title: Green synthesis of silver nanoparticles using cranberry powder aqueous extract: characterization and antimicrobial properties.
abstract: BACKGROUND
  The growing threat of microbial resistance against traditional antibiotics has prompted the development of several antimicrobial nanoparticles (NPs), including silver NPs (AgNPs). In this article, a simple and eco-friendly method for the synthesis of AgNPs using the cranberry powder aqueous extract is reported.
  
  
  METHODS
  Cranberry powder aqueous extracts (0.2%, 0.5%, and 0.8% w/v) were allowed to interact for 24 hours with a silver nitrate solution (10 mM) at 30°C at a ratio of 1:10. The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy and their concentrations were determined using atomic absorption spectroscopy. The prepared NPs were evaluated by transmission electron microscopy, measurement of ζ-potential, and Fourier-transform infrared spectroscopy. The in vitro antimicrobial properties of AgNPs were then investigated against several microbial strains. Finally, in vivo appraisal of both wound-healing and antimicrobial properties of either plain AgNPs (prepared using 0.2% extract) or AgNP-Pluronic F-127 gel was conducted in a rat model after induction of a Staphylococcus aureus ATCC 6538P wound infection.
  
  
  RESULTS
  The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy, where a surface-plasmon resonance absorption peak was observed between 432 and 438 nm. Both size and concentration of the formed AgNPs increased with increasing concentration of the extracts. The developed NPs were stable, almost spherical, and polydisperse, with a size range of 1.4-8.6 nm. The negative ζ-potential values, as well as Fourier-transform infrared spectroscopy analysis, indicated the presence of a capping agent adsorbed onto the surface of the particles. In vitro antimicrobial evaluation revealed a size-dependent activity of the AgNPs against the tested organisms. Finally, AgNPs prepared using 0.2% extract exhibited a substantial in vivo healing potential for full-thickness excision wounds in rats.
  
  
  CONCLUSIONS
  AgNPs were successfully synthesized from a silver nitrate solution through a simple green route, using cranberry powder aqueous extract as a reducing as well as capping agent.
authors.affiliation: Department of Pharmaceutics, Alexandria University, Alexandria, Egypt.
authors.forename: Asmaa A
authors.initials: AA
authors.lastname: Ashour
authors.affiliation: Department of Pharmaceutical Microbiology, Alexandria University, Alexandria, Egypt.
authors.forename: Dina
authors.initials: D
authors.lastname: Raafat
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
authors.forename: Hanan M
authors.initials: HM
authors.lastname: El-Gowelli
authors.affiliation: Department of Pharmaceutics, Alexandria University, Alexandria, Egypt.
authors.forename: Amal H
authors.initials: AH
authors.lastname: El-Kamel
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000648:ultrastructure; D005782:Gels / Q000494:pharmacology; D055772:Green Chemistry Technology / Q000379:methods*; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D020442:Poloxamer / Q000494:pharmacology; D011208:Powders; D051381:Rats; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D029799:Vaccinium macrocarpon / Q000737:chemistry*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D005782:Gels; D010936:Plant Extracts; D011208:Powders; D020442:Poloxamer; D012834:Silver
keywords: antimicrobial properties; cranberry; silver nanoparticles; wound healing