engleski

Biotransformation of silver nanoparticles in vivo

Excellent microbicidal properties of silver nanoparticles (AgNPs) instigated their use in medicine, cosmetics, textile and food industries. However, detailed information on their fate and effects on the human body is so far unknown. [1] When exposed to biological media, AgNPs are prone to intimate interactions with different biomolecules and biological structures.[2] This study demonstrates possible biotransformation patterns of AgNPs after in vivo exposure. Fate of AgNPs was investigated in ultrapure water, cell culture medium, phosphate buffer, artificial lysosomal fluid, artificial gastric fluid, and liver homogenates by means of agglomeration and dissolution behaviour. For this purpose size distribution, surface charge, Ag+ release and interaction with albumin and glutathione were evaluated using dynamic and electrophoretic light scattering methods, transmission electron microscopy, atomic absorption spectroscopy and proton nuclear magnetic resonance spectroscopy (1H NMR). For the first time, this study evidenced in vivo synthesis of AgNPs in the liver resulting from the interaction of Ag+ with glutathione. First, the binding of glutathione to the surface of AgNPs was investigated on the NPs synthesized by sodium borohydride reduction of silver nitrate. The process of NP formation and glutathione adsorption was tracked by 1H NMR in 20-minute time intervals. Initial and final spectra differ significantly in chemical shifts of C7, indicating the binding through the thiol group. In the second part, AgNPs were synthesized using glutathione as both the reducing and capping agent. This eliminated the interference from sodium borohydride, and demonstrated the potential mechanism of in vivo AgNP formation from ionic silver.

silver nanoparticles ; glutathione ; biotransformation ; NMR study

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