CA2462244C - A hydrophilic substance and a production method thereof - Google Patents
A hydrophilic substance and a production method thereof Download PDFInfo
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- CA2462244C CA2462244C CA 2462244 CA2462244A CA2462244C CA 2462244 C CA2462244 C CA 2462244C CA 2462244 CA2462244 CA 2462244 CA 2462244 A CA2462244 A CA 2462244A CA 2462244 C CA2462244 C CA 2462244C
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- polyvinylpyrrolidone
- polyethyleneimine
- hydrophilic substance
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- containing material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0088—Physical treatment with compounds, e.g. swelling, coating or impregnation
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L29/00—Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
- A61L29/04—Macromolecular materials
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L33/00—Antithrombogenic treatment of surgical articles, e.g. sutures, catheters, prostheses, or of articles for the manipulation or conditioning of blood; Materials for such treatment
- A61L33/0005—Use of materials characterised by their function or physical properties
- A61L33/0011—Anticoagulant, e.g. heparin, platelet aggregation inhibitor, fibrinolytic agent, other than enzymes, attached to the substrate
- A61L33/0035—Anticoagulant, e.g. heparin, platelet aggregation inhibitor, fibrinolytic agent, other than enzymes, attached to the substrate using a polymer with positively charged atoms in the polymeric backbone, e.g. ionenes
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
- A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
- A61M1/3672—Means preventing coagulation
- A61M1/3673—Anticoagulant coating, e.g. Heparin coating
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0011—Casting solutions therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0011—Casting solutions therefor
- B01D67/00111—Polymer pretreatment in the casting solutions
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/009—After-treatment of organic or inorganic membranes with wave-energy, particle-radiation or plasma
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0093—Chemical modification
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
- B01D71/68—Polysulfones; Polyethersulfones
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/30—Cross-linking
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/34—Use of radiation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/28—Degradation or stability over time
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/36—Hydrophilic membranes
Abstract
The present invention relates to a hydrophilic substance production method characterized in that polyvinylpyrrolidone-containing material wetted with an aqueous solution of a cationic polymer is treated with radiation. The invention makes it possible to produce material for blood treatment that prevents adsorption of blood platelets.
Description
Specification A Hydrophilic Substance And A Production Method Thereof Background Art The present invention relates to a hydrophilic substance and a production method thereof, particularly to a hydrophilic substance with resistance to adsorption of blood platelets, and a production method thereof. Consisting of a cationic polymer component, it is suited to uses that take advantage of good features of a cationic polymer.
Prior Art A variety of polymer materials are presently used in the medical field. When used in artificial blood vessels, catheters, artificial kidneys, or other products that directly contact with blood, serious problems can arise with adhesion of blood components, such as plasma protein and blood platelets, and resultant formation of blood clots. A separation membrane used for blood purification, for example, may suffer problems with blood residue on the membrane that results from the activation of blood platelets. To avoid such blood residue, hydrophilic substances that do not adsorb blood platelets significantly have been strongly sought for.
Conventional materials for blood purification include various polymers such as cellulose, cellulose acetate, cellulose triacetate, polyolefin, polyimide, polycarbonate, polyallylate, polyester, polyacrylonitrile, polymethyl methacrylate, polyamide, and polysulfone. In particular, polysulfones, with high heat resistance, have been used as material for dialysis membrane and other different products including separate membranes and films.
When used as material for blood purification, they are blended with a hydrophilic polymer, such as polyvinylpyrrolidone, to improve their compatibility with blood.
Objective of the invention Blending with a hydrophilic polymer, such as polyvinylpyrrolidone, alone is not significantly effective in controlling the activation of blood platelets.
The present invention aims to eliminate the defect of conventional materials to provide a method to produce a hydrophilic substance that does not suffer heavy adhesion of blood platelets.
Disclosure of the invention To solve the above problem, the present invention has the following features. Specifically, the invention relates to a hydrophilic substance production method characterized by irradiation of a polyvinylpyrrolidone-containing material wetted with an aqueous solution of a cationic polymer, and also relates to a hydrophilic substance consisting of a polyvinylpyrrolidone-containing material and a cationic polymer.
The invention further relates to a method of producing a hydrophilic substance, which comprises treating a polyvinylpyrrolidone-containing material wetted with an aqueous solution of a polyethyleneimine or polyethyleneimine derivative with radiation; and wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are made to be in a water-insoluble state.
The invention still further relates to a hydrophilic substance obtained by the method as defined above, the substance comprising polyvinylpyrrolidone-containing material and polyethyleneimine or polyethyleneimine derivative, wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are in a water-insoluble state.
The invention still further relates to an artificial kidney containing the hydrophilic substance as defined above.
Prior Art A variety of polymer materials are presently used in the medical field. When used in artificial blood vessels, catheters, artificial kidneys, or other products that directly contact with blood, serious problems can arise with adhesion of blood components, such as plasma protein and blood platelets, and resultant formation of blood clots. A separation membrane used for blood purification, for example, may suffer problems with blood residue on the membrane that results from the activation of blood platelets. To avoid such blood residue, hydrophilic substances that do not adsorb blood platelets significantly have been strongly sought for.
Conventional materials for blood purification include various polymers such as cellulose, cellulose acetate, cellulose triacetate, polyolefin, polyimide, polycarbonate, polyallylate, polyester, polyacrylonitrile, polymethyl methacrylate, polyamide, and polysulfone. In particular, polysulfones, with high heat resistance, have been used as material for dialysis membrane and other different products including separate membranes and films.
When used as material for blood purification, they are blended with a hydrophilic polymer, such as polyvinylpyrrolidone, to improve their compatibility with blood.
Objective of the invention Blending with a hydrophilic polymer, such as polyvinylpyrrolidone, alone is not significantly effective in controlling the activation of blood platelets.
The present invention aims to eliminate the defect of conventional materials to provide a method to produce a hydrophilic substance that does not suffer heavy adhesion of blood platelets.
Disclosure of the invention To solve the above problem, the present invention has the following features. Specifically, the invention relates to a hydrophilic substance production method characterized by irradiation of a polyvinylpyrrolidone-containing material wetted with an aqueous solution of a cationic polymer, and also relates to a hydrophilic substance consisting of a polyvinylpyrrolidone-containing material and a cationic polymer.
The invention further relates to a method of producing a hydrophilic substance, which comprises treating a polyvinylpyrrolidone-containing material wetted with an aqueous solution of a polyethyleneimine or polyethyleneimine derivative with radiation; and wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are made to be in a water-insoluble state.
The invention still further relates to a hydrophilic substance obtained by the method as defined above, the substance comprising polyvinylpyrrolidone-containing material and polyethyleneimine or polyethyleneimine derivative, wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are in a water-insoluble state.
The invention still further relates to an artificial kidney containing the hydrophilic substance as defined above.
1, 1 Best mode for carrying out the invention The weight average molecular weight of a polyvinylpyrrolidone material to be used for the invention is not limited to a particular range, but should preferably be 2,000 to 2,000,000, more preferably 10,000 to 1,500,000. High in availability, commercial products with a weight average molecular weight of 1,100,000, 45,000, 29,000, 9,000, or 29,000 have been used preferably. A
polyvinylpyrrolidone product should have a weight average molecular weight as cited above at the time of feeding to the production process. If such 2a a procedure as radiation-induced crosslinking is performed, the polyvinylpyrrolidone component of the resulting hydrophilic substance may have a larger molecular weight than at the time of feeding.
Commercial polyvinylpyrrolidone products include Kollidon 12 PF, 17 PF, 25, 30, and 90 (supplied by BASF) , Luviskol K 17, K 30, K 80, and K 90 (supplied by BASF) , and Plasdone K-29/32, K-25, K-90, K-90D, and K-90M (supplied by ISP).
A polyvinylpyrrolidone product used for the invention should preferably be a homopolymer, but may be a copolymer produced by combining it with other monomers unless it degrades the good features of the present invention. The content of said other monomers in the copolymer is not limited to a particular range, but should preferably be 80 wt% or less.
Commercial polyvinylpyrrolidone copolymer products include Kollidon VA 64 (supplied by BASF) , Luviskol VA 64 (supplied by BASF) , Luvitec VPI55 K18P, VPI55, K72W, Quat 73W, VPMA 91W, and VPC 55 K65W (supplied by BASF), and Plasdone S-630 (supplied by ISP).
The hydrophilic substance of the present invention contains a polyvinylpyrrolidone component, but a base material should preferably be used in combination with the polyvinylpyrrolidone in order to maintain the polyvinylpyrrolidone in a stable form and to prevent it from being easily eluted, deformed, or degraded. The structure and the combining method used for the polyvinylpyrrolidone and said base material are not limited to particular ones. The base material and polyvinylpyrrolidone may be laminated, but should preferably be in a mixed or compatible form.
The base material is not limited to particular substances, but should preferably be an organic polymer. Preferred organic polymers include polysulfones.
The content of the polyvinylpyrrolidone component in hydrophilic substance of the present invention is not limited to a particular range, but should preferably be in the range from 1 wt% to 50 wt%, more preferably from 1 wt% to 10 t%, considering that the base material needs to have a certain level of strength in most cases. An appropriate content may be determined by NMR and other methods used solely or in combination.
