Photoactivated Antimicrobial Wound Dressing and Method Relating Thereto

• US 20090209897A1
• Filed: 02/20/2008
• Published: 08/20/2009
• Est. Priority Date: 02/20/2008
• Status: Abandoned Application

• Current Assignee: Lotec, Inc., UT-Battelle LLC
• Original Assignee: Lotec, Inc., UT-Battelle LLC
• Inventors: Subramanian, Shanthi, Evans, Barbara R., O'Neill, Hugh M., Limaye, Santosh Y.
• Application Number:
  US12/034,629
• Publication Number:
  US 20090209897A1
• Time in Patent Office: Days
• US Class Current: 602/48
• CPC Class Codes: A61F 13/01021 characterised by the structure of the dressing
• CPC Class Codes: A61F 13/069 Decubitus ulcer bandages
• CPC Class Codes: A61F 2013/00157 for burns or skin transplants A61F2013/00187 takes precedence; not adhering to the wound A61F2013/00217
• CPC Class Codes: A61F 2013/00519 for treating burn
• CPC Class Codes: A61F 2013/0091 with disinfecting or anaesthetics means, e.g. anti-mycrobic
• CPC Class Codes: A61F 2013/00927 with biological activity, e.g. enzymes for debriding wounds or others, collagen or growth factors
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 35/59 Membranes

Abstract

A photoactivated antimicrobial wound dressing comprising a photocatalytic membrane is provided. The photocatalytic membrane comprises a bacterial cellulose hydrogel membrane having photocatalytic particles are immobilized within the membrane and are activated when exposed to light, at which time they react with oxygen-based species forming reactive oxygen species. The reactive oxygen species further react with microbes to kill the microbes.

Claims

1. A photoactivated antimicrobial wound dressing comprising:

a photocatalytic membrane comprising a bacterial cellulose hydrogel membrane having photocatalytic particles immobilized within the bacterial cellulose hydrogel membrane and wherein the photocatalytic particles when exposed to light react with oxygen-based species forming reactive oxygen species and wherein the reactive oxygen species react with microbes whereby the microbes are killed.

2. A photoactivated antimicrobial wound dressing according to claim 1, wherein the bacterial cellulose hydrogel membrane is prepared from at least one cellulose-producing bacteria.

3. A photoactivated antimicrobial wound dressing according to claim 2, wherein the cellulose-producing bacteria is selected from the group consisting of:

Gluconacetobacter hansenii and Gluconacetobacter xylinus.

4. A photoactivated antimicrobial wound dressing according to claim 1, wherein the photocatalytic particles are crystalline titanium dioxide nanoparticles having a particle size ranging from about 5 nm to about 100 nm.

5. A photoactivated antimicrobial wound dressing according to claim 4, wherein the titanium dioxide nanoparticles comprise from about 0.5 mg/cm² to about 4 mg/cm² per unit area of a membrane.

6. A photoactivated antimicrobial wound dressing according to claim 5, wherein the crystalline titanium dioxide nanoparticles comprise about 3 mg/cm² per unit area of a membrane.

7. A photoactivated antimicrobial wound dressing according to claim 1, wherein the photocatalytic particles are incorporated into the bacterial cellulose hydrogel membrane by chemically modifying the bacterial cellulose to receive the photocatalytic particles.

8. A photoactivated antimicrobial wound dressing according to claim 1, wherein the photocatalytic membrane is activated by ultraviolet light having a wavelength of about 365 nm.

9. A photoactivated antimicrobial wound dressing according to claim 1, further comprising an overdressing wherein the overdressing covers at least a portion of the photocatalytic membrane.

10. A method for treating a wound, the method comprising the steps of:

a) providing a photoactivated antimicrobial wound dressing comprising a photocatalytic membrane comprising a bacterial cellulose hydrogel membrane having photocatalytic particles immobilized within the bacterial cellulose hydrogel membrane;

b) applying the photoactivated antimicrobial wound dressing to a wound; and

c) exposing the photoactivated antimicrobial wound dressing to light wherein the photocatalytic particles when exposed to light react with oxygen-based species forming reactive oxygen species and wherein the reactive oxygen species react with microbes whereby the microbes are killed.

11. A method according to claim 10, wherein the photocatalytic particles are crystalline titanium dioxide nanoparticles.

12. A method according to claim 11, wherein the photoactivated antimicrobial wound dressing is exposed to ultraviolet light having a wavelength ranging from about 250 nm to about 400 nm.

13. A method according to claim 10, further comprising the step of applying an overdressing over at least a portion of the photocatalytic membrane after the photocatalytic membrane has been exposed to light.