title: Silver nanoparticles enhance Pseudomonas aeruginosa PAO1 biofilm detachment.
abstract: OBJECTIVE
  Silver nanoparticles (AgNPs) with a size ranging from 7 to 70 nm were synthesized using the ascorbic acid-citrate seed-mediated growth approach at room temperature.
  
  
  METHODS
  The 8 nm silver particles were prepared using gallic acid in alkaline conditions and used as seed to prepare AgNPs.
  
  
  RESULTS
  The presence of ascorbic acid and citrate allows the regulation of size and size distribution of the nanoparticles. The increase in free silver ion-to-seed ratio (Ag(+)/Ag(0)) resulted in changes of particle shape from spherical to pseudo-spherical and minor cylindrical shape. Further, a repetitive seeding approach resulted in the formation of pseudo-spherical particles with higher polydispersity index and minor distributions of tetrahedral particles. Citrate-capped AgNPs were stable and did not agglomerate upon centrifugation. The effect of AgNPs on biofilm reduction was evaluated using static culture on 96-well microtiter plates. Results showed that AgNPs with the smallest average diameter were most effective in the reduction of Pseudomonas aeruginosa biofilm colonies, which accounted for 90% of removal.
  
  
  CONCLUSIONS
  The biofilm removal activities of the nanoparticles were found to be concentration-independent particularly for the concentration within the range of 80-200 µg/mL.
authors.affiliation: Advanced Drug Delivery Group, Faculty of Pharmacy, University of Sydney , Sydney , Australia .
authors.forename: Ching-Yee
authors.initials: CY
authors.lastname: Loo
authors.forename: Paul M
authors.initials: PM
authors.lastname: Young
authors.forename: Rosalia
authors.initials: R
authors.lastname: Cavaliere
authors.forename: Cynthia B
authors.initials: CB
authors.lastname: Whitchurch
authors.forename: Wing-Hin
authors.initials: WH
authors.lastname: Lee
authors.forename: Ramin
authors.initials: R
authors.lastname: Rohanizadeh
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D004305:Dose-Response Relationship, Drug; D004339:Drug Compounding; D053768:Metal Nanoparticles / Q000737:chemistry*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013499:Surface Properties
chemical_list: D012834:Silver
keywords: Antibacterial; Pseudomonas aeruginosa; biofilm; chemical reduction; silver nanoparticles