Abstract
Here, we present a review of the antibacterial effects of silver nanomaterials, including proposed antibacterial mechanisms
and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles,
stabilized silver salts, silver–dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated
carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver
nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or
in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells
and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly
impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial
studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial
stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape,
and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules—all of which
influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any
immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science
reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of
silver nanomaterials.
and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles,
stabilized silver salts, silver–dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated
carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver
nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or
in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells
and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly
impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial
studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial
stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape,
and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules—all of which
influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any
immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science
reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of
silver nanomaterials.
- Content Type Journal Article
- Category Review Paper
- DOI 10.1007/s11051-010-9900-y
- Authors
- Catalina Marambio-Jones, University of California, Los Angeles Department of Civil and Environmental Engineering, California NanoSystems Institute 5732G Boelter Hall PO Box 951593 Los Angeles CA 90095-1593 USA
- Eric M. V. Hoek, University of California, Los Angeles Department of Civil and Environmental Engineering, California NanoSystems Institute 5732G Boelter Hall PO Box 951593 Los Angeles CA 90095-1593 USA
- Journal Journal of Nanoparticle Research
- Online ISSN 1572-896X
- Print ISSN 1388-0764
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