Toxicological effects of three types of silver nanoparticles and their salt precursors acting on human U-937 and HL-60 cells

Abstract

The growing popularity of nanomaterials requires a systematic study of their effects on the human body. Silver nanoparticles (AgNPs), due to their antiseptic properties, are used in almost every area of life. The purpose of the study was to examine whether the precursor used for the synthesis of nanoparticles affects their bio-influence and modifies their impact on cells of the human immune system. To compare the effects of precursor silver salts (AgNO₃, CH₃COOAg and AgClO₄) and corresponding nanoparticles (TAN TAA and TAC) cytotoxicity study was conducted on two cell lines U-937 and HL-60. For both cell lines, silver salts are more toxic than the corresponding nanoparticles. Cell viability after treatment with the two forms of silver (salt/particle) is dependent on silver dose and degree of cells differentiation. Addition of the silver salt of doses greater than 5 mg/L results in decreased cell viability by over 60%, whereas nanoparticles’ addition reduces cell viability on average by 30%. On the basis of the determined LD₅₀ values it can be stated that for the tested cells the most toxic are AgClO₄ and TAC. Production of nitric oxide, which is a mediator of inflammation, is the greatest after treatment of the cells by TAC. Different interactions of studied nanoparticles with albumin has been found and it was shown that addition of albumin to the cells treated by nanoparticles reduces their toxic effects. Obtained by us highly purified, mono-disperse AgNPs exhibit diverse effects relative to the biological systems, depending on the precursor salt used.

Keywords:

• Silver nanoparticles
• silver salts
• cytotoxicity
• human cells

Acknowledgements

The authors are grateful to Dr Elżbieta Bielańska for the invaluable help in the characteristics of the AgNPs with the use of transmission electron microscopy. The authors further thank Halina Mrowiec for the measurements of concentration of leached silver ions. The silver ion release measurements were carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.01.00-12-023/0).

Disclosure statement

No potential conflict of interest was reported by the authors.