Toxicity of gold and silver nanoparticles

Nanotehnologija se bavi česticama veličine do 100 nm zbog njihovih novih zanimljivih svojstava u odnosu na materijale makro dimenzija. Predmetom su proučavanja zbog potencijalne primjene u medicinske i druge najrazličitije svrhe. Nanočestice srebra se već koriste u komercijalne svrhe u raznim antibakterijskim sredstvima, a nanočestice zlata pokazuju potencijal za korištenje u dijagnozi i liječenju raka pa je bitno utvrditi njihove potencijalno toksične učinke na živi svijet. S tim ciljem rađena su istraživanja in vitro i in vivo na različitim modelima kojima je pokazano da se nanočestice srebra i zlata akumuliraju u jetri i slezeni, da mogu izazvati imunološki odgovor te djelovati toksično ovisno o veličini, konjugatima, koncentraciji i vremenu izloženosti tkiva i organa. Toksični učinci nanočestica srebra i zlata su indukcija proizvodnje ROS i RNS, narušavanje integriteta membrane i oštećenje DNA iako postoje i drugi specifični učinci koje još valja istražiti. Nanočestice srebra označene su toksičnijim od onih zlata jer lakše oksidiraju.Nanotechnology manipulates material at nanoscale (1-100 nm) for its interesting novel properties comparing to those of the materials in macro dimensions. Nanoparticles recieve much interest due to their potential applications in medicine and many other fileds. Silver nanoparticles are commercially available in various antibacterial products while gold nanoparticles show great potential in cancer treatment and diagnositcs. Thus, it is essential to determine possible toxic effects that silver and gold nanoparticles can have on both humans and wildlife. Following that purpose, experiments that have been taken on various different in vitro and in vivo models have shown that silver and gold nanoparticles tend to accumalate in spleen and liver, that they can stimulate immune response and can exert toxic effects depending on the size and capping agents of the particle, as well as on the dose and time of exposure. ROS and RNS production, membrane and DNA damage are some general effects silver and gold nanoparticles can have on cells, although there are many other specific effects that need further investigation. It is believed that silver nanoparticles are more toxic than the gold ones because they oxidize more readily