# US 10,500,549 B2 · Dialysis membrane and method for its production

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- Number: US 10,500,549 B2
- Document ID: US10500549B2
- Status: Granted
- Kind: B2
- Application number: 15/436,135
- Filed: 2017-02-17
- Published: 2017-08-17
- Granted: 2019-12-10
- Earliest claimed: 2016-02-17
- Assignees: B. Braun Avitum AG
- Applicants: B. Braun Avitum AG
- Inventors: Alexander Friebe; Roland Napierala; Angela Baier-Goschütz; Juliane Gäbler; Mathias Ulbricht; Clélia Jade Eléonore Victoria Emin
- Web page: https://patentgrep.com/patent/US10500549B2

## CPC

- B01D 71/68: Polysulfones; Polyethersulfones
- B01D 61/243: {Dialysis}
- B01D 63/02: Hollow fibre modules
- B01D 63/08: Flat membrane modules
- B01D 67/00046: {by deposition by filtration through a support or base layer}
- B01D 67/0013: {Casting processes}
- B01D 69/02: characterised by their properties
- B01D 69/06: Flat membranes
- B01D 69/08: Hollow fibre membranes (manufacture of hollow fibres D01D5/24, D01F1/08)
- B01D 69/1214: {Chemically bonded layers, e.g. cross-linking}
- B01D 69/1216: {Three or more layers}
- B01D 71/12: Cellulose derivatives
- B01D 71/601: {Polyethylenimine}
- B01J 41/13: obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
- B32B 27/286: {comprising polysulphones; polysulfides}
- A61M 1/16: with membranes
- B01D 2323/02: Hydrophilization
- B01D 2323/36: Introduction of specific chemical groups
- B01D 2325/04: Characteristic thickness
- B01D 2325/14: Membrane materials having negatively charged functional groups
- B01D 2325/16: Membrane materials having positively charged functional groups
- B01D 2325/36: Hydrophilic membranes
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

A membrane for the purification of blood, or a dialysis membrane, in hollow-fiber membrane or flat membrane geometry, made of a composite assembled from at least a base membrane based on at least one polysulfone or a polyphenylsulfone with at least one pore-forming hydrophilic additive and at least one functional layer arranged on the base membrane, whereby the functional layer is formed from at least one polymeric polycationic bonding agent and at least one polymeric polyanion, whereby the base membrane is made of a material which is selected from: a polysulfone [PSU], a sulfonated polysulfone [SPSU], a polyethersulfone [PES], a sulfonated polyethersulfone [SPES], a polyphenylsulfone [PPSU], a sulfonated polyphenylsulfone [SPPSU]; and mixtures of these.

## Claims

### Claim 1

A dialysis membrane in hollow-fiber membrane or flat membrane geometry comprising:
a composite assembled from:
at least one base membrane based on at least one polysulfone with at least one pore-forming hydrophilic additive, and
at least one functional layer arranged on the at least one base membrane, whereby the at least one functional layer is formed from at least one layer of a polymeric polycationic bonding agent and at least another layer of a polymeric polyanion,
wherein the base membrane is formed from a material which is selected from a group consisting of: a polysulfone, a sulfonated polysulfone, a polyethersulfone, a sulfonated polyethersulfone, a polyphenylsulfone, a sulfonated polyphenylsulfone, and mixtures thereof;
wherein the polymeric polycationic bonding agent is selected from a group consisting of: polyethylenimine, chitosan, polylysine, polyarginine, polyornithine, and mixtures thereof;
wherein the polymeric polyanion is a carboxylated polysaccharide or a sulfated polysaccharide which is selected from a group consisting of: a dextran sulfate with a molecular mass (Mw) of 15 kDa to 1 MDa, a sulfated chitosan with a molecular mass (Mw) of 30 kDa to 750 kDa, a cellulose sulfate with a molecular mass (Mw) of between 20 kDa and 1 MDa, and mixtures thereof; and
wherein the at least one pore-forming hydrophilic additive is selected from a group consisting of: polyvinylpyrrolidone, a short-chain glycol with 2 to 10 C atoms, triethylene glycol, propylene glycol, polyethylene glycol/polyethylene oxide, and mixtures thereof.

