Gold nanoparticles are taken up by human cells but do not cause acute cytotoxicity

The cellular uptake and cytotoxicity of gold nanoparticles with human cells to determine the interaction of series of defined nanoparticles containing a variety of surface modifiers and stabilizers with an established human cancer cell line was investigated. The nanoparticle library was tested for cytotoxicity using the K562 leukemia cell line. The nanoparticle preparations with glucose or cysteine surface modifiers or with a reduced gold surface were not toxic at concentrations up to 25 μM. No difference was seen in either the growth rate of the untreated control cells or the cells exposed to the nanoparticles. The lack of detectable cytotoxicity raised the question of whether the nanoparticles were capable of being taken up into the cells. The results show that gold nanoparticles with a variety of surface modifiers are not inherently toxic to human cells despite being taken up to the cells. The nanoparticles themselves are not necessarily detrimental to cellular functions.