title: Morphological observation of embryoid bodies completes the in vitro evaluation of nanomaterial embryotoxicity in the embryonic stem cell test (EST).
abstract: The wide and frequent use of engineered nanomaterials (NMs) raises serious concerns about their safety for human health. Our aim is to evaluate the embryotoxic potential of silver, uncoated and coated zinc oxide, titanium dioxide and silica NMs through the embryonic stem cell test (EST). EST is a validated in vitro assay that permits classification of chemicals into three classes (non, weakly or strongly embryotoxic). Because of the peculiar physico-chemical characteristics of NMs, we first adapted and simplified the differentiation protocol. To verify the efficiency of this adapted protocol we screened 3 well-characterized chemicals (5-fluorouracil, hydroxyurea and saccharin). Next, we assessed the embryotoxic potential of NMs. Our data showed that silver NM is classified as a strong embryotoxic compound, while coated and uncoated zinc oxide, titanium and silica NMs as weak embryotoxic compounds. In addition, we observed daily the formation and growth of embryoid bodies (EBs). We showed that multiple EBs formed in each well starting from 50 μg/ml of SiO2 while EB formation was inhibited starting from 20 μg/ml of ZnO NMs. This has never been reported with chemicals and could pose a risk of wrongly evaluating the NMs embryotoxic potential. For NMs, morphological observation of EBs can provide valuable information on early differentiation effects. Finally, we suggest that the prediction model should be revised for the assessment of NMs embryotoxicity.
authors.affiliation: Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Corradi
authors.affiliation: Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Eleni
authors.initials: E
authors.lastname: Dakou
authors.affiliation: Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Ajay
authors.initials: A
authors.lastname: Yadav
authors.affiliation: Lab4U, Katholieke Universiteit Leuven campus Diepenbeek, Agoralaan gebouw B, 3590 Diepenbeek, Belgium.
authors.forename: Leen C J
authors.initials: LC
authors.lastname: Thomassen
authors.affiliation: Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Micheline
authors.initials: M
authors.lastname: Kirsch-Volders
authors.affiliation: Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium. Electronic address: lleyns@vub.ac.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Leyns
mesh_terms: D000818:Animals; D041702:BALB 3T3 Cells; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D058732:Embryoid Bodies / Q000166:cytology / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects; D051379:Mice; D049329:Nanostructures / Q000633:toxicity*; D012822:Silicon Dioxide / Q000633:toxicity*; D012834:Silver / Q000633:toxicity*; D013723:Teratogens / Q000633:toxicity*; D014025:Titanium / Q000633:toxicity*; D018675:Toxicity Tests; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D013723:Teratogens; C009495:titanium dioxide; D012834:Silver; D012822:Silicon Dioxide; D014025:Titanium; D015034:Zinc Oxide
keywords: Embryoid bodies; Embryonic stem cell test; Embryotoxicity; Morphology; Nanomaterials