A laboratory study was undertaken to investigate the availability and anti- microbial efficacy of silver within a carboxymethyl cellulose (CMC) dress- ing for the management of partial thickness burns (PTB). The intended use of the burn dressing is for it to be applied to a clean PTB wound and left in place until the wound has reepithelialised up to a maximum of 21 days. It is therefore important for the silver content to remain effective throughout this period. The burn dressing is made up of a non-woven CMC fabric with nylon stitchbonding and contains 1.2 % ionic silver (Figure 1). Figure 1. Silver CMC Burn Dressing Antimicrobial Efficacy: An in vitro simulated wound fluid model was used to evaluate the anti- microbial activity of the silver CMC burn dressing against Staphylo- coccus aureus and Pseudomonas aeruginosa, 3 replicates were test- ed per challenge organism. Dressing samples were incubated with the challenge organism (~1 x 10 6 cfu/ mL) for 21 days, with re-inocula- tion of the challenge organism at days 4, 9 and 17 (at least 1x10 5 cfu) labelled R1, R2 and R3, to simulate wound conditions. The equivalent CMC burn dressings without silver were used as the negative control. The in vitro simulated wound fluid model data show that the silver CMC burn dressing rapidly and repeatedly reduced high populations of the challenge organisms throughout the test period of 21 days. Silver availability testing shows that silver is available throughout the test period and that availability is not adversely affected by dehydration and subsequent re-hydration of the dressing material. Silver CMC burn dressing is AQUACEL ® Ag BURN Dressing, CMC Dressing is AQUACEL ® Dressing ®/ ™ indicated a trademark of ConvaTec Inc. ©2013 ConvaTec Inc. AP-013566-MM In Vitro Studies on a Silver CMC Burn Dressing Lucy Ballamy, Victoria Towers, Darryl Short and Sarah Welsby Antimicrobial Efficacy: The silver CMC burn dressing was efficacious against both S. aureus and P. aeruginosa in the simulated wound fluid model over 21 days, as shown in Figure 2. Figure 2. Antimicrobial Efficacy -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 5 10 15 20 25 30 Timepoint (Days) Silver Availability (ppm) Silver Availability Analysis: The availability of silver from the silver CMC burn dressing was analysed by im- mersing dressing samples in 0.9 % w/v sodium chloride (saline solution) over a 28 day period at 37 O C with stirring. Aliquots of the solution were taken after 7, 11, 18, 25 and 28 days and tested for silver using a Perkin Elmer AAnalyst Atomic Absorption Spectrophotometer. At days 7 and 18 the dressing samples were re- moved from the saline solution and dried out for 24 hours before being replaced into fresh saline which created a further challenge and was designed to mimic a burn wound drying out and then being rehydrated with saline. The experiment was carried out in triplicate. Figure 3. Silver Availability Analysis 1 10 100 1000 10000 100000 1000000 10000000 100000000 1E+09 1E+10 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Silver CMC Burn Dressing vs S. aureus (n=3) CMC Dressing vs S. aureus (negative control, n=3) Silver CMC Burn Dressing vs P. aeruginosa (n=3) CMC Dressing vs P. aeruginosa (negative control, n=3) R1 R2 R3 Total Viable Counts (Log10 cfu/mL) Timepoint (Days) Silver Availability Analysis: The silver availability test showed the silver content of the silver CMC dress- ing at 28 days was comparable to that after 7 days as shown in Figure 3.
EWMA 2013 - Ep469 - 21 day in vitro antimicrobial efficacy study on a silver cmc burn dressing
Feb 17, 2017
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
A laboratory study was undertaken to investigate the availability and anti-microbial efficacy of silver within a carboxymethyl cellulose (CMC) dress-ing for the management of partial thickness burns (PTB). The intended use of the burn dressing is for it to be applied to a clean PTB wound and left in place until the wound has reepithelialised up to a maximum of 21 days. It is therefore important for the silver content to remain effective throughout this period. The burn dressing is made up of a non-woven CMC fabric with nylon stitchbonding and contains 1.2 % ionic silver (Figure 1).
Figure 1. Silver CMC Burn Dressing
Antimicrobial Efficacy:
An in vitro simulated wound fluid model was used to evaluate the anti-microbial activity of the silver CMC burn dressing against Staphylo-coccus aureus and Pseudomonas aeruginosa, 3 replicates were test-ed per challenge organism. Dressing samples were incubated with the challenge organism (~1 x 106 cfu/ mL) for 21 days, with re-inocula-tion of the challenge organism at days 4, 9 and 17 (at least 1x105 cfu) labelled R1, R2 and R3, to simulate wound conditions. The equivalent CMC burn dressings without silver were used as the negative control.
The in vitro simulated wound fluid model data show that the silver CMC burn dressing rapidly and repeatedly reduced high populations of the challenge organisms throughout the test period of 21 days. Silver availability testing shows that silver is available throughout the test period and that availability is not adversely affected by dehydration and subsequent re-hydration of the dressing material.
Silver CMC burn dressing is AQUACEL® Ag BURN Dressing, CMC Dressing is AQUACEL® Dressing ®/ ™ indicated a trademark of ConvaTec Inc.
©2013 ConvaTec Inc. AP-013566-MM
In Vitro Studies on a Silver CMC Burn DressingLucy Ballamy, Victoria Towers, Darryl Short and Sarah Welsby
Antimicrobial Efficacy:
The silver CMC burn dressing was efficacious against both S. aureus and P. aeruginosa in the simulated wound fluid model over 21 days, as shown in Figure 2.
Figure 2. Antimicrobial Efficacy
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 5 10 15 20 25 30
Timepoint (Days)
Silv
er A
vaila
bilit
y (p
pm)
Silver Availability Analysis:
The availability of silver from the silver CMC burn dressing was analysed by im-mersing dressing samples in 0.9 % w/v sodium chloride (saline solution) over a 28 day period at 37OC with stirring. Aliquots of the solution were taken after 7, 11, 18, 25 and 28 days and tested for silver using a Perkin Elmer AAnalyst Atomic Absorption Spectrophotometer. At days 7 and 18 the dressing samples were re-moved from the saline solution and dried out for 24 hours before being replaced into fresh saline which created a further challenge and was designed to mimic a burn wound drying out and then being rehydrated with saline. The experiment was carried out in triplicate.
Figure 3. Silver Availability Analysis
1
10
100
1000
10000
100000
1000000
10000000
100000000
1E+09
1E+10
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Silver CMC Burn Dressing vs S. aureus (n=3) CMC Dressing vs S. aureus (negative control, n=3)
Silver CMC Burn Dressing vs P. aeruginosa (n=3) CMC Dressing vs P. aeruginosa (negative control, n=3)
R1
R2
R3To
tal V
iabl
e C
ount
s (L
og10
cfu
/mL)
Timepoint (Days)
Silver Availability Analysis:
The silver availability test showed the silver content of the silver CMC dress-ing at 28 days was comparable to that after 7 days as shown in Figure 3.
Related Documents
