Silver nanoparticles enhance Pseudomonas aeruginosa PAO1 biofilm detachment

Drug Dev Ind Pharm. 2014 Jun;40(6):719-29. doi: 10.3109/03639045.2013.780182. Epub 2013 Apr 17.

Abstract

Objectives: 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.

Conclusion: 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.

Keywords: Antibacterial; Pseudomonas aeruginosa; biofilm; chemical reduction; silver nanoparticles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Adhesion / drug effects
  • Biofilms / drug effects*
  • Biofilms / growth & development*
  • Dose-Response Relationship, Drug
  • Drug Compounding
  • Metal Nanoparticles / chemistry*
  • Microscopy, Confocal
  • Microscopy, Electron, Transmission
  • Particle Size
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / physiology
  • Silver / chemistry
  • Silver / pharmacology*
  • Surface Properties

Substances

  • Silver