title: Changes in silver nanoparticles exposed to human synthetic stomach fluid: effects of particle size and surface chemistry.
abstract: The significant rise in consumer products and applications utilizing the antibacterial properties of silver nanoparticles (AgNPs) has increased the possibility of human exposure. The mobility and bioavailability of AgNPs through the ingestion pathway will depend, in part, on properties such as particle size and the surface chemistries that will influence their physical and chemical reactivities during transit through the gastrointestinal tract. This study investigates the interactions between synthetic stomach fluid and AgNPs of different sizes and with different capping agents. Changes in morphology, size and chemical composition were determined during a 30 min exposure to synthetic human stomach fluid (SSF) using Absorbance Spectroscopy, High Resolution Transmission Electron and Scanning Electron Microscopy (TEM/SEM), Dynamic Light Scattering (DLS), and Nanoparticle Tracking Analysis (NTA). AgNPs exposed to SSF were found to aggregate significantly and also released ionic silver which physically associated with the particle aggregates as silver chloride. Generally, the smaller sized AgNPs (<10nm) showed higher rates of aggregation and physical transformation than larger particles (75 nm). Polyvinylpyrrolidone (pvp)-stabilized AgNPs prepared in house behaved differently in SSF than particles obtained from a commercial source despite having similar surface coating and size distribution characteristics.
authors: U.S. National Research Council Associate, Environmental Protection Agency, Las Vegas, NV, USA.
authors: Samuel K
authors: SK
authors: Mwilu
authors: Amro M
authors: AM
authors: El Badawy
authors: Karen
authors: K
authors: Bradham
authors: Clay
authors: C
authors: Nelson
authors: David
authors: D
authors: Thomas
authors: Kirk G
authors: KG
authors: Scheckel
authors: Thabet
authors: T
authors: Tolaymat
authors: Longzhou
authors: L
authors: Ma
authors: Kim R
authors: KR
authors: Rogers
mesh_terms: D005750:Gastric Juice / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011205:Povidone / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D018030:Silver Compounds; D011205:Povidone; C037548:silver chloride