Preferred polysulfones to be used as material for the hydrophilic substance of the present invention include, but not limited to, those having an aromatic ring, sulfonyl group, or ether group in their backbone, such as those polysulfones represented by Chemical Formula 1 or 2, where n denotes an integer that shows the degree of polymerization and should preferably be in the range of 50 to 80.
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Commercial polysulfone products include Udel P-1700 and P-3500 (supplied by Teijin Amoco Engineering Plastics Limited), Ultrason S3010 and S6010 (supplied by BASF) , Victrex (supplied by Sumitomo Chemical Co., Ltd.), RadelA-200A, A-300, R-5000 and R-5800 (supplied by Teijin Amoco Engineering Plastics Limited), Ultrason E (supplied by BASF) , and Sumikaexcel (supplied by Sumitomo Chemical Co., Ltd.).
Polysulfone used for the invention should preferably be a polymer that comprises only those monomers which are represented by above-mentioned Chemical Formula 1 or 2, but may be a copolymer produced by combining it with other monomers unless it degrades the good features of the present invention. The content of said other monomers used to produce a copolymer is not limited to a particular range, but should preferably be 10 wt% or less.
In addition to said polyvinylpyrrolidone and base material (such as polysulfone), the hydrophilic substance of the invention may contain other polymers and additives unless it degrades the good features of the present invention. The content of such polymers and additives other than said polyvinylpyrrolidone and base material is not limited to a particular range, but should preferably be 10 wt% or less.
The hydrophilic substance of the invention is not limited to particular forms, and may be used in the form of a tube, bead, fabric, nonwoven fabric, cut fiber, flat membrane, or hollow fiber membrane.
Said hydrophilic substance may also be molded into a specific form after being dissolved in a solvent, or may be used as coatings.
Hollow fiber membrane, however, is preferred considering that said substance may be used to perform the function of an artificial kidney and should have a large surface area for cont;act with blood to achieve a high processing efficiency.
If the hydrophilic substance of the present invention is used as separation membrane, its thickness should preferably be in the range of 10pm to 80pm, more preferably 20-pm to 50pm. The pore size of said membrane should preferably be 0.5% or more, more preferably 1% or more, in terms of 1% albumin permeability. If it is used in the form of hollow fiber membrane, its inner diameter should preferably be in the range of 100pm to 300pm, more preferably 150pm to 200pm.
If it is used as hollow fiber membrane, it may be produced by a conventional method. Preferred methods include a separation membrane production process in which a solution prepared by admixing and dissolving polyvinylpyrrolidone in a polysulfone-based polymer using a solvent is employed as feedstock for membrane production.
The weight ratio of said polysulf one and polyvinylpyrrolidone should preferably be in the range of 2 0 : 1 to 1 : 5, more preferably 5:1 to 1:1.
Preferred solvents to be used for admixing and dissolving polyvinylpyrrolidone in polysulfone include N,N-dimethylacetamide, dimethylsulfoxide, dimethylformamide, N-methylpyrro1idone, and dioxane. The content of said polysulfone-based polymer should preferably be in the range of 10 wt% to 30 wt%, more preferably 15 wt% to 25 wt%.
Production of a membrane from said feedstock is not limited to particular methods, and any known method can be used. A useful method is to discharge said feedstock from a double-annular nozzle with a liquid being injected into the inside, allow the product to run through a dry step, and then feed it to a solidification bath. In doing this, as the humidity in the dry step can have significant influence, excessive densification likely to be caused by drying in the neighborhood of the outer surface may be prevented by supplying water through the outer surface of the membrane while it is running through the dry step, in order to provide a product that is low in permeability and diffusion resistance when used for dialysis. If the relative humidity is too high, however, water would act to form a dense layer on the outer surface, which will result in a product that is high in permeability and diffusion resistance when used for dialysis. To avoid this, the relative humidity in the dry step should preferably be in the range of 60% to 90%. To suit the process, the liquid to be injected should preferably consist mainly of the solvent that is used to prepare the feedstock.
When dimethylacetamide is used, for instance, the liquid to be injected should preferably be an aqueous solution of 45 wt% to 80 wt%, more preferably 60 wt% to 75 wt%.
Said cationic polymer is not limited to particular types, but should preferably be a nitrogen-containing polymer, such as one containing an amino, imino or amido group, which may have one or more selected from the group of primary, secondary or tertiary amino groups and quaternary ammonium salts. Copolymers consisting of feedstock components of these polymers and copolymers consisting of nonionic or anionic substances may also be preferred. Said cationic polymer may be linear, branched or cyclic. Its molecular weight should preferably be in the range of 600 to 10,000,000.
Typical polymers containing an amino group include polyalkyleneimine, polyallylamine, polyvinylamine, dialkylaminoalkyl dextran, chitosan, polyornithine, and polylysine, as well as those polymers produced by introducing a substituent thereinto, and copolymers consisting of monomer units thereof.
Linear or branched polyethyleneimines with a molecular weight of 600 to 10,000,000 are preferred.
Suitable polyethyleneimine derivatives may be produced by alkylation, arboxylation, phenylation, phosphorylation, or sulfonation of a polyethyleneimine up to a desired degree.
Such cationic polymers as branched polyethyleneimines and dialkylaminoethyl dextrans are preferred because of their low toxicity, high availability and easy handling.
A polyvinylpyrrolidone-containing material and a cationic polymer are integral parts of the invention, and it is necessary for both of them not to be in a significantly water-soluble form.
Such a state of not being significantly water-soluble, or a water-insoluble state, is defined as a state where the solubility of these hydrophilic substances in water is 1% or less. Solid material will be obtained if a hydrophilic substance is immersed in a 9-fold weight of 37 C water for one hour and then pulled out with tweezers or other tools, followed by vacuum drying below 50 C.
Said solubility represents the ratio of the weight of this solid material to the weight of the original hydrophilic substance before immersion. If the solubility is not sufficiently low, the final product would suffer significant elution during practical use, possibly resulting in a safety hazard. To make both insoluble, they may be kneaded with a water-insoluble base material at a molecular level, or they may be treated with heat or radiation energy after being molded into a certain form. In particular, treatment with radiation is preferred because polyvinylpyrrolidone is easily crosslinked.
In said solution that contains a cationic polymer to be used to wet a polyvinylpyrrolidone-containing material, said polymer should preferably have a content of 0.01 wt% or more, more preferably 0.05 wt% or more, still more preferably 0.1 wt % or more, in order to provide a product that does not adsorb blood platelets significantly.
Said radiation treatment can work to crosslink the polyvinylpyrrolidone component in the material though the mechanism is not clearly known. Said radiation treatment is not limited to particular methods, but may be carried out by irradiating the polyvinylpyrrolidone component blended in the material, or by coating the entirety or part of the surface of molded polysulfone with polyvinylpyrrolidone or a vinylpyrro1idone monomer, followed by irradiation of said polyvinylpyrrolidone to combine it with the polysulfone base. Radiation treatment may be performed by applying gamma or electron rays to polyvinylpyrrolidone-containing material wetted with a solution of a cationic polymer.
Thus, irradiating polyvinylpyrrolidone-containing material wetted with a solution of a cationic polymer is thought to act to introduce said cationic polymer into said polyvinylpyrrolidone-containing material. Preventing excessive crosslinking from taking place in said polyvinylpyrrolidone while maintaining the hydrophilic properties of said polyvinylpyrrolidone results in low adhesiveness to blood platelets.
Said wetted state referred to herein is defined as a condition where said polyvinylpyrrolidone-containing material is immersed in said solution, or in a non-dry state after removing the solution in which said polyvinylpyrrolidone-containing material has been immersed. In such a state, therefore, said polyvinylpyrrolidone-containing material contains water. The degree of said wetting is not limited to a particular range, but in most cases said polyvinylpyrrolidone-containing material should preferably contain 1 wt% or more water relative to the weight of said material. Or, said polyvinylpyrrolidone-containing material may be immersed in said aqueous solution. The absorbed radiation dose in said wetted state should preferably be about 10 - 50 kGy, and sterilization may be performed simultaneously if the material is irradiated up to a dose above 20 kGy. In this case, the absorbed dose may be determined by using a dosimetric label stuck to the surface of the module.
If the sterilization dose is insufficient, steam sterilization or other such treatment may be carried out after radiation treatment of polyvinylpyrrolidone.
Treatment of polyvinylpyrrolidone would be insufficient if the dose is less than 10 kGy. On the other hand, the polysulfone base, case, and other parts may suffer significant degradation if the dose exceeds 50 kGy.
Hydrophilic material produced by the production method of the present invention can serve effectively for blood purification.
The testing method used to determine the adsorption of blood platelets by hydrophilic material of the invention in the form of hollow fiber membranes is described below.
First, 30 hollow fiber membranes are combined, and both ends of the bundle are fixed to a glass tube module case with an epoxy-based potting agent in a way that does not block the hollow portion of the hollow fiber membranes to produce a mini-module.
Said mini-module is about 7mm in diameter and about 10cm in length.
