title: Organic-coated silver nanoparticles in biological and environmental conditions: fate, stability and toxicity.
abstract: This review paper presents the overview of processes involved in transformation of organic-coated silver nanoparticles (AgNPs) in biological systems and in the aquatic environment. The coating on AgNPs greatly influences the fate, stability, and toxicity of AgNPs in aqueous solutions, biological systems, and the environment. Several organic-coated AgNP systems are discussed to understand their stability and toxicity in biological media and natural water. Examples are presented to demonstrate how a transformation of organic-coated AgNPs in an aqueous solution is affected by the type of coating, pH, kind of electrolyte (mono- or divalent), ionic strength, organic ligands (inorganic and organic), organic matter (fulvic and humic acids), redox conditions (oxic and anoxic), and light. Results of cytotoxicity, genotoxicity, and ecotoxicity of coated AgNPs to food chain members (plants, bacteria, and aquatic and terrestrial organisms) are reviewed. Key factors contributing to toxicity are the size, shape, surface coating, surface charge, and conditions of silver ion release. AgNPs may directly damage the cell membranes, disrupt ATP production and DNA replication, alternate gene expressions, release toxic Ag(+) ion, and produce reactive oxygen species to oxidize biological components of the cell. A progress made on understanding the mechanism of organic-coated AgNP toxicity using different analytical techniques is presented.
authors.affiliation: Department of Environmental and Occupational Health, School of Rural Public Health, Texas A&M University, 1266 TAMU, College Station, TX 77843-1266, United States. Electronic address: vsharma@srph.tamhsc.edu.
authors.forename: Virender K
authors.initials: VK
authors.lastname: Sharma
authors.affiliation: Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, Slechtitelu 11, 78371 Olomouc, Czech Republic.
authors.forename: Karolina M
authors.initials: KM
authors.lastname: Siskova
authors.affiliation: Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, Slechtitelu 11, 78371 Olomouc, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Zboril
authors.affiliation: Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, United States.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Gardea-Torresdey
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D004247:DNA / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009930:Organic Chemicals / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D010944:Plants / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D017382:Reactive Oxygen Species; D012996:Solutions; D014867:Water; D012834:Silver; D004247:DNA
keywords: Aggregation; Bacteria; Dissolution; Ionic strength; Light; Organisms; Plants; Silver ion; Synthesis