present invention comprises a hollow fiber membrane and a cylindrical case.

[0015] The hollow fiber membrane in the present invention is an adsorbent that adsorbs blood components.

[0016] A hollow fiber membrane is a straw-shaped porous membrane. The surface of the hollow fiber membrane facing the lumen is the inner surface, and the surface on the opposite side of the membrane is the outer surface. In a cross section of a hollow fiber membrane cut along a plane perpendicular to the longitudinal direction, the diameter on the outer surface side is the outer diameter of the hollow fiber membrane, the diameter of the lumen is the inner diameter of the hollow fiber membrane, and the thickness of the membrane in the normal direction to the outer surface is the thickness of the hollow fiber membrane.

[0017] If the outer diameter of the hollow fiber membrane is too small, the membrane will not have sufficient strength and may be damaged during production or use. On the other hand, if the outer diameter of the hollow fiber membrane is too large, the outer surface area per unit volume will be small, resulting in a decrease in adsorption performance. Therefore, the outer diameter of the hollow fiber membrane is preferably 50 μm or more and 1 mm or less, more preferably 100 μm or more and 500 μm or less, and even more preferably 150 μm or more and 350 μm or less.

[0018] The membrane thickness of the hollow fiber membrane can be appropriately selected depending on the outer diameter of the hollow fiber membrane, but if it is too small, the membrane will not have enough strength and may be broken during production or use, while if it is too large, the material cost will increase and the weight will also increase, which are undesirable. Therefore, the membrane thickness of the hollow fiber membrane is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 100 μm or less.

[0019] The hollow fiber membrane of the present invention comprises, as a material, a polymer selected from the group consisting of polymethyl methacrylate, cellulose, cellulose ester, polyethylene, polypropylene, polyarylate, polystyrene, polyethersulfone, polyethylene terephthalate, polytetrafluoroethylene, polyurethane, polycarbonate, polyamide, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, polyvinylidene fluoride, and copolymers containing repeating units constituting these polymers. From the viewpoint of cytokine adsorption performance, the hollow fiber membrane of the present invention preferably comprises polymethyl methacrylate or a copolymer containing repeating units constituting polyacrylonitrile and repeating units constituting polymethallylsulfonic acid. The polymethyl methacrylate is preferably a stereocomplex of isotactic polymethyl methacrylate and syndiotactic polymethyl methacrylate.

[0020] As the hollow fiber membrane, either a homogeneous membrane or a heterogeneous membrane can be used. A homogeneous membrane is a membrane that has a homogeneous structure from the outer surface to the inner surface in a cross section of the hollow fiber membrane cut along a plane perpendicular to the longitudinal direction. A heterogeneous membrane is a membrane that has macrovoids on the outer surface side and / or the inner surface side. Of these, a homogeneous membrane that has no macrovoids and is composed only of a dense structure is preferred because it has a large internal surface area per unit volume and can adsorb cytokines that have penetrated into the membrane with high efficiency.

[0021] Whether a hollow fiber membrane is a homogeneous membrane can be evaluated by cutting the hollow fiber membrane in a plane perpendicular to the longitudinal direction, exposing the cross section of the membrane thickness portion, and observing the cross section with a scanning electron microscope (e.g., S-5500, manufactured by Hitachi, Ltd.). The specific evaluation method is as follows. In the cross section of the membrane thickness portion, the membrane thickness portion is divided at half its length in the thickness direction of the membrane, and the region of the membrane thickness portion close to the hollow portion of the hollow fiber is designated the inner surface near-region, and the region of the membrane thickness portion close to the outer surface of the hollow fiber is designated the outer surface near-region. In each of the inner surface near-region and outer surface near-region, 20 images within a 2 μm × 2 μm area are arbitrarily taken with a scanning electron microscope. In each image, the circle-equivalent diameter of the observed pores is determined, and further, for each region, the average pore diameter is determined by averaging the circle-equivalent diameters of all pores in the 20 images. A hollow fiber membrane having a ratio of the average pore size in the region near the outer surface to the average pore size in the region near the inner surface (average pore size in the region near the outer surface / average pore size in the region near the inner surface) of 0.5 or more and 2.0 or less can be determined to be a homogeneous membrane.

