Abstract

NMR Metabolic Profiling of the Effects of Silver Nanoparticles on Human Epidermis Keratinocytes

Iola Duarte, Principal Investigator, University of Aveiro

Due to their remarkable antimicrobial properties, silver nanoparticles (Ag-NPs) are being increasingly incorporated into consumer goods and medical products. Their potential toxicity to human cells is however a major concern [1], calling for improved understanding of the effects imparted by these particles on cell metabolism and function. In this work, we have applied NMR metabolomics to investigate the changes in the endo- and exometabolome of human epidermis keratinocytes (HaCaT cell line) upon exposure to Ag-NPs of different sizes (10, 30 and 60 nm) and coatings (citrate and polyethyleneglycol). A number of metabolites involved in different biochemical processes (e.g. antioxidative response, aminoacid and lipid metabolisms) were found to be altered in exposed cells, even in cases where there was little effect on cell viability (as assessed by standard MTT assay). NMR-based stable isotope tracing after feeding cells with [2-13C]-glucose further complemented the global profiling approach, revealing increased flux through the pentose phosphate pathway, probably in relation with NP-induced oxidative stress. The results show the potential of NMR metabolic profiling for highlighting new endpoint markers of Ag-NPs effects, thus demonstrating the value of metabolomics as a novel tool in the area of in vitro nanotoxicology [2].