Method for preparing a chitosan-based porous layer

• US 10,363,690 B2
• Filed: 08/01/2013
• Issued: 07/30/2019
• Est. Priority Date: 08/02/2012
• Status: Active Grant

• Current Assignee: Sofradim Production
• Original Assignee: Sofradim Production
• Inventors: Ladet, Sebastien, Francois, Sebastien, Claret, Julien, Buffin, Maud
• Primary Examiner(s): Calandra, Anthony
• Assistant Examiner(s): Moreno Hernandez, Jerzi H
• Application Number:
  US14/413,499
• Publication Number:
  US 20150158209A1
• Time in Patent Office: 2,189 Days
• CPC Class Codes: A61B 17/07292 Reinforcements for staple line, e.g. pledgets
• CPC Class Codes: A61L 27/20 Polysaccharides
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B29C 43/02 of articles of definite length, i.e. discrete articles B29C35/0227 takes precedence
• CPC Class Codes: B29K 2005/00 Use of polysaccharides or derivatives as moulding material
• CPC Class Codes: B29L 2007/00 Flat articles, e.g. films or sheets B29L2024/00 takes precedence
• CPC Class Codes: C08J 2201/0504 the liquid phase being aqueous
• CPC Class Codes: C08J 2305/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof

Abstract

Method for preparing a chitosan-based porous layer The present invention relates to a method or preparing a chitosan-based, neutralized compressed porous layer, comprising the following steps: —a) a chitosan solution is prepared, —b) said solution is poured into a mold in order to form a layer, —c) the layer obtained in b) is lyophilized so as to obtain a porous layer, —d) said porous layer obtained in c) is compressed, —e) the compressed porous layer obtained in d) is neutralized by means of an NH₄OH solution. It also relates to an implant comprising a layer obtained according to such a method.

Claims

1. A method for preparing a chitosan-based porous layer which has been compressed, neutralized and washed, comprising the following steps:

a) preparing a chitosan solution free of any other polymer, including a chitosan concentration ranging from 1.0% to 5% by weight, relative to a total weight of the solution and having a pH from 3 to 5,

b) pouring the chitosan solution into a mold in order to form a layer,

c) lyophilizing the layer obtained in b) to obtain a porous layer,

d) compressing the porous layer obtained in c) to obtain a compressed porous layer including a density of greater than or equal to 0.65 g/cm³,

e) neutralizing the compressed porous layer obtained in d) by using a NH₄OH solution comprising a NH₄OH concentration ranging from 0.6 to 2 mold to obtain a neutralized compressed porous layer, and,

f) subjecting the neutralized compressed porous layer obtained in e) to one or more washing steps.

2. The method according to claim 1, wherein the chitosan solution prepared in step a) is a solution of chitosan in water having a chitosan concentration ranging from 2% to 3% by weight, relative to a total weight of the solution.

3. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 0 to 70%.

4. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 1% to 10%.

5. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 2% to 3%.

6. The method according to claim 1, wherein the solution includes acetic acid.

7. The method according to claim 1, wherein the pH is 3.5 by adding acetic acid.

8. The method according to claim 1, wherein the step of compressing the porous layer includes compressing the porous layer until obtaining a thickness of less than or equal to 2 mm.

9. The method according to claim 1, wherein the step of compressing the porous layer includes compressing the porous layer until obtaining a thickness of less than or equal to 0.5 mm.

10. The method according to claim 1, wherein the NH₄OH solution used in step e) is a solution of NH₄OH in water or ethanol.

11. The method according to claim 1, wherein the NH₄OH solution used in step e) is a solution of NH₄OH in ethanol including a NH₄OH concentration ranging from 1 to 2 mol/l.

12. The method according to claim 1 wherein the step of neutralizing the compressed porous layer includes dipping the compressed porous layer in the NH₄OH solution for a period of less than or equal to 30 minutes.

13. The method according to claim 1 wherein the step of neutralizing the compressed porous layer includes dipping the compressed porous layer in the NH₄OH solution for a period ranging from 5 minutes to 20 minutes.

14. The method according to claim 1 wherein the one or more washing steps includes dipping the neutralized compressed porous layer of step e) in one or more baths of sterile water until a washing water with a pH close to 7 is obtained.

15. A method of forming an implant for reinforcing a staple zone including a chitosan based porous layer comprising the following steps:

a) preparing a chitosan solution free of any other polymer and including a chitosan concentration ranging from 1.0% to 5% by weight, relative to the total weight of the solution,

b) adjusting the pH of the chitosan solution to a pH ranging from 3 to 5,

c) pouring the solution into a mold in order to form a layer,

d) lyophilizing the layer obtained in c) to obtain a porous layer,

e) compressing the porous layer obtained in d) to obtain a compressed porous layer including a density of greater than equal to 0.65 g/cm³,

f) neutralizing the compressed porous layer obtained in e) by using a NH₄OH solution comprising a NH₄OH concentration ranging from 0.6 to 2 mol/l to obtain a neutralized compressed porous layer, and,

g) subjecting the neutralized compressed porous layer obtained in f) to one or more washing steps.

16. The method according to claim 15, wherein the chitosan solution prepared in step a) is a solution of chitosan in water having a chitosan concentration ranging from 2% to 3% by weight, relative to a total weight of the solution.

17. The method according to claim 15, wherein the chitosan includes a degree of acetylation ranging from 1% to 10%.

18. The method according to claim 15, wherein the chitosan includes a degree of acetylation ranging from 2% to 3%.

19. The method according to claim 15, wherein the pH is 3.5 by adding acetic acid.

20. The method according to claim 15, wherein the NH₄OH solution used in step e) is a solution of NH₄OH in water or ethanol including a NH₄OH concentration ranging from 1 to 2 mol/l.