[0022] In the blood purifier of the present invention, the hollow fiber membranes are packed in a cylindrical case (hereinafter, sometimes simply referred to as the "case"). The hollow fiber membranes may be packed in a bundled or coiled shape, or may be packed in chopped pieces. In consideration of the blood flow pattern and ease of manufacturing, it is preferable that the hollow fiber membranes be packed in a bundled shape.

[0023] A header can be attached to the end of the case as needed. A header is a member for closing the opening of the end of the case. The header can be fixed to the end of the case by screwing it into the end of the case with threads on the end of the case and the header, or by using an ultrasonic welder or adhesive. A blood inlet and / or a blood outlet may be attached to the header.

[0024] The case and header can be made of resin, glass, metal, or the like. However, considering the ease of handling in clinical settings, resin is preferred because it is lightweight and easy to dispose of. Transparent or translucent materials are particularly preferred, allowing for easy observation of the interior. From the viewpoint of moldability, thermoplastic resins are preferred, such as polypropylene, polyethylene, polystyrene, polycarbonate, polyester, polyamide, and polymethyl methacrylate. Rubber particles or glass fibers may be added to the thermoplastic resin to improve strength, or a pigment may be added to improve visibility.

[0025] The case of the present invention has a cylindrical shape, and is preferably cylindrical from the viewpoints of ensuring uniformity of blood flow and ease of manufacture. The size of the case can be selected appropriately depending on the intended use, but in consideration of ease of handling in clinical settings, the total length of the blood purifier with headers attached to both ends of the case is preferably 5 cm to 50 cm, and the outer diameter is preferably 2 cm to 10 cm.

[0026] The case and / or header have a blood inlet and a blood outlet. The blood inlet and the blood outlet can be of any shape. If the opening area of ​​the blood inlet and the blood outlet is too small, the resistance when passing blood increases, and if it is too large, it becomes difficult to connect them to the blood circuit. Therefore, the opening area of ​​the blood inlet and the blood outlet is set to 0.1 cm or less. ２ 7cm or more ２ Preferably, it is 0.3 cm or less. ２ More than 2cm ２ More preferably, it is:

[0027] If the blood outlet is located near the blood inlet, blood entering the case may be discharged from the blood outlet before sufficient contact with the hollow fiber membrane, potentially reducing the efficiency of leukocyte and cytokine removal. Therefore, it is preferable that the blood inlet and blood outlet are located as far apart as possible. When the blood inlet and blood outlet are located on the side of the case, a preferred configuration in which the blood inlet and blood outlet are located far apart is, for example, as shown in Figure 1 , where the blood inlet is located at one end of the case and the blood outlet is located at the other end of the case. Furthermore, a configuration in which the difference between the installation angle of the blood inlet and the installation angle of the blood outlet is large when observed from the end face of the case is also preferred. It is more preferable that the difference between the installation angle of the blood inlet and the installation angle of the blood outlet is 180 degrees, as shown in Figure 1 .

[0028] The blood purifier of the present invention has a configuration in which blood directly contacts the outer surface of the hollow fiber membrane. Specifically, this configuration is the following (a) or (b). By having the blood purifier have this configuration, leukocytes can be adsorbed. (a) A configuration in which a blood inlet is provided on the side of the case, and one end and the other end of the hollow fiber membrane are embedded in one end and the other end of the case, respectively. (b) A configuration in which both ends of the hollow fiber membrane are closed.

[0029] "The blood directly contacts the outer surface of the hollow fiber membrane" means that the blood entering the blood purifier from the blood inlet contacts the outer surface of the hollow fiber membrane without ever coming into contact with any part of the hollow fiber membrane other than the outer surface (the inner surface and the membrane thickness).

[0030] The term "embedding" means filling the gaps between the hollow fiber membranes and fixing the hollow fiber membranes inside the case. A potting agent can be used for embedding.

[0031] An example of a blood purifier having the above configuration (a) is the blood purifier shown in FIG. 1. The blood purifier shown in FIG. 1 has a blood inlet 2 and a blood outlet 3 on the side of a case 1, both ends of a hollow fiber membrane 6 are embedded in a potting agent 7, and a header 8 is attached to the end face of the case 1, with the header 8 having a solution inlet 4 or a solution outlet 5. The solution inlet 4 and the solution outlet 5 are sealed with sealing plugs 9 when blood is passed through. The end faces of the hollow fiber membranes embedded in the potting agent are open. In the blood purifier shown in FIG. 1, because both ends of the hollow fiber membranes are embedded in a potting agent, blood flowing in through the blood inlet on the side of the case cannot directly contact the inner surface and membrane thickness of the hollow fibers. On the other hand, blood flowing in through the blood inlet on the side of the case can directly contact the outer surface of the hollow fiber membrane.