The blood inlet of the mini-module and the dialysate outlet are connected with a silicone tube, and 100ml of distilled water is fed to the blood outlet at a flow rate of l0ml/min to wash the inside walls of the hollow fiber membranes and the module, followed by filling them with physiological saline and closing the dialysate inlet and outlet with a cap. Then, the hollow fiber membranes are washed with physiological saline for two hours at a flow rate of 0.59 mi/min, followed by perfusing with 7ml of a blood sample prepared by mixing 3.2% tri-sodium citrate dihydrate and fresh rabbit blood at a volume ratio of 1:9 for one hour at a flow rate of 0.59 ml/min. Then, washing is carried out with physiological saline using a 10ml syringe, and the hollow fiber membrane side portion and the dialysate side portion are filled with 3%
glutaraldehyde solution, which are left to stand overnight or more to ensure fixation with glutaraldehyde. After this, glutaraldehyde is washed away with distilled water, and the hollow fiber membranes are cut out from the mini-module, followed by vacuum drying for five hours. Part of the hollow fiber membranes is fixed with a double sided adhesive tape on the specimen table of a scanning electron microscope, and cut in the length direction to expose the inner surface. Then, sputtering is performed to form a thin Pt-Pd layer on the specimen. The inner.surface of the hollow fiber membrane specimen is observed with a scanning electron. microscope (S800 supplied by Hitachi, Ltd.) at a magnification ratio of 3,000, and the number of blood platelets found in an area of 1.0 x 103 pm2 is counted. A better separating membrane has a less number of adsorbed blood platelets.
The testing method used to determine the adsorption of blood platelets by hydrophilic material of the invention in the form of film is described below.
Molded film in the form of a sheet is placed on the bottom of a cylindrical polystyrene tube with a diameter of 18mm, and the tube is filled with physiological saline. A blood sample prepared by mixing 3.2% tri-sodium citrate dihydrate and fresh rabbit blood at a volume ratio of 1:9 is subjected to centrifugal separation for 10 min at 1,000rpm, and the supernatant is taken out (referred to as plasma 1) . Then, the blood left after removing the supernatant is further subjected to centrifugal separation for another 10 min at 3, 000rpm, and the supernatant is taken out (referred to as plasma 2) . Plasma 1 is diluted by adding plasma 2 (plasma 2 is lower in blood platelet content than plasma 1) to provide platelet-rich plasma (PRP) with a blood platelet content of 20 x 106/ml. After removing the physiological saline from the tube prepared above, 1.0m1 of said PRP is put in the tube, which is then shaken at 37 C
for one hour. After this, the specimen is washed three times with physiological saline, and the blood content is fixed with a 3%
glutaraldehyde solution, followed by washing with distilled water and vacuum drying for five hours. The film is fixed with a double sided adhesive tape on the specimen table of a scanning electron microscope, and sputtering is performed to form a thin Pt-Pd layer on the specimen. The surface of the specimen is observed with a Hitachi S800 scanning electron microscope (mainly the central part of the film is observed at a magnification ratio of 3, 000, because blood tends to gather in the portions of the film in contact with the tube) . The number of blood platelets found in an area of 1.0 x 103 Pm2 is counted.
The hydrophilic substance produced according to the invention is highly compatible with blood. In addition, as a cationic polymer is contained, adsorptivity to lipid peroxide or endotoxin can be imparted to the hydrophilic substance. The adsorptivity to lipid peroxide (oxidized LDL) is evaluated as follows.
(1) Preparation of antioxidized LDL antibody Antioxidized LDL antibody specimens prepared by Itabe et al.
(H. Itabe et al., J. Biol. Chem. 269; 15274, 1994) were used.
Specifically a human atherosclerotic lesion homogenate was injected to mice to immunize them, and hybridomas were prepared from the spleen of the mice, followed by selecting those which react with LDL that had been treated with copper sulfate. Their antibody was classified as mouse IgM, and they did not react with untreated LDL, acetyl LDL, or malondialdehyde LDL. They reacted with peroxides of some phosphatidylcholines, including aldehydes and hydroperoxides of phosphatidylcholines. Here, specimens were prepared by dissolving them in a 10mM boric acid buffer solution (pH8.5) containing 150mM NaCl (protein content 0.60 mg/ml).
(2) Preparation of oxidized LDL
A commercial LDL product (supplied by Funakoshi Co., Ltd.) was demineralized, diluted with a phosphate buffer solution (hereafter referred to as PBS) down to a concentration of 0.2 mg/ml, and after addition of 0.5mM copper sulfate solution up to lwt%, allowed to react at 37 C for 16 hours. Oxidized LDL specimens were prepared by adding 25mM ethylenediamine tetra-acetic acid (hereafter referred to as EDTA) up to lwt% and iOwto sodium azide up to 0.02wt%.
(3) Procedure for adsorption An oxidized LDL specimen as prepared above was added to blood plasma of a normal healthy human (30-year old Japanese).
From hollow fiber membranes with an inner diameter of 200pm.
and a thickness of 40pm, a 12cm-long mini-module consisting of 70 membranes (inner surface area 53cm2) was produced, and connected to a 2cm-long silicone tube with an inner diameter of 7mm (outer diameter 10mm, product name ARAM) and a silicone tube with an inner diameter of 0.8mm (outer diameter 1mm, product name ARAM, a 37cm-long tube at both ends) via an asymmetric connector, followed by perfusing with 1.5 ml of said blood plasma at 25 C which was passed through the hollow fiber membranes for four hours at a flow rate of 0.5ml/min (plasma supply rate was 8 x 102 ml per m2 of hollow fiber membrane's inner surface).
The same perfusing procedure was performed for the silicones tubes alone without using the mini-module.
The contents of oxidized LDL, LDL and HDL in the blood plasma were determined before and after the perfusing procedure, and the adsorptive removal rate was calculated by the following equation.
adsorptive removal rate (%) = rate of adsorptive removal in mini-module (%)- rate of adsorptive removal in silicone tubes (%) adsorptive removal rate (%) of each portion = 100 x (content before perfusing - content after perfusing) / content before perfusing (4) Determination of oxidized LDL content An antioxidized LDL antibody was diluted with PBS, dispensed to a 96-well plate at a rate of 100 ul/well, and after shaking at room temperature for two hours, allowed to stand at 4 C overnight or more to ensure adsorption on the walls.
The antibody solution was removed out of the wells, and a Tris-hydrochloric acid buffer solution (pH8.0) containing lwt%
bovine serum albumin (BSA Fraction V supplied by Seikagaku Corporation) was dispensed at a rate of 200 ul/well, followed by shaking at room temperature for two hours to block the walls. After removing the BSA solution out of the wells, said plasma containing oxidized LDL and a standard liquid for calibration curve plotting (PBS buffer containing 0-2 jig/ml oxidized LDL) were dispensed at a rate of 100 um/well. Then, the specimens were shaken at room temperature for 30 min and allowed to stand overnight at 4 C.
After allowing the specimens to come to room temperature, the solution was removed out of the wells, and the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05wt% Tween 20 (supplied by Katayama Chemical, Inc.).
Then, 100 ml of sheep anti-apoB antibody (thebindind site) diluted with a 2,000-fold volume of PBS was put in each washed well, and *Trade-mark shaken at room temperature for two hours, and after removing the sheep anti-apoB antibody out of the wells, the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05wt% Tween 20. Then, 100 ml of alkaline phosphatase labeled donky anti-sheep IgG antibody (Chemicon) diluted with a 2,000-fold volume of a Tris-hydrochloric acid buffer solution (pH8.0) containing 2 wt% Blockace* (supplied by Dainippon Pharmaceutical Co., Ltd.) was put in each well, and shaken at room temperature for two hours. Subsequently, after removing the labeled antibody out of the wells, the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05 wt% Tween 20 and two times with a Tris-hydrochloric acid buffer solution (pH8.0) . Then, 100 p1 of a 1 mg/ml solution (0.0005MMgC12i 1M diethanolamine buffer solution, pH9.8) of p-nitrophenylphosphoric acid (supplied by Boehringer Mannheim GmbH) was put in each well, and allowed to react at room temperature for an appropriate period of time, followed by determining the 415nm absorbance with a plate reader. A calibration curve was plotted using the results with the standard specimen, and the oxidized LDL
content was determined using the curve.
Example 1 Eighteen parts of polysulfone (Udel P-3500 supplied by Teijin Amoco Engineering Plastics Limited) and 9 parts of polyvinylpyrrolidone (Kollidon 30 supplied by BASF) were added to 73 parts of N,N-dimethylacetamide, and heated at 90 C for 14 hours to ensure dissolution.
This feedstock for membrane production was discharged from an orifice type double-annular nozzle with an outer diameter of 0.3mm and inner diameter of 0.2mm while a solution comprising 58 *Trade-mark parts of dimethylacetamide and 42 parts of water is used as core liquid. The resultant material was passed through a dry process, and introduced to a 100% water solidification bath to produce a hollow fiber membrane. The hollow fiber membrane obtained was then put in a 1 wt% polyethyleneimine (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 70, 000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The hollow fiber membrane was in an insoluble state. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1. The oxidized LDL removal rate for the hydrophilic substance used in Example 1 was 24%.
