Micro-organism-triggered release of silver nanoparticles from biodegradable oxide carriers allows preparation of self-sterilizing polymer surfaces

Small. 2008 Jun;4(6):824-32. doi: 10.1002/smll.200800047.

Abstract

The antimicrobial activity of silver has attracted significant research interest and contributes to an exponentially growing use of this noble metal in commodity products. In this investigation, we describe a general approach to increase the antimicrobial activity of a silver-containing surface by two to three orders of magnitude. The use of 1-2-nm silver particles decorating the surface of 20-50-nm carrier particles consisting of a phosphate-based, biodegradable ceramic allows the triggered release of silver in the presence of a growing microorganism. This effect is based on the organism's requirements for mineral uptake during growth creating a flux of calcium, phosphate, and other ions to the organism. The growing micro-organism dissolves the carrier containing these nutrients and thereby releases the silver nanoparticles. Further, we demonstrate the rapid self-sterilization of polymer surfaces containing silver on calcium phosphate nanoparticles using a series of human pathogens. Colony-forming units (viable bacteria or fungi counts) have been routinely reduced below detection limit and suggest application of these self-sterilizing surfaces in hospital environments, food and pharmaceutical processing, and personal care.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus niger / drug effects
  • Aspergillus niger / physiology
  • Escherichia coli / drug effects
  • Escherichia coli / physiology
  • Metal Nanoparticles*
  • Microscopy, Electron, Scanning Transmission
  • Microscopy, Electron, Transmission
  • Oxides / chemistry*
  • Polymers / chemistry*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / physiology
  • Silver / chemistry*
  • Spectrophotometry, Atomic
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / physiology
  • Surface Properties

Substances

  • Oxides
  • Polymers
  • Silver