[0032] In Figure 1, the end face of the embedded hollow fiber membrane is open. However, if both ends of the hollow fiber membrane are embedded, blood flowing in through the blood inlet on the side of the case cannot directly contact the inner surface of the hollow fiber or the membrane thickness portion. Therefore, in a blood purifier having the configuration (a) above, the end face of the embedded hollow fiber membrane may be open or closed, or one end face may be open and the other end face may be closed. Furthermore, even if at least one end face of the embedded hollow fiber membrane is open, the end face may be closed by attaching a cap or the like to the end face during use.

[0033] Examples of blood purifiers having the above configuration (b) include the blood purifiers shown in Figures 2, 4, and 5.

[0034] The blood purifier shown in Figure 2 has a header 8 attached to the end face of a case 1, the header 8 having a blood inlet 2 or a blood outlet 3, both ends of a hollow fiber membrane 6, including the end faces, embedded in a potting agent 7, and the potting agent 7 embedding the hollow fiber membrane 6 has through-holes 10 through which blood can flow from the header 8 into the case 1. Figure 3 is an enlarged view of the portion including the through-holes. In the blood purifier shown in Figure 2, because the end faces of the hollow fiber membrane are embedded in a potting agent (because both ends of the hollow fiber membrane 6 are closed), blood flowing in from the blood inlet cannot directly contact the inner surface or membrane thickness of the hollow fiber membrane. On the other hand, blood flowing in from the blood inlet flows into the case through the through-holes and directly contacts the outer surface of the hollow fiber membrane.

[0035] In the blood purifier shown in Fig. 4, hollow fiber membranes 6, both ends of which are closed, are packed loosely into a case 1. In the blood purifier shown in Fig. 4, because both ends of the hollow fiber membrane are closed, blood flowing in from the blood inlet cannot directly contact the inner surface and membrane thickness of the hollow fiber membrane. As long as blood flows into the case, it will directly contact the outer surface of the hollow fiber membrane, both ends of which are closed. Therefore, the blood inlet and blood outlet may be attached to the side of the case or to a header.

[0036] The method for closing both ends of the hollow fiber membrane is not particularly limited, and examples thereof include crimping with a heat source such as a heat sealer, crimping by cutting with scissors, or tying with thread, etc. Whether both ends of the hollow fiber membrane are closed can be confirmed visually or by observation with a microscope, depending on the size of the hollow fiber membrane.

[0037] The blood purifier shown in FIG. 5 has hollow fiber membranes 6, each closed at both ends, wound around a central pipe 12. The hollow fiber membranes 6, each closed at both ends, can be wound by passing them through the inner-outer pipe through-holes 13, which are holes provided on the surface of the central pipe 12, as shown in FIG. 6. In the blood purifier shown in FIG. 5, because both ends of the hollow fiber membranes are closed, blood flowing in through the blood inlet cannot directly contact the inner surface or membrane thickness of the hollow fiber membrane. Since blood directly contacts the outer surface of the hollow fiber membranes closed at both ends once it enters the case, the blood inlet and blood outlet may be attached to the side of the case or to a header. In FIG. 5, blood flowing in through the blood inlet passes through the mesh into the case, directly contacts the outer surface of the hollow fiber membranes closed at both ends, passes through the pipe through the inner-outer pipe through-holes, passes through the mesh that contacts the end face of the pipe without the sealing plug, and then flows out of the blood purifier.

[0038] In the present invention, if hollow fiber membranes adhere to each other, the adhered portions are less likely to come into contact with blood, which may reduce the efficiency of removing leukocytes and cytokines. Therefore, in order to prevent the hollow fiber membranes from adhering to each other, it is possible to impart crimps to the hollow fiber membranes or to arrange false-twisted yarns (spacer yarns). However, care must be taken when using spacer yarns, as they may cause thrombus formation depending on the material.

