Wound dressing with controllable permeability

• US 8,237,007 B2
• Filed: 01/10/2008
• Issued: 08/07/2012
• Est. Priority Date: 01/10/2007
• Status: Expired due to Fees

• Current Assignee: Nuvesse Skin Therapies Inc.
• Original Assignee: Polyremedy, Inc.
• Inventors: Siniaguine, Oleg
• Primary Examiner(s): Lewis, Kim M
• Application Number:
  US11/972,452
• Publication Number:
  US 20080167594A1
• Time in Patent Office: 1,671 Days
• Field of Search: 602 41- 59, 424443-449, 604304-308
• US Class Current: 602/41
• CPC Class Codes: A61F 13/00063 comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00
• CPC Class Codes: A61F 13/00995 for mechanical treatments
• CPC Class Codes: A61F 13/01021 characterised by the structure of the dressing
• CPC Class Codes: A61F 2013/00255 with pores
• CPC Class Codes: A61F 2013/00604 Multilayer
• CPC Class Codes: A61F 2013/00863 with pores
• CPC Class Codes: A61F 2013/0091 with disinfecting or anaesthetics means, e.g. anti-mycrobic

Abstract

Wound dressings and methods of manufacturing wound dressings are provided. The wound dressings include portions that are converted from a moisture vapor permeable material to a material having reduced moisture vapor permeability. The conversion may be accomplished in a variety of ways. In some embodiments, a solvent is used to dissolve a porous material to thereby form a non-porous film. In other embodiments, heat is applied to melt a porous material to thereby form a non-porous film. The heat may be applied using a heated gas or a heating element to directly or indirectly heat the material.

Claims

1. A wound dressing comprising:

a first layer having a first region characterized by a respective first moisture vapor transmission rate (MVTR1) and having a second region characterized by a respective second and smaller moisture vapor transmission rate (MVTR2), wherein said first and second regions are shaped and sized to match corresponding regions of the wound;

a second layer disposed adjacent the first layer, said second layer having a higher melting point than the first layer; and

a third layer provided above the first layer so that the first layer is sandwiched between the third layer and the second layer, said third layer having a higher melting point than the first layer, where the second and third layers are porous and the third layer has a larger average pore size than that of the second layer.

2. The wound dressing of claim 1, wherein:

the third layer comprises hydrophobic polymer microfibers.

3. The wound dressing of claim 2, wherein:

the first layer, the second layer, or the third layer includes a substance enhancing wound healing.

4. The wound dressing of claim 2, wherein:

the first layer, the second layer, or the third layer includes a pharmacological substance.

5. The wound dressing of claim 1, wherein:

at least one of the first and second layers comprises hydrophobic polymer microfibers.

6. The wound dressing of claim 1, wherein:

at least one of the first layer and the second layer has bacteriostatic, bactericidal, or antifungal properties.

7. A wound dressing comprising:

a first layer having a first region characterized by a respective first moisture vapor transmission rate (MVTR1) and having a second region characterized by a respective second and smaller moisture vapor transmission rate (MVTR2), wherein said first and second regions are shaped and sized to match corresponding regions of the wound; and

a second layer disposed adjacent the first layer, said second layer having a higher melting point than the first layer, wherein said second layer comprising a material insoluble in the first solvent and the first layer comprises a first microfiber type and a second micro fiber type, said first microfiber type being soluble in a first solvent and the second microfiber type being insoluble in the first solvent.

8. The wound dressing of claim 7, wherein:

the second layer comprises hydrophobic polymer microfibers.

9. A dressing for assisting in healing of a wound to skin of a patient where the wound may have different wound attributes in respective one or more regions of the wound, the dressing comprising:

a first sheet, said first sheet having a first layer generally characterized by a respective first moisture vapor transmission rate (MVTR1) greater than 0.05 g/sq·

cm/24 hour and having a second layer characterized by a respective melting point that is smaller than that of the first layer; and

a second sheet comprising a third layer and a fourth layer, wherein the third layer generally characterized by a respective second moisture vapor transmission rate (MVTR2) greater than 0.05 g/sq·

cm/24 hour and wherein the fourth layer is characterized by a respective melting point that is smaller than that of the third layer;

wherein the second layer of the first sheet is bonded to the third layer of the second sheet by a melted and resolidified portion of the second layer.

10. The dressing of claim 9, wherein:

a portion of the fourth layer of the second sheet is a selectively converted portion which is locally characterized by a respective third moisture vapor transmission rate (MVTR3) that is smaller than the general first moisture vapor transmission rate (MVTR1) of the first sheet.

11. The dressing of claim 9, wherein:

a lateral dimension of the second sheet is larger than a lateral dimension of the first sheet.

12. The dressing of claim 9, wherein:

the first sheet comprises a first layer and a second layer, wherein the second layer of the first sheet has a lower melting point than the first layer of the first sheet and is bonded to the second layer of the second sheet.

13. The dressing of claim 12, further comprising:

a third sheet comprising a first layer and a second layer, wherein the second layer of the third sheet has a lower melting point than the first layer of the third sheet and is bonded to the first layer of the first sheet.

14. The dressing of claim 13, wherein:

a lateral dimension of the third sheet is larger than a lateral dimension of the first sheet.

15. The dressing of claim 13, wherein:

a lateral dimension of the second sheet is larger than a lateral dimension of the first sheet and a lateral dimension of the third sheet.