Example 2 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a lwt% polyethyleneimine (Aldrich reagent, molecular weight 600) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Example 3 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a lwt% diethylaminoethyl dextrane (supplied by Sigma, molecular weight 500,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Comparative Example 1 A hollow fiber membranes produced by the same procedure as in Example 1 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1. The oxidized LDL removal rate for the material used in the present Comparative Example 1 was 10%.
Comparative Example 2 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a 0.2wt% polyvinylpyrrolidone (Kollidon 90 with molecular weight of 1,200,000 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Comparative Example 3 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a 0.2wt% polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 70,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
[Preparation of polysulfone film 1]
Ten parts of polysulfone (Udel P-3500 supplied by Teij in Amoco Engineering Plastics Limited) and 0.5 part of polyvinylpyrrolidone (Kollidon 90 supplied by BASF) were added to 89.5 parts of N,N-dimethylacetamide, and dissolved at room temperature to provide feedstock for membrane production. It was cast on a glass plate, heated on a hot plate up to a surface temperature of 100 C, into a layer with a thickness of 203~im. The surface temperature was measured with a contact-type thermometer. After being cast, the *Trade-mark material held on the glass plate was left to stand on the hot plate for five minutes to evaporate the solvent, and immersed in a water bath to produce polysulfone film 1. (Immersion in a water bath aims to allow the film to be peeled easily from the glass plate.) [Preparation of polysulfone film 2]
Ten parts of polysulfone (Udel P-3500 supplied by Teij in Amoco Engineering Plastics Limited) was added to 90 parts of N,N-dimethylacetamide, and dissolved at room temperature to provide feedstock for membrane production. It was cast by the same procedure as in the case of polysulfone film 1 to produce polysulfone film 2.
Example 4 Polysulfone film 1 was put in a 0.lwt% polyethyleneimide (supplied by Sigma, molecular weight 750,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy.
The film was in an insoluble state. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min.
The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethyleneimide. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 4 Polysulfone film 1 was put in a 0.lwt% polyvinylpyrrolidone (Kollidon K90 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was in an insoluble state. The film was then rinsed with purified water, * Trade-mark stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyvinylpyrrolidone. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 5 Polysulfone film 1 was put in a 0.lwto polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 2,000,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethylene glycol. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 6 Polysulfone film 1 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The firm was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 7 Polysulfone film 2 was put in a 0.lwto polyethyleneimine (supplied by Sigma, molecular weight 750,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy.
The film was. then rinsed with purified water, stirred in 80 C
purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethyleneimine. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 8 Polysulfone film 2 was put in a 0.lwt% polyvinylpyrrolidone (Kollidon 90 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyvinylpyrrolidone. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 9 Polysulfone film 2 was put in a 0.lwt% polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 2,000,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethylene glycol. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 10 Polysulfone film 2 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60. The number of blood platelets adsorbed by the film is shown in Table 1.
Table 1 Membrane component Polymer in :solution in feedstock Number of Form Type wt% Type wt% platelets (molecular weight) Example 1 Hollow fiber pSf/PVP 18/9 Polyethyleneimine 1 8.7 membrane (70,000) Example 2 Hollow fiber PSf/PVP 18/9 Polyethyleneimine 1 6.3 membrane (600) Hollow fiber Diethylaminoethyl Example 3 membrane PSf/PVP 18/9 dextran 1 18.7 (500,000) Comparative Hollow fiber PSf/PVP 18/9 None - 55.7 example 1 membrane Comparative Hollow fiber pSf/PVP 18/9 PVP 0.2 47.5 example 2 membrane (1,200,000) Comparative Hollow fiber pSf/PVP 18/9 Polyethylene glycol 0.2 30.4 example 3 membrane (20,000) Example 4 Film PSf/PVP 10/0.5 Polyethyleneimine 0.1 4.3 (750,000) Comparative Film PSf/PVP 10/0.5 PVP 0.1 18 example 4 (1,200,000) Comparative Film PSf/PVP 10/0.5 Polyethylene glycol 0.1 24.7 example 5 (2,000,000) Comparative Film PSf/PVP 10/0.5 None - 56 example 6 Comparative Film PSf 10 Polyethyleneimine 0.1 64 example 7 (750,000) Comparative Film PSf 10 PVP 0.1 54.5 example 8 (1,200,000) Comparative Film Psf 10 Polyethylene glycol 0.1 53 example 9 (2,000,000) Comparative Film PSf 10 None - 74.7 example 10 PSf: polysulfone PVP: polyvinylpyrrolidone From Table 1, it is seen that the number of adsorbed blood platelets is small in Examples, while the number is large in Comparative example 1 where cationic polymers were not used and Comparative examples 2 and 3 where polyvinylpyrrolidone and polyethylene glycol, which are neutral, are used respectively.
Industrial applicability The hydrophilic substance production method of the present invention can be used for such applications as blood purification, and can provide materials particularly high in compatibility with blood, indicating that it is extremely useful.
polyvinylpyrrolidone product should have a weight average molecular weight as cited above at the time of feeding to the production process. If such 2a a procedure as radiation-induced crosslinking is performed, the polyvinylpyrrolidone component of the resulting hydrophilic substance may have a larger molecular weight than at the time of feeding.
Commercial polyvinylpyrrolidone products include Kollidon 12 PF, 17 PF, 25, 30, and 90 (supplied by BASF) , Luviskol K 17, K 30, K 80, and K 90 (supplied by BASF) , and Plasdone K-29/32, K-25, K-90, K-90D, and K-90M (supplied by ISP).
A polyvinylpyrrolidone product used for the invention should preferably be a homopolymer, but may be a copolymer produced by combining it with other monomers unless it degrades the good features of the present invention. The content of said other monomers in the copolymer is not limited to a particular range, but should preferably be 80 wt% or less.
Commercial polyvinylpyrrolidone copolymer products include Kollidon VA 64 (supplied by BASF) , Luviskol VA 64 (supplied by BASF) , Luvitec VPI55 K18P, VPI55, K72W, Quat 73W, VPMA 91W, and VPC 55 K65W (supplied by BASF), and Plasdone S-630 (supplied by ISP).
The hydrophilic substance of the present invention contains a polyvinylpyrrolidone component, but a base material should preferably be used in combination with the polyvinylpyrrolidone in order to maintain the polyvinylpyrrolidone in a stable form and to prevent it from being easily eluted, deformed, or degraded. The structure and the combining method used for the polyvinylpyrrolidone and said base material are not limited to particular ones. The base material and polyvinylpyrrolidone may be laminated, but should preferably be in a mixed or compatible form.
The base material is not limited to particular substances, but should preferably be an organic polymer. Preferred organic polymers include polysulfones.
The content of the polyvinylpyrrolidone component in hydrophilic substance of the present invention is not limited to a particular range, but should preferably be in the range from 1 wt% to 50 wt%, more preferably from 1 wt% to 10 t%, considering that the base material needs to have a certain level of strength in most cases. An appropriate content may be determined by NMR and other methods used solely or in combination.
Preferred polysulfones to be used as material for the hydrophilic substance of the present invention include, but not limited to, those having an aromatic ring, sulfonyl group, or ether group in their backbone, such as those polysulfones represented by Chemical Formula 1 or 2, where n denotes an integer that shows the degree of polymerization and should preferably be in the range of 50 to 80.
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Commercial polysulfone products include Udel P-1700 and P-3500 (supplied by Teijin Amoco Engineering Plastics Limited), Ultrason S3010 and S6010 (supplied by BASF) , Victrex (supplied by Sumitomo Chemical Co., Ltd.), RadelA-200A, A-300, R-5000 and R-5800 (supplied by Teijin Amoco Engineering Plastics Limited), Ultrason E (supplied by BASF) , and Sumikaexcel (supplied by Sumitomo Chemical Co., Ltd.).
Polysulfone used for the invention should preferably be a polymer that comprises only those monomers which are represented by above-mentioned Chemical Formula 1 or 2, but may be a copolymer produced by combining it with other monomers unless it degrades the good features of the present invention. The content of said other monomers used to produce a copolymer is not limited to a particular range, but should preferably be 10 wt% or less.
In addition to said polyvinylpyrrolidone and base material (such as polysulfone), the hydrophilic substance of the invention may contain other polymers and additives unless it degrades the good features of the present invention. The content of such polymers and additives other than said polyvinylpyrrolidone and base material is not limited to a particular range, but should preferably be 10 wt% or less.
The hydrophilic substance of the invention is not limited to particular forms, and may be used in the form of a tube, bead, fabric, nonwoven fabric, cut fiber, flat membrane, or hollow fiber membrane.
Said hydrophilic substance may also be molded into a specific form after being dissolved in a solvent, or may be used as coatings.
Hollow fiber membrane, however, is preferred considering that said substance may be used to perform the function of an artificial kidney and should have a large surface area for cont;act with blood to achieve a high processing efficiency.
If the hydrophilic substance of the present invention is used as separation membrane, its thickness should preferably be in the range of 10pm to 80pm, more preferably 20-pm to 50pm. The pore size of said membrane should preferably be 0.5% or more, more preferably 1% or more, in terms of 1% albumin permeability. If it is used in the form of hollow fiber membrane, its inner diameter should preferably be in the range of 100pm to 300pm, more preferably 150pm to 200pm.
