Formation of colloidal silver nanoparticles stabilized by Na+-poly(gamma-glutamic acid)-silver nitrate complex via chemical reduction process

Colloids Surf B Biointerfaces. 2007 Oct 1;59(2):171-8. doi: 10.1016/j.colsurfb.2007.05.007. Epub 2007 May 18.


Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have been assessed.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Cell Line
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Colloids
  • Metal Nanoparticles / chemistry*
  • Methicillin Resistance
  • Mice
  • Oxidation-Reduction
  • Particle Size
  • Polyglutamic Acid / analogs & derivatives*
  • Pseudomonas aeruginosa / drug effects
  • Silver Nitrate*
  • Silver*
  • Sodium*
  • Staphylococcus aureus / drug effects


  • Anti-Bacterial Agents
  • Colloids
  • poly(gamma-glutamic acid)
  • Polyglutamic Acid
  • Silver
  • Silver Nitrate
  • Sodium