# US 10,478,521 B2 · Antibacterial sheet material that can be used as a wound dressing and method for producing same

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- Number: US 10,478,521 B2
- Document ID: US10478521B2
- Status: Granted
- Kind: B2
- Application number: 14/383,802
- Filed: 2013-02-26
- Published: 2015-05-07
- Granted: 2019-11-19
- Earliest claimed: 2012-03-13
- Assignees: aap Implantate AG
- Applicants: aap Biomaterials GmbH
- Inventors: Marco Wolfstaedter; Birgit Schaefer
- Web page: https://patentgrep.com/patent/US10478521B2

## CPC

- A61L 26/0033: {Collagen}
- A61K 33/38: Silver; Compounds thereof
- A61L 15/325: {Collagen}
- A61L 15/46: Deodorants or malodour counteractants, e.g. to inhibit the formation of ammonia or bacteria
- A61L 31/044: {Collagen}
- A61L 31/16: Biologically active materials, e.g. therapeutic substances {(A61L31/047 takes precedence)}
- A61L 2300/104: Silver, e.g. silver sulfadiazine
- A61L 2300/404: Biocides, antimicrobial agents, antiseptic agents
- Y10S 977/773: Nanoparticle, i.e. structure having three dimensions of 100 nm or less
- 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 (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A sheet material that can be used as a wound dressing and contains elemental metal particles.

## Claims

### Claim 1

A method comprising:
providing porcine skin;
administering an alkaline and oxidative treatment to said porcine skin comprising dipping said porcine skin alternately in hydrogen peroxide and sodium hydroxide;
acidifying the alkaline and oxidatively treated porcine skin with an acid selected from the group consisting of: phosphoric acid, hydrochloric acid, and acetic acid;
mechanically comminuting the acidified porcine skin until a collagen-containing suspension is produced, said suspension having a solids content from 0.5 to 5%;
adjusting said collagen-containing suspension to a neutral to slightly alkaline pH from 6.5 to 8.5 by adding a phosphate buffer;
separately producing an elemental-metal containing suspension that is stabilized with a stabilizing agent, wherein the elemental metal particles include silver particles and have an average particle size between 10 nm and 10 μm;
adding the elemental-metal-containing suspension to the pH-adjusted collagen-containing suspension while promoting dispersion using a dispersion promoting means selected from the group consisting of: an ultrasonic bath, and rotor-stator mill, in order to produce a collagen and elemental metal containing suspension;
drying the collagen-and-elemental-metal-containing suspension until a translucent sheet material is produced, wherein the drying of the liquid collagen-containing starting material is performed at a temperature above 20° C. under vacuum; and
sterilizing the dried sheet material using ethylene oxide such that additional cross-links are produced in the sheet material,
wherein the elemental metal particles are incorporated into the sheet material both at the near-surface regions and in the middle of the sheet material, wherein the sheet material has a thickness between 0.1 and 1 mm, a closed porosity of less than 50%, an elemental metal particle content from 10 to 100,000 ppm.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising applying the sheet material to a wound to dress said wound.

### Claim 3 (depends on 1)

The method as claimed in claim 1, wherein the elemental metal particles have an average particle size of less than 50 nm.

### Claim 4 (depends on 1)

The method of claim 1, wherein the sheet material has a closed porosity of less than 20%.

### Claim 5 (depends on 1)

The method of claim 1, wherein the sheet material comprises more than 90% of collagen.