Antimicrobial Wound Dressings as Potential Materials for Skin Tissue Regeneration

Abstract

The most important properties of performant wound dressings are biocompatibility, the ability to retain large amount of exudate and to avoid complications related with persistent infection which could lead to delayed wound healing. This research aimed to obtain and characterize a new type of antimicrobial dressings, based on zinc oxide/sodium alginate/polyvinyl alcohol (PVA). Zinc oxide nanostructures, obtained with different morphology and grain size by hydrothermal and polyol methods, are used as antimicrobial agents along with sodium alginate, which is used to improve the biocompatibility of the dressing. The nanofiber dressing was obtained through the electrospinning method. Characterization techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to determine the structural and morphological properties of the obtained powders and composite fibers. Their antimicrobial activity was tested against Gram negative Escherichia coli (E. coli), Gram positive Staphylococcus aureus (S. aureus) bacteria and Candida albicans (C. albicans) yeast strains. The in vitro biocompatibility of the obtained composites was tested on human diploid cells. The obtained results suggest that the composite fibers based on zinc oxide and alginate are suitable for antimicrobial protection, are not toxic and may be useful for skin tissue regeneration if applied as a dressing.

Antibiotic Delivery Strategies to Treat Skin Infections When Innate Antimicrobial Defense Fails

“…Hydrogels can provide slow release of the antimicrobial agents over extended periods of time, which could decrease dressing change frequency and limit exposure to sub-inhibitory concentrations of antimicrobials. Polyvinyl alcohol (PVA), made by hydrolyzing polyvinyl acetate, is a hydrophilic polymer that absorbs moisture and maintains a moist wound environment [40,110]. The polymer properties depend on the degree of hydrolysis, concentration, temperature, and freezing cycles, which enables tunability of properties for various applications [110,144].…”

“…Polyvinyl alcohol (PVA), made by hydrolyzing polyvinyl acetate, is a hydrophilic polymer that absorbs moisture and maintains a moist wound environment [40,110]. The polymer properties depend on the degree of hydrolysis, concentration, temperature, and freezing cycles, which enables tunability of properties for various applications [110,144]. PVA has been blended and modified using synthetic and natural polymers in order to achieve desirable hydrogels [129].…”

“…Both antibiotics released simultaneously with light at concentrations above the minimum inhibitory concentration for E. coli, S. epidermidis, and S. aureus. Su et al developed a nanofiber mat containing a core of pluronic F127 and an electrosprayed shell made from poly(ε-caprolactone) (PCL) and an antimicrobial peptide [110]. The electrosprayed mat generated an initial burst release, which may be favorable in wound applications to achieve an effective concentration rapidly and then sustain the release over time.…”

“…The electrosprayed mat generated an initial burst release, which may be favorable in wound applications to achieve an effective concentration rapidly and then sustain the release over time. The electrosprayed mat eliminated P. aeruginosa bacterial colonies within three days of daily dressing changes in an in vivo full-thickness excisional wound treated initially by debridement [110]. These recent studies suggest excellent wound treatment using nanofibers; however, their use in clinical practice is limited due to toxicity, large-scale production, and ability to control capacity and functionality [206].…”

“…Because silver is widely used in topical antimicrobial products, its use in nanoparticle form has received substantial attention, demonstrating antimicrobial activity [109,115,181]. Other metallic nanoparticles such as gold, zinc, and copper also show good antimicrobial properties [110,136,207]. However, several metal nanoparticles, including silver, copper oxide, and zinc oxide, have exhibited toxic effects in the body [25].…”