Nanosilver Induced DNA Damage does not Correlate with Cell Survival

Abstract

Abstract Although silver and titanium dioxide nanoparticles (Ag NP and TiO2 NP) belong to the NP most often studied, the mechanisms of their biological effects are still not fully understood. Moreover, there are numerous discrepancies in the reports on the extent of DNA damage induced by Ag NP in various mammalian cells in in vitro studies. The available data on Ag NP genotoxicity in vitro are based on short-term assays, such as MTT or Neutral Red assay, and no attempt has been made to directly relate DNA damage to clonogenicity loss. Therefore, we undertook a detailed study of unfunctionalised Ag NP and TiO2 NP action on 3 mammalian cell lines: human hepatocellular liver carcinoma HepG2, human lung carcinoma A549 and human colorectal adenocarcinoma HT-29. The end-points examined in this report after 2h and 24h treatment with NP, were DNA breakage estimated by the comet assay and oxidative base damage recognized by formamido-pyrimidine glycosylase (FPG) and estimated with the FPG+comet assay. Further, the...