[0039] The amount of hollow fiber membranes packed in the blood purifier is not particularly limited, but is preferably 1.0 cm 2 or less. ３ For a surface area of ​​15 cm ２ More than 400cm ２ It is preferable that the filling is less than 20 cm ２ 280cm or more ２It is more preferable that the blood purifier is filled with the following. In the present invention, the "internal volume of the blood purifier" refers to the internal volume within the blood purifier through which blood can pass in direct contact with the surface of the hollow fiber membrane. Specifically, in the case of a blood purifier configured so that blood directly contacts the outer surface of the hollow fiber membrane, the internal volume of the blood purifier is the volume obtained by subtracting the volume of the membrane portion and lumen portion of the hollow fiber membrane from the internal volume of the case. In addition, in the case of a blood purifier configured so that blood directly contacts the inner surface of the hollow fiber membrane, the volume of the lumen portion of the hollow fiber membrane is the internal volume of the blood purifier. Note that the internal volume of the case does not include the volumes of the blood inlet and blood outlet of the case. In the present invention, the "surface area" of the hollow fiber membrane refers to the area of ​​the surface of the hollow fiber membrane that directly contacts the blood. Specifically, in the case of a blood purifier configured so that blood directly contacts the outer surface of the hollow fiber membrane, the "surface area" is the area of ​​the outer surface of the hollow fiber membrane calculated from the outer diameter of the hollow fiber membrane. In addition, in the case of a blood purifier having a configuration in which blood directly contacts the inner surface of the hollow fiber membrane, the area of ​​the inner surface of the hollow fiber membrane calculated from the inner diameter of the hollow fiber membrane is the "surface area."

[0040] Blood consists of corpuscular components, red blood cells, white blood cells, and platelets, and a liquid component, plasma, which is made up of water, proteins such as cytokines, electrolytes, and other components.

[0041] "White blood cells" refer to immune cell components contained in blood, and specifically include granulocytes, monocytes, lymphocytes, etc. Granulocytes are further classified into neutrophils, eosinophils, and basophils.

[0042] "Removal of leukocytes" refers to the adsorption and / or adhesion of leukocytes in blood to the hollow fiber membrane. The removal of leukocytes can be measured by passing blood through a blood purifier, confirming that the blood inside the blood purifier has been replaced with blood, and then calculating the difference between the number of leukocytes in the blood at the blood inlet and the blood outlet of the blood purifier as the blood passes through the blood purifier. The number of leukocytes in the blood can be measured using a hemocytometer.

[0043] Leukocytes can be activated by cytokines and the like. Activated leukocytes express adhesion molecules and are known to have a higher ability to induce immune responses than non-activated leukocytes. Neutrophils, which account for 60-70% of leukocytes, have a higher ability to migrate, phagocytose, and initiate defense responses against infection when exposed to endotoxins (e.g., lipopolysaccharides) than non-exposed neutrophils.

[0044] The method for measuring the activation rate of leukocytes is not particularly limited, and for example, fluorescently labeled anti-human CD45 and anti-human CD11b can be added to blood, followed by hemolyzing and washing the red blood cells, followed by adding paraformaldehyde-phosphate buffer to fix them, and then measuring the fluorescence intensity of CD11b expression in CD45-positive cells using a flow cytometer, thereby measuring the activation rate.

[0045] "Cytokines" are proteins secreted from cells that transmit information to specific cells, and examples thereof include interleukins (IL) produced by phagocytes, chemokines involved in phagocyte migration, as well as hematopoietic factors, interferons, tumor necrosis factors (TNF), and growth factors. Among these, cytokines that induce inflammatory responses include IL-1, IL-6, IL-8, IL-17, IL-18, and TNF-α, and in the treatment of inflammatory diseases, it is particularly preferable to remove IL-6 and IL-8.

[0046] "Removal of cytokines" refers to the adsorption and / or adhesion of cytokines in blood to the hollow fiber membrane. Specifically, cytokine-added blood or simulated blood is passed through a blood purifier, and after confirming that the blood in the blood purifier has been replaced with blood, the cytokine concentration can be calculated as the difference between the cytokine concentration in blood at the blood inlet and the cytokine concentration in blood at the blood outlet of the blood purifier as the blood passes through the blood purifier. The cytokine concentration in blood can be measured by ELISA.

[0047] The cytokine removal rate is preferably 5% or more, and more preferably 10% or more.

