title: Development of a multilevel approach for the evaluation of nanomaterials' toxicity.
abstract: OBJECTIVE
  To develop a multilevel approach that includes different toxicity tests and gene-expression studies for toxicity evaluation of engineered nanomaterials developed for biomedical applications.
  
  
  METHODS
  K-562, MCF-7 and U-937 human-derived cell lines were used as models for in vitro toxicity tests. These tests included viability assays (3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium [MTS] assay); evaluation of apoptosis/necrosis by propidium iodide staining and DNA laddering assay; evaluation of mitochondrial toxicity (5,5´,6,6´-tetrachloro-1,1´,3,3´-tetraethyl-benzimidazolcarbocyanine iodide [JC-1] assay); transmission electron microscopy analysis and gene expression analysis by DNA microarray. For in vivo toxicity evaluation, Swiss mice were used for monitoring acute or chronic effects. Two superparamagnetic contrast agents approved for human use (Resovist and Primovist) and two new lanthanide-based luminescent nanoparticles were tested.
  
  
  CONCLUSIONS
  The nanomaterials approved for human use did not show significant toxicities in our assays. Toxicity studies performed on lanthanide-based nanoparticles (EDTA120 and EDTA120D) complexed with the chelating agent EDTA revealed that these nanomaterials induced necrosis in U-937 and K-562 cells while no toxicity was observed in MCF-7 cells. Moreover, no in vivo effects have been observed. The comparative analysis of the nanomaterials and their separated components showed that the toxicity in U-937 and K-562 cells was mainly due to the presence of EDTA.
  
  
  CONCLUSIONS
  The multilevel approach proved to be useful for nanomaterial toxicity characterization. In particular, for the lanthanide-based nanoparticles tested in this work, the EDTA was identified as the main cause of the toxicity in vitro, suggesting a possible applicability of these nanoparticle suspensions for in vivo optical imaging.
authors: Department of Biomolecular Sciences, University of Urbino, 61029 Urbino (PU), Italy.
authors: Luca
authors: L
authors: Galluzzi
authors: Laura
authors: L
authors: Chiarantini
authors: Elena
authors: E
authors: Pantucci
authors: Rosa
authors: R
authors: Curci
authors: Jacqueline
authors: J
authors: Merikhi
authors: Helga
authors: H
authors: Hummel
authors: Peter K
authors: PK
authors: Bachmann
authors: Elisabetta
authors: E
authors: Manuali
authors: Giovanni
authors: G
authors: Pezzotti
authors: Mauro
authors: M
authors: Magnani
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D049329:Nanostructures / Q000737:chemistry / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*