### Claim 2 (depends on 1)

The dialysis membrane according to claim 1, wherein the sulfonated polysulfone exhibits at least one of a sulfonation degree of 0.1 to 20 weight %, in relation to the weight of the unsulfonated polysulfone;
the sulfonated polyethersulfone exhibits a sulfonation degree of 0.1 to 20 weight %, in relation to the weight of the unsulfonated polyethersulfone; or
the sulfonated polyphenylsulfone exhibits a sulfonation degree of 0.1 to 20 weight %, in relation to the weight of the unsulfonated polyphenylsulfone.

### Claim 3 (depends on 2)

The dialysis membrane according to claim 2, wherein the sulfonated polysulfone exhibits a sulfonation degree of 9.3 or 13.4 weight %, in relation to the weight of the sulfonated polysulfone.

### Claim 4 (depends on 2)

The dialysis membrane according to claim 2, wherein the sulfonated polyethersulfone exhibits a sulfonation degree of 1.1, 3.6, or 14.1 weight %, in relation to the weight of the unsulfonated polyethersulfone.

### Claim 5 (depends on 2)

The dialysis membrane according to claim 2, wherein the sulfonated polyphenylsulfone exhibits a sulfonation degree of 1.0, 2.0, 10.1 or 14.7 weight %, in relation to the weight of the unsulfonated polyphenylsulfone.

### Claim 6 (depends on 1)

The dialysis membrane according to claim 1, wherein the dialysis membrane exhibits a hydraulic permeability of 10 to 2,000 L/bar*h*m2 and a sieving coefficient (@22±2°) for bovine serum albumin in the range of 0.0001 to 0.5 and a molecular mass cut-off value of 20 to 50 kDa.

### Claim 7 (depends on 1)

The dialysis membrane according to claim 1, wherein the dialysis membrane exhibits a wall thickness of 20 to 200 μm.

### Claim 8 (depends on 1)

The dialysis membrane according to claim 1, wherein the dialysis membrane exhibits a lumen diameter of 100 to 400 μm.

### Claim 9 (depends on 1)

The dialysis membrane according to claim 1, wherein the cellulose sulfate has a molecular mass (Mw) of approximately 100 kDa.

### Claim 10 (depends on 1)

A dialysis membrane module, wherein the module contains as filling dialysis membranes according to claim 1.

### Claim 11

A dialysis membrane in hollow-fiber membrane or flat membrane geometry comprising:
a composite assembled from:
at least one base membrane, and
at least one functional layer arranged on the at least one base membrane, whereby the at least one functional layer is formed from at least one layer of a polymeric polycationic bonding agent and at least another layer of a polymeric polyanion,
wherein the base membrane is formed from a material comprising at least one polysulfone with at least one pore-forming hydrophilic additive and one or more of: a polyamide, a polyacrylonitrile, a polymethyl methacrylate, a polyacrylic acid, a polycarbonate, and a polyurethane;
wherein the polymeric polycationic bonding agent is selected from a group consisting of: polyethylenimine, chitosan, polylysine, polyarginine, polyornithine, and mixtures thereof;
wherein the polymeric polyanion is a carboxylated polysaccharide or a sulfated polysaccharide which is selected from a group consisting of: a dextran sulfate with a molecular mass (Mw) of 15 kDa to 1 MDa, a sulfated chitosan with a molecular mass (Mw) of 30 kDa to 750 kDa, a cellulose sulfate with a molecular mass (Mw) of between 20 kDa and 1 MDa, and mixtures thereof; and
wherein the at least one pore-forming hydrophilic additive is selected from a group consisting of: polyvinylpyrrolidone, a short-chain glycol with 2 to 10 C atoms, triethylene glycol, propylene glycol, polyethylene glycol/polyethylene oxide, and mixtures thereof.