[0048] The term "inflammatory disease" refers to all diseases in which an inflammatory response is induced in the body, and includes, for example, systemic inflammatory response syndrome (SIRS), systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, ulcerative colitis, Crohn's disease, drug-induced hepatitis, alcoholic hepatitis, hepatitis A, hepatitis B, hepatitis C, hepatitis D, or hepatitis E, sepsis (e.g., gram-negative bacterial sepsis, gram-positive bacterial sepsis, culture-negative sepsis, fungal sepsis), influenza, acute respiratory distress syndrome (ARDS; also referred to as acute respiratory distress syndrome or acute respiratory distress syndrome), acute lung injury (ALI), pancreatitis, idiopathic interstitial pneumonia (IDP), and the like. Examples of such diseases include inflammatory bowel disease (IPF), inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease), polyarteritis nodosa, Wegener's granulomatosis, cardiopulmonary bypass syndrome, autoimmune vasculitis, chronic obstructive pulmonary disease (COPD), acute renal failure, chronic renal failure, end-stage renal disease, cardiorenal syndrome, transfusion-related acute lung injury, reperfusion injury after organ transplantation, cholecystitis, cholangitis, and neonatal blood type incompatibility. Among these, blood purification is expected to be effective in treating systemic inflammatory syndrome, drug-induced hepatitis, alcoholic hepatitis, hepatitis A, hepatitis B, hepatitis C, hepatitis D, hepatitis E, sepsis, acute respiratory distress syndrome, acute lung injury, pancreatitis, and idiopathic interstitial pneumonia, because causative substances are released into the blood. The blood purifier of the present invention is preferably used, for example, for the treatment of the above-mentioned inflammatory diseases, and more preferably for the treatment of systemic inflammatory response syndrome, sepsis, acute respiratory distress syndrome, acute lung injury, or idiopathic interstitial pneumonia, which are difficult to treat with drugs alone and involve both cytokines and leukocytes.

[0049] When using the blood purifier of the present invention, anticoagulants, platelet aggregation inhibitors, protease inhibitors, antithrombin agents, etc. can be used. Anticoagulants include, but are not limited to, heparin, low molecular weight heparin, argatroban, nafamostat mesylate, and calcium chelators, such as citrate.

[0050] The blood purifier of the present invention may be used in combination with other medical devices and / or pharmaceuticals used in the treatment of inflammatory diseases.

[0051] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0052] <Method for Evaluating Leukocyte and Cytokine Removal Rate of a Blood Purifier> (Passing Blood Through a Blood Purifier) ​​Venous blood was collected from a healthy adult, and heparin sodium (heparin sodium injection 50,000 units / 50 mL "AY", manufactured by AY Pharmaceuticals Co., Ltd.) was added to 50 mL of the collected blood to a final concentration of 30 IU / mL. Furthermore, LPS (lipopolysaccharide) was added to a final concentration of 70 EU / mL, IL-8 to a final concentration of 300 pg / mL, and IL-6 to a final concentration of 300 pg / mL, and the mixture was shaken at 150 rpm at 37°C for 30 minutes to activate the leukocytes. Next, 1.25 mL of blood preservation solution (JMS ACD-A Solution, manufactured by JMS Co., Ltd.) was added, and the ionized calcium (iCa) concentration was confirmed to be 0.28 using a general-purpose blood gas analyzer / hematocrit analyzer (i-STAT (registered trademark) cartridge EG7+, manufactured by Abbott Point of Care). Furthermore, the activation rate of leukocytes in the blood was measured using a flow cytometer (FACSLyric (registered trademark), manufactured by Nippon Becton Dickinson Co., Ltd.), and the activation rate of leukocytes was found to be 95% or higher. This blood was used in the following evaluations.

[0053] Before passing blood through the blood purifier, physiological saline was passed through the blood inlet or solution inlet to fill the inside of the blood purifier with physiological saline. The solution inlet and solution outlet were then sealed with sealing plugs. The blood purifier was then tilted 45 degrees or 90 degrees from the horizontal (90 degrees only for the blood purifier of Example 6 described below) and fixed.

[0054] Using a peristaltic pump, blood was passed through the blood purifier from the blood inlet. The flow rate of the blood is shown in Table 1. Once it was confirmed that the inside of the blood purifier had been replaced with blood, 3 mL of blood discharged from the blood outlet was discarded, and 3 mL of blood discharged thereafter was collected as a blood outlet sample. The blood before passing through the blood purifier was used as the blood inlet sample.

