Porous bioresorbable dressing conformable to a wound and methods of making same

• US 20080114277A1
• Filed: 11/09/2007
• Published: 05/15/2008
• Est. Priority Date: 11/09/2006
• Status: Abandoned Application

• Current Assignee: KCI Licensing Incorporated (3M Company)
• Original Assignee: KCI Licensing Incorporated (3M Company)
• Inventors: Payne, Joanna, Kieswetter, Kristine, Ambrosio, Archel
• Application Number:
  US11/983,548
• Publication Number:
  US 20080114277A1
• Time in Patent Office: Days
• US Class Current: 602/46
• CPC Class Codes: A61F 13/00987 Apparatus or processes for manufacturing non-adhesive dressings or bandages
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61F 2013/00927 with biological activity, e.g. enzymes for debriding wounds or others, collagen or growth factors
• CPC Class Codes: A61L 15/425 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 15/64 specially adapted to be resorbable inside the body
• CPC Class Codes: A61M 1/915 Constructional details of the pressure distribution manifold
• CPC Class Codes: A61P 17/02 for treating wounds, ulcers, burns, scars, keloids, or the like
• CPC Class Codes: Y10T 156/1005 by inward collapsing of portion of hollow body

Abstract

A method of making a porous bioresorbable dressing is provided for use in applying reduced pressure therapy to a wound site. The process includes manufacture of a dressing by use of one or more bioresorbable polymers and a porogen system. The malleability of the dressing allows the dressing to be placed into the wound site such that it fills the shape and size of the wound. Embodiments include use of hand molding and formation of a rope dressing. The porogen system may be activated external to the wound site or formed in situ within the wound site, thus creating a porous dressing. A reduced pressure delivery tube is fluidly connected to the wound site to delivery a reduced pressure to the wound site.

Claims

1. A method for promoting new tissue growth and/or wound healing at a wound site comprising:

forming a dressing by dissolving one or more bioresorbable polymers and a porogen system in a solvent, and removing said solvent;

positioning the dressing into the wound site such that the dressing fills the size and shape of the wound site;

positioning a manifold in contact with the dressing;

covering the manifold with a drape;

securing the drape to the skin surface about the wound circumference;

applying a reduced pressure to the wound site through the dressing and manifold; and

forming pores within the dressing in situ by wound fluids contacting the porogen system within the dressing.

2. The method of claim 1, wherein said porogen system is sodium biocarbonate and at least one acid.

3. The method of claim 2, wherein said acid is citric acid.

4. The method of claim 1, wherein said porogen system is a salt.

5. The method of claim 1, wherein said forming a dressing further comprises the addition of one or more plasticizers to said solvent.

6. The method of claim 1, wherein the pores are between 100 and 500 microns in size.

7. The method of claim 1, wherein positioning the dressing into the wound site occurs by hand molding the dressing.

8. A method for promoting new tissue growth and/or wound healing at a wound site comprising:

forming a dressing by dissolving one or more bioresorbable polymer in a solvent, mixing a porogen system with said polymer in said solvent, and removing said solvent;

contacting the dressing with a fluid such that the porogen system forms pores;

positioning the dressing into the wound site such that the dressing contacts the wound site;

positioning a manifold in contact with the dressing;

covering the manifold with a drape;

securing the drape to the skin surface about the wound circumference;

applying a reduced pressure to the wound site through the dressing and manifold.

9. The method of claim 8 wherein said porogen system is sodium biocarbonate and at least one acid.

10. The method of claim 9, wherein said acid is citric acid.

11. The method of claim 8, wherein said porogen system is a salt.

12. The method of claim 8, wherein said forming a dressing further comprises the addition of one or more plasticizers to said solvent.

13. The method of claim 8, wherein positioning the dressing into the wound site occurs by hand molding the dressing.

14. A method for forming a dressing to be used to support new tissue growth and/or wound healing at a wound site, said method comprising:

dissolving one or more bioresorbable polymers in a solvent;

adding porogen system particles to said solvent;

removing the solvent to form a solid dressing;

heat pressing the dressing;

initiating formation of pores by contacting the dressing with a fluid.

15. The method of claim 14, wherein said method further comprises:

coating the dressing with porogen system particles before heat pressing the dressing.

16. The method of claim 14, wherein said method further comprises:

imprinting a wafer on the top and/or bottom of the dressing by use of the heat pressing plates.

17. The method of claim 14, wherein said method further comprises:

coating the dressing with one or more substances that facilitate healing.

18. A method of promoting new tissue growth and/or healing at a wound site comprising:

forming a dressing by

i) dissolving one or more bioresorbable polymer and a porogen system to a solvent to form a mixture;

ii) placing said mixture in a non solvent such that the one or more bioresorbable polymer and porogen system precipitates out of ii) solution; and

removing excess non solvent;

positioning the dressing into the wound site such that the dressing contacts the wound site;

positioning a manifold in contact with the dressing;

covering the manifold with a drape;

securing the drape to the skin surface about the wound circumference;

applying a reduced pressure to the wound site through the dressing and manifold.

19. The method of claim 18, wherein said dressing further comprises at least one plasticizer.

20. The method of claim 18, wherein said porogen system is sodium biocarbonate and at least one acid.

21. The method of claim 18, wherein said acid is citric acid.

22. The method of claim 18, wherein said porogen system is a salt.

23. The method of claim 18, wherein said positioning the dressing into the wound site occurs by hand molding the dressing.

24. The method of claim 18, wherein said method further comprises:

forming said dressing into a rope configuration before positioning the dressing into the wound site.

25. A method of promoting new tissue growth at a wound site comprising:

forming a dressing by

i) forming a mixture by dissolving one or more bioresorbable polymer in a solvent and adding a porogen system to said solvent;

ii) extruding said mixture in a non solvent by use of a device with a desired tip diameter such that the mixture precipitates in the shape of a rope with a desired diameter; and

iii) removing excess non solvent;

positioning the dressing into the wound site such that the dressing contacts the wound site;

positioning a manifold in contact with the dressing;

covering the manifold with a drape;

securing the drape to the skin surface about the wound circumference;

applying a reduced pressure to the wound site through the dressing and manifold.