Randomized Controlled Trial Comparing Collagen/Oxidized Regenerated Cellulose/Silver to Standard of Care in the Management of Venous Leg Ulcers.

OBJECTIVE: To assess healing outcomes in venous leg ulcers (VLUs) treated with a combination of collagen, oxidized regenerated cellulose, and silver in conjunction with standard of care (SOC; intervention group) compared with SOC alone (control group). Standard of care included ADAPTIC nonadhering dressing (Acelity, San Antonio, Texas) and compression. DESIGN AND SETTING: Randomized controlled trial that followed patients in 3 US facilities for 12 weeks or until complete healing. PATIENTS AND INTERVENTION: Forty-nine patients with VLUs were randomized to either the intervention group (n = 22) or the control group (n = 27). MAIN OUTCOME MEASURE: Wound healing over 12 weeks. MAIN RESULTS: Intent-to-treat analysis showed a mean percentage wound area reduction at 12 weeks of 85.6% (SD, 28.6%) for the intervention group and 72.5% (SD, 77.8%) for the control group. There was a higher healing rate in the intervention group compared with patients who received SOC only at both week 4 (23% vs 11%) and week 12 (64% vs 59%). There were no adverse events related to the study therapy. CONCLUSIONS: Although the results were not significant, there was a trend toward faster healing in the intervention group. The results of this study indicate that collagen/oxidized regenerated cellulose/silver is a suitable and safe adjunctive intervention for use with SOC to manage VLUs.

Biofilms and delayed healing - an in vitro evaluation of silver- and iodine-containing dressings and their effect on bacterial and human cells.

This study investigated whether there are differences in the ability of wound dressings to modulate certain factors known to affect wound healing. A selection of antimicrobial dressings (AQUACEL® Ag Extra™ , AQUACEL® Ag+ Extra™ , IODOFLEX™ , ACTICOAT™ 7 and PROMOGRAN PRISMA™ matrix) were tested for their effect on both bacterial bioburden and human dermal fibroblasts. Some dressings underwent further evaluation for activity against Pseudomonas aeruginosa biofilms using a colony-drip flow reactor model. The ability of in vitro biofilms to produce proteases, and the effect of PROMOGRAN PRISMA matrix on such proteases, was also investigated. All antimicrobial dressings tested reduced vegetative bacterial load; however, only PROMOGRAN PRISMA matrix was able to significantly reduce biofilm populations (P = 0·01). Additionally, PROMOGRAN PRISMA matrix was the only dressing that did not inhibit dermal fibroblast growth. All other dressings were detrimental to cell viability. In vitro biofilms of Pseudomonas aeruginosa were demonstrated as being capable of releasing bacterial proteases into their surroundings, and incubation with PROMOGRAN PRISMA matrix led to a 77% reduction in activity of such proteases (P = 0·002). The unique ability of PROMOGRAN PRISMA matrix to reduce in vitro vegetative bacteria, biofilm bacteria and bacterial proteases while still allowing dermal fibroblast proliferation may help rebalance the wound environment and reduce the occurrence of infection.

Defining a new diagnostic assessment parameter for wound care: Elevated protease activity, an indicator of nonhealing, for targeted protease-modulating treatment.

It is widely accepted that elevated protease activity (EPA) in chronic wounds impedes healing. However, little progress has occurred in quantifying the level of protease activity that is detrimental for healing. The aim of this study was to determine the relationship between inflammatory protease activity and wound healing status, and to establish the level of EPA above which human neutrophil-derived elastase (HNE) and matrix metalloproteases (MMP) activities correlate with nonhealing wounds. Chronic wound swab samples (n = 290) were collected from four wound centers across the USA to measure HNE and MMP activity. Healing status was determined according to percentage reduction in wound area over the previous 2-4 weeks; this was available for 211 wounds. Association between protease activity and nonhealing wounds was determined by receiver operating characteristic analysis (ROC), a statistical technique used for visualizing and analyzing the performance of diagnostic tests. ROC analysis showed that area under the curve (AUC) for HNE were 0.69 for all wounds and 0.78 for wounds with the most reliable wound trajectory information, respectively. For MMP, the corresponding AUC values were 0.70 and 0.82. Analysis suggested that chronic wounds having values of HNE >5 and/or MMP ≥13, should be considered wound healing impaired. EPA is indicative of nonhealing wounds. Use of a diagnostic test to detect EPA in clinical practice could enable clinicians to identify wounds that are nonhealing, thus enabling targeted treatment with protease modulating therapies.

Contrasting host immuno-inflammatory responses to bacterial challenge within venous and diabetic ulcers.

Within chronic wounds, the relationship between the clinical diagnosis of infection and bacterial/immuno-inflammatory responses is imprecise. This study prospectively examined the interrelationship between clinical, microbiological, and proinflammatory biomarker levels between chronic venous leg ulcers (CVLUs) and diabetic foot ulcers (DFUs). Wound swabs and fluids were collected from CVLUs (n = 18) and DFUs (n = 15) and diagnosed clinically as noninfected or infected; and qualitative/quantitative microbiology was performed. CVLU and DFU fluids were also analyzed for cytokine, growth factor, receptor, proteinase/proteinase inhibitor; and oxidative stress biomarker (protein carbonyl, malondialdehyde, and antioxidant capacity) levels. While no correlations existed between clinical diagnosis, microbiology, or biomarker profiles, increasing bacterial bioburden (≥10(7) colony-forming unit/mL) was associated with significant alterations in cytokine, growth factor, and receptor levels. These responses contrasted between ulcer type, with elevated and decreased cytokine, growth factor, and receptor levels in CVLUs and DFUs with increasing bioburden, respectively. Despite proteinase biomarkers exhibiting few differences between CVLUs and DFUs, significant elevations in antioxidant capacities correlated with increased bioburden in CVLU fluids, but not in DFUs. Furthermore, oxidative stress biomarker levels were significantly elevated in all DFU fluids compared with CVLUs. This study provides further insight into the contrasting disease-specific host responses to bacterial challenge within infected CVLUs and DFUs.