Repeated exposure of Caco-2 versus Caco-2/HT29-MTX intestinal cell models to (nano)silver in vitro: Comparison of two commercially available colloidal silver products

Colloidal silver products are sold for a wide range of disinfectant and health applications. This has increased the potential human exposure to nanoparticles (AgNPs) ions (Ag+), which oral ingestion is considered be major route exposure. Our objective was evaluate compare toxicity two commercially available colloidal on intestinal epithelial models under realistic conditions. Mesosilver™ AgC were characterized concentration between 0.1 12 ?g/mL chosen. Caco-2 cells vs. co-culture mucus-secreting HT29-MTX (90/10) used. Repeated carried out determine cell viability over 18 days differentiation in 24-well plates. Selected concentrations (0.1, 1, 3 ?g/mL) tested cultured E-plates Transwells with same repeated regimen, impedance, trans-epithelial electrical resistance (TEER), respectively. Silver uptake, intracellular localisation, translocation determined by CytoViva™, HIM-SIMS, ICP-MS. Genotoxicity acutely-exposed proliferating ?H2AX immunofluorescence staining. given AgC, composed solely ionic silver, generally exerted more toxic effects than Mesosilver™, contains mix AgNPs silver. Due its patchy structure, presence mucus Caco-2/HT29-MTX only slightly mitigated deleterious viability. Increased genotoxicity observed cells. similar. In conclusion, show different levels gut due forms distinct (AgNPs and/or Ag+) contained within. study highlights applicability high-resolution (chemical) imaging detect localize provides insights into uptake mechanisms, fate cellular effects.