[0055] The replacement of the inside of the blood purifier with blood was determined by measuring the red blood cell concentrations of the blood before it was passed through the blood purifier and the blood discharged from the blood outlet using a blood cell counter (multi-parameter automated blood cell analyzer XN-1000V, manufactured by Sysmex Corporation) and confirming that the difference between these values ​​was within 10%.

[0056] (Calculation of leukocyte removal rate) The number of leukocytes in the blood inlet sample or the blood outlet sample was measured using a blood cell counter, and the leukocyte removal rate was calculated using the following formula 1. In formula 1, WC ｉｎ is the number of white blood cells (cells / μL) in the blood inlet sample, and WC ｏｕｔ is the number of white blood cells (cells / μL) in the outlet sample. ｉｎ -WC ｏｕｔ ) / WC ｉｎ ×100...Formula 1

[0057] (Calculation of cytokine removal rate) Plasma was separated from the blood inlet sample or blood outlet sample, and the concentration of cytokine (IL-6 or IL-8) in each plasma was measured using an ELISA kit, and the cytokine removal rate was calculated using the following formula 2. The ELISA kits used were a Human IL-6 Quantikine ELISA kit (D6050, manufactured by R&D Systems) and a Human CXCL8 / IL-8 Quantikine ELISA kit (D8000C, manufactured by R&D Systems). In formula 2, IC ｉｎ is the cytokine concentration in the blood inlet sample (pg / mL), and IC ｏｕｔ is the cytokine concentration (pg / mL) in the outlet sample. Cytokine removal rate (%) = (IC ｉｎ -IC ｏｕｔ) / IC ｉｎ ×100...Formula 2

[0058] Example 1: A Filtriser NF (registered trademark) (NF-2.1US, manufactured by Toray Industries, Inc.) was disassembled, the hollow fiber membranes that had been packed inside were cut out, and the spacer yarns were removed from the hollow fiber membranes. The hollow fiber membranes packed inside the Filtriser NF were made of polymethyl methacrylate, a stereocomplex of isotactic polymethyl methacrylate and syndiotactic polymethyl methacrylate. The membrane structure was porous, and the porous structure was dense and homogeneous on both the lumen and the exterior (Hidetoshi Ozawa, Artificial Organs, 2014, Vol. 43, No. 3, pp. 228-232; High Performance Dialyzer 2008, pp. 25-36). Using the obtained hollow fiber membranes, a blood purifier with the structure shown in Figure 1 was produced. In this case, a plastic case with an outer diameter of 0.58 cm, an inner diameter of 0.53 cm, and a length of 12.5 cm was used (inner diameter of 0.53 cm and effective length of 10.7 cm as a blood purifier), and 182 hollow fiber membranes were packed in the case. The same case was used in other examples. In this case, the internal volume of the blood purifier was 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 149 cm ２ The produced blood purifier was designated as the blood purifier of Example 1.

[0059] (Example 2) Using the method for producing the blood purifier of Example 1 as a reference, the blood purifier of Example 2 was produced in the same manner, except that the number of hollow fiber membranes packed in the case was changed from 182 to 137. At this time, the internal volume of the blood purifier was 1.0 cm ３ In contrast, the surface area of ​​the hollow fiber membrane is 91 cm ２ It was.

[0060] (Example 3) Using the method for producing the blood purifier of Example 1 as a reference, the blood purifier of Example 3 was produced in the same manner, except that the number of hollow fiber membranes packed in the case was changed from 182 to 70. At this time, the internal volume of the blood purifier was 1.0 cm ３ In contrast, the surface area of ​​the hollow fiber membrane is 36 cm ２ It was.

[0061] Example 4: Hollow fiber membranes were obtained from the Filtrator NF in the same manner as in Example 1. Using these hollow fiber membranes, a blood purifier with the structure shown in Figure 2 was fabricated. Specifically, 137 hollow fiber membranes were divided into five bundles of 27 or 28 hollow fiber membranes. Each bundle of hollow fiber membranes was aligned one by one on a flat surface so that the sides of the hollow fiber membranes were in contact with each other, and both ends of the 11.7 cm long hollow fiber membranes were crimped with a heat sealer. It was confirmed using a microscope (DG-3x, manufactured by Scalar Corporation) that both ends of the crimped hollow fiber membranes were closed. The hollow fiber membranes were bundled while multiple cylindrical pins for forming through holes were inserted into both ends of the hollow fiber membranes, and then packed into a case. Both ends of the hollow fiber membranes were fixed inside the case with a potting agent, and the pins were then removed. An end surface of the hardened potting material was cut out and observed under a microscope. It was confirmed that the ends of all hollow fiber membranes were buried in the potting material (both ends of the hollow fiber membranes were closed) and that there were through-holes formed by pins. Headers were attached to both ends of the case to prepare the blood purifier of Example 4. At this time, the internal volume of the blood purifier was 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 91 cm ２ It was.

