Ciencias Médicas y de la Salud
DEVELOPMENT AND EVALUATION OF A WOUND DRESSING WITH ANTIBACTERIAL ACTIVITY.
MOGROVEJO VALDIVIA Alejandra Corina1*, RAHMOUNI Oumaïra2, AUBERT-VIARD François1, CHAI Feng1, MATON Mickaël1, NEUT Christel2, TABARY Nicolas3, MARTEL Bernard3, BLANCHEMAIN Nicolas1
1INSERM U1008, Groupe de Recherche sur les Biomatériaux, University of Lille, France.
2 INSERM U995 Laboratoire de Bactériologie, University of Lille, France.
3UMET, UMR-CNRS8207, Ingénierie des Systèmes Polymères, University of Lille, France.
* email@example.com, Tel: +33 3 20 62 69 75, Fax: +33 3 20 62 68 54
Infected wounds delay healing process. Silver-based wound dressings are marketed for treating infection. Nevertheless, the large amount of silver diffusion in the wound damages the skin. The aim of this work was to determine the best dressing to provide antibacterial activity without silver diffusion in the wound.
A non woven polyethylene terephthalate textile (PET) was functionalized by pad-dry-cure method with chitosan (CHT, 2.5%wt) or ß-cyclodextrin (ßCD, 10%wt); both with citric acid (10%wt) as a crossliking agent to obtain negative charges on the surface (PET-CHT / PET-CD) to load the textile with silver sulfate (10 g/L) as previously reported . A stable multi-layer system was built by dip-coating technique with CHT as positive polyelectrolyte (0.5% w/v) and ßCD polymer as negative polyelectrolyte (0.3% w/v) [2, 3]. First, the growth curve of E. coli and S. aureus, in presence of different concentrations of silver (0.013, 0.025, 0.05 and 0.1 g/L) were determined. The antibacterial activity of the textile was determined with Kill Time test (bacterial reduction) on these two bacteria. Finally, a diffusion test on agar gel seeded with the same bacteria was performed to observe the diffusion of silver out of the wound dressing after 0, 1, 2 and 3 days of staying in PBS (pH7.4, 37°C).
The construction of the multilayer system was linear on both textiles (PET-CD and PET-CHT) with or without silver as first layer. The silver loading did not affect the multilayer build-up. We can note that the weight gain was greater in the case of PET-CD (50%) than PET-CHT (loaded or not with silver). The growth curves show an antibacterial activity of silver from 0.025 g/L faster on negative gram bacteria (E. coli – 2 hours) than on positive Gram bacteria (S. aureus – 8 hours). Kill Time test revealed a 6 log bacterial reduction of E. coli and a 5 log reduction of S. aureus (5 log) after 24 hours on all textiles containing silver. The textiles coated by multilayer system showed similar bacterial reduction in both strains (4 log). The diffusion test showed that the multilayer system can prevent the diffusion of silver on the agar gel thanks to a barrier effect. In conclusion, the wound dressing based on a multilayer system provides an anti-infective therapy and a barrier effect that limits the silver release in the wound.
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