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Aim:

Hydroactive dressings mainly consist of alginate or carboxymethylcellulose fibers that can be processed to compresses or tamponade strips and exhibit high fluid uptake. Highly exuding wounds may lead to macerated wound edges and during gel formation, loss of shape might occur, which results in reduced wound coverage. Hence, fluid management of hydroactive dressings was analyzed using a special maceration model.

Methods:

Two dressings with carboxymethylcellulose (A-B), one consisting of cellulose/ ethylsulfonatecellulose (C), and an alginate tamponade (D) were investigated. They were applied to an artificial wound in a tissue substitute for maceration-tests. Evaluation of fluid uptake and distribution in dressings was performed by video recording. Shape loss of dressings, maximal fluid uptake and time to maceration was determined.

Results:

A and B exhibited a distinct shrinkage during fluid uptake with 29 and 36%.

C showed significantly higher form stability (18%shrinkage). For D, no loss of surface coverage was observed. D demonstrated the lowest fluid holding capacity (20mL fluid uptake). A similar fluid uptake till maceration break point was found for A. B and C exhibited significantly higher values with 25 and 30mL. Moreover, with A and B maceration already occurred before the dressings were completely soaked. Leakage with dressings C and D was only observed after they were gelled.

Conclusions:

An in vitro maceration model was successfully used to quantify and evaluate the differences between hydroactive wound dressings. This model is hence suitable to analyse fluid management in an in vivo like situation.

Aim:

Biofilm development is a major impediment of wound healing. Current research targets antibiofilm strategies to restore optimal wound-healing. Combined treatment involving debridement and addition of antibacterial agents may provide high success rates. A monofilament debrider* consisting of polyester presents a fast and painless option for biofilm removal. We analyzed the re-growth properties of biofilm underneath different wound dressings.

Methods:

A S.aureus biofilm was cultivated on glass plates. The monofilament debrider* was used to wipe the glass plates under standardized conditions (p=0.067N/cm2, v=1.6cm/s). Afterwards, glass plates were covered with various antimicrobially active wound dressings# and incubated for 24h at 37°C. Then, dressings were removed and glass plates further incubated for 48h. Biofilm on the glass plates was evaluated directly after dressing removal and following 48h re-growth period using the fluorescent alamar blue assay.

Results:

It was shown that the monofilament debrider* effectively removed biofilm. It was observed that subsequent treatment with dressings reduced formation of new biomass. Significantly fewer bacteria were found after incubation with dressings containing antimicrobials. Polihexanide-containing dressings further exhibited a persistent decrease of biofilm re-growth, while biofilm quickly reformed in untreated controls and after removal of antimicrobial-free and silver-containing dressings.

Conclusions:

It can be concluded that the combination of biofilm removal on the infected or critically colonized wound using a monofilament debrider* and subsequent treatment with antimicrobial dressings presents a successful antibiofilm strategy.

Introduction:

A silicone coating of dressings can prevent adherence to the wound surface which otherwise would disrupt the wound bed and destroy newly formed, healthy tissue on removal. This happens often with simple gauze pads but may also appear with foams. We evaluated the adhesion disposition of modern silicone-coated PU foam dressings in vitro.

Methods:

Three silicone-coated PU foams (**-****) were tested. For measurement of the adhesion disposition, a tissue substitute with a fibrinogen/thrombin layer was prepared. Dressing samples were cut corresponding to 3cm x 4cm and fixed to a plaster with a holding noose for the force gauge. In each case, only the dressing padding zone was employed for testing. Cotton gauze* was treated in the same manner and used as positive control. Evaluation of the adhesion disposition was carried out by measurement of the force necessary to remove the dressing from the tissue substitute.

Results:

Dressings ** and **** exhibited a similarly low adhesion disposition compared to the positive control. Only for dressing*** a significantly higher force was needed to remove the adhesive wound pad from the tissue substitute which accounts for the

stronger adhesion observed.

Conclusions:

The adhesion disposition of PU foam dressings with a silicone coating could be quantified and evaluated in vitro using a special tissue substitute. It could be shown that the dressings ** and **** demonstrated a significantly lower adhesion than simple cotton gauze pads.