[0062] (Example 5) Hollow fiber membranes were obtained from Filtrizer NF in the same manner as in Example 1. Using the hollow fiber membranes, a blood purifier with the structure shown in Figure 4 was produced. Specifically, 137 hollow fiber membranes were cut with scissors into approximately 1 cm lengths, corresponding to 10.7 cm of the effective length of the blood purifier. It was confirmed using a microscope that both ends of the cut hollow fiber membranes were closed. The cut hollow fiber membranes were packed into a case to produce the blood purifier of Example 5. At this time, the internal volume of the blood purifier was 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 91 cm ２ It was.

[0063] (Example 6) Hollow fiber membranes were obtained from the Filtrator NF in the same manner as in Example 1. Using the hollow fiber membranes, a blood purifier with the structure shown in Figure 5 was produced. Specifically, 70 hollow fiber membranes were cut with scissors to a length of 10.7 cm, which is the effective length of the blood purifier. Both ends of the hollow fiber were tied and closed with polyethylene terephthalate monofilament, and then the hollow fiber was spirally wound around a cylindrical plastic central pipe, and this was packed into a column case to produce the blood purifier of Example 6. At this time, the internal volume of the blood purifier was 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 36 cm ２ It was.

[0064] Example 7: Filtlyzer BG (registered trademark) (BG-1.0PQ, manufactured by Toray Industries, Inc.) was disassembled, and the hollow fiber membranes were cut out and the spacer yarns were removed from the hollow fiber membranes. The hollow fiber membranes packed in Filtlyzer BG, like the hollow fiber membranes packed in Filtlyzer NF, consisted of polymethyl methacrylate, a stereocomplex of isotactic polymethyl methacrylate and syndiotactic polymethyl methacrylate (Hidetoshi Ozawa, Artificial Organs, Vol. 43, No. 3, 2014, pp. 228-232). The membrane structure was porous, and the porous structure was dense and uniform on both the lumen and exterior sides (High Performance Dialyzer 2008, pp. 25-36). However, the membrane surface was not modified. Using 182 of the resulting hollow fiber membranes, a blood purifier with the structure shown in FIG. 1 was fabricated, similar to the blood purifier of Example 1. The blood purifier had an internal volume of 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 149 cm ２ The prepared blood purifier was designated as the blood purifier of Example 7.

[0065] Example 8 Sepxilis® (150 type, manufactured by Baxter) was disassembled, and the hollow fiber membranes packed therein were cut out. The hollow fiber membranes packed in the Sepxilis® were hydrogel-like hollow fiber membranes made of a copolymer of acrylonitrile and sodium methallylsulfonate (Sepxilis® Product Information, JP / MG176 / 20-0004, February 2020, Baxter Corporation). Because they contained water, they were dense and had a symmetrical structure between the lumen and the exterior (Kazuhiro Moriyama et al., Artificial Organs, Vol. 43, No. 3, 2014, pp. 233-237). Using 121 of the obtained hollow fiber membranes, a blood purifier with the structure shown in FIG. 1 was produced, similar to the blood purifier of Example 1. At this time, the blood purifier had an internal volume of 1.0 cm . ３ In contrast, the surface area of ​​the hollow fiber membrane is 149 cm ２ The prepared blood purifier was designated as the blood purifier of Example 8.

[0066] Comparative Example 1 Using the method for producing the blood purifier of Example 1 as a reference, the blood purifier of Comparative Example 1 was produced in the same manner, except that the structure shown in FIG. 7 was adopted instead of the structure shown in FIG. 1 (except that the blood inlet and blood outlet were located on the header rather than on the side of the case).