If it is used as hollow fiber membrane, it may be produced by a conventional method. Preferred methods include a separation membrane production process in which a solution prepared by admixing and dissolving polyvinylpyrrolidone in a polysulfone-based polymer using a solvent is employed as feedstock for membrane production.
The weight ratio of said polysulf one and polyvinylpyrrolidone should preferably be in the range of 2 0 : 1 to 1 : 5, more preferably 5:1 to 1:1.
Preferred solvents to be used for admixing and dissolving polyvinylpyrrolidone in polysulfone include N,N-dimethylacetamide, dimethylsulfoxide, dimethylformamide, N-methylpyrro1idone, and dioxane. The content of said polysulfone-based polymer should preferably be in the range of 10 wt% to 30 wt%, more preferably 15 wt% to 25 wt%.
Production of a membrane from said feedstock is not limited to particular methods, and any known method can be used. A useful method is to discharge said feedstock from a double-annular nozzle with a liquid being injected into the inside, allow the product to run through a dry step, and then feed it to a solidification bath. In doing this, as the humidity in the dry step can have significant influence, excessive densification likely to be caused by drying in the neighborhood of the outer surface may be prevented by supplying water through the outer surface of the membrane while it is running through the dry step, in order to provide a product that is low in permeability and diffusion resistance when used for dialysis. If the relative humidity is too high, however, water would act to form a dense layer on the outer surface, which will result in a product that is high in permeability and diffusion resistance when used for dialysis. To avoid this, the relative humidity in the dry step should preferably be in the range of 60% to 90%. To suit the process, the liquid to be injected should preferably consist mainly of the solvent that is used to prepare the feedstock.
When dimethylacetamide is used, for instance, the liquid to be injected should preferably be an aqueous solution of 45 wt% to 80 wt%, more preferably 60 wt% to 75 wt%.
Said cationic polymer is not limited to particular types, but should preferably be a nitrogen-containing polymer, such as one containing an amino, imino or amido group, which may have one or more selected from the group of primary, secondary or tertiary amino groups and quaternary ammonium salts. Copolymers consisting of feedstock components of these polymers and copolymers consisting of nonionic or anionic substances may also be preferred. Said cationic polymer may be linear, branched or cyclic. Its molecular weight should preferably be in the range of 600 to 10,000,000.
Typical polymers containing an amino group include polyalkyleneimine, polyallylamine, polyvinylamine, dialkylaminoalkyl dextran, chitosan, polyornithine, and polylysine, as well as those polymers produced by introducing a substituent thereinto, and copolymers consisting of monomer units thereof.
Linear or branched polyethyleneimines with a molecular weight of 600 to 10,000,000 are preferred.
Suitable polyethyleneimine derivatives may be produced by alkylation, arboxylation, phenylation, phosphorylation, or sulfonation of a polyethyleneimine up to a desired degree.
Such cationic polymers as branched polyethyleneimines and dialkylaminoethyl dextrans are preferred because of their low toxicity, high availability and easy handling.
A polyvinylpyrrolidone-containing material and a cationic polymer are integral parts of the invention, and it is necessary for both of them not to be in a significantly water-soluble form.
Such a state of not being significantly water-soluble, or a water-insoluble state, is defined as a state where the solubility of these hydrophilic substances in water is 1% or less. Solid material will be obtained if a hydrophilic substance is immersed in a 9-fold weight of 37 C water for one hour and then pulled out with tweezers or other tools, followed by vacuum drying below 50 C.
Said solubility represents the ratio of the weight of this solid material to the weight of the original hydrophilic substance before immersion. If the solubility is not sufficiently low, the final product would suffer significant elution during practical use, possibly resulting in a safety hazard. To make both insoluble, they may be kneaded with a water-insoluble base material at a molecular level, or they may be treated with heat or radiation energy after being molded into a certain form. In particular, treatment with radiation is preferred because polyvinylpyrrolidone is easily crosslinked.
In said solution that contains a cationic polymer to be used to wet a polyvinylpyrrolidone-containing material, said polymer should preferably have a content of 0.01 wt% or more, more preferably 0.05 wt% or more, still more preferably 0.1 wt % or more, in order to provide a product that does not adsorb blood platelets significantly.
Said radiation treatment can work to crosslink the polyvinylpyrrolidone component in the material though the mechanism is not clearly known. Said radiation treatment is not limited to particular methods, but may be carried out by irradiating the polyvinylpyrrolidone component blended in the material, or by coating the entirety or part of the surface of molded polysulfone with polyvinylpyrrolidone or a vinylpyrro1idone monomer, followed by irradiation of said polyvinylpyrrolidone to combine it with the polysulfone base. Radiation treatment may be performed by applying gamma or electron rays to polyvinylpyrrolidone-containing material wetted with a solution of a cationic polymer.
Thus, irradiating polyvinylpyrrolidone-containing material wetted with a solution of a cationic polymer is thought to act to introduce said cationic polymer into said polyvinylpyrrolidone-containing material. Preventing excessive crosslinking from taking place in said polyvinylpyrrolidone while maintaining the hydrophilic properties of said polyvinylpyrrolidone results in low adhesiveness to blood platelets.
Said wetted state referred to herein is defined as a condition where said polyvinylpyrrolidone-containing material is immersed in said solution, or in a non-dry state after removing the solution in which said polyvinylpyrrolidone-containing material has been immersed. In such a state, therefore, said polyvinylpyrrolidone-containing material contains water. The degree of said wetting is not limited to a particular range, but in most cases said polyvinylpyrrolidone-containing material should preferably contain 1 wt% or more water relative to the weight of said material. Or, said polyvinylpyrrolidone-containing material may be immersed in said aqueous solution. The absorbed radiation dose in said wetted state should preferably be about 10 - 50 kGy, and sterilization may be performed simultaneously if the material is irradiated up to a dose above 20 kGy. In this case, the absorbed dose may be determined by using a dosimetric label stuck to the surface of the module.
If the sterilization dose is insufficient, steam sterilization or other such treatment may be carried out after radiation treatment of polyvinylpyrrolidone.
Treatment of polyvinylpyrrolidone would be insufficient if the dose is less than 10 kGy. On the other hand, the polysulfone base, case, and other parts may suffer significant degradation if the dose exceeds 50 kGy.
Hydrophilic material produced by the production method of the present invention can serve effectively for blood purification.
The testing method used to determine the adsorption of blood platelets by hydrophilic material of the invention in the form of hollow fiber membranes is described below.
First, 30 hollow fiber membranes are combined, and both ends of the bundle are fixed to a glass tube module case with an epoxy-based potting agent in a way that does not block the hollow portion of the hollow fiber membranes to produce a mini-module.
Said mini-module is about 7mm in diameter and about 10cm in length.
The blood inlet of the mini-module and the dialysate outlet are connected with a silicone tube, and 100ml of distilled water is fed to the blood outlet at a flow rate of l0ml/min to wash the inside walls of the hollow fiber membranes and the module, followed by filling them with physiological saline and closing the dialysate inlet and outlet with a cap. Then, the hollow fiber membranes are washed with physiological saline for two hours at a flow rate of 0.59 mi/min, followed by perfusing with 7ml of a blood sample prepared by mixing 3.2% tri-sodium citrate dihydrate and fresh rabbit blood at a volume ratio of 1:9 for one hour at a flow rate of 0.59 ml/min. Then, washing is carried out with physiological saline using a 10ml syringe, and the hollow fiber membrane side portion and the dialysate side portion are filled with 3%
glutaraldehyde solution, which are left to stand overnight or more to ensure fixation with glutaraldehyde. After this, glutaraldehyde is washed away with distilled water, and the hollow fiber membranes are cut out from the mini-module, followed by vacuum drying for five hours. Part of the hollow fiber membranes is fixed with a double sided adhesive tape on the specimen table of a scanning electron microscope, and cut in the length direction to expose the inner surface. Then, sputtering is performed to form a thin Pt-Pd layer on the specimen. The inner.surface of the hollow fiber membrane specimen is observed with a scanning electron. microscope (S800 supplied by Hitachi, Ltd.) at a magnification ratio of 3,000, and the number of blood platelets found in an area of 1.0 x 103 pm2 is counted. A better separating membrane has a less number of adsorbed blood platelets.
The testing method used to determine the adsorption of blood platelets by hydrophilic material of the invention in the form of film is described below.
