ANTIMICROBIAL DRESSING

Abstract

A wound dressing comprises an antimicrobial layer. The antimicrobial layer comprises a knitted silver thread, optionally with a non-metallic thread. The thread or threads may be knitted onto a non-woven sheet of a thermoplastic material. The wound dressing may further comprise any of an absorbent material and a hydrophobic gel and may be used in a system for negative pressure wound therapy.

Claims

1. A wound dressing comprising an antimicrobial layer, wherein said antimicrobial layer comprises a yarn comprising gelling and non-gelling fibres, and silver.

2-5. (canceled)

6. A wound dressing as claimed in claim 1, wherein the yarn is from a blend of gelling-, non-gelling-, and silver fibres.

7. A wound dressing as claimed in claim 1, further comprising an absorbent material.

8. A wound dressing as claimed in claim 7, wherein the absorbent material is an absorbent foam.

9. A wound dressing as claimed in claim 7, wherein the absorbent material is an absorbent polymeric material.

10. A wound dressing as claimed in claim 7, wherein the absorbent material is a superabsorbent material.

11. A wound dressing as claimed in claim 1, further comprising a hydrophobic gel.

12. A wound dressing as claimed in claim 11, wherein the hydrophobic gel is a soft silicone gel.

13. A wound dressing as claimed in claim 11, wherein the hydrophobic gel is perforated.

14. A wound dressing as claimed in claim 11, wherein the hydrophobic gel is provided as a coating on a wound-contacting surface of the dressing.

15. A wound dressing as claimed in claim 11, wherein the hydrophobic gel impregnates the antimicrobial layer of the dressing.

16. A wound dressing as claimed in claim 1, further comprising a backing layer secured to a non-wound-contacting surface of the dressing.

17. A wound dressing as claimed in claim 16, wherein the backing layer extends beyond the antimicrobial layer or the antimicrobial layer and an absorber on all sides, to form a border around the wound dressing.

18. A wound dressing as claimed in claim 17, wherein the backing layer is provided with an adhesive for securing the dressing to a patient.

19. A wound dressing as claimed in claim 1, further comprising a release liner on the wound-facing surface of the dressing.

20. A system for negative pressure wound therapy, including a wound dressing according to claim 1.

Description

EXAMPLE

[0059] Dressings in accordance with the present invention, including an antimicrobial layer fused to an absorbent foam, were tested for capability to kill organisms upon contact.

[0060] The inhibitory activity of the material was tested against Staphylococcus aureus (ATCC 6538) and Pseudomonas aeruginosa (ATCC 9027).

Procedure

[0061] Tryptone Soya Agar (TSA) plates were seeded with approximately 10.sup.4 cfu/ml of the bacteria.

[0062] Small pieces of the dressing were added to each TSA plate. In addition, control samples were prepared using small pieces of non-antimicrobial based dressings. These were added to each type of seeded agar plate.

[0063] At intervals of 1, 4 and 24 hours, the inhibitory material was removed from the surface of the appropriate seeded plate. The plates were incubated at 30° C. (+/−2° C.) for a minimum period of 24 hours. This was used to establish whether dressing contact time had any effect on the inhibitory capability of the material. Any leaching of the inhibitory substance from the dressing into the agar, causing inhibition away from the dressing, was also assessed.

Results

[0064] At each time interval, almost complete inhibition was observed for both organisms.

[0065] Leaching was observed for Staphylococcus aureus at 1 and 4 hours, with extensive leaching at 24 hours.

[0066] No leaching was observed for Pseudomonas aeruginosa.

Conclusion

[0067] Anti-microbial effect was observed against both organisms in comparison to control samples, particularly after 24 hours. The material was found to be very effective at inhibiting organisms. Extensive leaching of the anti-microbial substance was also seen with Staphylococcus aureus.