[0067] Comparative Example 2: 19 parts by weight of polysulfone (Udel® P1700, low dimer grade, manufactured by Solvay) and 5 parts by weight of polyvinylpyrrolidone (K90, weight-average molecular weight 1.2 million, manufactured by ISP) were added to a solvent containing 75 parts by weight of dimethylacetamide and 1 part by weight of water, and the mixture was heated and dissolved. The dissolved solution was sent to a spinneret with a surface temperature of 50°C, and a solution consisting of 67 parts by weight of dimethylacetamide as a core liquid was extruded from a double-slit tube with an outer diameter of 0.35 mm and an inner diameter of 0.25 mm to form a hollow fiber membrane with an inner diameter of 200 μm and a membrane thickness of 40 μm. The hollow fiber membrane was passed through a 350 mm dry section, passed through a coagulation bath (20 parts by weight of dimethylacetamide) at 40°C, a water bath at 75°C, and a hot water treatment bath at 90°C, dried in a dryer heated to 150°C, and then wound up on a skein. The obtained hollow fiber membrane was cut into a semi-cylindrical shape with a single-edged blade, and the surface was coated with a Pt-Pd thin film. The cross section of the hollow fiber membrane was observed with a scanning electron microscope (S-5500, manufactured by Hitachi, Ltd.). It was confirmed that the membrane had an asymmetric porous structure between the inner and outer sides, with the inner side being dense and the pore size becoming coarser toward the outer surface, and that the ratio of the average pore size in the region near the inner surface to the average pore size in the region near the outer surface was greater than 2.0. Using 164 of these hollow fiber membranes, a blood purifier with the structure shown in Figure 1 was produced, similar to the blood purifier of Example 1. The blood purifier had an internal volume of 1.0 cm. ３ In contrast, the surface area of ​​the hollow fiber membrane is 151 cm ２ The produced blood purifier was designated as the blood purifier of Comparative Example 2.

[0068] The evaluation results for the blood purifiers of Examples 1 to 8 and Comparative Examples 1 and 2 are shown in Table 1.

[0069]

[0070] As shown in Table 1, the blood purifier of Comparative Example 1, which is a blood purifier configured so that blood does not come into direct contact with the outer surface of the hollow fiber membrane, did not remove leukocytes. In contrast, it was revealed that the blood purifier of the present invention, which is configured so that blood comes into direct contact with the outer surface of the hollow fiber membrane, can remove both cytokines and leukocytes from the blood. Furthermore, it was revealed that the blood purification material of Comparative Example 2, which is filled with hollow fiber membranes made of polysulfone, like the hollow fiber membranes in the examples of Patent Documents 3 and 4, does not adsorb leukocytes, even though it is configured so that blood comes into direct contact with the outer surface of the hollow fiber membrane.

[0071] The blood purifier of the present invention can remove both cytokines and leukocytes, and therefore can be used as a blood purifier for extracorporeal circulation therapy to treat inflammatory diseases.

[0072] REFERENCE SIGNS LIST 1 Case 2 Blood inlet 3 Blood outlet 4 Solution inlet 5 Solution outlet 6 Hollow fiber membrane 7 Potting agent 8 Header 9 Sealing plug 10 Through-hole 11 Mesh 12 Central pipe 13 Pipe inner and outer through-hole 14 Filter

Claims

1. A blood purifier having hollow fiber membranes and a cylindrical case, wherein the hollow fiber membranes are packed in the case, and blood comes into direct contact with the outer surface of the hollow fiber membranes, and having the following configuration (a) or (b), wherein the hollow fiber membranes contain a polymer selected from the group consisting of polymethyl methacrylate, cellulose, cellulose ester, polyethylene, polypropylene, polyarylate, polystyrene, polyethersulfone, polyethylene terephthalate, polytetrafluoroethylene, polyurethane, polycarbonate, polyamide, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, and polyvinylidene fluoride, and copolymers containing repeating units constituting these polymers. (a) A configuration in which a blood inlet is provided on the side of the case, and one end and the other end of the hollow fiber membrane are embedded in one end and the other end of the case, respectively. (b) A configuration in which both ends of the hollow fiber membrane are closed.

2. The blood purifier according to claim 1, wherein the hollow fiber membrane comprises a copolymer containing repeating units constituting polymethyl methacrylate or polyacrylonitrile and repeating units constituting polymethallylsulfonic acid.

3. The blood purifier according to claim 2, wherein the polymethyl methacrylate is a stereocomplex of isotactic polymethyl methacrylate and syndiotactic polymethyl methacrylate.

4. The blood purifier according to any one of claims 1 to 3, wherein the hollow fiber membrane is a homogeneous membrane.

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