Molded film in the form of a sheet is placed on the bottom of a cylindrical polystyrene tube with a diameter of 18mm, and the tube is filled with physiological saline. A blood sample prepared by mixing 3.2% tri-sodium citrate dihydrate and fresh rabbit blood at a volume ratio of 1:9 is subjected to centrifugal separation for 10 min at 1,000rpm, and the supernatant is taken out (referred to as plasma 1) . Then, the blood left after removing the supernatant is further subjected to centrifugal separation for another 10 min at 3, 000rpm, and the supernatant is taken out (referred to as plasma 2) . Plasma 1 is diluted by adding plasma 2 (plasma 2 is lower in blood platelet content than plasma 1) to provide platelet-rich plasma (PRP) with a blood platelet content of 20 x 106/ml. After removing the physiological saline from the tube prepared above, 1.0m1 of said PRP is put in the tube, which is then shaken at 37 C
for one hour. After this, the specimen is washed three times with physiological saline, and the blood content is fixed with a 3%
glutaraldehyde solution, followed by washing with distilled water and vacuum drying for five hours. The film is fixed with a double sided adhesive tape on the specimen table of a scanning electron microscope, and sputtering is performed to form a thin Pt-Pd layer on the specimen. The surface of the specimen is observed with a Hitachi S800 scanning electron microscope (mainly the central part of the film is observed at a magnification ratio of 3, 000, because blood tends to gather in the portions of the film in contact with the tube) . The number of blood platelets found in an area of 1.0 x 103 Pm2 is counted.
The hydrophilic substance produced according to the invention is highly compatible with blood. In addition, as a cationic polymer is contained, adsorptivity to lipid peroxide or endotoxin can be imparted to the hydrophilic substance. The adsorptivity to lipid peroxide (oxidized LDL) is evaluated as follows.
(1) Preparation of antioxidized LDL antibody Antioxidized LDL antibody specimens prepared by Itabe et al.
(H. Itabe et al., J. Biol. Chem. 269; 15274, 1994) were used.
Specifically a human atherosclerotic lesion homogenate was injected to mice to immunize them, and hybridomas were prepared from the spleen of the mice, followed by selecting those which react with LDL that had been treated with copper sulfate. Their antibody was classified as mouse IgM, and they did not react with untreated LDL, acetyl LDL, or malondialdehyde LDL. They reacted with peroxides of some phosphatidylcholines, including aldehydes and hydroperoxides of phosphatidylcholines. Here, specimens were prepared by dissolving them in a 10mM boric acid buffer solution (pH8.5) containing 150mM NaCl (protein content 0.60 mg/ml).
(2) Preparation of oxidized LDL
A commercial LDL product (supplied by Funakoshi Co., Ltd.) was demineralized, diluted with a phosphate buffer solution (hereafter referred to as PBS) down to a concentration of 0.2 mg/ml, and after addition of 0.5mM copper sulfate solution up to lwt%, allowed to react at 37 C for 16 hours. Oxidized LDL specimens were prepared by adding 25mM ethylenediamine tetra-acetic acid (hereafter referred to as EDTA) up to lwt% and iOwto sodium azide up to 0.02wt%.
(3) Procedure for adsorption An oxidized LDL specimen as prepared above was added to blood plasma of a normal healthy human (30-year old Japanese).
From hollow fiber membranes with an inner diameter of 200pm.
and a thickness of 40pm, a 12cm-long mini-module consisting of 70 membranes (inner surface area 53cm2) was produced, and connected to a 2cm-long silicone tube with an inner diameter of 7mm (outer diameter 10mm, product name ARAM) and a silicone tube with an inner diameter of 0.8mm (outer diameter 1mm, product name ARAM, a 37cm-long tube at both ends) via an asymmetric connector, followed by perfusing with 1.5 ml of said blood plasma at 25 C which was passed through the hollow fiber membranes for four hours at a flow rate of 0.5ml/min (plasma supply rate was 8 x 102 ml per m2 of hollow fiber membrane's inner surface).
The same perfusing procedure was performed for the silicones tubes alone without using the mini-module.
The contents of oxidized LDL, LDL and HDL in the blood plasma were determined before and after the perfusing procedure, and the adsorptive removal rate was calculated by the following equation.
adsorptive removal rate (%) = rate of adsorptive removal in mini-module (%)- rate of adsorptive removal in silicone tubes (%) adsorptive removal rate (%) of each portion = 100 x (content before perfusing - content after perfusing) / content before perfusing (4) Determination of oxidized LDL content An antioxidized LDL antibody was diluted with PBS, dispensed to a 96-well plate at a rate of 100 ul/well, and after shaking at room temperature for two hours, allowed to stand at 4 C overnight or more to ensure adsorption on the walls.
The antibody solution was removed out of the wells, and a Tris-hydrochloric acid buffer solution (pH8.0) containing lwt%
bovine serum albumin (BSA Fraction V supplied by Seikagaku Corporation) was dispensed at a rate of 200 ul/well, followed by shaking at room temperature for two hours to block the walls. After removing the BSA solution out of the wells, said plasma containing oxidized LDL and a standard liquid for calibration curve plotting (PBS buffer containing 0-2 jig/ml oxidized LDL) were dispensed at a rate of 100 um/well. Then, the specimens were shaken at room temperature for 30 min and allowed to stand overnight at 4 C.
After allowing the specimens to come to room temperature, the solution was removed out of the wells, and the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05wt% Tween 20 (supplied by Katayama Chemical, Inc.).
Then, 100 ml of sheep anti-apoB antibody (thebindind site) diluted with a 2,000-fold volume of PBS was put in each washed well, and *Trade-mark shaken at room temperature for two hours, and after removing the sheep anti-apoB antibody out of the wells, the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05wt% Tween 20. Then, 100 ml of alkaline phosphatase labeled donky anti-sheep IgG antibody (Chemicon) diluted with a 2,000-fold volume of a Tris-hydrochloric acid buffer solution (pH8.0) containing 2 wt% Blockace* (supplied by Dainippon Pharmaceutical Co., Ltd.) was put in each well, and shaken at room temperature for two hours. Subsequently, after removing the labeled antibody out of the wells, the wells were washed three times with a Tris-hydrochloric acid buffer solution (pH8.0) containing 0.05 wt% Tween 20 and two times with a Tris-hydrochloric acid buffer solution (pH8.0) . Then, 100 p1 of a 1 mg/ml solution (0.0005MMgC12i 1M diethanolamine buffer solution, pH9.8) of p-nitrophenylphosphoric acid (supplied by Boehringer Mannheim GmbH) was put in each well, and allowed to react at room temperature for an appropriate period of time, followed by determining the 415nm absorbance with a plate reader. A calibration curve was plotted using the results with the standard specimen, and the oxidized LDL
content was determined using the curve.
Example 1 Eighteen parts of polysulfone (Udel P-3500 supplied by Teijin Amoco Engineering Plastics Limited) and 9 parts of polyvinylpyrrolidone (Kollidon 30 supplied by BASF) were added to 73 parts of N,N-dimethylacetamide, and heated at 90 C for 14 hours to ensure dissolution.
This feedstock for membrane production was discharged from an orifice type double-annular nozzle with an outer diameter of 0.3mm and inner diameter of 0.2mm while a solution comprising 58 *Trade-mark parts of dimethylacetamide and 42 parts of water is used as core liquid. The resultant material was passed through a dry process, and introduced to a 100% water solidification bath to produce a hollow fiber membrane. The hollow fiber membrane obtained was then put in a 1 wt% polyethyleneimine (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 70, 000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The hollow fiber membrane was in an insoluble state. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1. The oxidized LDL removal rate for the hydrophilic substance used in Example 1 was 24%.
Example 2 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a lwt% polyethyleneimine (Aldrich reagent, molecular weight 600) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Example 3 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a lwt% diethylaminoethyl dextrane (supplied by Sigma, molecular weight 500,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Comparative Example 1 A hollow fiber membranes produced by the same procedure as in Example 1 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1. The oxidized LDL removal rate for the material used in the present Comparative Example 1 was 10%.
Comparative Example 2 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a 0.2wt% polyvinylpyrrolidone (Kollidon 90 with molecular weight of 1,200,000 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
Comparative Example 3 A hollow fiber membranes produced by the same procedure as in Example 1 was put in a 0.2wt% polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 70,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy. The number of blood platelets adsorbed by the hollow fiber membrane is shown in Table 1.
[Preparation of polysulfone film 1]
Ten parts of polysulfone (Udel P-3500 supplied by Teij in Amoco Engineering Plastics Limited) and 0.5 part of polyvinylpyrrolidone (Kollidon 90 supplied by BASF) were added to 89.5 parts of N,N-dimethylacetamide, and dissolved at room temperature to provide feedstock for membrane production. It was cast on a glass plate, heated on a hot plate up to a surface temperature of 100 C, into a layer with a thickness of 203~im. The surface temperature was measured with a contact-type thermometer. After being cast, the *Trade-mark material held on the glass plate was left to stand on the hot plate for five minutes to evaporate the solvent, and immersed in a water bath to produce polysulfone film 1. (Immersion in a water bath aims to allow the film to be peeled easily from the glass plate.) [Preparation of polysulfone film 2]
Ten parts of polysulfone (Udel P-3500 supplied by Teij in Amoco Engineering Plastics Limited) was added to 90 parts of N,N-dimethylacetamide, and dissolved at room temperature to provide feedstock for membrane production. It was cast by the same procedure as in the case of polysulfone film 1 to produce polysulfone film 2.
Example 4 Polysulfone film 1 was put in a 0.lwt% polyethyleneimide (supplied by Sigma, molecular weight 750,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 29 kGy.
The film was in an insoluble state. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min.
