Method for producing collagen-containing sheet material

Abstract

A method for producing a collagen-containing sheet material, wherein a collagen-containing suspension is dried in such a manner that the collagen settles during drying and forms a transparent skin.

Claims

1. A method for producing a collagen-containing sheet material, comprising: treating a mammalian skin starting material with wet chemicals; mechanically comminuting the treated starting material into a slurry; preparing an aqueous suspension of the comminuted, treated starting material from the slurry, said aqueous suspension having a solid content from 0.5 to 5%; adjusting the pH of the aqueous suspension to a pH between 5.5 and 8; transferring the aqueous suspension to a tray; waiting until at least a portion of the suspension in the tray settles out before drying; and drying the aqueous suspension in the tray such that a transparent film of the collagen-containing sheet material is formed having a closed porosity of less than 20%; wherein said collagen-containing sheet material comprises more than 70% of collagen; and wherein said collagen-containing sheet material has a thickness between 0.05 and 2 mm.

2. The method for producing a collagen-containing sheet material as claimed in claim 1, wherein metal particles are added to the aqueous suspension.

3. The method for producing a collagen-containing sheet material as claimed in claim 2, wherein metal particles are added as a suspension.

4. The method for producing a collagen-containing sheet material as claimed in claim 2, wherein silver particles are added to the aqueous suspension.

5. The method for producing a collagen-containing sheet material as claimed in claim 2, wherein the metal particles have an average particle size of less than 50 nm.

6. The method for producing a collagen-containing sheet material as claimed in claim 1, wherein metal particles are added, which have an average particle size between 10 nm and 10 μm.

7. The method for producing a collagen-containing sheet material as claimed in claim 1, wherein bactericidal agents are added to the aqueous suspension.

8. The method for producing a collagen-containing sheet material as claimed in claim 1, wherein antifungal agents are added to the aqueous suspension.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a flowchart of a method for producing a collagen-containing sheet material.

DETAILED DESCRIPTION

(2) First, porcine skin is prepared by an alkaline, oxidative, and acidic treatment.

(3) For this purpose, hydrogen peroxide, sodium hydroxide, and phosphoric acid may be used, for example, in which the starting material is alternately dipped and is then rinsed.

(4) Through this wet-chemical preparation, a starting material is provided which comprises more than 70%, preferably more than 80% of collagen.

(5) Then, the wet-chemically purified porcine skin is acidified. Preferably, phosphoric acid is used for this purpose.

(6) To prepare a suspension, the porcine skin is first comminuted mechanically by mincing, and then an aqueous suspension is produced from the slurry resulting from further comminuting steps. This suspension in particular has a solids content from 0.5 to 5%.

(7) Then, the aqueous suspension is adjusted to a neutral to slightly alkaline pH from 6.5 to 8.5 by adding a phosphate buffer.

(8) Subsequently, a nano-silver containing aqueous suspension may be added. For this purpose, a suspension should be used which is stable over a longer period. The metal is not added as a salt, but as elemental silver.

(9) To achieve a good distribution, the addition of the nano-silver containing suspension may be accomplished using suitable dispersion promoting means, for example in an ultrasonic bath, or a suitable rotor-stator type mill.

(10) Subsequently, the suspension is dried in trays at a temperature above 20° C. under reduced pressure.

(11) The collagen will thereby mostly settle on the bottom of the tray as a film-like structure, with a large part of the silver particles trapped in the material being formed.

(12) Subsequently, the dried sheet material can be packaged and sterilized.

(13) Sterilization may be accomplished using ethylene oxide, for example.

(14) Also, sterilization of the already packaged material is possible by irradiation.

(15) The produced material rehydrates very fast, has a good hemostatic effect, and is bendable, rollable and can be cut easily, even in its dry state.

(16) Additionally, the material is translucent at least to an extent so that the applied material permits to perceive the underlying tissue. Complications such as inflammation arising under the sheet material can be easily identified.

(17) Furthermore, the material is less prone to sticking and can be easily removed.