The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethyleneimide. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 4 Polysulfone film 1 was put in a 0.lwt% polyvinylpyrrolidone (Kollidon K90 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was in an insoluble state. The film was then rinsed with purified water, * Trade-mark stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyvinylpyrrolidone. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 5 Polysulfone film 1 was put in a 0.lwto polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 2,000,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethylene glycol. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 6 Polysulfone film 1 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The firm was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 7 Polysulfone film 2 was put in a 0.lwto polyethyleneimine (supplied by Sigma, molecular weight 750,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy.
The film was. then rinsed with purified water, stirred in 80 C
purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethyleneimine. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 8 Polysulfone film 2 was put in a 0.lwt% polyvinylpyrrolidone (Kollidon 90 supplied by BASF) solution and irradiated with gamma ray. The gamma ray absorbed dose was 28 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyvinylpyrrolidone. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 9 Polysulfone film 2 was put in a 0.lwt% polyethylene glycol (supplied by Wako Pure Chemical Industries, Ltd., molecular weight 2,000,000) solution and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60 min to ensure complete removal of adsorbed polyethylene glycol. The number of blood platelets adsorbed by the film is shown in Table 1.
Comparative Example 10 Polysulfone film 2 was put in water and irradiated with gamma ray. The gamma ray absorbed dose was 27 kGy. The film was then rinsed with purified water, stirred in 80 C purified water for 60 min, and after replacing the purified water, stirred at 80 C for another 60 min. The purified water was replaced again and stirring was performed at 80 C for another 60. The number of blood platelets adsorbed by the film is shown in Table 1.
Table 1 Membrane component Polymer in :solution in feedstock Number of Form Type wt% Type wt% platelets (molecular weight) Example 1 Hollow fiber pSf/PVP 18/9 Polyethyleneimine 1 8.7 membrane (70,000) Example 2 Hollow fiber PSf/PVP 18/9 Polyethyleneimine 1 6.3 membrane (600) Hollow fiber Diethylaminoethyl Example 3 membrane PSf/PVP 18/9 dextran 1 18.7 (500,000) Comparative Hollow fiber PSf/PVP 18/9 None - 55.7 example 1 membrane Comparative Hollow fiber pSf/PVP 18/9 PVP 0.2 47.5 example 2 membrane (1,200,000) Comparative Hollow fiber pSf/PVP 18/9 Polyethylene glycol 0.2 30.4 example 3 membrane (20,000) Example 4 Film PSf/PVP 10/0.5 Polyethyleneimine 0.1 4.3 (750,000) Comparative Film PSf/PVP 10/0.5 PVP 0.1 18 example 4 (1,200,000) Comparative Film PSf/PVP 10/0.5 Polyethylene glycol 0.1 24.7 example 5 (2,000,000) Comparative Film PSf/PVP 10/0.5 None - 56 example 6 Comparative Film PSf 10 Polyethyleneimine 0.1 64 example 7 (750,000) Comparative Film PSf 10 PVP 0.1 54.5 example 8 (1,200,000) Comparative Film Psf 10 Polyethylene glycol 0.1 53 example 9 (2,000,000) Comparative Film PSf 10 None - 74.7 example 10 PSf: polysulfone PVP: polyvinylpyrrolidone From Table 1, it is seen that the number of adsorbed blood platelets is small in Examples, while the number is large in Comparative example 1 where cationic polymers were not used and Comparative examples 2 and 3 where polyvinylpyrrolidone and polyethylene glycol, which are neutral, are used respectively.
Industrial applicability The hydrophilic substance production method of the present invention can be used for such applications as blood purification, and can provide materials particularly high in compatibility with blood, indicating that it is extremely useful.
Claims (14)
1. A method of producing a hydrophilic substance, which comprises treating a polyvinylpyrrolidone-containing material wetted with an aqueous solution of a polyethyleneimine or polyethyleneimine derivative with radiation; and wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are made to be in a water-insoluble state.
2. The method according to claim 1, wherein the polyethyleneimine or polyethyleneimine derivative in the solution is contained at a concentration of 0.1 wt% or more.
3. The method according to claim 2, wherein the polyethyleneimine or polyethyleneimine derivative in the solution is contained at a concentration of 1 wt%.
4. The method according to any one of claims 1 to 3, wherein the radiation is conducted at an absorbed radiation dose of about 10-50 kGy.
5. The method according to any one of claims 1 to 4, wherein the radiation is performed by gamma rays.
6. The method according to claim 4 or 5, wherein the absorbed radiation dose is above 20 kGy.
7. The method according to any one of claims 1 to 6, wherein the polyvinylpyrrolidone-containing material contains both polyvinylpyrrolidone and a polysulfone-based polymer.
8. The method according to claim 7, wherein the polyvinylpyrrolidone and the polysulfone-based polymer are present in a weight ratio of 20:1 to 1:5.
9. The method according to claim 8, wherein the weight ratio is 5:1 to 1:1.
10. The method according to any one of claims 1 to 9, wherein the polyvinylpyrrolidone-containing material is in the form of a hollow fiber membrane.
11. The method according to any one of claims 1 to 9, wherein the polyvinylpyrrolidone-containing material is a separation membrane for artificial kidneys.
12. A hydrophilic substance obtained by the method as defined in any one of claims 1 to 11, the substance comprising polyvinylpyrrolidone-containing material and polyethyleneimine or polyethyleneimine derivative, wherein both the polyvinylpyrrolidone-containing material and the polyethyleneimine or polyethyleneimine derivative are in a water-insoluble state.
13. The hydrophilic substance according to claim 12 wherein the hydrophilic substance is a separation membrane for artificial kidneys.
14. An artificial kidney containing the hydrophilic substance as defined in claim 12 or 13.
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| JP2001/308677 | 2001-10-04 | ||
| JP2001308677 | 2001-10-04 | ||
| PCT/JP2002/010320 WO2003031533A1 (en) | 2001-10-04 | 2002-10-03 | Hydrophilic material and process for producing the same |
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| CA2462244A1 CA2462244A1 (en) | 2003-04-17 |
| CA2462244C true CA2462244C (en) | 2010-11-09 |
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| EP (1) | EP1439212B1 (en) |
| JP (1) | JP4534486B2 (en) |
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| ES (1) | ES2299602T3 (en) |
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Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004018085A1 (en) * | 2002-08-21 | 2004-03-04 | Toray Industries, Inc. | Modified substrate and process for producing modified substrate |
| JP4433821B2 (en) * | 2004-02-23 | 2010-03-17 | 東レ株式会社 | Modified substrate |
| JP4569315B2 (en) * | 2004-02-23 | 2010-10-27 | 東レ株式会社 | Modified hollow fiber membrane |
| WO2006024902A1 (en) * | 2004-08-06 | 2006-03-09 | Asahi Kasei Medical Co., Ltd. | Polysulfone hemodialyzer |
| US8070964B2 (en) * | 2005-03-29 | 2011-12-06 | Toray Industries, Inc. | Modified substrate and process for production thereof |
| JP3772909B1 (en) * | 2005-04-04 | 2006-05-10 | 東洋紡績株式会社 | Blood purifier |
| EP1710011A1 (en) * | 2005-04-07 | 2006-10-11 | Gambro Lundia AB | Filtration membrane |
| DK2279767T3 (en) | 2005-07-18 | 2012-11-26 | Dentsply Ih Ab | Urinary catheter |
| US9095818B2 (en) * | 2009-06-15 | 2015-08-04 | Biovec Transfusion, Llc | Method of filtering platelets to remove antiplatelet and anticoagulant agents |
| FR2902670B1 (en) * | 2006-06-22 | 2009-04-24 | Gambro Lundia Ab | USE OF A SUSPENSION FOR TREATING MEDICAL MEDIA, MEDICAL MEDIA, EXCHANGER, AND ADSORPTION DEVICE COMPRISING THE MEDIUM |
| KR101525642B1 (en) * | 2008-03-31 | 2015-06-03 | 도레이 카부시키가이샤 | Separation membrane, method of producing the same and separation membrane module using the separation membrane |
| EP2168668A1 (en) | 2008-09-25 | 2010-03-31 | Gambro Lundia AB | Membrane for cell expansion |
| EP2314672B1 (en) | 2008-09-25 | 2015-04-15 | Gambro Lundia AB | Hybrid bioartificial kidney |
| EP2168666A1 (en) | 2008-09-25 | 2010-03-31 | Gambro Lundia AB | Irradiated membrane for cell expansion |
| EP2177603A1 (en) | 2008-09-25 | 2010-04-21 | Gambro Lundia AB | Device for renal cell expansion |
| SG178596A1 (en) * | 2009-08-28 | 2012-04-27 | Genentech Inc | Methods of treatment using anti-oxidized ldl antibodies |
| WO2013065819A1 (en) * | 2011-11-04 | 2013-05-10 | 旭化成メディカル株式会社 | Separation membrane for use in treatment of blood, and blood treatment device having said membrane integrated therein |
| TWI549744B (en) * | 2012-03-28 | 2016-09-21 | 東麗股份有限公司 | Hollow fiber membrane of polysulfone and hollow fiber membrane module for purification of blood product |
| US9248414B2 (en) * | 2012-03-30 | 2016-02-02 | Pall Corporation | Large pore polymeric membrane |
| KR102056871B1 (en) | 2013-03-15 | 2019-12-17 | 도레이첨단소재 주식회사 | Positive charged poly(vinylidene fluoride) porous membranes and manufacturing method thereof |
| EP2845641B1 (en) * | 2013-09-05 | 2018-05-09 | Gambro Lundia AB | Permselective asymmetric membranes with high molecular weight polyvinylpyrrolidone, the preparation and use thereof |
| CN104923091B (en) * | 2014-03-20 | 2020-03-27 | 上海世龙科技有限公司 | Leukocyte filtration membrane, method for producing same, and use thereof |
| CN109562219B (en) | 2016-09-09 | 2021-05-18 | 东丽株式会社 | Material for purifying blood |
| JP6699731B2 (en) | 2017-06-06 | 2020-05-27 | 東レ株式会社 | Material for removing activated leukocyte-activated platelet complex |
| CN107551822B (en) * | 2017-09-05 | 2020-03-10 | 泉州市科茂利通智能科技有限公司 | Polyacrylonitrile-carboxymethyl chitosan composite hemodialysis membrane and preparation method thereof |
Family Cites Families (36)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53134876A (en) * | 1977-04-30 | 1978-11-24 | Sumitomo Electric Ind Ltd | Production of hydrophilic composite construction |
| JPS5417978A (en) * | 1977-07-11 | 1979-02-09 | Sumitomo Electric Ind Ltd | Hydrophilic and porous composite structure and its production |
| DE3149976A1 (en) * | 1981-12-17 | 1983-06-30 | Hoechst Ag, 6230 Frankfurt | MACROPOROUS ASYMMETRIC HYDROPHILE MEMBRANE MADE OF SYNTHETIC POLYMER |
| JPH0675667B2 (en) * | 1985-04-17 | 1994-09-28 | 東レ株式会社 | Method for producing semi-permeable membrane of polysulfone resin |
| JPH089668B2 (en) | 1986-10-14 | 1996-01-31 | 東レ株式会社 | Hydrophilized film and method for producing the same |
| US5004543A (en) * | 1988-06-21 | 1991-04-02 | Millipore Corporation | Charge-modified hydrophobic membrane materials and method for making the same |
| US5079272A (en) * | 1989-11-30 | 1992-01-07 | Millipore Corporation | Porous membrane formed from interpenetrating polymer network having hydrophilic surface |
| JPH0379668A (en) * | 1990-04-20 | 1991-04-04 | Kuraray Co Ltd | Solution for preparing film |
| US5269931A (en) * | 1990-09-17 | 1993-12-14 | Gelman Sciences Inc. | Cationic charge modified microporous membranes |
| JP2957021B2 (en) * | 1991-01-25 | 1999-10-04 | テルモ株式会社 | Medical material, medical device, and method of manufacturing medical material |
| US5762798A (en) * | 1991-04-12 | 1998-06-09 | Minntech Corporation | Hollow fiber membranes and method of manufacture |
| US5623588A (en) * | 1992-12-14 | 1997-04-22 | New York University | Computer user interface with non-salience deemphasis |
| JP3714686B2 (en) * | 1994-04-27 | 2005-11-09 | 旭化成メディカル株式会社 | Polysulfone-based hollow fiber membrane and method for producing the same |
| US6355730B1 (en) * | 1995-06-30 | 2002-03-12 | Toray Industries, Inc. | Permselective membranes and methods for their production |
| JP3651121B2 (en) * | 1995-06-30 | 2005-05-25 | 東レ株式会社 | Permselective separation membrane |
| FR2747591B1 (en) * | 1996-04-19 | 1998-05-22 | Hospal Ind | MEDICAL DEVICE FOR EXTRACORPOREAL BLOOD OR PLASMA TREATMENT AND METHODS OF MAKING THE SAME |
| ES2259947T3 (en) * | 1996-07-08 | 2006-11-01 | Pall Corporation | POLYMER MEMBRANE WITH POSITIVE LOAD. |
| ATE196148T1 (en) * | 1996-07-10 | 2000-09-15 | American Nat Red Cross | METHOD FOR THE SELECTIVE SEPARATION OF ORGANIC COMPONENTS FROM BIOLOGICAL LIQUIDS |
| FR2758990B1 (en) * | 1996-09-19 | 1999-05-28 | Hospal Ind | APPARATUS FOR THE TREATMENT OF BLOOD BY EXTRACORPOREAL CIRCULATION AND MANUFACTURING METHOD |
| US6168718B1 (en) * | 1996-11-08 | 2001-01-02 | Pall Corporation | Method for purifying blood plasma and apparatus suitable therefor |
| JP3690019B2 (en) | 1996-12-17 | 2005-08-31 | 東レ株式会社 | Aromatic polysulfone polymer and process for producing the same |
| JP3474205B2 (en) | 1997-05-19 | 2003-12-08 | 旭メディカル株式会社 | Polysulfone hollow fiber type blood purification membrane and method for producing the same |
| US6945257B2 (en) * | 1997-06-23 | 2005-09-20 | Princeton Trade & Technology | Method for cleaning hollow tubing and fibers |
| EP1121972A3 (en) * | 1997-07-08 | 2001-08-16 | USF Filtration and Separations Group Inc. | Cationically charge-modified membranes |
| DE69839622D1 (en) * | 1997-12-17 | 2008-07-31 | Asahi Kasei Kuraray Medical Co | Process for the preparation of an artificial organ, hollow fiber membrane, and hollow fiber dialyzer |
| FR2772639B1 (en) * | 1997-12-24 | 2000-02-04 | Hospal Ind | USE OF A NEUTRAL OR CATIONIC POLYMER TO PREVENT ACTIVATION OF THE CONTACT PHASE OF BLOOD OR PLASMA IN CONTACT WITH A SEMI-PERMEABLE MEMBRANE |
| WO2000012154A1 (en) * | 1998-08-27 | 2000-03-09 | Toray Industries, Inc. | Blood processing device |
| EP2189213A1 (en) * | 1999-01-22 | 2010-05-26 | Dow Global Technologies Inc. | Method for producing a surface modified divinylbenzene resin having a hemocompatible coating |
| JP4190079B2 (en) * | 1999-03-12 | 2008-12-03 | 旭化成クラレメディカル株式会社 | Hollow fiber membrane for blood purification and hollow fiber membrane artificial kidney |
| JP4211168B2 (en) * | 1999-12-21 | 2009-01-21 | 東レ株式会社 | Dialyzer manufacturing method and sterilization method |
| ES2220328T3 (en) * | 1999-12-23 | 2004-12-16 | Membrana Gmbh | MOLDED BODIES FOR THE RETENTION OF PYROGENS, PROCEDURE FOR PRODUCTION AND USE. |
| JP2001205057A (en) * | 2000-01-27 | 2001-07-31 | Toyobo Co Ltd | Hollow fiber membrane |
| JP4830181B2 (en) | 2000-07-14 | 2011-12-07 | 東レ株式会社 | Hollow fiber membrane for lipid peroxide adsorption and module using the same |
| JP4686836B2 (en) | 2000-09-29 | 2011-05-25 | 東レ株式会社 | Method for producing lipid peroxide adsorbent |
| JP4843841B2 (en) | 2000-09-29 | 2011-12-21 | 東レ株式会社 | Adsorbent for adsorption of oxidized low density lipoprotein |
| WO2004018085A1 (en) * | 2002-08-21 | 2004-03-04 | Toray Industries, Inc. | Modified substrate and process for producing modified substrate |
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- 2002-10-03 KR KR1020047004901A patent/KR100929463B1/en not_active IP Right Cessation
- 2002-10-03 CN CNB028193938A patent/CN1283741C/en not_active Expired - Fee Related
- 2002-10-03 ES ES02772971T patent/ES2299602T3/en not_active Expired - Lifetime
- 2002-10-03 EP EP20020772971 patent/EP1439212B1/en not_active Expired - Lifetime
- 2002-10-03 WO PCT/JP2002/010320 patent/WO2003031533A1/en active IP Right Grant
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- 2002-10-03 JP JP2003534506A patent/JP4534486B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
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| CN1561380A (en) | 2005-01-05 |
| EP1439212A4 (en) | 2006-01-25 |
| JPWO2003031533A1 (en) | 2005-01-20 |
| EP1439212A1 (en) | 2004-07-21 |
| US7470368B2 (en) | 2008-12-30 |
| KR20040047887A (en) | 2004-06-05 |
| US20080061002A1 (en) | 2008-03-13 |
| CA2462244A1 (en) | 2003-04-17 |
| WO2003031533A1 (en) | 2003-04-17 |
| DE60224425D1 (en) | 2008-02-14 |
| EP1439212B1 (en) | 2008-01-02 |
| ATE382670T1 (en) | 2008-01-15 |
| CN1283741C (en) | 2006-11-08 |
| DE60224425T2 (en) | 2008-12-18 |
| ES2299602T3 (en) | 2008-06-01 |
| JP4534486B2 (en) | 2010-09-01 |
| KR100929463B1 (en) | 2009-12-02 |
| US20040247682A1 (en) | 2004-12-09 |
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